llvm-project/clang/test/OpenMP/nvptx_target_parallel_reduc...

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[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// Test target codegen - host bc file has to be created first.
// RUN: %clang_cc1 -verify -fopenmp -fopenmp-cuda-mode -x c++ -triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm-bc %s -o %t-ppc-host.bc
// RUN: %clang_cc1 -verify -fopenmp -fopenmp-cuda-mode -x c++ -triple nvptx64-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-ppc-host.bc -o - | FileCheck %s --check-prefix CHECK --check-prefix CHECK-64
// RUN: %clang_cc1 -verify -fopenmp -fopenmp-cuda-mode -x c++ -triple i386-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm-bc %s -o %t-x86-host.bc
// RUN: %clang_cc1 -verify -fopenmp -fopenmp-cuda-mode -x c++ -triple nvptx-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -o - | FileCheck %s --check-prefix CHECK --check-prefix CHECK-32
// RUN: %clang_cc1 -verify -fopenmp -fopenmp-cuda-mode -fexceptions -fcxx-exceptions -x c++ -triple nvptx-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -o - | FileCheck %s --check-prefix CHECK --check-prefix CHECK-32
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// expected-no-diagnostics
#ifndef HEADER
#define HEADER
// Check for the data transfer medium in shared memory to transfer the reduction list to the first warp.
// CHECK-DAG: [[TRANSFER_STORAGE:@.+]] = common addrspace([[SHARED_ADDRSPACE:[0-9]+]]) global [32 x i32]
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// Check that the execution mode of all 3 target regions is set to Spmd Mode.
// CHECK-DAG: {{@__omp_offloading_.+l27}}_exec_mode = weak constant i8 0
// CHECK-DAG: {{@__omp_offloading_.+l32}}_exec_mode = weak constant i8 0
// CHECK-DAG: {{@__omp_offloading_.+l38}}_exec_mode = weak constant i8 0
template<typename tx>
tx ftemplate(int n) {
int a;
short b;
tx c;
float d;
double e;
#pragma omp target parallel reduction(+: e)
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
{
e += 5;
}
#pragma omp target parallel reduction(^: c) reduction(*: d)
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
{
c ^= 2;
d *= 33;
}
#pragma omp target parallel reduction(|: a) reduction(max: b)
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
{
a |= 1;
b = 99 > b ? 99 : b;
}
return a+b+c+d+e;
}
int bar(int n){
int a = 0;
a += ftemplate<char>(n);
return a;
}
// CHECK: define {{.*}}void {{@__omp_offloading_.+template.+l27}}(
//
// CHECK: call void @__kmpc_spmd_kernel_init(i32 {{.+}}, i16 1, i16 0)
// CHECK: call void @__kmpc_data_sharing_init_stack_spmd
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[EXECUTE:.+]]
//
// CHECK: [[EXECUTE]]
// CHECK: {{call|invoke}} void [[PFN:@.+]](i32*
// CHECK: call void @__kmpc_spmd_kernel_deinit_v2(i16 1)
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
//
// define internal void [[PFN]](
// CHECK: store double {{[0\.e\+]+}}, double* [[E:%.+]], align
// CHECK: [[EV:%.+]] = load double, double* [[E]], align
// CHECK: [[ADD:%.+]] = fadd double [[EV]], 5
// CHECK: store double [[ADD]], double* [[E]], align
// CHECK: [[PTR1:%.+]] = getelementptr inbounds [[RLT:.+]], [1 x i8*]* [[RL:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[E_CAST:%.+]] = bitcast double* [[E]] to i8*
// CHECK: store i8* [[E_CAST]], i8** [[PTR1]], align
// CHECK: [[ARG_RL:%.+]] = bitcast [[RLT]]* [[RL]] to i8*
// CHECK: [[RET:%.+]] = call i32 @__kmpc_nvptx_parallel_reduce_nowait_v2(%struct.ident_t* @{{.+}}, i32 {{.+}}, i32 1, i{{32|64}} {{4|8}}, i8* [[ARG_RL]], void (i8*, i16, i16, i16)* [[SHUFFLE_REDUCE_FN:@.+]], void (i8*, i32)* [[WARP_COPY_FN:@.+]])
// CHECK: [[CMP:%.+]] = icmp eq i32 [[RET]], 1
// CHECK: br i1 [[CMP]], label
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[E_INV:%.+]] = load double, double* [[E_IN:%.+]], align
// CHECK: [[EV:%.+]] = load double, double* [[E]], align
// CHECK: [[ADD:%.+]] = fadd double [[E_INV]], [[EV]]
// CHECK: store double [[ADD]], double* [[E_IN]], align
// CHECK: call void @__kmpc_nvptx_end_reduce_nowait(
// CHECK: br label
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// CHECK: ret
//
// Reduction function
// CHECK: define internal void [[REDUCTION_FUNC:@.+]](i8*, i8*)
// CHECK: [[VAR_RHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_RHS:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[VAR_RHS_VOID:%.+]] = load i8*, i8** [[VAR_RHS_REF]],
// CHECK: [[VAR_RHS:%.+]] = bitcast i8* [[VAR_RHS_VOID]] to double*
//
// CHECK: [[VAR_LHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_LHS:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[VAR_LHS_VOID:%.+]] = load i8*, i8** [[VAR_LHS_REF]],
// CHECK: [[VAR_LHS:%.+]] = bitcast i8* [[VAR_LHS_VOID]] to double*
//
// CHECK: [[VAR_LHS_VAL:%.+]] = load double, double* [[VAR_LHS]],
// CHECK: [[VAR_RHS_VAL:%.+]] = load double, double* [[VAR_RHS]],
// CHECK: [[RES:%.+]] = fadd double [[VAR_LHS_VAL]], [[VAR_RHS_VAL]]
// CHECK: store double [[RES]], double* [[VAR_LHS]],
// CHECK: ret void
//
// Shuffle and reduce function
// CHECK: define internal void [[SHUFFLE_REDUCE_FN]](i8*, i16 {{.*}}, i16 {{.*}}, i16 {{.*}})
// CHECK: [[REMOTE_RED_LIST:%.+]] = alloca [[RLT]], align
// CHECK: [[REMOTE_ELT:%.+]] = alloca double
//
// CHECK: [[LANEID:%.+]] = load i16, i16* {{.+}}, align
// CHECK: [[LANEOFFSET:%.+]] = load i16, i16* {{.+}}, align
// CHECK: [[ALGVER:%.+]] = load i16, i16* {{.+}}, align
//
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to double*
//
// CHECK: [[ELT_CAST:%.+]] = bitcast double* [[ELT]] to i64*
// CHECK: [[REMOTE_ELT_CAST:%.+]] = bitcast double* [[REMOTE_ELT]] to i64*
// CHECK: [[ELT_VAL:%.+]] = load i64, i64* [[ELT_CAST]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[WS32:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
// CHECK: [[WS:%.+]] = trunc i32 [[WS32]] to i16
// CHECK: [[REMOTE_ELT_VAL64:%.+]] = call i64 @__kmpc_shuffle_int64(i64 [[ELT_VAL]], i16 [[LANEOFFSET]], i16 [[WS]])
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// CHECK: store i64 [[REMOTE_ELT_VAL64]], i64* [[REMOTE_ELT_CAST]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[REMOTE_ELT_VOID:%.+]] = bitcast double* [[REMOTE_ELT]] to i8*
// CHECK: store i8* [[REMOTE_ELT_VOID]], i8** [[REMOTE_ELT_REF]], align
//
// Condition to reduce
// CHECK: [[CONDALG0:%.+]] = icmp eq i16 [[ALGVER]], 0
//
// CHECK: [[COND1:%.+]] = icmp eq i16 [[ALGVER]], 1
// CHECK: [[COND2:%.+]] = icmp ult i16 [[LANEID]], [[LANEOFFSET]]
// CHECK: [[CONDALG1:%.+]] = and i1 [[COND1]], [[COND2]]
//
// CHECK: [[COND3:%.+]] = icmp eq i16 [[ALGVER]], 2
// CHECK: [[COND4:%.+]] = and i16 [[LANEID]], 1
// CHECK: [[COND5:%.+]] = icmp eq i16 [[COND4]], 0
// CHECK: [[COND6:%.+]] = and i1 [[COND3]], [[COND5]]
// CHECK: [[COND7:%.+]] = icmp sgt i16 [[LANEOFFSET]], 0
// CHECK: [[CONDALG2:%.+]] = and i1 [[COND6]], [[COND7]]
//
// CHECK: [[COND8:%.+]] = or i1 [[CONDALG0]], [[CONDALG1]]
// CHECK: [[SHOULD_REDUCE:%.+]] = or i1 [[COND8]], [[CONDALG2]]
// CHECK: br i1 [[SHOULD_REDUCE]], label {{%?}}[[DO_REDUCE:.+]], label {{%?}}[[REDUCE_ELSE:.+]]
//
// CHECK: [[DO_REDUCE]]
// CHECK: [[RED_LIST1_VOID:%.+]] = bitcast [[RLT]]* [[RED_LIST]] to i8*
// CHECK: [[RED_LIST2_VOID:%.+]] = bitcast [[RLT]]* [[REMOTE_RED_LIST]] to i8*
// CHECK: call void [[REDUCTION_FUNC]](i8* [[RED_LIST1_VOID]], i8* [[RED_LIST2_VOID]])
// CHECK: br label {{%?}}[[REDUCE_CONT:.+]]
//
// CHECK: [[REDUCE_ELSE]]
// CHECK: br label {{%?}}[[REDUCE_CONT]]
//
// CHECK: [[REDUCE_CONT]]
// Now check if we should just copy over the remote reduction list
// CHECK: [[COND1:%.+]] = icmp eq i16 [[ALGVER]], 1
// CHECK: [[COND2:%.+]] = icmp uge i16 [[LANEID]], [[LANEOFFSET]]
// CHECK: [[SHOULD_COPY:%.+]] = and i1 [[COND1]], [[COND2]]
// CHECK: br i1 [[SHOULD_COPY]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// CHECK: [[DO_COPY]]
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[REMOTE_ELT_VOID:%.+]] = load i8*, i8** [[REMOTE_ELT_REF]],
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT:%.+]] = bitcast i8* [[REMOTE_ELT_VOID]] to double*
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to double*
// CHECK: [[REMOTE_ELT_VAL:%.+]] = load double, double* [[REMOTE_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: store double [[REMOTE_ELT_VAL]], double* [[ELT]], align
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// CHECK: [[COPY_CONT]]
// CHECK: void
//
// Inter warp copy function
// CHECK: define internal void [[WARP_COPY_FN]](i8*, i32)
// CHECK-DAG: [[LANEID:%.+]] = and i32 {{.+}}, 31
// CHECK-DAG: [[WARPID:%.+]] = ashr i32 {{.+}}, 5
// CHECK-DAG: [[RED_LIST:%.+]] = bitcast i8* {{.+}} to [[RLT]]*
// CHECK: store i32 0, i32* [[CNT_ADDR:%.+]],
// CHECK: br label
// CHECK: [[CNT:%.+]] = load i32, i32* [[CNT_ADDR]],
// CHECK: [[DONE_COPY:%.+]] = icmp ult i32 [[CNT]], 2
// CHECK: br i1 [[DONE_COPY]], label
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// [[DO_COPY]]
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[BASE_ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
// CHECK: [[ELT:%.+]] = getelementptr i32, i32* [[BASE_ELT]], i32 [[CNT]]
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// CHECK: [[MEDIUM_ELT:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[WARPID]]
// CHECK: [[ELT_VAL:%.+]] = load i32, i32* [[ELT]],
// CHECK: store volatile i32 [[ELT_VAL]], i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]],
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
// CHECK: br i1 [[IS_W0_ACTIVE_THREAD]], label {{%?}}[[DO_READ:.+]], label {{%?}}[[READ_ELSE:.+]]
//
// CHECK: [[DO_READ]]
// CHECK: [[MEDIUM_ELT:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[TID]]
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[ELT_BASE:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
// CHECK: [[ELT:%.+]] = getelementptr i32, i32* [[ELT_BASE]], i32 [[CNT]]
// CHECK: [[MEDIUM_ELT_VAL:%.+]] = load volatile i32, i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]],
// CHECK: store i32 [[MEDIUM_ELT_VAL]], i32* [[ELT]],
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[READ_CONT:.+]]
//
// CHECK: [[READ_ELSE]]
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
// CHECK: [[NEXT:%.+]] = add nsw i32 [[CNT]], 1
// CHECK: store i32 [[NEXT]], i32* [[CNT_ADDR]],
// CHECK: br label
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: ret
// CHECK: define {{.*}}void {{@__omp_offloading_.+template.+l32}}(
//
// CHECK: call void @__kmpc_spmd_kernel_init(i32 {{.+}}, i16 1, i16 0)
// CHECK: call void @__kmpc_data_sharing_init_stack_spmd
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[EXECUTE:.+]]
//
// CHECK: [[EXECUTE]]
// CHECK: {{call|invoke}} void [[PFN1:@.+]](i32*
// CHECK: call void @__kmpc_spmd_kernel_deinit_v2(i16 1)
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
//
// define internal void [[PFN1]](
// CHECK: store float {{1\.[0e\+]+}}, float* [[D:%.+]], align
// CHECK: [[C_VAL:%.+]] = load i8, i8* [[C:%.+]], align
// CHECK: [[CONV:%.+]] = sext i8 [[C_VAL]] to i32
// CHECK: [[XOR:%.+]] = xor i32 [[CONV]], 2
// CHECK: [[TRUNC:%.+]] = trunc i32 [[XOR]] to i8
// CHECK: store i8 [[TRUNC]], i8* [[C]], align
// CHECK: [[DV:%.+]] = load float, float* [[D]], align
// CHECK: [[MUL:%.+]] = fmul float [[DV]], {{[0-9e\.\+]+}}
// CHECK: store float [[MUL]], float* [[D]], align
// CHECK: [[PTR1:%.+]] = getelementptr inbounds [[RLT:.+]], [2 x i8*]* [[RL:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: store i8* [[C]], i8** [[PTR1]], align
// CHECK: [[PTR2:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RL]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[D_CAST:%.+]] = bitcast float* [[D]] to i8*
// CHECK: store i8* [[D_CAST]], i8** [[PTR2]], align
// CHECK: [[ARG_RL:%.+]] = bitcast [[RLT]]* [[RL]] to i8*
// CHECK: [[RET:%.+]] = call i32 @__kmpc_nvptx_parallel_reduce_nowait_v2(%struct.ident_t* @{{.+}}, i32 {{.+}}, i32 2, i{{32|64}} {{8|16}}, i8* [[ARG_RL]], void (i8*, i16, i16, i16)* [[SHUFFLE_REDUCE_FN:@.+]], void (i8*, i32)* [[WARP_COPY_FN:@.+]])
// CHECK: [[CMP:%.+]] = icmp eq i32 [[RET]], 1
// CHECK: br i1 [[CMP]], label
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[C_INV8:%.+]] = load i8, i8* [[C_IN:%.+]], align
// CHECK: [[C_INV:%.+]] = sext i8 [[C_INV8]] to i32
// CHECK: [[CV8:%.+]] = load i8, i8* [[C]], align
// CHECK: [[CV:%.+]] = sext i8 [[CV8]] to i32
// CHECK: [[XOR:%.+]] = xor i32 [[C_INV]], [[CV]]
// CHECK: [[TRUNC:%.+]] = trunc i32 [[XOR]] to i8
// CHECK: store i8 [[TRUNC]], i8* [[C_IN]], align
// CHECK: [[D_INV:%.+]] = load float, float* [[D_IN:%.+]], align
// CHECK: [[DV:%.+]] = load float, float* [[D]], align
// CHECK: [[MUL:%.+]] = fmul float [[D_INV]], [[DV]]
// CHECK: store float [[MUL]], float* [[D_IN]], align
// CHECK: call void @__kmpc_nvptx_end_reduce_nowait(
// CHECK: br label
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// CHECK: ret
//
// Reduction function
// CHECK: define internal void [[REDUCTION_FUNC:@.+]](i8*, i8*)
// CHECK: [[VAR1_RHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_RHS:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[VAR1_RHS:%.+]] = load i8*, i8** [[VAR1_RHS_REF]],
//
// CHECK: [[VAR1_LHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_LHS:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[VAR1_LHS:%.+]] = load i8*, i8** [[VAR1_LHS_REF]],
//
// CHECK: [[VAR2_RHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_RHS]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[VAR2_RHS_VOID:%.+]] = load i8*, i8** [[VAR2_RHS_REF]],
// CHECK: [[VAR2_RHS:%.+]] = bitcast i8* [[VAR2_RHS_VOID]] to float*
//
// CHECK: [[VAR2_LHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_LHS]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[VAR2_LHS_VOID:%.+]] = load i8*, i8** [[VAR2_LHS_REF]],
// CHECK: [[VAR2_LHS:%.+]] = bitcast i8* [[VAR2_LHS_VOID]] to float*
//
// CHECK: [[VAR1_LHS_VAL8:%.+]] = load i8, i8* [[VAR1_LHS]],
// CHECK: [[VAR1_LHS_VAL:%.+]] = sext i8 [[VAR1_LHS_VAL8]] to i32
// CHECK: [[VAR1_RHS_VAL8:%.+]] = load i8, i8* [[VAR1_RHS]],
// CHECK: [[VAR1_RHS_VAL:%.+]] = sext i8 [[VAR1_RHS_VAL8]] to i32
// CHECK: [[XOR:%.+]] = xor i32 [[VAR1_LHS_VAL]], [[VAR1_RHS_VAL]]
// CHECK: [[RES:%.+]] = trunc i32 [[XOR]] to i8
// CHECK: store i8 [[RES]], i8* [[VAR1_LHS]],
//
// CHECK: [[VAR2_LHS_VAL:%.+]] = load float, float* [[VAR2_LHS]],
// CHECK: [[VAR2_RHS_VAL:%.+]] = load float, float* [[VAR2_RHS]],
// CHECK: [[RES:%.+]] = fmul float [[VAR2_LHS_VAL]], [[VAR2_RHS_VAL]]
// CHECK: store float [[RES]], float* [[VAR2_LHS]],
// CHECK: ret void
//
// Shuffle and reduce function
// CHECK: define internal void [[SHUFFLE_REDUCE_FN]](i8*, i16 {{.*}}, i16 {{.*}}, i16 {{.*}})
// CHECK: [[REMOTE_RED_LIST:%.+]] = alloca [[RLT]], align
// CHECK: [[REMOTE_ELT1:%.+]] = alloca i8
// CHECK: [[REMOTE_ELT2:%.+]] = alloca float
//
// CHECK: [[LANEID:%.+]] = load i16, i16* {{.+}}, align
// CHECK: [[LANEOFFSET:%.+]] = load i16, i16* {{.+}}, align
// CHECK: [[ALGVER:%.+]] = load i16, i16* {{.+}}, align
//
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VAL:%.+]] = load i8, i8* [[ELT_VOID]], align
//
// CHECK: [[ELT_CAST:%.+]] = sext i8 [[ELT_VAL]] to i32
// CHECK: [[WS32:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
// CHECK: [[WS:%.+]] = trunc i32 [[WS32]] to i16
// CHECK: [[REMOTE_ELT1_VAL32:%.+]] = call i32 @__kmpc_shuffle_int32(i32 [[ELT_CAST]], i16 [[LANEOFFSET]], i16 [[WS]])
// CHECK: [[REMOTE_ELT1_VAL:%.+]] = trunc i32 [[REMOTE_ELT1_VAL32]] to i8
//
// CHECK: store i8 [[REMOTE_ELT1_VAL]], i8* [[REMOTE_ELT1]], align
// CHECK: store i8* [[REMOTE_ELT1]], i8** [[REMOTE_ELT_REF]], align
//
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to float*
//
// CHECK: [[ELT_CAST:%.+]] = bitcast float* [[ELT]] to i32*
// CHECK: [[REMOTE_ELT2_CAST:%.+]] = bitcast float* [[REMOTE_ELT2]] to i32*
// CHECK: [[ELT_VAL:%.+]] = load i32, i32* [[ELT_CAST]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[WS32:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
// CHECK: [[WS:%.+]] = trunc i32 [[WS32]] to i16
// CHECK: [[REMOTE_ELT2_VAL32:%.+]] = call i32 @__kmpc_shuffle_int32(i32 [[ELT_VAL]], i16 [[LANEOFFSET]], i16 [[WS]])
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// CHECK: store i32 [[REMOTE_ELT2_VAL32]], i32* [[REMOTE_ELT2_CAST]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[REMOTE_ELT2C:%.+]] = bitcast float* [[REMOTE_ELT2]] to i8*
// CHECK: store i8* [[REMOTE_ELT2C]], i8** [[REMOTE_ELT_REF]], align
//
// Condition to reduce
// CHECK: [[CONDALG0:%.+]] = icmp eq i16 [[ALGVER]], 0
//
// CHECK: [[COND1:%.+]] = icmp eq i16 [[ALGVER]], 1
// CHECK: [[COND2:%.+]] = icmp ult i16 [[LANEID]], [[LANEOFFSET]]
// CHECK: [[CONDALG1:%.+]] = and i1 [[COND1]], [[COND2]]
//
// CHECK: [[COND3:%.+]] = icmp eq i16 [[ALGVER]], 2
// CHECK: [[COND4:%.+]] = and i16 [[LANEID]], 1
// CHECK: [[COND5:%.+]] = icmp eq i16 [[COND4]], 0
// CHECK: [[COND6:%.+]] = and i1 [[COND3]], [[COND5]]
// CHECK: [[COND7:%.+]] = icmp sgt i16 [[LANEOFFSET]], 0
// CHECK: [[CONDALG2:%.+]] = and i1 [[COND6]], [[COND7]]
//
// CHECK: [[COND8:%.+]] = or i1 [[CONDALG0]], [[CONDALG1]]
// CHECK: [[SHOULD_REDUCE:%.+]] = or i1 [[COND8]], [[CONDALG2]]
// CHECK: br i1 [[SHOULD_REDUCE]], label {{%?}}[[DO_REDUCE:.+]], label {{%?}}[[REDUCE_ELSE:.+]]
//
// CHECK: [[DO_REDUCE]]
// CHECK: [[RED_LIST1_VOID:%.+]] = bitcast [[RLT]]* [[RED_LIST]] to i8*
// CHECK: [[RED_LIST2_VOID:%.+]] = bitcast [[RLT]]* [[REMOTE_RED_LIST]] to i8*
// CHECK: call void [[REDUCTION_FUNC]](i8* [[RED_LIST1_VOID]], i8* [[RED_LIST2_VOID]])
// CHECK: br label {{%?}}[[REDUCE_CONT:.+]]
//
// CHECK: [[REDUCE_ELSE]]
// CHECK: br label {{%?}}[[REDUCE_CONT]]
//
// CHECK: [[REDUCE_CONT]]
// Now check if we should just copy over the remote reduction list
// CHECK: [[COND1:%.+]] = icmp eq i16 [[ALGVER]], 1
// CHECK: [[COND2:%.+]] = icmp uge i16 [[LANEID]], [[LANEOFFSET]]
// CHECK: [[SHOULD_COPY:%.+]] = and i1 [[COND1]], [[COND2]]
// CHECK: br i1 [[SHOULD_COPY]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// CHECK: [[DO_COPY]]
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[REMOTE_ELT_VOID:%.+]] = load i8*, i8** [[REMOTE_ELT_REF]],
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT_VAL:%.+]] = load i8, i8* [[REMOTE_ELT_VOID]], align
// CHECK: store i8 [[REMOTE_ELT_VAL]], i8* [[ELT_VOID]], align
//
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[REMOTE_ELT_VOID:%.+]] = load i8*, i8** [[REMOTE_ELT_REF]],
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT:%.+]] = bitcast i8* [[REMOTE_ELT_VOID]] to float*
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to float*
// CHECK: [[REMOTE_ELT_VAL:%.+]] = load float, float* [[REMOTE_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: store float [[REMOTE_ELT_VAL]], float* [[ELT]], align
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// CHECK: [[COPY_CONT]]
// CHECK: void
//
// Inter warp copy function
// CHECK: define internal void [[WARP_COPY_FN]](i8*, i32)
// CHECK-DAG: [[LANEID:%.+]] = and i32 {{.+}}, 31
// CHECK-DAG: [[WARPID:%.+]] = ashr i32 {{.+}}, 5
// CHECK-DAG: [[RED_LIST:%.+]] = bitcast i8* {{.+}} to [[RLT]]*
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// [[DO_COPY]]
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
//
// CHECK: [[MEDIUM_ELT64:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[WARPID]]
// CHECK: [[MEDIUM_ELT:%.+]] = bitcast i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT64]] to i8 addrspace([[SHARED_ADDRSPACE]])*
// CHECK: [[ELT_VAL:%.+]] = load i8, i8* [[ELT_VOID]], align
// CHECK: store volatile i8 [[ELT_VAL]], i8 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
// CHECK: br i1 [[IS_W0_ACTIVE_THREAD]], label {{%?}}[[DO_READ:.+]], label {{%?}}[[READ_ELSE:.+]]
//
// CHECK: [[DO_READ]]
// CHECK: [[MEDIUM_ELT32:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[TID]]
// CHECK: [[MEDIUM_ELT:%.+]] = bitcast i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT32]] to i8 addrspace([[SHARED_ADDRSPACE]])*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[MEDIUM_ELT_VAL:%.+]] = load volatile i8, i8 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: store i8 [[MEDIUM_ELT_VAL]], i8* [[ELT_VOID]], align
// CHECK: br label {{%?}}[[READ_CONT:.+]]
//
// CHECK: [[READ_ELSE]]
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// [[DO_COPY]]
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// CHECK: [[MEDIUM_ELT:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[WARPID]]
// CHECK: [[ELT_VAL:%.+]] = load i32, i32* [[ELT]], align
// CHECK: store volatile i32 [[ELT_VAL]], i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
// CHECK: br i1 [[IS_W0_ACTIVE_THREAD]], label {{%?}}[[DO_READ:.+]], label {{%?}}[[READ_ELSE:.+]]
//
// CHECK: [[DO_READ]]
// CHECK: [[MEDIUM_ELT:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[TID]]
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
// CHECK: [[MEDIUM_ELT_VAL:%.+]] = load volatile i32, i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
// CHECK: store i32 [[MEDIUM_ELT_VAL]], i32* [[ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[READ_CONT:.+]]
//
// CHECK: [[READ_ELSE]]
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
// CHECK: ret
// CHECK: define {{.*}}void {{@__omp_offloading_.+template.+l38}}(
//
// CHECK: call void @__kmpc_spmd_kernel_init(i32 {{.+}}, i16 1, i16 0)
// CHECK: call void @__kmpc_data_sharing_init_stack_spmd
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[EXECUTE:.+]]
//
// CHECK: [[EXECUTE]]
// CHECK: {{call|invoke}} void [[PFN2:@.+]](i32*
// CHECK: call void @__kmpc_spmd_kernel_deinit_v2(i16 1)
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
//
// define internal void [[PFN2]](
// CHECK: store i32 0, i32* [[A:%.+]], align
// CHECK: store i16 -32768, i16* [[B:%.+]], align
// CHECK: [[A_VAL:%.+]] = load i32, i32* [[A:%.+]], align
// CHECK: [[OR:%.+]] = or i32 [[A_VAL]], 1
// CHECK: store i32 [[OR]], i32* [[A]], align
// CHECK: [[BV16:%.+]] = load i16, i16* [[B]], align
// CHECK: [[BV:%.+]] = sext i16 [[BV16]] to i32
// CHECK: [[CMP:%.+]] = icmp sgt i32 99, [[BV]]
// CHECK: br i1 [[CMP]], label {{%?}}[[DO_MAX:.+]], label {{%?}}[[MAX_ELSE:.+]]
//
// CHECK: [[DO_MAX]]
// CHECK: br label {{%?}}[[MAX_CONT:.+]]
//
// CHECK: [[MAX_ELSE]]
// CHECK: [[BV:%.+]] = load i16, i16* [[B]], align
// CHECK: [[MAX:%.+]] = sext i16 [[BV]] to i32
// CHECK: br label {{%?}}[[MAX_CONT]]
//
// CHECK: [[MAX_CONT]]
// CHECK: [[B_LVALUE:%.+]] = phi i32 [ 99, %[[DO_MAX]] ], [ [[MAX]], %[[MAX_ELSE]] ]
// CHECK: [[TRUNC:%.+]] = trunc i32 [[B_LVALUE]] to i16
// CHECK: store i16 [[TRUNC]], i16* [[B]], align
// CHECK: [[PTR1:%.+]] = getelementptr inbounds [[RLT:.+]], [2 x i8*]* [[RL:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[A_CAST:%.+]] = bitcast i32* [[A]] to i8*
// CHECK: store i8* [[A_CAST]], i8** [[PTR1]], align
// CHECK: [[PTR2:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RL]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[B_CAST:%.+]] = bitcast i16* [[B]] to i8*
// CHECK: store i8* [[B_CAST]], i8** [[PTR2]], align
// CHECK: [[ARG_RL:%.+]] = bitcast [[RLT]]* [[RL]] to i8*
// CHECK: [[RET:%.+]] = call i32 @__kmpc_nvptx_parallel_reduce_nowait_v2(%struct.ident_t* @{{.+}}, i32 {{.+}}, i32 2, i{{32|64}} {{8|16}}, i8* [[ARG_RL]], void (i8*, i16, i16, i16)* [[SHUFFLE_REDUCE_FN:@.+]], void (i8*, i32)* [[WARP_COPY_FN:@.+]])
// CHECK: [[CMP:%.+]] = icmp eq i32 [[RET]], 1
// CHECK: br i1 [[CMP]], label
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[A_INV:%.+]] = load i32, i32* [[A_IN:%.+]], align
// CHECK: [[AV:%.+]] = load i32, i32* [[A]], align
// CHECK: [[OR:%.+]] = or i32 [[A_INV]], [[AV]]
// CHECK: store i32 [[OR]], i32* [[A_IN]], align
// CHECK: [[B_INV16:%.+]] = load i16, i16* [[B_IN:%.+]], align
// CHECK: [[B_INV:%.+]] = sext i16 [[B_INV16]] to i32
// CHECK: [[BV16:%.+]] = load i16, i16* [[B]], align
// CHECK: [[BV:%.+]] = sext i16 [[BV16]] to i32
// CHECK: [[CMP:%.+]] = icmp sgt i32 [[B_INV]], [[BV]]
// CHECK: br i1 [[CMP]], label {{%?}}[[DO_MAX:.+]], label {{%?}}[[MAX_ELSE:.+]]
//
// CHECK: [[DO_MAX]]
// CHECK: [[MAX1:%.+]] = load i16, i16* [[B_IN]], align
// CHECK: br label {{%?}}[[MAX_CONT:.+]]
//
// CHECK: [[MAX_ELSE]]
// CHECK: [[MAX2:%.+]] = load i16, i16* [[B]], align
// CHECK: br label {{%?}}[[MAX_CONT]]
//
// CHECK: [[MAX_CONT]]
// CHECK: [[B_MAX:%.+]] = phi i16 [ [[MAX1]], %[[DO_MAX]] ], [ [[MAX2]], %[[MAX_ELSE]] ]
// CHECK: store i16 [[B_MAX]], i16* [[B_IN]], align
// CHECK: call void @__kmpc_nvptx_end_reduce_nowait(
// CHECK: br label
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// CHECK: ret
//
// Reduction function
// CHECK: define internal void [[REDUCTION_FUNC:@.+]](i8*, i8*)
// CHECK: [[VAR1_RHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_RHS:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[VAR1_RHS_VOID:%.+]] = load i8*, i8** [[VAR1_RHS_REF]],
// CHECK: [[VAR1_RHS:%.+]] = bitcast i8* [[VAR1_RHS_VOID]] to i32*
//
// CHECK: [[VAR1_LHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_LHS:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[VAR1_LHS_VOID:%.+]] = load i8*, i8** [[VAR1_LHS_REF]],
// CHECK: [[VAR1_LHS:%.+]] = bitcast i8* [[VAR1_LHS_VOID]] to i32*
//
// CHECK: [[VAR2_RHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_RHS]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[VAR2_RHS_VOID:%.+]] = load i8*, i8** [[VAR2_RHS_REF]],
// CHECK: [[VAR2_RHS:%.+]] = bitcast i8* [[VAR2_RHS_VOID]] to i16*
//
// CHECK: [[VAR2_LHS_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST_LHS]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[VAR2_LHS_VOID:%.+]] = load i8*, i8** [[VAR2_LHS_REF]],
// CHECK: [[VAR2_LHS:%.+]] = bitcast i8* [[VAR2_LHS_VOID]] to i16*
//
// CHECK: [[VAR1_LHS_VAL:%.+]] = load i32, i32* [[VAR1_LHS]],
// CHECK: [[VAR1_RHS_VAL:%.+]] = load i32, i32* [[VAR1_RHS]],
// CHECK: [[OR:%.+]] = or i32 [[VAR1_LHS_VAL]], [[VAR1_RHS_VAL]]
// CHECK: store i32 [[OR]], i32* [[VAR1_LHS]],
//
// CHECK: [[VAR2_LHS_VAL16:%.+]] = load i16, i16* [[VAR2_LHS]],
// CHECK: [[VAR2_LHS_VAL:%.+]] = sext i16 [[VAR2_LHS_VAL16]] to i32
// CHECK: [[VAR2_RHS_VAL16:%.+]] = load i16, i16* [[VAR2_RHS]],
// CHECK: [[VAR2_RHS_VAL:%.+]] = sext i16 [[VAR2_RHS_VAL16]] to i32
//
// CHECK: [[CMP:%.+]] = icmp sgt i32 [[VAR2_LHS_VAL]], [[VAR2_RHS_VAL]]
// CHECK: br i1 [[CMP]], label {{%?}}[[DO_MAX:.+]], label {{%?}}[[MAX_ELSE:.+]]
//
// CHECK: [[DO_MAX]]
// CHECK: [[MAX1:%.+]] = load i16, i16* [[VAR2_LHS]], align
// CHECK: br label {{%?}}[[MAX_CONT:.+]]
//
// CHECK: [[MAX_ELSE]]
// CHECK: [[MAX2:%.+]] = load i16, i16* [[VAR2_RHS]], align
// CHECK: br label {{%?}}[[MAX_CONT]]
//
// CHECK: [[MAX_CONT]]
// CHECK: [[MAXV:%.+]] = phi i16 [ [[MAX1]], %[[DO_MAX]] ], [ [[MAX2]], %[[MAX_ELSE]] ]
// CHECK: store i16 [[MAXV]], i16* [[VAR2_LHS]],
// CHECK: ret void
//
// Shuffle and reduce function
// CHECK: define internal void [[SHUFFLE_REDUCE_FN]](i8*, i16 {{.*}}, i16 {{.*}}, i16 {{.*}})
// CHECK: [[REMOTE_RED_LIST:%.+]] = alloca [[RLT]], align
// CHECK: [[REMOTE_ELT1:%.+]] = alloca i32
// CHECK: [[REMOTE_ELT2:%.+]] = alloca i16
//
// CHECK: [[LANEID:%.+]] = load i16, i16* {{.+}}, align
// CHECK: [[LANEOFFSET:%.+]] = load i16, i16* {{.+}}, align
// CHECK: [[ALGVER:%.+]] = load i16, i16* {{.+}}, align
//
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
// CHECK: [[ELT_VAL:%.+]] = load i32, i32* [[ELT]], align
//
// CHECK: [[WS32:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
// CHECK: [[WS:%.+]] = trunc i32 [[WS32]] to i16
// CHECK: [[REMOTE_ELT1_VAL:%.+]] = call i32 @__kmpc_shuffle_int32(i32 [[ELT_VAL]], i16 [[LANEOFFSET]], i16 [[WS]])
//
// CHECK: store i32 [[REMOTE_ELT1_VAL]], i32* [[REMOTE_ELT1]], align
// CHECK: [[REMOTE_ELT1C:%.+]] = bitcast i32* [[REMOTE_ELT1]] to i8*
// CHECK: store i8* [[REMOTE_ELT1C]], i8** [[REMOTE_ELT_REF]], align
//
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i16*
// CHECK: [[ELT_VAL:%.+]] = load i16, i16* [[ELT]], align
//
// CHECK: [[ELT_CAST:%.+]] = sext i16 [[ELT_VAL]] to i32
// CHECK: [[WS32:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
// CHECK: [[WS:%.+]] = trunc i32 [[WS32]] to i16
// CHECK: [[REMOTE_ELT2_VAL32:%.+]] = call i32 @__kmpc_shuffle_int32(i32 [[ELT_CAST]], i16 [[LANEOFFSET]], i16 [[WS]])
// CHECK: [[REMOTE_ELT2_VAL:%.+]] = trunc i32 [[REMOTE_ELT2_VAL32]] to i16
//
// CHECK: store i16 [[REMOTE_ELT2_VAL]], i16* [[REMOTE_ELT2]], align
// CHECK: [[REMOTE_ELT2C:%.+]] = bitcast i16* [[REMOTE_ELT2]] to i8*
// CHECK: store i8* [[REMOTE_ELT2C]], i8** [[REMOTE_ELT_REF]], align
//
// Condition to reduce
// CHECK: [[CONDALG0:%.+]] = icmp eq i16 [[ALGVER]], 0
//
// CHECK: [[COND1:%.+]] = icmp eq i16 [[ALGVER]], 1
// CHECK: [[COND2:%.+]] = icmp ult i16 [[LANEID]], [[LANEOFFSET]]
// CHECK: [[CONDALG1:%.+]] = and i1 [[COND1]], [[COND2]]
//
// CHECK: [[COND3:%.+]] = icmp eq i16 [[ALGVER]], 2
// CHECK: [[COND4:%.+]] = and i16 [[LANEID]], 1
// CHECK: [[COND5:%.+]] = icmp eq i16 [[COND4]], 0
// CHECK: [[COND6:%.+]] = and i1 [[COND3]], [[COND5]]
// CHECK: [[COND7:%.+]] = icmp sgt i16 [[LANEOFFSET]], 0
// CHECK: [[CONDALG2:%.+]] = and i1 [[COND6]], [[COND7]]
//
// CHECK: [[COND8:%.+]] = or i1 [[CONDALG0]], [[CONDALG1]]
// CHECK: [[SHOULD_REDUCE:%.+]] = or i1 [[COND8]], [[CONDALG2]]
// CHECK: br i1 [[SHOULD_REDUCE]], label {{%?}}[[DO_REDUCE:.+]], label {{%?}}[[REDUCE_ELSE:.+]]
//
// CHECK: [[DO_REDUCE]]
// CHECK: [[RED_LIST1_VOID:%.+]] = bitcast [[RLT]]* [[RED_LIST]] to i8*
// CHECK: [[RED_LIST2_VOID:%.+]] = bitcast [[RLT]]* [[REMOTE_RED_LIST]] to i8*
// CHECK: call void [[REDUCTION_FUNC]](i8* [[RED_LIST1_VOID]], i8* [[RED_LIST2_VOID]])
// CHECK: br label {{%?}}[[REDUCE_CONT:.+]]
//
// CHECK: [[REDUCE_ELSE]]
// CHECK: br label {{%?}}[[REDUCE_CONT]]
//
// CHECK: [[REDUCE_CONT]]
// Now check if we should just copy over the remote reduction list
// CHECK: [[COND1:%.+]] = icmp eq i16 [[ALGVER]], 1
// CHECK: [[COND2:%.+]] = icmp uge i16 [[LANEID]], [[LANEOFFSET]]
// CHECK: [[SHOULD_COPY:%.+]] = and i1 [[COND1]], [[COND2]]
// CHECK: br i1 [[SHOULD_COPY]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// CHECK: [[DO_COPY]]
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[REMOTE_ELT_VOID:%.+]] = load i8*, i8** [[REMOTE_ELT_REF]],
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT:%.+]] = bitcast i8* [[REMOTE_ELT_VOID]] to i32*
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
// CHECK: [[REMOTE_ELT_VAL:%.+]] = load i32, i32* [[REMOTE_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: store i32 [[REMOTE_ELT_VAL]], i32* [[ELT]], align
//
// CHECK: [[REMOTE_ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[REMOTE_RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[REMOTE_ELT_VOID:%.+]] = load i8*, i8** [[REMOTE_ELT_REF]],
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[REMOTE_ELT:%.+]] = bitcast i8* [[REMOTE_ELT_VOID]] to i16*
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i16*
// CHECK: [[REMOTE_ELT_VAL:%.+]] = load i16, i16* [[REMOTE_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: store i16 [[REMOTE_ELT_VAL]], i16* [[ELT]], align
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// CHECK: [[COPY_CONT]]
// CHECK: void
//
// Inter warp copy function
// CHECK: define internal void [[WARP_COPY_FN]](i8*, i32)
// CHECK-DAG: [[LANEID:%.+]] = and i32 {{.+}}, 31
// CHECK-DAG: [[WARPID:%.+]] = ashr i32 {{.+}}, 5
// CHECK-DAG: [[RED_LIST:%.+]] = bitcast i8* {{.+}} to [[RLT]]*
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// [[DO_COPY]]
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
//
// CHECK: [[MEDIUM_ELT:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[WARPID]]
// CHECK: [[ELT_VAL:%.+]] = load i32, i32* [[ELT]], align
// CHECK: store volatile i32 [[ELT_VAL]], i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
// CHECK: br i1 [[IS_W0_ACTIVE_THREAD]], label {{%?}}[[DO_READ:.+]], label {{%?}}[[READ_ELSE:.+]]
//
// CHECK: [[DO_READ]]
// CHECK: [[MEDIUM_ELT:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[TID]]
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 0
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i32*
// CHECK: [[MEDIUM_ELT_VAL:%.+]] = load volatile i32, i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: store i32 [[MEDIUM_ELT_VAL]], i32* [[ELT]], align
// CHECK: br label {{%?}}[[READ_CONT:.+]]
//
// CHECK: [[READ_ELSE]]
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
// [[DO_COPY]]
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i16*
//
// CHECK: [[MEDIUM_ELT32:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[WARPID]]
// CHECK: [[MEDIUM_ELT:%.+]] = bitcast i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT32]] to i16 addrspace([[SHARED_ADDRSPACE]])*
// CHECK: [[ELT_VAL:%.+]] = load i16, i16* [[ELT]], align
// CHECK: store volatile i16 [[ELT_VAL]], i16 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: br label {{%?}}[[COPY_CONT:.+]]
//
// CHECK: [[COPY_ELSE]]
// CHECK: br label {{%?}}[[COPY_CONT]]
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
// CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
// CHECK: br i1 [[IS_W0_ACTIVE_THREAD]], label {{%?}}[[DO_READ:.+]], label {{%?}}[[READ_ELSE:.+]]
//
// CHECK: [[DO_READ]]
// CHECK: [[MEDIUM_ELT32:%.+]] = getelementptr inbounds [32 x i32], [32 x i32] addrspace([[SHARED_ADDRSPACE]])* [[TRANSFER_STORAGE]], i64 0, i32 [[TID]]
// CHECK: [[MEDIUM_ELT:%.+]] = bitcast i32 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT32]] to i16 addrspace([[SHARED_ADDRSPACE]])*
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: [[ELT_REF:%.+]] = getelementptr inbounds [[RLT]], [[RLT]]* [[RED_LIST:%.+]], i{{32|64}} 0, i{{32|64}} 1
// CHECK: [[ELT_VOID:%.+]] = load i8*, i8** [[ELT_REF]],
// CHECK: [[ELT:%.+]] = bitcast i8* [[ELT_VOID]] to i16*
// CHECK: [[MEDIUM_ELT_VAL:%.+]] = load volatile i16, i16 addrspace([[SHARED_ADDRSPACE]])* [[MEDIUM_ELT]], align
[OpenMP] Parallel reduction on the NVPTX device. This patch implements codegen for the reduction clause on any parallel construct for elementary data types. An efficient implementation requires hierarchical reduction within a warp and a threadblock. It is complicated by the fact that variables declared in the stack of a CUDA thread cannot be shared with other threads. The patch creates a struct to hold reduction variables and a number of helper functions. The OpenMP runtime on the GPU implements reduction algorithms that uses these helper functions to perform reductions within a team. Variables are shared between CUDA threads using shuffle intrinsics. An implementation of reductions on the NVPTX device is substantially different to that of CPUs. However, this patch is written so that there are minimal changes to the rest of OpenMP codegen. The implemented design allows the compiler and runtime to be decoupled, i.e., the runtime does not need to know of the reduction operation(s), the type of the reduction variable(s), or the number of reductions. The design also allows reuse of host codegen, with appropriate specialization for the NVPTX device. While the patch does introduce a number of abstractions, the expected use case calls for inlining of the GPU OpenMP runtime. After inlining and optimizations in LLVM, these abstractions are unwound and performance of OpenMP reductions is comparable to CUDA-canonical code. Patch by Tian Jin in collaboration with Arpith Jacob Reviewers: ABataev Differential Revision: https://reviews.llvm.org/D29758 llvm-svn: 295333
2017-02-17 00:20:16 +08:00
// CHECK: store i16 [[MEDIUM_ELT_VAL]], i16* [[ELT]], align
// CHECK: br label {{%?}}[[READ_CONT:.+]]
//
// CHECK: [[READ_ELSE]]
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
// CHECK: ret
#endif