[OpenMP] Support for the num_threads-clause on 'target parallel' on the NVPTX device.

This patch adds support for the Spmd construct 'target parallel' on the
NVPTX device. This involves ignoring the num_threads clause on the device
since the number of threads in this combined construct is already set on
the host through the call to __tgt_target_teams().

Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29083

llvm-svn: 292999
This commit is contained in:
Arpith Chacko Jacob 2017-01-25 01:18:34 +00:00
parent 99259ee40c
commit e04da5dee2
3 changed files with 145 additions and 0 deletions

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@ -642,6 +642,17 @@ CGOpenMPRuntimeNVPTX::CGOpenMPRuntimeNVPTX(CodeGenModule &CGM)
llvm_unreachable("OpenMP NVPTX can only handle device code.");
}
void CGOpenMPRuntimeNVPTX::emitNumThreadsClause(CodeGenFunction &CGF,
llvm::Value *NumThreads,
SourceLocation Loc) {
// Do nothing in case of Spmd mode and L0 parallel.
// TODO: If in Spmd mode and L1 parallel emit the clause.
if (isInSpmdExecutionMode())
return;
CGOpenMPRuntime::emitNumThreadsClause(CGF, NumThreads, Loc);
}
void CGOpenMPRuntimeNVPTX::emitNumTeamsClause(CodeGenFunction &CGF,
const Expr *NumTeams,
const Expr *ThreadLimit,

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@ -170,6 +170,14 @@ protected:
public:
explicit CGOpenMPRuntimeNVPTX(CodeGenModule &CGM);
/// \brief Emits call to void __kmpc_push_num_threads(ident_t *loc, kmp_int32
/// global_tid, kmp_int32 num_threads) to generate code for 'num_threads'
/// clause.
/// \param NumThreads An integer value of threads.
virtual void emitNumThreadsClause(CodeGenFunction &CGF,
llvm::Value *NumThreads,
SourceLocation Loc) override;
/// \brief This function ought to emit, in the general case, a call to
// the openmp runtime kmpc_push_num_teams. In NVPTX backend it is not needed
// as these numbers are obtained through the PTX grid and block configuration.

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@ -0,0 +1,126 @@
// Test target codegen - host bc file has to be created first.
// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=45 -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-version=45 -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-version=45 -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-version=45 -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-version=45 -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
// expected-no-diagnostics
#ifndef HEADER
#define HEADER
// Check that the execution mode of all 2 target regions on the gpu is set to SPMD Mode.
// CHECK-DAG: {{@__omp_offloading_.+l21}}_exec_mode = weak constant i8 0
// CHECK-DAG: {{@__omp_offloading_.+l26}}_exec_mode = weak constant i8 0
template<typename tx>
tx ftemplate(int n) {
tx a = 0;
short aa = 0;
tx b[10];
#pragma omp target parallel map(tofrom: aa) num_threads(1024)
{
aa += 1;
}
#pragma omp target parallel map(tofrom:a, aa, b) if(target: n>40) num_threads(n)
{
a += 1;
aa += 1;
b[2] += 1;
}
return a;
}
int bar(int n){
int a = 0;
a += ftemplate<int>(n);
return a;
}
// CHECK-LABEL: define {{.*}}void {{@__omp_offloading_.+template.+l21}}(
// CHECK: [[AA_ADDR:%.+]] = alloca i16*, align
// CHECK: store i16* {{%.+}}, i16** [[AA_ADDR]], align
// CHECK: [[AA:%.+]] = load i16*, i16** [[AA_ADDR]], align
// CHECK: [[THREAD_LIMIT:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.ntid.x()
// CHECK: call void @__kmpc_spmd_kernel_init(i32 [[THREAD_LIMIT]],
// CHECK: br label {{%?}}[[EXEC:.+]]
//
// CHECK: [[EXEC]]
// CHECK-NOT: call void @__kmpc_push_num_threads
// CHECK: {{call|invoke}} void [[OP1:@.+]](i32* null, i32* null, i16* [[AA]])
// CHECK: br label {{%?}}[[DONE:.+]]
//
// CHECK: [[DONE]]
// CHECK: call void @__kmpc_spmd_kernel_deinit()
// CHECK: br label {{%?}}[[EXIT:.+]]
//
// CHECK: [[EXIT]]
// CHECK: ret void
// CHECK: }
// CHECK: define internal void [[OP1]](i32* noalias %.global_tid., i32* noalias %.bound_tid., i16* {{[^%]*}}[[ARG:%.+]])
// CHECK: = alloca i32*, align
// CHECK: = alloca i32*, align
// CHECK: [[AA_ADDR:%.+]] = alloca i16*, align
// CHECK: store i16* [[ARG]], i16** [[AA_ADDR]], align
// CHECK: [[AA:%.+]] = load i16*, i16** [[AA_ADDR]], align
// CHECK: [[VAL:%.+]] = load i16, i16* [[AA]], align
// CHECK: store i16 {{%.+}}, i16* [[AA]], align
// CHECK: ret void
// CHECK: }
// CHECK-LABEL: define {{.*}}void {{@__omp_offloading_.+template.+l26}}(
// CHECK: [[A_ADDR:%.+]] = alloca i32*, align
// CHECK: [[AA_ADDR:%.+]] = alloca i16*, align
// CHECK: [[B_ADDR:%.+]] = alloca [10 x i32]*, align
// CHECK: store i32* {{%.+}}, i32** [[A_ADDR]], align
// CHECK: store i16* {{%.+}}, i16** [[AA_ADDR]], align
// CHECK: store [10 x i32]* {{%.+}}, [10 x i32]** [[B_ADDR]], align
// CHECK: [[A:%.+]] = load i32*, i32** [[A_ADDR]], align
// CHECK: [[AA:%.+]] = load i16*, i16** [[AA_ADDR]], align
// CHECK: [[B:%.+]] = load [10 x i32]*, [10 x i32]** [[B_ADDR]], align
// CHECK: [[THREAD_LIMIT:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.ntid.x()
// CHECK: call void @__kmpc_spmd_kernel_init(i32 [[THREAD_LIMIT]],
// CHECK: br label {{%?}}[[EXEC:.+]]
//
// CHECK: [[EXEC]]
// CHECK-NOT: call void @__kmpc_push_num_threads
// CHECK: {{call|invoke}} void [[OP2:@.+]](i32* null, i32* null, i32* [[A]], i16* [[AA]], [10 x i32]* [[B]])
// CHECK: br label {{%?}}[[DONE:.+]]
//
// CHECK: [[DONE]]
// CHECK: call void @__kmpc_spmd_kernel_deinit()
// CHECK: br label {{%?}}[[EXIT:.+]]
//
// CHECK: [[EXIT]]
// CHECK: ret void
// CHECK: }
// CHECK: define internal void [[OP2]](i32* noalias %.global_tid., i32* noalias %.bound_tid., i32* {{[^%]*}}[[ARG1:%.+]], i16* {{[^%]*}}[[ARG2:%.+]], [10 x i32]* {{[^%]*}}[[ARG3:%.+]])
// CHECK: = alloca i32*, align
// CHECK: = alloca i32*, align
// CHECK: [[A_ADDR:%.+]] = alloca i32*, align
// CHECK: [[AA_ADDR:%.+]] = alloca i16*, align
// CHECK: [[B_ADDR:%.+]] = alloca [10 x i32]*, align
// CHECK: store i32* [[ARG1]], i32** [[A_ADDR]], align
// CHECK: store i16* [[ARG2]], i16** [[AA_ADDR]], align
// CHECK: store [10 x i32]* [[ARG3]], [10 x i32]** [[B_ADDR]], align
// CHECK: [[A:%.+]] = load i32*, i32** [[A_ADDR]], align
// CHECK: [[AA:%.+]] = load i16*, i16** [[AA_ADDR]], align
// CHECK: [[B:%.+]] = load [10 x i32]*, [10 x i32]** [[B_ADDR]], align
// CHECK: store i32 {{%.+}}, i32* [[A]], align
// CHECK: store i16 {{%.+}}, i16* [[AA]], align
// CHECK: [[ELT:%.+]] = getelementptr inbounds [10 x i32], [10 x i32]* [[B]],
// CHECK: store i32 {{%.+}}, i32* [[ELT]], align
// CHECK: ret void
// CHECK: }
#endif