llvm-project/llvm/test/CodeGen/AMDGPU/uniform-cfg.ll

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; RUN: llc -march=amdgcn -mcpu=verde -amdgpu-early-ifcvt=0 -machine-sink-split-probability-threshold=0 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefix=GCN -check-prefix=SI %s
; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -amdgpu-early-ifcvt=0 -machine-sink-split-probability-threshold=0 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefix=GCN -check-prefix=VI %s
; GCN-LABEL: {{^}}uniform_if_scc:
; GCN-DAG: s_cmp_eq_u32 s{{[0-9]+}}, 0
; GCN-DAG: s_mov_b32 [[S_VAL:s[0-9]+]], 0
; GCN: s_cbranch_scc1 [[IF_LABEL:[0-9_A-Za-z]+]]
; Fall-through to the else
; GCN: s_mov_b32 [[S_VAL]], 1
; GCN: [[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[V_VAL:v[0-9]+]], [[S_VAL]]
; GCN: buffer_store_dword [[V_VAL]]
define amdgpu_kernel void @uniform_if_scc(i32 %cond, i32 addrspace(1)* %out) {
entry:
%cmp0 = icmp eq i32 %cond, 0
br i1 %cmp0, label %if, label %else
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}uniform_if_vcc:
; GCN-DAG: v_cmp_eq_f32_e64 [[COND:vcc|s\[[0-9]+:[0-9]+\]]], s{{[0-9]+}}, 0{{$}}
; GCN-DAG: s_mov_b32 [[S_VAL:s[0-9]+]], 0
; GCN: s_cbranch_vccnz [[IF_LABEL:[0-9_A-Za-z]+]]
; Fall-through to the else
; GCN: s_mov_b32 [[S_VAL]], 1
; GCN: [[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[V_VAL:v[0-9]+]], [[S_VAL]]
; GCN: buffer_store_dword [[V_VAL]]
define amdgpu_kernel void @uniform_if_vcc(float %cond, i32 addrspace(1)* %out) {
entry:
%cmp0 = fcmp oeq float %cond, 0.0
br i1 %cmp0, label %if, label %else
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}uniform_if_swap_br_targets_scc:
; GCN-DAG: s_cmp_lg_u32 s{{[0-9]+}}, 0
; GCN-DAG: s_mov_b32 [[S_VAL:s[0-9]+]], 0
; GCN: s_cbranch_scc1 [[IF_LABEL:[0-9_A-Za-z]+]]
; Fall-through to the else
; GCN: s_mov_b32 [[S_VAL]], 1
; GCN: [[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[V_VAL:v[0-9]+]], [[S_VAL]]
; GCN: buffer_store_dword [[V_VAL]]
define amdgpu_kernel void @uniform_if_swap_br_targets_scc(i32 %cond, i32 addrspace(1)* %out) {
entry:
%cmp0 = icmp eq i32 %cond, 0
br i1 %cmp0, label %else, label %if
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}uniform_if_swap_br_targets_vcc:
; GCN-DAG: v_cmp_neq_f32_e64 [[COND:vcc|s\[[0-9]+:[0-9]+\]]], s{{[0-9]+}}, 0{{$}}
; GCN-DAG: s_mov_b32 [[S_VAL:s[0-9]+]], 0
; GCN: s_cbranch_vccnz [[IF_LABEL:[0-9_A-Za-z]+]]
; Fall-through to the else
; GCN: s_mov_b32 [[S_VAL]], 1
; GCN: [[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[V_VAL:v[0-9]+]], [[S_VAL]]
; GCN: buffer_store_dword [[V_VAL]]
define amdgpu_kernel void @uniform_if_swap_br_targets_vcc(float %cond, i32 addrspace(1)* %out) {
entry:
%cmp0 = fcmp oeq float %cond, 0.0
br i1 %cmp0, label %else, label %if
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}uniform_if_move_valu:
; GCN: v_add_f32_e32 [[CMP:v[0-9]+]]
; Using a floating-point value in an integer compare will cause the compare to
; be selected for the SALU and then later moved to the VALU.
; GCN: v_cmp_ne_u32_e32 [[COND:vcc|s\[[0-9]+:[0-9]+\]]], 5, [[CMP]]
; GCN: s_and_b64 vcc, exec, [[COND]]
; GCN: s_cbranch_vccnz [[ENDIF_LABEL:[0-9_A-Za-z]+]]
; GCN: buffer_store_dword
; GCN: [[ENDIF_LABEL]]:
; GCN: s_endpgm
define amdgpu_kernel void @uniform_if_move_valu(i32 addrspace(1)* %out, float %a) {
entry:
%a.0 = fadd float %a, 10.0
%cond = bitcast float %a.0 to i32
%cmp = icmp eq i32 %cond, 5
br i1 %cmp, label %if, label %endif
if:
store i32 0, i32 addrspace(1)* %out
br label %endif
endif:
ret void
}
; GCN-LABEL: {{^}}uniform_if_move_valu_commute:
; GCN: v_add_f32_e32 [[CMP:v[0-9]+]]
; Using a floating-point value in an integer compare will cause the compare to
; be selected for the SALU and then later moved to the VALU.
; GCN: v_cmp_gt_u32_e32 [[COND:vcc|s\[[0-9]+:[0-9]+\]]], 6, [[CMP]]
; GCN: s_and_b64 vcc, exec, [[COND]]
; GCN: s_cbranch_vccnz [[ENDIF_LABEL:[0-9_A-Za-z]+]]
; GCN: buffer_store_dword
; GCN: [[ENDIF_LABEL]]:
; GCN: s_endpgm
define amdgpu_kernel void @uniform_if_move_valu_commute(i32 addrspace(1)* %out, float %a) {
entry:
%a.0 = fadd float %a, 10.0
%cond = bitcast float %a.0 to i32
%cmp = icmp ugt i32 %cond, 5
br i1 %cmp, label %if, label %endif
if:
store i32 0, i32 addrspace(1)* %out
br label %endif
endif:
ret void
}
; GCN-LABEL: {{^}}uniform_if_else_ret:
; GCN: s_cmp_lg_u32 s{{[0-9]+}}, 0
; GCN: s_cbranch_scc0 [[IF_LABEL:[0-9_A-Za-z]+]]
; GCN: v_mov_b32_e32 [[TWO:v[0-9]+]], 2
; GCN: buffer_store_dword [[TWO]]
; GCN: s_endpgm
; GCN: {{^}}[[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[ONE:v[0-9]+]], 1
; GCN: buffer_store_dword [[ONE]]
; GCN: s_endpgm
define amdgpu_kernel void @uniform_if_else_ret(i32 addrspace(1)* nocapture %out, i32 %a) {
entry:
%cmp = icmp eq i32 %a, 0
br i1 %cmp, label %if.then, label %if.else
if.then: ; preds = %entry
store i32 1, i32 addrspace(1)* %out
br label %if.end
if.else: ; preds = %entry
store i32 2, i32 addrspace(1)* %out
br label %if.end
if.end: ; preds = %if.else, %if.then
ret void
}
; GCN-LABEL: {{^}}uniform_if_else:
; GCN: s_cmp_lg_u32 s{{[0-9]+}}, 0
AMDGPU: Add pass to lower kernel arguments to loads This replaces most argument uses with loads, but for now not all. The code in SelectionDAG for calling convention lowering is actively harmful for amdgpu_kernel. It attempts to split the argument types into register legal types, which results in low quality code for arbitary types. Since all kernel arguments are passed in memory, we just want the raw types. I've tried a couple of methods of mitigating this in SelectionDAG, but it's easier to just bypass this problem alltogether. It's possible to hack around the problem in the initial lowering, but the real problem is the DAG then expects to be able to use CopyToReg/CopyFromReg for uses of the arguments outside the block. Exposing the argument loads in the IR also has the advantage that the LoadStoreVectorizer can merge them. I'm not sure the best approach to dealing with the IR argument list is. The patch as-is just leaves the IR arguments in place, so all the existing code will still compute the same kernarg size and pointlessly lowers the arguments. Arguably the frontend should emit kernels with an empty argument list in the first place. Alternatively a dummy array could be inserted as a single argument just to reserve space. This does have some disadvantages. Local pointer kernel arguments can no longer have AssertZext placed on them as the equivalent !range metadata is not valid on pointer typed loads. This is mostly bad for SI which needs to know about the known bits in order to use the DS instruction offset, so in this case this is not done. More importantly, this skips noalias arguments since this pass does not yet convert this to the equivalent !alias.scope and !noalias metadata. Producing this metadata correctly seems to be tricky, although this logically is the same as inlining into a function which doesn't exist. Additionally, exposing these loads to the vectorizer may result in degraded aliasing information if a pointer load is merged with another argument load. I'm also not entirely sure this is preserving the current clover ABI, although I would greatly prefer if it would stop widening arguments and match the HSA ABI. As-is I think it is extending < 4-byte arguments to 4-bytes but doesn't align them to 4-bytes. llvm-svn: 335650
2018-06-27 03:10:00 +08:00
; GCN: s_cbranch_scc0 [[IF_LABEL:[0-9_A-Za-z]+]]
; GCN: v_mov_b32_e32 [[IMM_REG:v[0-9]+]], 2
; GCN: s_branch [[ENDIF_LABEL:[0-9_A-Za-z]+]]
; GCN: [[IF_LABEL]]:
; GCN-NEXT: v_mov_b32_e32 [[IMM_REG]], 1
; GCN-NEXT: [[ENDIF_LABEL]]:
; GCN: buffer_store_dword [[IMM_REG]]
; GCN: v_mov_b32_e32 [[THREE:v[0-9]+]], 3
; GCN: buffer_store_dword [[THREE]]
; GCN: s_endpgm
define amdgpu_kernel void @uniform_if_else(i32 addrspace(1)* nocapture %out0, i32 addrspace(1)* nocapture %out1, i32 %a) {
entry:
%cmp = icmp eq i32 %a, 0
br i1 %cmp, label %if.then, label %if.else
if.then: ; preds = %entry
store i32 1, i32 addrspace(1)* %out0
br label %if.end
if.else: ; preds = %entry
store i32 2, i32 addrspace(1)* %out0
br label %if.end
if.end: ; preds = %if.else, %if.then
store i32 3, i32 addrspace(1)* %out1
ret void
}
; GCN-LABEL: {{^}}icmp_2_users:
; GCN: s_cmp_lt_i32 s{{[0-9]+}}, 1
; GCN: s_cbranch_scc1 [[LABEL:[a-zA-Z0-9_]+]]
; GCN: buffer_store_dword
; GCN: [[LABEL]]:
; GCN: s_endpgm
define amdgpu_kernel void @icmp_2_users(i32 addrspace(1)* %out, i32 %cond) {
main_body:
%0 = icmp sgt i32 %cond, 0
%1 = sext i1 %0 to i32
br i1 %0, label %IF, label %ENDIF
IF:
store i32 %1, i32 addrspace(1)* %out
br label %ENDIF
ENDIF: ; preds = %IF, %main_body
ret void
}
; GCN-LABEL: {{^}}icmp_users_different_blocks:
AMDGPU: Add pass to lower kernel arguments to loads This replaces most argument uses with loads, but for now not all. The code in SelectionDAG for calling convention lowering is actively harmful for amdgpu_kernel. It attempts to split the argument types into register legal types, which results in low quality code for arbitary types. Since all kernel arguments are passed in memory, we just want the raw types. I've tried a couple of methods of mitigating this in SelectionDAG, but it's easier to just bypass this problem alltogether. It's possible to hack around the problem in the initial lowering, but the real problem is the DAG then expects to be able to use CopyToReg/CopyFromReg for uses of the arguments outside the block. Exposing the argument loads in the IR also has the advantage that the LoadStoreVectorizer can merge them. I'm not sure the best approach to dealing with the IR argument list is. The patch as-is just leaves the IR arguments in place, so all the existing code will still compute the same kernarg size and pointlessly lowers the arguments. Arguably the frontend should emit kernels with an empty argument list in the first place. Alternatively a dummy array could be inserted as a single argument just to reserve space. This does have some disadvantages. Local pointer kernel arguments can no longer have AssertZext placed on them as the equivalent !range metadata is not valid on pointer typed loads. This is mostly bad for SI which needs to know about the known bits in order to use the DS instruction offset, so in this case this is not done. More importantly, this skips noalias arguments since this pass does not yet convert this to the equivalent !alias.scope and !noalias metadata. Producing this metadata correctly seems to be tricky, although this logically is the same as inlining into a function which doesn't exist. Additionally, exposing these loads to the vectorizer may result in degraded aliasing information if a pointer load is merged with another argument load. I'm also not entirely sure this is preserving the current clover ABI, although I would greatly prefer if it would stop widening arguments and match the HSA ABI. As-is I think it is extending < 4-byte arguments to 4-bytes but doesn't align them to 4-bytes. llvm-svn: 335650
2018-06-27 03:10:00 +08:00
; GCN: s_load_dwordx2 s{{\[}}[[COND0:[0-9]+]]:[[COND1:[0-9]+]]{{\]}}
; GCN: s_cmp_lt_i32 s[[COND0]], 1
; GCN: s_cbranch_scc1 [[EXIT:[A-Za-z0-9_]+]]
AMDGPU: Add pass to lower kernel arguments to loads This replaces most argument uses with loads, but for now not all. The code in SelectionDAG for calling convention lowering is actively harmful for amdgpu_kernel. It attempts to split the argument types into register legal types, which results in low quality code for arbitary types. Since all kernel arguments are passed in memory, we just want the raw types. I've tried a couple of methods of mitigating this in SelectionDAG, but it's easier to just bypass this problem alltogether. It's possible to hack around the problem in the initial lowering, but the real problem is the DAG then expects to be able to use CopyToReg/CopyFromReg for uses of the arguments outside the block. Exposing the argument loads in the IR also has the advantage that the LoadStoreVectorizer can merge them. I'm not sure the best approach to dealing with the IR argument list is. The patch as-is just leaves the IR arguments in place, so all the existing code will still compute the same kernarg size and pointlessly lowers the arguments. Arguably the frontend should emit kernels with an empty argument list in the first place. Alternatively a dummy array could be inserted as a single argument just to reserve space. This does have some disadvantages. Local pointer kernel arguments can no longer have AssertZext placed on them as the equivalent !range metadata is not valid on pointer typed loads. This is mostly bad for SI which needs to know about the known bits in order to use the DS instruction offset, so in this case this is not done. More importantly, this skips noalias arguments since this pass does not yet convert this to the equivalent !alias.scope and !noalias metadata. Producing this metadata correctly seems to be tricky, although this logically is the same as inlining into a function which doesn't exist. Additionally, exposing these loads to the vectorizer may result in degraded aliasing information if a pointer load is merged with another argument load. I'm also not entirely sure this is preserving the current clover ABI, although I would greatly prefer if it would stop widening arguments and match the HSA ABI. As-is I think it is extending < 4-byte arguments to 4-bytes but doesn't align them to 4-bytes. llvm-svn: 335650
2018-06-27 03:10:00 +08:00
; GCN: v_cmp_gt_i32_e64 {{[^,]*}}, s[[COND1]], 0{{$}}
; GCN: s_cbranch_vccz [[BODY:[A-Za-z0-9_]+]]
; GCN: {{^}}[[EXIT]]:
; GCN: s_endpgm
; GCN: {{^}}[[BODY]]:
; GCN: buffer_store
; GCN: s_endpgm
define amdgpu_kernel void @icmp_users_different_blocks(i32 %cond0, i32 %cond1, i32 addrspace(1)* %out) {
bb:
%tmp = tail call i32 @llvm.amdgcn.workitem.id.x() #0
%cmp0 = icmp sgt i32 %cond0, 0
%cmp1 = icmp sgt i32 %cond1, 0
br i1 %cmp0, label %bb2, label %bb9
bb2: ; preds = %bb
%tmp2 = sext i1 %cmp1 to i32
%tmp3 = add i32 %tmp2, %tmp
br i1 %cmp1, label %bb9, label %bb7
bb7: ; preds = %bb5
store i32 %tmp3, i32 addrspace(1)* %out
br label %bb9
bb9: ; preds = %bb8, %bb4
ret void
}
; SI-LABEL: {{^}}uniform_loop:
; SI: {{^}}[[LOOP_LABEL:[A-Z0-9_a-z]+]]:
; SI: s_add_i32 [[I:s[0-9]+]], s{{[0-9]+}}, -1
; SI: s_cmp_lg_u32 [[I]], 0
; SI: s_cbranch_scc1 [[LOOP_LABEL]]
; SI: s_endpgm
define amdgpu_kernel void @uniform_loop(i32 addrspace(1)* %out, i32 %a) {
entry:
br label %loop
loop:
%i = phi i32 [0, %entry], [%i.i, %loop]
%i.i = add i32 %i, 1
%cmp = icmp eq i32 %a, %i.i
br i1 %cmp, label %done, label %loop
done:
ret void
}
; Test uniform and divergent.
; GCN-LABEL: {{^}}uniform_inside_divergent:
; GCN: v_cmp_gt_u32_e32 vcc, 16, v{{[0-9]+}}
; GCN: s_and_saveexec_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], vcc
; GCN: s_cmp_lg_u32 {{s[0-9]+}}, 0
; GCN: s_cbranch_scc0 [[IF_UNIFORM_LABEL:[A-Z0-9_a-z]+]]
; GCN: s_endpgm
; GCN: {{^}}[[IF_UNIFORM_LABEL]]:
; GCN: v_mov_b32_e32 [[ONE:v[0-9]+]], 1
; GCN: buffer_store_dword [[ONE]]
define amdgpu_kernel void @uniform_inside_divergent(i32 addrspace(1)* %out, i32 %cond) {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x() #0
%d_cmp = icmp ult i32 %tid, 16
br i1 %d_cmp, label %if, label %endif
if:
store i32 0, i32 addrspace(1)* %out
%u_cmp = icmp eq i32 %cond, 0
br i1 %u_cmp, label %if_uniform, label %endif
if_uniform:
store i32 1, i32 addrspace(1)* %out
br label %endif
endif:
ret void
}
; GCN-LABEL: {{^}}divergent_inside_uniform:
; GCN: s_cmp_lg_u32 s{{[0-9]+}}, 0
; GCN: s_cbranch_scc1 [[ENDIF_LABEL:[0-9_A-Za-z]+]]
; GCN: v_cmp_gt_u32_e32 vcc, 16, v{{[0-9]+}}
; GCN: s_and_saveexec_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], vcc
; GCN: ; mask branch [[ENDIF_LABEL]]
; GCN: v_mov_b32_e32 [[ONE:v[0-9]+]], 1
; GCN: buffer_store_dword [[ONE]]
; GCN: [[ENDIF_LABEL]]:
; GCN: s_endpgm
define amdgpu_kernel void @divergent_inside_uniform(i32 addrspace(1)* %out, i32 %cond) {
entry:
%u_cmp = icmp eq i32 %cond, 0
br i1 %u_cmp, label %if, label %endif
if:
store i32 0, i32 addrspace(1)* %out
%tid = call i32 @llvm.amdgcn.workitem.id.x() #0
%d_cmp = icmp ult i32 %tid, 16
br i1 %d_cmp, label %if_uniform, label %endif
if_uniform:
store i32 1, i32 addrspace(1)* %out
br label %endif
endif:
ret void
}
; GCN-LABEL: {{^}}divergent_if_uniform_if:
; GCN: v_cmp_eq_u32_e32 vcc, 0, v0
; GCN: s_and_saveexec_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], vcc
; GCN: v_mov_b32_e32 [[ONE:v[0-9]+]], 1
; GCN: buffer_store_dword [[ONE]]
; GCN: s_or_b64 exec, exec, [[MASK]]
; GCN: s_cmp_lg_u32 s{{[0-9]+}}, 0
; GCN: s_cbranch_scc0 [[IF_UNIFORM:[A-Z0-9_]+]]
; GCN: s_endpgm
; GCN: [[IF_UNIFORM]]:
; GCN: v_mov_b32_e32 [[TWO:v[0-9]+]], 2
; GCN: buffer_store_dword [[TWO]]
define amdgpu_kernel void @divergent_if_uniform_if(i32 addrspace(1)* %out, i32 %cond) {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x() #0
%d_cmp = icmp eq i32 %tid, 0
br i1 %d_cmp, label %if, label %endif
if:
store i32 1, i32 addrspace(1)* %out
br label %endif
endif:
%u_cmp = icmp eq i32 %cond, 0
br i1 %u_cmp, label %if_uniform, label %exit
if_uniform:
store i32 2, i32 addrspace(1)* %out
br label %exit
exit:
ret void
}
; The condition of the branches in the two blocks are
; uniform. MachineCSE replaces the 2nd condition with the inverse of
; the first, leaving an scc use in a different block than it was
; defed.
; GCN-LABEL: {{^}}cse_uniform_condition_different_blocks:
; GCN: s_load_dword [[COND:s[0-9]+]]
; GCN: s_cmp_lt_i32 [[COND]], 1
; GCN: s_cbranch_scc1 BB[[FNNUM:[0-9]+]]_3
; GCN: %bb.1:
; GCN-NOT: cmp
; GCN: buffer_load_dword
; GCN: buffer_store_dword
; GCN: s_cbranch_scc1 BB[[FNNUM]]_3
; GCN: BB[[FNNUM]]_3:
; GCN: s_endpgm
define amdgpu_kernel void @cse_uniform_condition_different_blocks(i32 %cond, i32 addrspace(1)* %out) {
bb:
%tmp = tail call i32 @llvm.amdgcn.workitem.id.x() #0
%tmp1 = icmp sgt i32 %cond, 0
br i1 %tmp1, label %bb2, label %bb9
bb2: ; preds = %bb
%tmp3 = load volatile i32, i32 addrspace(1)* undef
store volatile i32 0, i32 addrspace(1)* undef
%tmp9 = icmp sle i32 %cond, 0
br i1 %tmp9, label %bb9, label %bb7
bb7: ; preds = %bb5
store i32 %tmp3, i32 addrspace(1)* %out
br label %bb9
bb9: ; preds = %bb8, %bb4
ret void
}
; GCN-LABEL: {{^}}uniform_if_scc_i64_eq:
; VI-DAG: s_cmp_eq_u64 s{{\[[0-9]+:[0-9]+\]}}, 0
; GCN-DAG: s_mov_b32 [[S_VAL:s[0-9]+]], 0
AMDGPU: Add pass to lower kernel arguments to loads This replaces most argument uses with loads, but for now not all. The code in SelectionDAG for calling convention lowering is actively harmful for amdgpu_kernel. It attempts to split the argument types into register legal types, which results in low quality code for arbitary types. Since all kernel arguments are passed in memory, we just want the raw types. I've tried a couple of methods of mitigating this in SelectionDAG, but it's easier to just bypass this problem alltogether. It's possible to hack around the problem in the initial lowering, but the real problem is the DAG then expects to be able to use CopyToReg/CopyFromReg for uses of the arguments outside the block. Exposing the argument loads in the IR also has the advantage that the LoadStoreVectorizer can merge them. I'm not sure the best approach to dealing with the IR argument list is. The patch as-is just leaves the IR arguments in place, so all the existing code will still compute the same kernarg size and pointlessly lowers the arguments. Arguably the frontend should emit kernels with an empty argument list in the first place. Alternatively a dummy array could be inserted as a single argument just to reserve space. This does have some disadvantages. Local pointer kernel arguments can no longer have AssertZext placed on them as the equivalent !range metadata is not valid on pointer typed loads. This is mostly bad for SI which needs to know about the known bits in order to use the DS instruction offset, so in this case this is not done. More importantly, this skips noalias arguments since this pass does not yet convert this to the equivalent !alias.scope and !noalias metadata. Producing this metadata correctly seems to be tricky, although this logically is the same as inlining into a function which doesn't exist. Additionally, exposing these loads to the vectorizer may result in degraded aliasing information if a pointer load is merged with another argument load. I'm also not entirely sure this is preserving the current clover ABI, although I would greatly prefer if it would stop widening arguments and match the HSA ABI. As-is I think it is extending < 4-byte arguments to 4-bytes but doesn't align them to 4-bytes. llvm-svn: 335650
2018-06-27 03:10:00 +08:00
; SI-DAG: v_cmp_eq_u64_e64
; SI: s_cbranch_vccnz [[IF_LABEL:[0-9_A-Za-z]+]]
; VI: s_cbranch_scc1 [[IF_LABEL:[0-9_A-Za-z]+]]
; Fall-through to the else
; GCN: s_mov_b32 [[S_VAL]], 1
; GCN: [[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[V_VAL:v[0-9]+]], [[S_VAL]]
; GCN: buffer_store_dword [[V_VAL]]
define amdgpu_kernel void @uniform_if_scc_i64_eq(i64 %cond, i32 addrspace(1)* %out) {
entry:
%cmp0 = icmp eq i64 %cond, 0
br i1 %cmp0, label %if, label %else
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}uniform_if_scc_i64_ne:
; VI-DAG: s_cmp_lg_u64 s{{\[[0-9]+:[0-9]+\]}}, 0
; GCN-DAG: s_mov_b32 [[S_VAL:s[0-9]+]], 0
AMDGPU: Add pass to lower kernel arguments to loads This replaces most argument uses with loads, but for now not all. The code in SelectionDAG for calling convention lowering is actively harmful for amdgpu_kernel. It attempts to split the argument types into register legal types, which results in low quality code for arbitary types. Since all kernel arguments are passed in memory, we just want the raw types. I've tried a couple of methods of mitigating this in SelectionDAG, but it's easier to just bypass this problem alltogether. It's possible to hack around the problem in the initial lowering, but the real problem is the DAG then expects to be able to use CopyToReg/CopyFromReg for uses of the arguments outside the block. Exposing the argument loads in the IR also has the advantage that the LoadStoreVectorizer can merge them. I'm not sure the best approach to dealing with the IR argument list is. The patch as-is just leaves the IR arguments in place, so all the existing code will still compute the same kernarg size and pointlessly lowers the arguments. Arguably the frontend should emit kernels with an empty argument list in the first place. Alternatively a dummy array could be inserted as a single argument just to reserve space. This does have some disadvantages. Local pointer kernel arguments can no longer have AssertZext placed on them as the equivalent !range metadata is not valid on pointer typed loads. This is mostly bad for SI which needs to know about the known bits in order to use the DS instruction offset, so in this case this is not done. More importantly, this skips noalias arguments since this pass does not yet convert this to the equivalent !alias.scope and !noalias metadata. Producing this metadata correctly seems to be tricky, although this logically is the same as inlining into a function which doesn't exist. Additionally, exposing these loads to the vectorizer may result in degraded aliasing information if a pointer load is merged with another argument load. I'm also not entirely sure this is preserving the current clover ABI, although I would greatly prefer if it would stop widening arguments and match the HSA ABI. As-is I think it is extending < 4-byte arguments to 4-bytes but doesn't align them to 4-bytes. llvm-svn: 335650
2018-06-27 03:10:00 +08:00
; SI-DAG: v_cmp_ne_u64_e64
; SI: s_cbranch_vccnz [[IF_LABEL:[0-9_A-Za-z]+]]
; VI: s_cbranch_scc1 [[IF_LABEL:[0-9_A-Za-z]+]]
; Fall-through to the else
; GCN: s_mov_b32 [[S_VAL]], 1
; GCN: [[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[V_VAL:v[0-9]+]], [[S_VAL]]
; GCN: buffer_store_dword [[V_VAL]]
define amdgpu_kernel void @uniform_if_scc_i64_ne(i64 %cond, i32 addrspace(1)* %out) {
entry:
%cmp0 = icmp ne i64 %cond, 0
br i1 %cmp0, label %if, label %else
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}uniform_if_scc_i64_sgt:
AMDGPU: Add pass to lower kernel arguments to loads This replaces most argument uses with loads, but for now not all. The code in SelectionDAG for calling convention lowering is actively harmful for amdgpu_kernel. It attempts to split the argument types into register legal types, which results in low quality code for arbitary types. Since all kernel arguments are passed in memory, we just want the raw types. I've tried a couple of methods of mitigating this in SelectionDAG, but it's easier to just bypass this problem alltogether. It's possible to hack around the problem in the initial lowering, but the real problem is the DAG then expects to be able to use CopyToReg/CopyFromReg for uses of the arguments outside the block. Exposing the argument loads in the IR also has the advantage that the LoadStoreVectorizer can merge them. I'm not sure the best approach to dealing with the IR argument list is. The patch as-is just leaves the IR arguments in place, so all the existing code will still compute the same kernarg size and pointlessly lowers the arguments. Arguably the frontend should emit kernels with an empty argument list in the first place. Alternatively a dummy array could be inserted as a single argument just to reserve space. This does have some disadvantages. Local pointer kernel arguments can no longer have AssertZext placed on them as the equivalent !range metadata is not valid on pointer typed loads. This is mostly bad for SI which needs to know about the known bits in order to use the DS instruction offset, so in this case this is not done. More importantly, this skips noalias arguments since this pass does not yet convert this to the equivalent !alias.scope and !noalias metadata. Producing this metadata correctly seems to be tricky, although this logically is the same as inlining into a function which doesn't exist. Additionally, exposing these loads to the vectorizer may result in degraded aliasing information if a pointer load is merged with another argument load. I'm also not entirely sure this is preserving the current clover ABI, although I would greatly prefer if it would stop widening arguments and match the HSA ABI. As-is I think it is extending < 4-byte arguments to 4-bytes but doesn't align them to 4-bytes. llvm-svn: 335650
2018-06-27 03:10:00 +08:00
; GCN-DAG: s_mov_b32 [[S_VAL:s[0-9]+]], 0
; GCN-DAG: v_cmp_gt_i64_e64
; GCN: s_cbranch_vccnz [[IF_LABEL:[0-9_A-Za-z]+]]
; Fall-through to the else
; GCN: s_mov_b32 [[S_VAL]], 1
; GCN: [[IF_LABEL]]:
; GCN: v_mov_b32_e32 [[V_VAL:v[0-9]+]], [[S_VAL]]
; GCN: buffer_store_dword [[V_VAL]]
define amdgpu_kernel void @uniform_if_scc_i64_sgt(i64 %cond, i32 addrspace(1)* %out) {
entry:
%cmp0 = icmp sgt i64 %cond, 0
br i1 %cmp0, label %if, label %else
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}move_to_valu_i64_eq:
; GCN: v_cmp_eq_u64_e32
define amdgpu_kernel void @move_to_valu_i64_eq(i32 addrspace(1)* %out) {
%cond = load volatile i64, i64 addrspace(3)* undef
%cmp0 = icmp eq i64 %cond, 0
br i1 %cmp0, label %if, label %else
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}move_to_valu_i64_ne:
; GCN: v_cmp_ne_u64_e32
define amdgpu_kernel void @move_to_valu_i64_ne(i32 addrspace(1)* %out) {
%cond = load volatile i64, i64 addrspace(3)* undef
%cmp0 = icmp ne i64 %cond, 0
br i1 %cmp0, label %if, label %else
if:
br label %done
else:
br label %done
done:
%value = phi i32 [0, %if], [1, %else]
store i32 %value, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}move_to_valu_vgpr_operand_phi:
; GCN: v_add_{{[iu]}}32_e32
; GCN: ds_write_b32
define void @move_to_valu_vgpr_operand_phi(i32 addrspace(3)* %out) {
bb0:
br label %bb1
bb1: ; preds = %bb3, %bb0
%tmp0 = phi i32 [ 8, %bb0 ], [ %tmp4, %bb3 ]
%tmp1 = add nsw i32 %tmp0, -1
%tmp2 = getelementptr inbounds i32, i32 addrspace(3)* %out, i32 %tmp1
br i1 undef, label %bb2, label %bb3
bb2: ; preds = %bb1
store volatile i32 1, i32 addrspace(3)* %tmp2, align 4
br label %bb3
bb3: ; preds = %bb2, %bb1
%tmp4 = add nsw i32 %tmp0, 2
br label %bb1
}
declare i32 @llvm.amdgcn.workitem.id.x() #0
attributes #0 = { nounwind readnone }