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AMDGPU: Fold fneg into fp_extend
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291777 91177308-0d34-0410-b5e6-96231b3b80d8
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@arsenm
arsenm committed Jan 12, 2017
1 parent 28fbf6c commit e652041
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14 changes: 14 additions & 0 deletions lib/Target/AMDGPU/AMDGPUISelLowering.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2899,6 +2899,20 @@ SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
return Res;
}
case ISD::FP_EXTEND: {
SDValue CvtSrc = N0.getOperand(0);
if (CvtSrc.getOpcode() == ISD::FNEG) {
// (fneg (fp_extend (fneg x))) -> (fp_extend x)
return DAG.getNode(ISD::FP_EXTEND, SL, VT, CvtSrc.getOperand(0));
}

if (!N0.hasOneUse())
return SDValue();

// (fneg (fp_extend x)) -> (fp_extend (fneg x))
SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
return DAG.getNode(ISD::FP_EXTEND, SL, VT, Neg);
}
default:
return SDValue();
}
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126 changes: 126 additions & 0 deletions test/CodeGen/AMDGPU/fneg-combines.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -655,6 +655,132 @@ define void @v_fneg_fmad_multi_use_fmad_f32(float addrspace(1)* %out, float addr
ret void
}

; --------------------------------------------------------------------------------
; fp_extend tests
; --------------------------------------------------------------------------------

; GCN-LABEL: {{^}}v_fneg_fp_extend_f32_to_f64:
; GCN: {{buffer|flat}}_load_dword [[A:v[0-9]+]]
; GCN: v_cvt_f64_f32_e64 [[RESULT:v\[[0-9]+:[0-9]+\]]], -[[A]]
; GCN: buffer_store_dwordx2 [[RESULT]]
define void @v_fneg_fp_extend_f32_to_f64(double addrspace(1)* %out, float addrspace(1)* %a.ptr) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%tid.ext = sext i32 %tid to i64
%a.gep = getelementptr inbounds float, float addrspace(1)* %a.ptr, i64 %tid.ext
%out.gep = getelementptr inbounds double, double addrspace(1)* %out, i64 %tid.ext
%a = load volatile float, float addrspace(1)* %a.gep
%fpext = fpext float %a to double
%fneg = fsub double -0.000000e+00, %fpext
store double %fneg, double addrspace(1)* %out.gep
ret void
}

; GCN-LABEL: {{^}}v_fneg_fp_extend_fneg_f32_to_f64:
; GCN: {{buffer|flat}}_load_dword [[A:v[0-9]+]]
; GCN: v_cvt_f64_f32_e32 [[RESULT:v\[[0-9]+:[0-9]+\]]], [[A]]
; GCN: buffer_store_dwordx2 [[RESULT]]
define void @v_fneg_fp_extend_fneg_f32_to_f64(double addrspace(1)* %out, float addrspace(1)* %a.ptr) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%tid.ext = sext i32 %tid to i64
%a.gep = getelementptr inbounds float, float addrspace(1)* %a.ptr, i64 %tid.ext
%out.gep = getelementptr inbounds double, double addrspace(1)* %out, i64 %tid.ext
%a = load volatile float, float addrspace(1)* %a.gep
%fneg.a = fsub float -0.000000e+00, %a
%fpext = fpext float %fneg.a to double
%fneg = fsub double -0.000000e+00, %fpext
store double %fneg, double addrspace(1)* %out.gep
ret void
}

; GCN-LABEL: {{^}}v_fneg_fp_extend_store_use_fneg_f32_to_f64:
; GCN: {{buffer|flat}}_load_dword [[A:v[0-9]+]]
; GCN-DAG: v_cvt_f64_f32_e32 [[RESULT:v\[[0-9]+:[0-9]+\]]], [[A]]
; GCN-DAG: v_xor_b32_e32 [[FNEG_A:v[0-9]+]], 0x80000000, [[A]]
; GCN: buffer_store_dwordx2 [[RESULT]]
; GCN: buffer_store_dword [[FNEG_A]]
define void @v_fneg_fp_extend_store_use_fneg_f32_to_f64(double addrspace(1)* %out, float addrspace(1)* %a.ptr) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%tid.ext = sext i32 %tid to i64
%a.gep = getelementptr inbounds float, float addrspace(1)* %a.ptr, i64 %tid.ext
%out.gep = getelementptr inbounds double, double addrspace(1)* %out, i64 %tid.ext
%a = load volatile float, float addrspace(1)* %a.gep
%fneg.a = fsub float -0.000000e+00, %a
%fpext = fpext float %fneg.a to double
%fneg = fsub double -0.000000e+00, %fpext
store volatile double %fneg, double addrspace(1)* %out.gep
store volatile float %fneg.a, float addrspace(1)* undef
ret void
}

; GCN-LABEL: {{^}}v_fneg_multi_use_fp_extend_fneg_f32_to_f64:
; GCN: {{buffer|flat}}_load_dword [[A:v[0-9]+]]
; GCN-DAG: v_cvt_f64_f32_e32 v{{\[}}[[CVT_LO:[0-9]+]]:[[CVT_HI:[0-9]+]]{{\]}}, [[A]]
; GCN-DAG: v_xor_b32_e32 v[[FNEG_A:[0-9]+]], 0x80000000, v[[CVT_HI]]
; GCN: buffer_store_dwordx2 v{{\[[0-9]+}}:[[FNEG_A]]{{\]}}
; GCN: buffer_store_dwordx2 v{{\[}}[[CVT_LO]]:[[CVT_HI]]{{\]}}
define void @v_fneg_multi_use_fp_extend_fneg_f32_to_f64(double addrspace(1)* %out, float addrspace(1)* %a.ptr) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%tid.ext = sext i32 %tid to i64
%a.gep = getelementptr inbounds float, float addrspace(1)* %a.ptr, i64 %tid.ext
%out.gep = getelementptr inbounds double, double addrspace(1)* %out, i64 %tid.ext
%a = load volatile float, float addrspace(1)* %a.gep
%fpext = fpext float %a to double
%fneg = fsub double -0.000000e+00, %fpext
store volatile double %fneg, double addrspace(1)* %out.gep
store volatile double %fpext, double addrspace(1)* undef
ret void
}

; GCN-LABEL: {{^}}v_fneg_multi_foldable_use_fp_extend_fneg_f32_to_f64:
; GCN: {{buffer|flat}}_load_dword [[A:v[0-9]+]]
; GCN-DAG: v_cvt_f64_f32_e32 v{{\[}}[[CVT_LO:[0-9]+]]:[[CVT_HI:[0-9]+]]{{\]}}, [[A]]
; GCN-DAG: v_xor_b32_e32 v[[FNEG_A:[0-9]+]], 0x80000000, v[[CVT_HI]]
; GCN-DAG: v_mul_f64 [[MUL:v\[[0-9]+:[0-9]+\]]], v{{\[}}[[CVT_LO]]:[[CVT_HI]]{{\]}}, 4.0
; GCN: buffer_store_dwordx2 v{{\[[0-9]+}}:[[FNEG_A]]{{\]}}
; GCN: buffer_store_dwordx2 [[MUL]]
define void @v_fneg_multi_foldable_use_fp_extend_fneg_f32_to_f64(double addrspace(1)* %out, float addrspace(1)* %a.ptr) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%tid.ext = sext i32 %tid to i64
%a.gep = getelementptr inbounds float, float addrspace(1)* %a.ptr, i64 %tid.ext
%out.gep = getelementptr inbounds double, double addrspace(1)* %out, i64 %tid.ext
%a = load volatile float, float addrspace(1)* %a.gep
%fpext = fpext float %a to double
%fneg = fsub double -0.000000e+00, %fpext
%mul = fmul double %fpext, 4.0
store volatile double %fneg, double addrspace(1)* %out.gep
store volatile double %mul, double addrspace(1)* %out.gep
ret void
}

; FIXME: Source modifiers not folded for f16->f32
; GCN-LABEL: {{^}}v_fneg_multi_use_fp_extend_fneg_f16_to_f32:
define void @v_fneg_multi_use_fp_extend_fneg_f16_to_f32(float addrspace(1)* %out, half addrspace(1)* %a.ptr) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%tid.ext = sext i32 %tid to i64
%a.gep = getelementptr inbounds half, half addrspace(1)* %a.ptr, i64 %tid.ext
%out.gep = getelementptr inbounds float, float addrspace(1)* %out, i64 %tid.ext
%a = load volatile half, half addrspace(1)* %a.gep
%fpext = fpext half %a to float
%fneg = fsub float -0.000000e+00, %fpext
store volatile float %fneg, float addrspace(1)* %out.gep
store volatile float %fpext, float addrspace(1)* %out.gep
ret void
}

; GCN-LABEL: {{^}}v_fneg_multi_foldable_use_fp_extend_fneg_f16_to_f32:
define void @v_fneg_multi_foldable_use_fp_extend_fneg_f16_to_f32(float addrspace(1)* %out, half addrspace(1)* %a.ptr) #0 {
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%tid.ext = sext i32 %tid to i64
%a.gep = getelementptr inbounds half, half addrspace(1)* %a.ptr, i64 %tid.ext
%out.gep = getelementptr inbounds float, float addrspace(1)* %out, i64 %tid.ext
%a = load volatile half, half addrspace(1)* %a.gep
%fpext = fpext half %a to float
%fneg = fsub float -0.000000e+00, %fpext
%mul = fmul float %fpext, 4.0
store volatile float %fneg, float addrspace(1)* %out.gep
store volatile float %mul, float addrspace(1)* %out.gep
ret void
}

declare i32 @llvm.amdgcn.workitem.id.x() #1
declare float @llvm.fma.f32(float, float, float) #1
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