[llvm] 65c8bfb - [AMDGPU] Enable output modifiers for double precision instructions

Brendon Cahoon via llvm-commits llvm-commits at lists.llvm.org
Thu Apr 1 07:14:25 PDT 2021


Author: Brendon Cahoon
Date: 2021-04-01T10:08:17-04:00
New Revision: 65c8bfb5094e73f15a826d37146e4bb7c74a5a7e

URL: https://github.com/llvm/llvm-project/commit/65c8bfb5094e73f15a826d37146e4bb7c74a5a7e
DIFF: https://github.com/llvm/llvm-project/commit/65c8bfb5094e73f15a826d37146e4bb7c74a5a7e.diff

LOG: [AMDGPU] Enable output modifiers for double precision instructions

Update SIFoldOperands pass to recognize v_add_f64 and v_mul_f64
instructions for folding output modifiers.

Differential Revision: https://reviews.llvm.org/D99505

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
    llvm/test/CodeGen/AMDGPU/omod.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
index 18d72528e289..2e5843757712 100644
--- a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
@@ -1406,6 +1406,18 @@ bool SIFoldOperands::tryFoldClamp(MachineInstr &MI) {
 
 static int getOModValue(unsigned Opc, int64_t Val) {
   switch (Opc) {
+  case AMDGPU::V_MUL_F64_e64: {
+    switch (Val) {
+    case 0x3fe0000000000000: // 0.5
+      return SIOutMods::DIV2;
+    case 0x4000000000000000: // 2.0
+      return SIOutMods::MUL2;
+    case 0x4010000000000000: // 4.0
+      return SIOutMods::MUL4;
+    default:
+      return SIOutMods::NONE;
+    }
+  }
   case AMDGPU::V_MUL_F32_e64: {
     switch (static_cast<uint32_t>(Val)) {
     case 0x3f000000: // 0.5
@@ -1442,11 +1454,13 @@ std::pair<const MachineOperand *, int>
 SIFoldOperands::isOMod(const MachineInstr &MI) const {
   unsigned Op = MI.getOpcode();
   switch (Op) {
+  case AMDGPU::V_MUL_F64_e64:
   case AMDGPU::V_MUL_F32_e64:
   case AMDGPU::V_MUL_F16_e64: {
     // If output denormals are enabled, omod is ignored.
     if ((Op == AMDGPU::V_MUL_F32_e64 && MFI->getMode().FP32OutputDenormals) ||
-        (Op == AMDGPU::V_MUL_F16_e64 && MFI->getMode().FP64FP16OutputDenormals))
+        ((Op == AMDGPU::V_MUL_F64_e64 || Op == AMDGPU::V_MUL_F16_e64) &&
+         MFI->getMode().FP64FP16OutputDenormals))
       return std::make_pair(nullptr, SIOutMods::NONE);
 
     const MachineOperand *RegOp = nullptr;
@@ -1472,11 +1486,13 @@ SIFoldOperands::isOMod(const MachineInstr &MI) const {
 
     return std::make_pair(RegOp, OMod);
   }
+  case AMDGPU::V_ADD_F64_e64:
   case AMDGPU::V_ADD_F32_e64:
   case AMDGPU::V_ADD_F16_e64: {
     // If output denormals are enabled, omod is ignored.
     if ((Op == AMDGPU::V_ADD_F32_e64 && MFI->getMode().FP32OutputDenormals) ||
-        (Op == AMDGPU::V_ADD_F16_e64 && MFI->getMode().FP64FP16OutputDenormals))
+        ((Op == AMDGPU::V_ADD_F64_e64 || Op == AMDGPU::V_ADD_F16_e64) &&
+         MFI->getMode().FP64FP16OutputDenormals))
       return std::make_pair(nullptr, SIOutMods::NONE);
 
     // Look through the DAGCombiner canonicalization fmul x, 2 -> fadd x, x

diff  --git a/llvm/test/CodeGen/AMDGPU/omod.ll b/llvm/test/CodeGen/AMDGPU/omod.ll
index d9a89bd34fe8..94cb156c842c 100644
--- a/llvm/test/CodeGen/AMDGPU/omod.ll
+++ b/llvm/test/CodeGen/AMDGPU/omod.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -march=amdgcn -mcpu=tahiti -verify-machineinstrs < %s | FileCheck -check-prefix=GCN %s
 ; RUN: llc -march=amdgcn -mcpu=fiji -verify-machineinstrs < %s | FileCheck --check-prefixes=GCN,VI %s
 
-; IEEE bit enabled for compute kernel, no shouldn't use.
+; IEEE bit enabled for compute kernel, so shouldn't use.
 ; GCN-LABEL: {{^}}v_omod_div2_f32_enable_ieee_signed_zeros:
 ; GCN: {{buffer|flat}}_load_dword [[A:v[0-9]+]]
 ; GCN: v_add_f32_e32 [[ADD:v[0-9]+]], 1.0, [[A]]{{$}}
@@ -17,7 +17,23 @@ define amdgpu_kernel void @v_omod_div2_f32_enable_ieee_signed_zeros(float addrsp
   ret void
 }
 
-; IEEE bit enabled for compute kernel, no shouldn't use even though nsz is allowed
+; IEEE bit enabled for compute kernel, so shouldn't use.
+; GCN-LABEL: {{^}}v_omod_div2_f64_enable_ieee_signed_zeros:
+; GCN: {{buffer|flat}}_load_dwordx2 [[A:v\[[0-9]+:[0-9]+\]]]
+; GCN: v_add_f64 [[ADD:v\[[0-9]+:[0-9]+\]]], [[A]], 1.0{{$}}
+; GCN: v_mul_f64 v{{\[[0-9]+:[0-9]+\]}}, [[ADD]], 0.5{{$}}
+define amdgpu_kernel void @v_omod_div2_f64_enable_ieee_signed_zeros(double addrspace(1)* %out, double addrspace(1)* %aptr) #4 {
+  %tid = call i32 @llvm.amdgcn.workitem.id.x()
+  %gep0 = getelementptr double, double addrspace(1)* %aptr, i32 %tid
+  %out.gep = getelementptr double, double addrspace(1)* %out, i32 %tid
+  %a = load double, double addrspace(1)* %gep0
+  %add = fadd double %a, 1.0
+  %div2 = fmul double %add, 0.5
+  store double %div2, double addrspace(1)* %out.gep
+  ret void
+}
+
+; IEEE bit enabled for compute kernel, so shouldn't use even though nsz is allowed
 ; GCN-LABEL: {{^}}v_omod_div2_f32_enable_ieee_nsz:
 ; GCN: {{buffer|flat}}_load_dword [[A:v[0-9]+]]
 ; GCN: v_add_f32_e32 [[ADD:v[0-9]+]], 1.0, [[A]]{{$}}
@@ -33,6 +49,22 @@ define amdgpu_kernel void @v_omod_div2_f32_enable_ieee_nsz(float addrspace(1)* %
   ret void
 }
 
+; IEEE bit enabled for compute kernel, so shouldn't use even though nsz is allowed.
+; GCN-LABEL: {{^}}v_omod_div2_f64_enable_ieee_nsz:
+; GCN: {{buffer|flat}}_load_dwordx2 [[A:v\[[0-9]+:[0-9]+\]]]
+; GCN: v_add_f64 [[ADD:v\[[0-9]+:[0-9]+\]]], [[A]], 1.0{{$}}
+; GCN: v_mul_f64 v{{\[[0-9]+:[0-9]+\]}}, [[ADD]], 0.5{{$}}
+define amdgpu_kernel void @v_omod_div2_f64_enable_ieee_nsz(double addrspace(1)* %out, double addrspace(1)* %aptr) #5 {
+  %tid = call i32 @llvm.amdgcn.workitem.id.x()
+  %gep0 = getelementptr double, double addrspace(1)* %aptr, i32 %tid
+  %out.gep = getelementptr double, double addrspace(1)* %out, i32 %tid
+  %a = load double, double addrspace(1)* %gep0
+  %add = fadd double %a, 1.0
+  %div2 = fmul double %add, 0.5
+  store double %div2, double addrspace(1)* %out.gep
+  ret void
+}
+
 ; Only allow without IEEE bit if signed zeros are significant.
 ; GCN-LABEL: {{^}}v_omod_div2_f32_signed_zeros:
 ; GCN: v_add_f32_e32 [[ADD:v[0-9]+]], 1.0, v0{{$}}
@@ -44,6 +76,17 @@ define amdgpu_ps void @v_omod_div2_f32_signed_zeros(float %a) #4 {
   ret void
 }
 
+; Only allow without IEEE bit if signed zeros are significant.
+; GCN-LABEL: {{^}}v_omod_div2_f64_signed_zeros:
+; GCN: v_add_f64 [[ADD:v\[[0-9]+:[0-9]+\]]], v{{\[[0-9]+:[0-9]+\]}}, 1.0{{$}}
+; GCN: v_mul_f64 v{{\[[0-9]+:[0-9]+\]}}, [[ADD]], 0.5{{$}}
+define amdgpu_ps void @v_omod_div2_f64_signed_zeros(double %a) #4 {
+  %add = fadd double %a, 1.0
+  %div2 = fmul double %add, 0.5
+  store double %div2, double addrspace(1)* undef
+  ret void
+}
+
 ; GCN-LABEL: {{^}}v_omod_div2_f32:
 ; GCN: v_add_f32_e64 v{{[0-9]+}}, v0, 1.0 div:2{{$}}
 define amdgpu_ps void @v_omod_div2_f32(float %a) #0 {
@@ -53,6 +96,15 @@ define amdgpu_ps void @v_omod_div2_f32(float %a) #0 {
   ret void
 }
 
+; GCN-LABEL: {{^}}v_omod_div2_f64:
+; GCN: v_add_f64  v{{\[[0-9]+:[0-9]+\]}}, v{{\[[0-9]+:[0-9]+\]}}, 1.0 div:2{{$}}
+define amdgpu_ps void @v_omod_div2_f64(double %a) #5 {
+  %add = fadd nsz double %a, 1.0
+  %div2 = fmul nsz double %add, 0.5
+  store double %div2, double addrspace(1)* undef
+  ret void
+}
+
 ; GCN-LABEL: {{^}}v_omod_mul2_f32:
 ; GCN: v_add_f32_e64 v{{[0-9]+}}, v0, 1.0 mul:2{{$}}
 define amdgpu_ps void @v_omod_mul2_f32(float %a) #0 {
@@ -62,6 +114,15 @@ define amdgpu_ps void @v_omod_mul2_f32(float %a) #0 {
   ret void
 }
 
+; GCN-LABEL: {{^}}v_omod_mul2_f64:
+; GCN: v_add_f64  v{{\[[0-9]+:[0-9]+\]}}, v{{\[[0-9]+:[0-9]+\]}}, 1.0 mul:2{{$}}
+define amdgpu_ps void @v_omod_mul2_f64(double %a) #5 {
+  %add = fadd nsz double %a, 1.0
+  %div2 = fmul nsz double %add, 2.0
+  store double %div2, double addrspace(1)* undef
+  ret void
+}
+
 ; GCN-LABEL: {{^}}v_omod_mul4_f32:
 ; GCN: v_add_f32_e64 v{{[0-9]+}}, v0, 1.0 mul:4{{$}}
 define amdgpu_ps void @v_omod_mul4_f32(float %a) #0 {
@@ -71,6 +132,15 @@ define amdgpu_ps void @v_omod_mul4_f32(float %a) #0 {
   ret void
 }
 
+; GCN-LABEL: {{^}}v_omod_mul4_f64:
+; GCN: v_add_f64  v{{\[[0-9]+:[0-9]+\]}}, v{{\[[0-9]+:[0-9]+\]}}, 1.0 mul:4{{$}}
+define amdgpu_ps void @v_omod_mul4_f64(double %a) #5 {
+  %add = fadd nsz double %a, 1.0
+  %div2 = fmul nsz double %add, 4.0
+  store double %div2, double addrspace(1)* undef
+  ret void
+}
+
 ; GCN-LABEL: {{^}}v_omod_mul4_multi_use_f32:
 ; GCN: v_add_f32_e32 [[ADD:v[0-9]+]], 1.0, v0{{$}}
 ; GCN: v_mul_f32_e32 v{{[0-9]+}}, 4.0, [[ADD]]{{$}}
@@ -207,6 +277,17 @@ define amdgpu_ps void @v_omod_div2_f32_denormals(float %a) #2 {
   ret void
 }
 
+; Don't fold omod if denorms enabled.
+; GCN-LABEL: {{^}}v_omod_div2_f64_denormals:
+; GCN: v_add_f64 [[ADD:v\[[0-9]+:[0-9]+\]]], v{{\[[0-9]+:[0-9]+\]}}, 1.0{{$}}
+; GCN: v_mul_f64 v{{\[[0-9]+:[0-9]+\]}}, [[ADD]], 0.5{{$}}
+define amdgpu_ps void @v_omod_div2_f64_denormals(double %a) #6 {
+  %add = fadd double %a, 1.0
+  %div2 = fmul double %add, 0.5
+  store double %div2, double addrspace(1)* undef
+  ret void
+}
+
 ; Don't fold omod if denorms enabled for add form.
 ; GCN-LABEL: {{^}}v_omod_mul2_f32_denormals:
 ; GCN: v_add_f32_e32 [[ADD:v[0-9]+]], 1.0, v0{{$}}
@@ -218,6 +299,17 @@ define amdgpu_ps void @v_omod_mul2_f32_denormals(float %a) #2 {
   ret void
 }
 
+; Don't fold omod if denorms enabled for add form.
+; GCN-LABEL: {{^}}v_omod_mul2_f64_denormals:
+; GCN: v_add_f64 [[ADD:v\[[0-9]+:[0-9]+\]]], v{{\[[0-9]+:[0-9]+\]}}, 1.0{{$}}
+; GCN: v_add_f64 v{{\[[0-9]+:[0-9]+\]}}, [[ADD]], [[ADD]]{{$}}
+define amdgpu_ps void @v_omod_mul2_f64_denormals(double %a) #2 {
+  %add = fadd double %a, 1.0
+  %mul2 = fadd double %add, %add
+  store double %mul2, double addrspace(1)* undef
+  ret void
+}
+
 ; Don't fold omod if denorms enabled
 ; GCN-LABEL: {{^}}v_omod_div2_f16_denormals:
 ; VI: v_add_f16_e32 [[ADD:v[0-9]+]], 1.0, v0{{$}}
@@ -280,6 +372,8 @@ attributes #1 = { nounwind readnone }
 attributes #2 = { nounwind "denormal-fp-math-f32"="ieee,ieee" "no-signed-zeros-fp-math"="true" }
 attributes #3 = { nounwind "denormal-fp-math"="preserve-sign,preserve-sign" "no-signed-zeros-fp-math"="true" }
 attributes #4 = { nounwind "no-signed-zeros-fp-math"="false" }
+attributes #5 = { nounwind "denormal-fp-math"="preserve-sign,preserve-sign" }
+attributes #6 = { nounwind "denormal-fp-math"="ieee,ieee" "no-signed-zeros-fp-math"="true" }
 
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!2, !3}


        


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