[AMDGPU] fcanonicalize elimination optimization

[rampitec]

Summary

We are using multiplication by 1.0 to flush denormals and quiet sNaNs.
That is possible to omit this multiplication if source of the
fcanonicalize instruction is known to be flushed/quieted, i.e.
if it comes from another instruction known to do the normalization
and we are using IEEE mode to quiet sNaNs.

[arsenm]

lib/Target/AMDGPU/SIISelLowering.cpp

4638

fcanonicalize should have the idempotent optimization applied so there shouldn't be a need to handle it

4662

We don't handle this

4665–4668

The output is never flushed anywhere?

4669–4670

We don't handle these

4671–4672

I don't think this is true, but should have a named check in the subtarget

4678–4680

We constant fold this already so this shouldn't be necessary

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4638

It is not:

v_mul_f32_e32 v2, 1.0, v2
v_mul_f32_e32 v2, 1.0, v2

4662

We do not handle this now, but may handle later. The idea is still the same as with FSIN and FCOS.

4665–4668

GFX9 flushes.

4669–4670

This again only now. I had a use of it in HSAIL and may actually port it.

4671–4672

I would rather think about denorm support flag in TD for every single instruction wrt subtarget. Why add just a single one?

4678–4680

This is necessary. We may constant fold it to remove fcanonicalize on a constant, but consider:

canonicalize(fmax(x, 0.0f));

Without above code it would not be handled because we have to look though arguments of min/max/fneg/fabs. I have a test for it actually.

In particular it is needed to fold an extremely common case like max(max, ...).

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4638

And I do not think there are idempotent SDNodes.

[arsenm]

lib/Target/AMDGPU/SIISelLowering.cpp

4638

I don't think it's done now, but fcanonicalize (fcanonicalize x) should fold to just one canonicalize

4665–4668

That is broken. If that is the case we probably shouldn't be using the regular minnum/maxnum intrinsics without denormals, and then it's an optimization to fold canonicalize (min/max) to the weird target behavior.

4671–4672

We don't need a full fledged subtarget feature, just put the generation check in a function with name/description rather than adding more random looking generation checks

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4638

...and that is what I am doing here.

4665–4668

The library is common for different targets.

4671–4672

I'm not sure I follow. Could you please describe a name of such check?

[rampitec]

Rebase to master.
Updated test for commuted instruction after latest changes.

[arsenm]

lib/Target/AMDGPU/SIISelLowering.cpp

4665–4668

We need to fix that then. If it's not returning exactly one of the inputs it's not implementing the IEEE min/max

4671–4672

hasAddr64() or hasMed3_16()

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4638

In fact even if a general folding is implemented in DAGCombiner, I believe it shall stay here as well. It is the same idea as with constants, something else which also normalizes can be combined with it.

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4671–4672

hasNormalizingMinMax()? It returns us to the initial point.

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4665–4668

In fact IEEE754-2008 (as described for maxnum/minnum llvm ir) tells to return canonicalized numbers, so it is the opposite: GFX9 is finally IEEE compliant.

[rampitec]

GFX9 handles denorms in min/max instructions, although its behavior in respect to signaling NaN handling is not identical if they are quieted or not before the instruction. That is still possible to perform GFX9 specific part of min/max handling given non-nans flag.
However, given the controversy and that GFX9 part of the change is non-essential I have removed specialization here, replacing it with todo. It can be done separately when needed.

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4665–4668

This part is split-off the patch.

[arsenm]

lib/Target/AMDGPU/SIISelLowering.cpp

4636

Since FMAD always flushes I don't think it's OK to handle it

4671–4672

The SC name was SupportsMinMaxDenormModes. Either way works

4696–4699

This is really a check for whether SNaNs are enabled. We have the isKnownNeverSNan check for this already. I think we need to fix having separate FPExceptions and enableIEEEBit subtarget checks

test/CodeGen/AMDGPU/fcanonicalize-elimination.ll

3

This needs a run line for gfx9 with denormals disabled too

[rampitec]

lib/Target/AMDGPU/SIISelLowering.cpp

4636

FMAD - Perform a * b + c, while getting the same result as the separately rounded operations.
It is essentially v_mac_f32 which always flushes, but if denorms are disabled it is lowered as fma.
So handling it here is correct, and there is a test test_fold_canonicalize_fmuladd_value_f32 for it.

4671–4672

This code part is dropped for now.

[rampitec]

Switched to use of isKnownNeverSNan() and added test for it.
Added test run line for GFX9 without denorms.

[arsenm]

LGTM. Can you file a bug for the broken minnum/maxnum denormal handling

lib/Target/AMDGPU/SIISelLowering.cpp

4699

This would read more accurately as IsIEEEMode || isKnownNeverSNan.

[rampitec]

Reorganized IEEE/knowNeverSNan condition per review.

[rampitec]

In D35218#807080, @arsenm wrote:

LGTM. Can you file a bug for the broken minnum/maxnum denormal handling

Bug filed.

lib/Target/AMDGPU/SIISelLowering.cpp

SDValue SITargetLowering::performClassCombine(SDNode *N,
   }
 
   if (N->getOperand(0).isUndef())
     return DAG.getUNDEF(MVT::i1);
 
   return SDValue();
 }
 
+static bool isCanonicalized(SDValue Op, const SISubtarget *ST,
+                            unsigned MaxDepth=5) {
+  // If source is a result of another standard FP operation it is already in
+  // canonical form.
+
+  switch (Op.getOpcode()) {
+  default:
+    break;
+
+  // These will flush denorms if required.
+  case ISD::FADD:
+  case ISD::FSUB:
+  case ISD::FMUL:
+  case ISD::FSQRT:
+  case ISD::FCEIL:
+  case ISD::FFLOOR:
+  case ISD::FMA:
+  case ISD::FMAD:
+
+  case ISD::FCANONICALIZE:
+    return true;
+
+  case ISD::FP_ROUND:
+    return Op.getValueType().getScalarType() != MVT::f16 ||
+           ST->hasFP16Denormals();
+
+  case ISD::FP_EXTEND:
+    return Op.getOperand(0).getValueType().getScalarType() != MVT::f16 ||
+           ST->hasFP16Denormals();
+
+  case ISD::FP16_TO_FP:
+  case ISD::FP_TO_FP16:
+    return ST->hasFP16Denormals();
+
+  // It can/will be lowered or combined as a bit operation.
+  // Need to check their input recursively to handle.
+  case ISD::FNEG:
+  case ISD::FABS:
+    return (MaxDepth > 0) &&
+           isCanonicalized(Op.getOperand(0), ST, MaxDepth - 1);
+
+  case ISD::FSIN:
+  case ISD::FCOS:
+  case ISD::FSINCOS:
+    return Op.getValueType().getScalarType() != MVT::f16;
+
+  // In pre-GFX9 targets V_MIN_F32 and others do not flush denorms.
+  // For such targets need to check their input recursively.
+  case ISD::FMINNUM:
+  case ISD::FMAXNUM:
+  case ISD::FMINNAN:
+  case ISD::FMAXNAN:
+    if (ST->getGeneration() >= SISubtarget::GFX9)
+      return true;
+
+    return (MaxDepth > 0) &&
+           isCanonicalized(Op.getOperand(0), ST, MaxDepth - 1) &&
+           isCanonicalized(Op.getOperand(1), ST, MaxDepth - 1);
+
+  case ISD::ConstantFP: {
+    auto F = cast<ConstantFPSDNode>(Op)->getValueAPF();
+    return !F.isDenormal() && !(F.isNaN() && F.isSignaling());
+  }
+  }
+  return false;
+}
+
 // Constant fold canonicalize.
 SDValue SITargetLowering::performFCanonicalizeCombine(
   SDNode *N,
   DAGCombinerInfo &DCI) const {
+  SelectionDAG &DAG = DCI.DAG;
   ConstantFPSDNode *CFP = isConstOrConstSplatFP(N->getOperand(0));
-  if (!CFP)
+
+  if (!CFP) {
+    SDValue N0 = N->getOperand(0);
+
+    bool IsIEEEMode = Subtarget->enableIEEEBit(DAG.getMachineFunction()) ||
+                      getTargetMachine().Options.NoNaNsFPMath ||
+                      N->getFlags().hasNoNaNs();
+
+    if (IsIEEEMode && isCanonicalized(N0, getSubtarget()))
+      return N0;
+
     return SDValue();
+  }
 
-  SelectionDAG &DAG = DCI.DAG;
   const APFloat &C = CFP->getValueAPF();
 
   // Flush denormals to 0 if not enabled.
   if (C.isDenormal()) {
     EVT VT = N->getValueType(0);
     EVT SVT = VT.getScalarType();
     if (SVT == MVT::f32 && !Subtarget->hasFP32Denormals())
       return DAG.getConstantFP(0.0, SDLoc(N), VT);

test/CodeGen/AMDGPU/fcanonicalize-elimination.ll

+; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -mattr=-fp32-denormals < %s | FileCheck -check-prefix=GCN -check-prefix=VI %s
+; RUN: llc -march=amdgcn -mcpu=gfx901 -verify-machineinstrs -mattr=+fp32-denormals < %s | FileCheck -check-prefix=GCN -check-prefix=GFX9 %s
+
+; GCN-LABEL: {{^}}test_no_fold_canonicalize_loaded_value_f32:
+; GCN: v_mul_f32_e32 v{{[0-9]+}}, 1.0, v{{[0-9]+}}
+define amdgpu_kernel void @test_no_fold_canonicalize_loaded_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %v = load float, float addrspace(1)* %gep, align 4
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: {{^}}test_fold_canonicalize_fmul_value_f32:
+; GCN: v_mul_f32_e32 [[V:v[0-9]+]], 0x41700000, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fmul_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = fmul float %load, 15.0
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: {{^}}test_fold_canonicalize_sub_value_f32:
+; GCN: v_sub_f32_e32 [[V:v[0-9]+]], 0x41700000, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_sub_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = fsub float 15.0, %load
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: {{^}}test_fold_canonicalize_add_value_f32:
+; GCN: v_add_f32_e32 [[V:v[0-9]+]], 0x41700000, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_add_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = fadd float %load, 15.0
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: {{^}}test_fold_canonicalize_sqrt_value_f32:
+; GCN: v_sqrt_f32_e32 [[V:v[0-9]+]], v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_sqrt_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = call float @llvm.sqrt.f32(float %load)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fceil_value_f32:
+; GCN: v_ceil_f32_e32 [[V:v[0-9]+]], v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fceil_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = call float @llvm.ceil.f32(float %load)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_floor_value_f32:
+; GCN: v_floor_f32_e32 [[V:v[0-9]+]], v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_floor_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = call float @llvm.floor.f32(float %load)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fma_value_f32:
+; GCN: v_fma_f32 [[V:v[0-9]+]], v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fma_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = call float @llvm.fma.f32(float %load, float 15.0, float 15.0)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fmuladd_value_f32:
+; VI: v_mac_f32_e32 [[V:v[0-9]+]], v{{[0-9]+}}, v{{[0-9]+}}
+; GFX9: v_fma_f32 [[V:v[0-9]+]], v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fmuladd_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = call float @llvm.fmuladd.f32(float %load, float 15.0, float 15.0)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_canonicalize_value_f32:
+; GCN: flat_load_dword [[LOAD:v[0-9]+]],
+; GCN: v_mul_f32_e32 [[V:v[0-9]+]], 1.0, [[LOAD]]
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_canonicalize_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = call float @llvm.canonicalize.f32(float %load)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fpextend_value_f64_f32:
+; GCN: v_cvt_f64_f32_e32 [[V:v\[[0-9]+:[0-9]+\]]], v{{[0-9]+}}
+; GCN: flat_store_dwordx2 v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fpextend_value_f64_f32(float addrspace(1)* %arg, double addrspace(1)* %out) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = fpext float %load to double
+  %canonicalized = tail call double @llvm.canonicalize.f64(double %v)
+  %gep2 = getelementptr inbounds double, double addrspace(1)* %out, i32 %id
+  store double %canonicalized, double addrspace(1)* %gep2, align 8
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fpextend_value_f32_f16:
+; GCN: v_cvt_f32_f16_e32 [[V:v[0-9]+]], v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fpextend_value_f32_f16(half addrspace(1)* %arg, float addrspace(1)* %out) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds half, half addrspace(1)* %arg, i32 %id
+  %load = load half, half addrspace(1)* %gep, align 2
+  %v = fpext half %load to float
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  %gep2 = getelementptr inbounds float, float addrspace(1)* %out, i32 %id
+  store float %canonicalized, float addrspace(1)* %gep2, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fpround_value_f32_f64:
+; GCN: v_cvt_f32_f64_e32 [[V:v[0-9]+]], v[{{[0-9:]+}}]
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fpround_value_f32_f64(double addrspace(1)* %arg, float addrspace(1)* %out) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds double, double addrspace(1)* %arg, i32 %id
+  %load = load double, double addrspace(1)* %gep, align 8
+  %v = fptrunc double %load to float
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  %gep2 = getelementptr inbounds float, float addrspace(1)* %out, i32 %id
+  store float %canonicalized, float addrspace(1)* %gep2, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fpround_value_f16_f32:
+; GCN: v_cvt_f16_f32_e32 [[V:v[0-9]+]], v{{[0-9]+}}
+; GCN: flat_store_short v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fpround_value_f16_f32(float addrspace(1)* %arg, half addrspace(1)* %out) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = fptrunc float %load to half
+  %canonicalized = tail call half @llvm.canonicalize.f16(half %v)
+  %gep2 = getelementptr inbounds half, half addrspace(1)* %out, i32 %id
+  store half %canonicalized, half addrspace(1)* %gep2, align 2
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fpround_value_v2f16_v2f32:
+; GCN-DAG: v_cvt_f16_f32_e32 [[V0:v[0-9]+]], v{{[0-9]+}}
+; VI-DAG: v_cvt_f16_f32_sdwa [[V1:v[0-9]+]], v{{[0-9]+}}
+; VI: v_or_b32_e32 [[V:v[0-9]+]], [[V0]], [[V1]]
+; GFX9: v_cvt_f16_f32_e32 [[V1:v[0-9]+]], v{{[0-9]+}}
+; GFX9: v_and_b32_e32 [[V0_16:v[0-9]+]], 0xffff, [[V0]]
+; GFX9: v_lshl_or_b32 [[V:v[0-9]+]], [[V1]], 16, [[V0_16]]
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fpround_value_v2f16_v2f32(<2 x float> addrspace(1)* %arg, <2 x half> addrspace(1)* %out) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds <2 x float>, <2 x float> addrspace(1)* %arg, i32 %id
+  %load = load <2 x float>, <2 x float> addrspace(1)* %gep, align 8
+  %v = fptrunc <2 x float> %load to <2 x half>
+  %canonicalized = tail call <2 x half> @llvm.canonicalize.v2f16(<2 x half> %v)
+  %gep2 = getelementptr inbounds <2 x half>, <2 x half> addrspace(1)* %out, i32 %id
+  store <2 x half> %canonicalized, <2 x half> addrspace(1)* %gep2, align 4
+  ret void
+}
+
+; GCN-LABEL: test_no_fold_canonicalize_fneg_value_f32:
+; GCN: v_mul_f32_e64 v{{[0-9]+}}, 1.0, -v{{[0-9]+}}
+define amdgpu_kernel void @test_no_fold_canonicalize_fneg_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = fsub float -0.0, %load
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fneg_value_f32:
+; GCN: v_xor_b32_e32 [[V:v[0-9]+]], 0x80000000, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fneg_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v0 = fadd float %load, 0.0
+  %v = fsub float -0.0, %v0
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_no_fold_canonicalize_fabs_value_f32:
+; GCN: v_mul_f32_e64 v{{[0-9]+}}, 1.0, |v{{[0-9]+}}|
+define amdgpu_kernel void @test_no_fold_canonicalize_fabs_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = tail call float @llvm.fabs.f32(float %load)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_fabs_value_f32:
+; GCN: v_and_b32_e32 [[V:v[0-9]+]], 0x7fffffff, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_fabs_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v0 = fadd float %load, 0.0
+  %v = tail call float @llvm.fabs.f32(float %v0)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_sin_value_f32:
+; GCN: v_sin_f32_e32 [[V:v[0-9]+]], v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_sin_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = tail call float @llvm.sin.f32(float %load)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_cos_value_f32:
+; GCN: v_cos_f32_e32 [[V:v[0-9]+]], v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_cos_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = tail call float @llvm.cos.f32(float %load)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_sin_value_f16:
+; GCN: v_sin_f32_e32 [[V0:v[0-9]+]], v{{[0-9]+}}
+; GCN: v_cvt_f16_f32_e32 [[V:v[0-9]+]], [[V0]]
+; GCN: flat_store_short v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_sin_value_f16(half addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds half, half addrspace(1)* %arg, i32 %id
+  %load = load half, half addrspace(1)* %gep, align 2
+  %v = tail call half @llvm.sin.f16(half %load)
+  %canonicalized = tail call half @llvm.canonicalize.f16(half %v)
+  store half %canonicalized, half addrspace(1)* %gep, align 2
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_cos_value_f16:
+; GCN: v_cos_f32_e32 [[V0:v[0-9]+]], v{{[0-9]+}}
+; GCN: v_cvt_f16_f32_e32 [[V:v[0-9]+]], [[V0]]
+; GCN: flat_store_short v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_cos_value_f16(half addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds half, half addrspace(1)* %arg, i32 %id
+  %load = load half, half addrspace(1)* %gep, align 2
+  %v = tail call half @llvm.cos.f16(half %load)
+  %canonicalized = tail call half @llvm.canonicalize.f16(half %v)
+  store half %canonicalized, half addrspace(1)* %gep, align 2
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_qNaN_value_f32:
+; GCN: v_mov_b32_e32 [[V:v[0-9]+]], 0x7fc00000
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_qNaN_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %canonicalized = tail call float @llvm.canonicalize.f32(float 0x7FF8000000000000)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_minnum_value_from_load_f32:
+; VI: v_mul_f32_e32 v{{[0-9]+}}, 1.0, v{{[0-9]+}}
+; GFX9: v_min_f32_e32 [[V:v[0-9]+]], 0, v{{[0-9]+}}
+; GFX9: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GFX9-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_minnum_value_from_load_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = tail call float @llvm.minnum.f32(float %load, float 0.0)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_minnum_value_f32:
+; GCN: v_min_f32_e32 [[V:v[0-9]+]], 0, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_minnum_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v0 = fadd float %load, 0.0
+  %v = tail call float @llvm.minnum.f32(float %v0, float 0.0)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_sNaN_value_f32:
+; GCN:  v_min_f32_e32 [[V0:v[0-9]+]], 0x7f800001, v{{[0-9]+}}
+; VI:   v_mul_f32_e32 v{{[0-9]+}}, 1.0, [[V0]]
+; VI:   flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GFX9: flat_store_dword v[{{[0-9:]+}}], [[V0]]
+; GFX9-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_sNaN_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = tail call float @llvm.minnum.f32(float %load, float bitcast (i32 2139095041 to float))
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_denorm_value_f32:
+; GCN:  v_min_f32_e32 [[V0:v[0-9]+]], 0x7fffff, v{{[0-9]+}}
+; VI:   v_mul_f32_e32 v{{[0-9]+}}, 1.0, [[V0]]
+; VI:   flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GFX9: flat_store_dword v[{{[0-9:]+}}], [[V0]]
+; GFX9-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_denorm_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = tail call float @llvm.minnum.f32(float %load, float bitcast (i32 8388607 to float))
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_maxnum_value_from_load_f32:
+; GCN:  v_max_f32_e32 [[V0:v[0-9]+]], 0, v{{[0-9]+}}
+; VI:   v_mul_f32_e32 v{{[0-9]+}}, 1.0, [[V0]]
+; VI:   flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GFX9: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GFX9-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_maxnum_value_from_load_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v = tail call float @llvm.maxnum.f32(float %load, float 0.0)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_maxnum_value_f32:
+; GCN: v_max_f32_e32 [[V:v[0-9]+]], 0, v{{[0-9]+}}
+; GCN: flat_store_dword v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_maxnum_value_f32(float addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds float, float addrspace(1)* %arg, i32 %id
+  %load = load float, float addrspace(1)* %gep, align 4
+  %v0 = fadd float %load, 0.0
+  %v = tail call float @llvm.maxnum.f32(float %v0, float 0.0)
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  store float %canonicalized, float addrspace(1)* %gep, align 4
+  ret void
+}
+
+; GCN-LABEL: test_fold_canonicalize_maxnum_value_f64:
+; GCN: v_max_f64 [[V:v\[[0-9]+:[0-9]+\]]], v[{{[0-9:]+}}], 0
+; GCN: flat_store_dwordx2 v[{{[0-9:]+}}], [[V]]
+; GCN-NOT: 1.0
+define amdgpu_kernel void @test_fold_canonicalize_maxnum_value_f64(double addrspace(1)* %arg) {
+  %id = tail call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds double, double addrspace(1)* %arg, i32 %id
+  %load = load double, double addrspace(1)* %gep, align 8
+  %v0 = fadd double %load, 0.0
+  %v = tail call double @llvm.maxnum.f64(double %v0, double 0.0)
+  %canonicalized = tail call double @llvm.canonicalize.f64(double %v)
+  store double %canonicalized, double addrspace(1)* %gep, align 8
+  ret void
+}
+
+; GCN-LABEL: test_no_fold_canonicalize_fmul_value_f32_no_ieee:
+; GCN: v_mul_f32_e32 v{{[0-9]+}}, 1.0, v{{[0-9]+}}
+define amdgpu_ps float @test_no_fold_canonicalize_fmul_value_f32_no_ieee(float %arg) {
+entry:
+  %v = fmul float %arg, 15.0
+  %canonicalized = tail call float @llvm.canonicalize.f32(float %v)
+  ret float %canonicalized
+}
+
+declare float @llvm.canonicalize.f32(float) #0
+declare double @llvm.canonicalize.f64(double) #0
+declare half @llvm.canonicalize.f16(half) #0
+declare <2 x half> @llvm.canonicalize.v2f16(<2 x half>) #0
+declare i32 @llvm.amdgcn.workitem.id.x() #0
+declare float @llvm.sqrt.f32(float) #0
+declare float @llvm.ceil.f32(float) #0
+declare float @llvm.floor.f32(float) #0
+declare float @llvm.fma.f32(float, float, float) #0
+declare float @llvm.fmuladd.f32(float, float, float) #0
+declare float @llvm.fabs.f32(float) #0
+declare float @llvm.sin.f32(float) #0
+declare float @llvm.cos.f32(float) #0
+declare half @llvm.sin.f16(half) #0
+declare half @llvm.cos.f16(half) #0
+declare float @llvm.minnum.f32(float, float) #0
+declare float @llvm.maxnum.f32(float, float) #0
+declare double @llvm.maxnum.f64(double, double) #0
+
+attributes #0 = { nounwind readnone }