AMDGPU: Refactor treatment of denormal mode

Start moving towards treating this as a property of the calling
convention, and not the subtarget. The default denormal mode should
not be part of the subtarget, and be moved into a separate function
attribute.

This patch is still NFC. The denormal mode remains as a subtarget
feature for now, but make the necessary changes to switch to using an
attribute.

1 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp b/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp
index ed495bd40b8..cf908766caa 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp
@@ -70,6 +70,7 @@ class AMDGPUCodeGenPrepare : public FunctionPass,
   Module *Mod = nullptr;
   const DataLayout *DL = nullptr;
   bool HasUnsafeFPMath = false;
+  bool HasFP32Denormals = false;
 
   /// Copies exact/nsw/nuw flags (if any) from binary operation \p I to
   /// binary operation \p V.
@@ -575,7 +576,6 @@ bool AMDGPUCodeGenPrepare::visitFDiv(BinaryOperator &FDiv) {
 
   Value *NewFDiv = nullptr;
 
-  bool HasDenormals = ST->hasFP32Denormals();
   if (VectorType *VT = dyn_cast<VectorType>(Ty)) {
     NewFDiv = UndefValue::get(VT);
 
@@ -586,7 +586,7 @@ bool AMDGPUCodeGenPrepare::visitFDiv(BinaryOperator &FDiv) {
       Value *DenEltI = Builder.CreateExtractElement(Den, I);
       Value *NewElt;
 
-      if (shouldKeepFDivF32(NumEltI, UnsafeDiv, HasDenormals)) {
+      if (shouldKeepFDivF32(NumEltI, UnsafeDiv, HasFP32Denormals)) {
         NewElt = Builder.CreateFDiv(NumEltI, DenEltI);
       } else {
         NewElt = Builder.CreateCall(Decl, { NumEltI, DenEltI });
@@ -595,7 +595,7 @@ bool AMDGPUCodeGenPrepare::visitFDiv(BinaryOperator &FDiv) {
       NewFDiv = Builder.CreateInsertElement(NewFDiv, NewElt, I);
     }
   } else {
-    if (!shouldKeepFDivF32(Num, UnsafeDiv, HasDenormals))
+    if (!shouldKeepFDivF32(Num, UnsafeDiv, HasFP32Denormals))
       NewFDiv = Builder.CreateCall(Decl, { Num, Den });
   }
 
@@ -1034,6 +1034,7 @@ bool AMDGPUCodeGenPrepare::runOnFunction(Function &F) {
   AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
   DA = &getAnalysis<LegacyDivergenceAnalysis>();
   HasUnsafeFPMath = hasUnsafeFPMath(F);
+  HasFP32Denormals = ST->hasFP32Denormals(F);
 
   bool MadeChange = false;