[llvm] [DirectX] Infrastructure to collect shader flags for each function (PR #112967)

[Justin Bogner via llvm-commits]

================
@@ -13,36 +13,70 @@
 
 #include "DXILShaderFlags.h"
 #include "DirectX.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Module.h"
+#include "llvm/Support/Error.h"
 #include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 using namespace llvm::dxil;
 
-static void updateFlags(ComputedShaderFlags &Flags, const Instruction &I) {
+static void updateFlags(ComputedShaderFlags &CSF, const Instruction &I) {
   Type *Ty = I.getType();
-  if (Ty->isDoubleTy()) {
-    Flags.Doubles = true;
+  bool DoubleTyInUse = Ty->isDoubleTy();
+  for (Value *Op : I.operands()) {
+    DoubleTyInUse |= Op->getType()->isDoubleTy();
+  }
+
+  if (DoubleTyInUse) {
+    CSF.Doubles = true;
     switch (I.getOpcode()) {
     case Instruction::FDiv:
     case Instruction::UIToFP:
     case Instruction::SIToFP:
     case Instruction::FPToUI:
     case Instruction::FPToSI:
-      Flags.DX11_1_DoubleExtensions = true;
+      // TODO: To be set if I is a call to DXIL intrinsic DXIL::Opcode::Fma
+      CSF.DX11_1_DoubleExtensions = true;
       break;
     }
   }
 }
 
-ComputedShaderFlags ComputedShaderFlags::computeFlags(Module &M) {
-  ComputedShaderFlags Flags;
-  for (const auto &F : M)
-    for (const auto &BB : F)
+static bool compareFunctions(Function const *F1, Function const *F2) {
+  return (F1->getName().compare(F2->getName()) < 0);
+}
+
+static bool compareFuncSFPairs(const FuncShaderFlagsMask &First,
+                               const FuncShaderFlagsMask &Second) {
+  return compareFunctions(First.first, Second.first);
+}
----------------
bogner wrote:

Why are we sorting by function name at all here? We don't need the structure to be in a deterministic order if we're just doing lookups on it, so we should really just sort all of these by address.

https://github.com/llvm/llvm-project/pull/112967