[llvm] [DXIL] Add constraint specification and backend implementation of DXIL Ops (PR #97593)

[S. Bharadwaj Yadavalli via llvm-commits]

================
@@ -249,19 +191,59 @@ static FunctionType *getDXILOpFunctionType(const OpCodeProperty *Prop,
       ArgTys[0], ArrayRef<Type *>(&ArgTys[1], ArgTys.size() - 1), false);
 }
 
+static int getValidConstraintIndex(const OpCodeProperty *Prop,
+                                   const VersionTuple SMVer) {
+  // std::vector Prop->SMConstraints is in ascending order of SM Version
+  // Overloads of highest SM version that is not greater than SMVer
+  // are the ones that are valid for SMVer.
+  auto Size = Prop->SMConstraints.size();
+  for (unsigned I = Size - 1; I >= 0; I--) {
+    auto OL = Prop->SMConstraints[I];
+    if (VersionTuple(OL.ShaderModelVer.Major, OL.ShaderModelVer.Minor) <=
+        SMVer) {
+      return I;
+    }
+  }
+  report_fatal_error(
+      StringRef(SMVer.getAsString().append(": Unhandled Shader Model Version")),
+      /*gen_crash_diag*/ false);
+
+  return -1;
+}
+
 namespace llvm {
 namespace dxil {
 
-CallInst *DXILOpBuilder::createDXILOpCall(dxil::OpCode OpCode, Type *ReturnTy,
+CallInst *DXILOpBuilder::createDXILOpCall(dxil::OpCode OpCode,
+                                          VersionTuple SMVer,
+                                          StringRef StageKind, Type *ReturnTy,
                                           Type *OverloadTy,
                                           SmallVector<Value *> Args) {
   const OpCodeProperty *Prop = getOpCodeProperty(OpCode);
+  int Index = getValidConstraintIndex(Prop, SMVer);
+  uint16_t ValidTyMask = Prop->SMConstraints[Index].ValidTys;
 
   OverloadKind Kind = getOverloadKind(OverloadTy);
-  if ((Prop->OverloadTys & (uint16_t)Kind) == 0) {
+  if ((ValidTyMask & (uint16_t)Kind) == 0) {
     report_fatal_error("Invalid Overload Type", /* gen_crash_diag=*/false);
   }
 
+  // Ensure Opcode is valid in the targetted shader kind
+
+  uint16_t ValidShaderKindMask = Prop->SMConstraints[Index].ValidShaderKinds;
+
+  if (ValidShaderKindMask == ShaderKind::Unknown) {
+    report_fatal_error(
+        StringRef(SMVer.getAsString().append(": Unhandled Shader Kind")),
----------------
bharadwajy wrote:

> The error message is SMVer.getAsString().append(": Unhandled Shader Kind"). Should it be something like ShaderKind.getAsString().append(": Unhandled Shader Kind") or SMVer.getString().append(": Unhandled Shader Model Version") or something else?

Updated the message to emit the following (assume SM version is 6.0 and operation is `Cos`):
`LLVM ERROR: 6.0: Unknown Target Shader Stage for DXIL operation - Cos`
to signify unknown stage specification for operation `Cos` for Shader Model version 6.0 

https://github.com/llvm/llvm-project/pull/97593