[SPIRV][HLSL] Add mad intrinsic lowering for spirv

Author: farzonl

clang/lib/CodeGen/CGBuiltin.cpp

@@ -18186,6 +18186,40 @@ Intrinsic::ID getDotProductIntrinsic(QualType QT, int elementCount) {
   return Intrinsic::dx_udot;
 }
 
+Value *CodeGenFunction::EmitHLSLMadIntrinsic(const CallExpr *E) {
+  Value *M = EmitScalarExpr(E->getArg(0));
+  Value *A = EmitScalarExpr(E->getArg(1));
+  Value *B = EmitScalarExpr(E->getArg(2));
+  if (E->getArg(0)->getType()->hasFloatingRepresentation())
+    return Builder.CreateIntrinsic(
+        /*ReturnType*/ M->getType(), Intrinsic::fmuladd,
+        ArrayRef<Value *>{M, A, B}, nullptr, "hlsl.fmad");
+
+  auto EmitHLSLIMadDirectX = [E, M, A, B, this]() -> Value * {
+    if (E->getArg(0)->getType()->hasSignedIntegerRepresentation())
+      return Builder.CreateIntrinsic(
+          /*ReturnType*/ M->getType(), Intrinsic::dx_imad,
+          ArrayRef<Value *>{M, A, B}, nullptr, "dx.imad");
+    assert(E->getArg(0)->getType()->hasUnsignedIntegerRepresentation());
+    return Builder.CreateIntrinsic(
+        /*ReturnType=*/M->getType(), Intrinsic::dx_umad,
+        ArrayRef<Value *>{M, A, B}, nullptr, "dx.umad");
+  };
+
+  auto EmitHLSLIMadGeneric = [E, M, A, B, this]() -> Value * {
+    if (E->getArg(0)->getType()->hasSignedIntegerRepresentation()) {
+      Value *Mul = Builder.CreateNSWMul(M, A);
+      return Builder.CreateNSWAdd(Mul, B);
+    }
+    assert(E->getArg(0)->getType()->hasUnsignedIntegerRepresentation());
+    Value *Mul = Builder.CreateNUWMul(M, A);
+    return Builder.CreateNUWAdd(Mul, B);
+  };
+
+  return CGM.getHLSLRuntime().emitHLSLIntrinsic(
+      EmitHLSLIMadDirectX, EmitHLSLIMadGeneric, EmitHLSLIMadGeneric);
+}
+
 Value *CodeGenFunction::EmitHLSLBuiltinExpr(unsigned BuiltinID,
                                             const CallExpr *E) {
   if (!getLangOpts().HLSL)
@@ -18291,23 +18325,7 @@ Value *CodeGenFunction::EmitHLSLBuiltinExpr(unsigned BuiltinID,
                                    ArrayRef<Value *>{Op0}, nullptr, "dx.isinf");
   }
   case Builtin::BI__builtin_hlsl_mad: {
-    Value *M = EmitScalarExpr(E->getArg(0));
-    Value *A = EmitScalarExpr(E->getArg(1));
-    Value *B = EmitScalarExpr(E->getArg(2));
-    if (E->getArg(0)->getType()->hasFloatingRepresentation()) {
-      return Builder.CreateIntrinsic(
-          /*ReturnType*/ M->getType(), Intrinsic::fmuladd,
-          ArrayRef<Value *>{M, A, B}, nullptr, "dx.fmad");
-    }
-    if (E->getArg(0)->getType()->hasSignedIntegerRepresentation()) {
-      return Builder.CreateIntrinsic(
-          /*ReturnType*/ M->getType(), Intrinsic::dx_imad,
-          ArrayRef<Value *>{M, A, B}, nullptr, "dx.imad");
-    }
-    assert(E->getArg(0)->getType()->hasUnsignedIntegerRepresentation());
-    return Builder.CreateIntrinsic(
-        /*ReturnType=*/M->getType(), Intrinsic::dx_umad,
-        ArrayRef<Value *>{M, A, B}, nullptr, "dx.umad");
+    return EmitHLSLMadIntrinsic(E);
   }
   case Builtin::BI__builtin_hlsl_elementwise_rcp: {
     Value *Op0 = EmitScalarExpr(E->getArg(0));

clang/lib/CodeGen/CGHLSLRuntime.cpp

@@ -119,6 +119,21 @@ llvm::Triple::ArchType CGHLSLRuntime::getArch() {
   return CGM.getTarget().getTriple().getArch();
 }
 
+Value *
+CGHLSLRuntime::emitHLSLIntrinsic(llvm::function_ref<Value *()> DxilEmitter,
+                                 llvm::function_ref<Value *()> SPIRVEmitter,
+                                 llvm::function_ref<Value *()> GenericEmitter) {
+  llvm::Triple::ArchType Arch = getArch();
+  switch (Arch) {
+  case llvm::Triple::dxil:
+    return DxilEmitter();
+  case llvm::Triple::spirv:
+    return SPIRVEmitter();
+  default:
+    return GenericEmitter();
+  }
+}
+
 void CGHLSLRuntime::addConstant(VarDecl *D, Buffer &CB) {
   if (D->getStorageClass() == SC_Static) {
     // For static inside cbuffer, take as global static.

clang/lib/CodeGen/CGHLSLRuntime.h

@@ -50,6 +50,7 @@ namespace llvm {
 class GlobalVariable;
 class Function;
 class StructType;
+class Value;
 } // namespace llvm
 
 namespace clang {
@@ -79,7 +80,13 @@ class CGHLSLRuntime {
   //===----------------------------------------------------------------------===//
   // End of reserved area for HLSL intrinsic getters.
   //===----------------------------------------------------------------------===//
-
+  llvm::Value *emitHLSLIntrinsic(
+      llvm::function_ref<llvm::Value *()> DxilEmitter,
+      llvm::function_ref<llvm::Value *()> SPIRVEmitter,
+      llvm::function_ref<llvm::Value *()> GenericEmitter =
+          []() -> llvm::Value * {
+        llvm_unreachable("Intrinsic not supported by target architecture.");
+      });
   struct BufferResBinding {
     // The ID like 2 in register(b2, space1).
     std::optional<unsigned> Reg;

clang/lib/CodeGen/CodeGenFunction.h

@@ -4548,6 +4548,7 @@ class CodeGenFunction : public CodeGenTypeCache {
   llvm::Value *EmitPPCBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitHLSLBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
+  llvm::Value *EmitHLSLMadIntrinsic(const CallExpr *E);
   llvm::Value *EmitScalarOrConstFoldImmArg(unsigned ICEArguments, unsigned Idx,
                                            const CallExpr *E);
   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);