[clang] [llvm] [HLSL][DXIL] Implement `refract` intrinsic (PR #136026)

[via cfe-commits]

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@@ -69,6 +69,49 @@ bool SemaSPIRV::CheckSPIRVBuiltinFunctionCall(unsigned BuiltinID,
     TheCall->setType(RetTy);
     break;
   }
+  case SPIRV::BI__builtin_spirv_refract: {
+    if (SemaRef.checkArgCount(TheCall, 3))
+      return true;
+
+    ExprResult A = TheCall->getArg(0);
+    QualType ArgTyA = A.get()->getType();
+    auto *VTyA = ArgTyA->getAs<VectorType>();
+    if (VTyA == nullptr) {
+      SemaRef.Diag(A.get()->getBeginLoc(),
+                   diag::err_typecheck_convert_incompatible)
+          << ArgTyA
+          << SemaRef.Context.getVectorType(ArgTyA, 2, VectorKind::Generic) << 1
+          << 0 << 0;
+      return true;
+    }
+
+    ExprResult B = TheCall->getArg(1);
+    QualType ArgTyB = B.get()->getType();
+    auto *VTyB = ArgTyB->getAs<VectorType>();
+    if (VTyB == nullptr) {
+      SemaRef.Diag(B.get()->getBeginLoc(),
+                   diag::err_typecheck_convert_incompatible)
+          << ArgTyB
+          << SemaRef.Context.getVectorType(ArgTyB, 2, VectorKind::Generic) << 1
+          << 0 << 0;
+      return true;
+    }
+
+    ExprResult C = TheCall->getArg(2);
+    QualType ArgTyC = C.get()->getType();
+    if (!ArgTyC->hasFloatingRepresentation()) {
+      SemaRef.Diag(C.get()->getBeginLoc(),
+                   diag::err_builtin_invalid_arg_type)
+          << 3 << /* scalar or vector */ 5 << /* no int */ 0 << /* fp */ 1
+          << ArgTyC;
+      return true;
+    }
+
+    QualType RetTy = ArgTyA;
+    TheCall->setType(RetTy);
+    assert(RetTy == ArgTyA);
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raoanag wrote:

yes, this is remanent of some debugging that I was doing 

https://github.com/llvm/llvm-project/pull/136026