[clang] [HLSL] Make memory representation of boolean vectors in HLSL, vectors of i32. Add support for boolean swizzling. (PR #123977)

[Sarah Spall via cfe-commits]

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@@ -1984,6 +1984,15 @@ llvm::Constant *ConstantEmitter::emitForMemory(CodeGenModule &CGM,
     return Res;
   }
 
+  // In HLSL bool vectors are stored in memory as a vector of i32
+  if (destType->isExtVectorBoolType() && CGM.getContext().getLangOpts().HLSL) {
+    llvm::Type *boolVecTy = CGM.getTypes().ConvertTypeForMem(destType);
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spall wrote:

I don't believe so. This code is necessary for HLSL because the constant 'C' is a <2 x i1> but HLSL needs it to be a <2 x i32> hence the zero extension. For non HLSL vectors the expected form would be <2 x i1> so nothing needs to be done. 
https://hlsl.godbolt.org/z/nsb6jd1vn

https://github.com/llvm/llvm-project/pull/123977