[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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@@ -110,6 +131,24 @@ float2 HowManyFloats(float V) {
   return V.rr.rr;
 }
 
+// CHECK-LABEL: HowManyBools
+// CHECK: [[VAddr:%.*]] = alloca i32, align 4
+// CHECK-NEXT: [[Vec2Ptr:%.*]] = alloca <2 x i32>, align 8
+// CHECK-NEXT: [[Tmp:%.*]] = zext i1 {{.*}} to i32
+// CHECK-NEXT: store i32 [[Tmp]], ptr [[VAddr]], align 4
+// CHECK-NEXT: [[VVal:%.*]] = load i32, ptr [[VAddr]], align 4
+// CHECK-NEXT: [[Splat:%.*]] = insertelement <1 x i32> poison, i32 [[VVal]], i64 0
+// CHECK-NEXT: [[Vec2:%.*]] = shufflevector <1 x i32> [[Splat]], <1 x i32> poison, <2 x i32> zeroinitializer
+// CHECK-NEXT: [[Trunc:%.*]] = trunc <2 x i32> [[Vec2]] to <2 x i1>
+// CHECK-NEXT: store <2 x i1> [[Trunc]], ptr [[Vec2Ptr]], align 8
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spall wrote:

Looks like the trunc shouldn't be happening at all possibly! thanks for noticing

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