Fix assert from matrix lower needlessly casting constant to instruction. (#4115) (#4118)

(cherry picked from commit 39dd31f)

Author: tex3d

lib/HLSL/HLMatrixLowerPass.cpp

@@ -1309,9 +1309,11 @@ static Value *convertScalarOrVector(Value *SrcVal, Type *DstTy, HLCastOpcode Opc
   // Conversions to bools are comparisons
   if (DstTy->getScalarSizeInBits() == 1) {
     // fcmp une is what regular clang uses in C++ for (bool)f;
-    return cast<Instruction>(SrcTy->isIntOrIntVectorTy()
-      ? Builder.CreateICmpNE(SrcVal, llvm::Constant::getNullValue(SrcTy), "tobool")
-      : Builder.CreateFCmpUNE(SrcVal, llvm::Constant::getNullValue(SrcTy), "tobool"));
+    return SrcTy->isIntOrIntVectorTy()
+               ? Builder.CreateICmpNE(
+                     SrcVal, llvm::Constant::getNullValue(SrcTy), "tobool")
+               : Builder.CreateFCmpUNE(
+                     SrcVal, llvm::Constant::getNullValue(SrcTy), "tobool");
   }
 
   // Cast necessary
@@ -1321,7 +1323,7 @@ static Value *convertScalarOrVector(Value *SrcVal, Type *DstTy, HLCastOpcode Opc
     Opcode == HLCastOpcode::UnsignedUnsignedCast;
   auto CastOp = static_cast<Instruction::CastOps>(HLModule::GetNumericCastOp(
     SrcTy, SrcIsUnsigned, DstTy, DstIsUnsigned));
-  return cast<Instruction>(Builder.CreateCast(CastOp, SrcVal, DstTy));
+  return Builder.CreateCast(CastOp, SrcVal, DstTy);
 }
 
 Value *HLMatrixLowerPass::lowerHLCast(CallInst *Call, Value *Src, Type *DstTy,

tools/clang/test/HLSLFileCheck/hlsl/types/matrix/constMat5.hlsl

@@ -0,0 +1,32 @@
+// RUN: %dxc -E main -T ps_6_2 -enable-16bit-types %s | FileCheck %s
+
+// CHECK: [9 x half] [half 0xH3C00, half 0xH4400, half 0xH4700, half 0xH4000, half 0xH4500, half 0xH4800, half 0xH4200, half 0xH4600, half 0xH4880]
+// CHECK: fptoui float
+// CHECK: getelementptr [9 x half]
+// CHECK: load half
+// CHECK: call half @dx.op.tertiary.f16(i32 46, half 0xH4000,
+// CHECK: lshr i32 411,
+// CHECK: icmp ne
+// CHECK: %[[all:[^ ]*]] = uitofp i1 %{{.*}} to float
+// CHECK: call void @dx.op.storeOutput.f32(i32 5, i32 0, i32 0, i8 0,
+// CHECK: call void @dx.op.storeOutput.f32(i32 5, i32 0, i32 0, i8 1,
+// CHECK: call void @dx.op.storeOutput.f32(i32 5, i32 0, i32 0, i8 2,
+// CHECK: call void @dx.op.storeOutput.f32(i32 5, i32 0, i32 0, i8 3, float %[[all]])
+
+struct Foo {
+    half3x3 hmat;
+    bool3x3 bmat;
+};
+
+Foo fn() {
+    Foo foo;
+    foo.hmat = float3x3(1, 2, 3, 4, 5, 6, 7, 8, 9);
+    foo.bmat = int3x3(1, 2, 0, -5, 14, 3, 0, 0, 21);
+    return foo;
+}
+
+float4 main(float a : A) : SV_Target {
+    Foo foo = fn();
+    float3 v = float3(a, a * a, a + a);
+    return float4(mul(foo.hmat, foo.hmat[a]), all(foo.bmat[a]));
+}