[clang] Switch DirectX Target to use the Itanium ABI (PR #111632)

[Greg Roth via cfe-commits]

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@@ -289,17 +289,19 @@ void setFour(inout int I) {
 // CHECK: [[B:%.*]] = alloca %struct.B
 // CHECK: [[Tmp:%.*]] = alloca i32
 
-// CHECK: [[BFLoad:%.*]] = load i32, ptr [[B]]
-// CHECK: [[BFshl:%.*]] = shl i32 [[BFLoad]], 24
-// CHECK: [[BFashr:%.*]] = ashr i32 [[BFshl]], 24
-// CHECK: store i32 [[BFashr]], ptr [[Tmp]]
+// CHECK: [[BFLoad:%.*]] = load i16, ptr [[B]]
+// CHECK: [[BFshl:%.*]] = shl i16 [[BFLoad]], 8
+// CHECK: [[BFashr:%.*]] = ashr i16 [[BFshl]], 8
+// CHECK: [[BFcast:%.*]] = sext i16 [[BFashr]] to i32
+// CHECK: store i32 [[BFcast]], ptr [[Tmp]]
 // CHECK: call void {{.*}}setFour{{.*}}(ptr noalias noundef nonnull align 4 dereferenceable(4) [[Tmp]])
 // CHECK: [[RetVal:%.*]] = load i32, ptr [[Tmp]]
-// CHECK: [[BFLoad:%.*]] = load i32, ptr [[B]]
-// CHECK: [[BFValue:%.*]] = and i32 [[RetVal]], 255
-// CHECK: [[ZerodField:%.*]] = and i32 [[BFLoad]], -256
-// CHECK: [[BFSet:%.*]] = or i32 [[ZerodField]], [[BFValue]]
-// CHECK: store i32 [[BFSet]], ptr [[B]]
+// CHECK: [[TruncVal:%.*]] = trunc i32 [[RetVal]] to i16
+// CHECK: [[BFLoad:%.*]] = load i16, ptr [[B]]
+// CHECK: [[BFValue:%.*]] = and i16 [[TruncVal]], 255
+// CHECK: [[ZerodField:%.*]] = and i16 [[BFLoad]], -256
+// CHECK: [[BFSet:%.*]] = or i16 [[ZerodField]], [[BFValue]]
+// CHECK: store i16 [[BFSet]], ptr [[B]]
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pow2clk wrote:

This is an instance of using smaller types where possible. Doing so introduced some additional commands.

https://github.com/llvm/llvm-project/pull/111632