[clang] [llvm] Reland "[HLSL] Implement the reflect HLSL function" (PR #125599)

[via cfe-commits]

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@@ -0,0 +1,177 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 5
+// RUN: %clang_cc1 -finclude-default-header -triple \
+// RUN:   dxil-pc-shadermodel6.3-library %s -fnative-half-type \
+// RUN:   -emit-llvm -O1 -o - | FileCheck %s
+// RUN: %clang_cc1 -finclude-default-header -triple \
+// RUN:   spirv-unknown-vulkan-compute %s -fnative-half-type \
+// RUN:   -emit-llvm -O1 -o - | FileCheck %s --check-prefix=SPVCHECK
+
+// CHECK-LABEL: define noundef nofpclass(nan inf) half @_Z17test_reflect_halfDhDh(
+// CHECK-SAME: half noundef nofpclass(nan inf) [[I:%.*]], half noundef nofpclass(nan inf) [[N:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[MUL_I:%.*]] = fmul reassoc nnan ninf nsz arcp afn half [[I]], 0xH4000
+// CHECK-NEXT:    [[TMP0:%.*]] = fmul reassoc nnan ninf nsz arcp afn half [[N]], [[N]]
+// CHECK-NEXT:    [[MUL2_I:%.*]] = fmul reassoc nnan ninf nsz arcp afn half [[TMP0]], [[MUL_I]]
+// CHECK-NEXT:    [[SUB_I:%.*]] = fsub reassoc nnan ninf nsz arcp afn half [[I]], [[MUL2_I]]
+// CHECK-NEXT:    ret half [[SUB_I]]
+//
+// SPVCHECK-LABEL: define spir_func noundef nofpclass(nan inf) half @_Z17test_reflect_halfDhDh(
+// SPVCHECK-SAME: half noundef nofpclass(nan inf) [[I:%.*]], half noundef nofpclass(nan inf) [[N:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// SPVCHECK-NEXT:  [[ENTRY:.*:]]
+// SPVCHECK-NEXT:    [[MUL_I:%.*]] = fmul reassoc nnan ninf nsz arcp afn half [[I]], 0xH4000
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joaosaffran wrote:

Are those important to be tested? 

```suggestion
// SPVCHECK-NEXT:    [[MUL_I:%.*]] = fmul {{.*}} [[I]], 0xH4000
```

https://github.com/llvm/llvm-project/pull/125599