[clang] [clang][AMDGPU] Don't define feature macros on host code (PR #83558)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Pierre van Houtryve (Pierre-vh)

<details>
<summary>Changes</summary>

Those macros are unreliable because our features are mostly uninitialized at that stage, so any macro we define is unreliable.

Fixes SWDEV-447308

---
Full diff: https://github.com/llvm/llvm-project/pull/83558.diff


2 Files Affected:

- (modified) clang/lib/Basic/Targets/AMDGPU.cpp (+7-1) 
- (modified) clang/test/Preprocessor/predefined-arch-macros.c (+1-1) 


``````````diff
diff --git a/clang/lib/Basic/Targets/AMDGPU.cpp b/clang/lib/Basic/Targets/AMDGPU.cpp
index 5742885df0461b..df9a5855068ed3 100644
--- a/clang/lib/Basic/Targets/AMDGPU.cpp
+++ b/clang/lib/Basic/Targets/AMDGPU.cpp
@@ -292,8 +292,14 @@ void AMDGPUTargetInfo::getTargetDefines(const LangOptions &Opts,
   }
 
   Builder.defineMacro(Twine("__") + Twine(CanonName) + Twine("__"));
+
+  // Don't emit feature macros in host code because in such cases the
+  // feature list is not accurate.
+  if (IsHIPHost)
+    return;
+
   // Emit macros for gfx family e.g. gfx906 -> __GFX9__, gfx1030 -> __GFX10___
-  if (isAMDGCN(getTriple()) && !IsHIPHost) {
+  if (isAMDGCN(getTriple())) {
     assert(StringRef(CanonName).starts_with("gfx") &&
            "Invalid amdgcn canonical name");
     StringRef CanonFamilyName = getArchFamilyNameAMDGCN(GPUKind);
diff --git a/clang/test/Preprocessor/predefined-arch-macros.c b/clang/test/Preprocessor/predefined-arch-macros.c
index ca51f2fc22c517..8904bcea1a1f68 100644
--- a/clang/test/Preprocessor/predefined-arch-macros.c
+++ b/clang/test/Preprocessor/predefined-arch-macros.c
@@ -4340,7 +4340,7 @@
 // RUN: %clang -x hip -E -dM %s -o - 2>&1 --offload-host-only -nogpulib \
 // RUN:     -nogpuinc --offload-arch=gfx803 -target x86_64-unknown-linux \
 // RUN:   | FileCheck -match-full-lines %s -check-prefixes=CHECK_HIP_HOST
-// CHECK_HIP_HOST: #define __AMDGCN_WAVEFRONT_SIZE__ 64
+// CHECK_HIP_HOST-NOT: #define __AMDGCN_WAVEFRONT_SIZE__ 64
 // CHECK_HIP_HOST: #define __AMDGPU__ 1
 // CHECK_HIP_HOST: #define __AMD__ 1
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/83558