[clang] dbed898 - [AMDGPU] Add missing `__builtin_amdgcn_wavefrontsize` builtin (#80741)

[via cfe-commits]

Author: Joseph Huber
Date: 2024-02-05T17:58:19-06:00
New Revision: dbed89814e5b9ba25a349a5b9acf4a7164e33834

URL: https://github.com/llvm/llvm-project/commit/dbed89814e5b9ba25a349a5b9acf4a7164e33834
DIFF: https://github.com/llvm/llvm-project/commit/dbed89814e5b9ba25a349a5b9acf4a7164e33834.diff

LOG: [AMDGPU] Add missing `__builtin_amdgcn_wavefrontsize` builtin (#80741)

Summary:
The backend supports the wavefrontsize intrinsic, and suggests that it
is tied to a corresponding clang builtin, but it is not actually
present. This simply adds it in so it can be used from clang. This
attribute likely isn't the best to rely on, but for the `libc` use-case
we will need to detect a struct's differing size in a way that will
depend on the wavefront size.

Added: 
    

Modified: 
    clang/include/clang/Basic/BuiltinsAMDGPU.def
    clang/test/CodeGenOpenCL/builtins-amdgcn.cl

Removed: 
    


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diff  --git a/clang/include/clang/Basic/BuiltinsAMDGPU.def b/clang/include/clang/Basic/BuiltinsAMDGPU.def
index 5f8001e61a028..213311b96df74 100644
--- a/clang/include/clang/Basic/BuiltinsAMDGPU.def
+++ b/clang/include/clang/Basic/BuiltinsAMDGPU.def
@@ -69,6 +69,7 @@ BUILTIN(__builtin_amdgcn_s_dcache_inv, "v", "n")
 BUILTIN(__builtin_amdgcn_buffer_wbinvl1, "v", "n")
 BUILTIN(__builtin_amdgcn_fence, "vUicC*", "n")
 BUILTIN(__builtin_amdgcn_groupstaticsize, "Ui", "n")
+BUILTIN(__builtin_amdgcn_wavefrontsize, "Ui", "nc")
 
 BUILTIN(__builtin_amdgcn_atomic_inc32, "UZiUZiD*UZiUicC*", "n")
 BUILTIN(__builtin_amdgcn_atomic_inc64, "UWiUWiD*UWiUicC*", "n")

diff  --git a/clang/test/CodeGenOpenCL/builtins-amdgcn.cl b/clang/test/CodeGenOpenCL/builtins-amdgcn.cl
index 8d9e4e018b12e..7d9010ee9067d 100644
--- a/clang/test/CodeGenOpenCL/builtins-amdgcn.cl
+++ b/clang/test/CodeGenOpenCL/builtins-amdgcn.cl
@@ -832,6 +832,13 @@ void test_atomic_inc_dec(local uint *lptr, global uint *gptr, uint val) {
   res = __builtin_amdgcn_atomic_dec32((volatile global uint*)gptr, val, __ATOMIC_SEQ_CST, "");
 }
 
+// CHECK-LABEL test_wavefrontsize(
+unsigned test_wavefrontsize() {
+
+  // CHECK: call i32 @llvm.amdgcn.wavefrontsize()
+  return __builtin_amdgcn_wavefrontsize();
+}
+
 // CHECK-DAG: [[$WI_RANGE]] = !{i32 0, i32 1024}
 // CHECK-DAG: [[$WS_RANGE]] = !{i16 1, i16 1025}
 // CHECK-DAG: attributes #[[$NOUNWIND_READONLY]] = { convergent mustprogress nocallback nofree nounwind willreturn memory(none) }