clang/AMDGPU: Define macro for -munsafe-fp-atomics

[arsenm]

Summary

The HIP headers want to use this to swap the implementation of the
function, rather than relying on backend expansion of the generic
atomic instruction.

[rampitec]

Thanks!

[arsenm]

a1303b23c9de6ef6d667aa923ec266ca4a0334e7

clang/lib/Basic/Targets/AMDGPU.cpp

if (isAMDGCN(getTriple())) {
           Builder.defineMacro(Twine("__amdgcn_feature_") + Twine(NewF) +
                                   Twine("__"),
                               Loc->second ? "1" : "0");
         }
       }
     }
   }
 
+  if (AllowAMDGPUUnsafeFPAtomics)
+    Builder.defineMacro("__AMDGCN_UNSAFE_FP_ATOMICS__");
+
   // TODO: __HAS_FMAF__, __HAS_LDEXPF__, __HAS_FP64__ are deprecated and will be
   // removed in the near future.
   if (hasFMAF())
     Builder.defineMacro("__HAS_FMAF__");
   if (hasFastFMAF())
     Builder.defineMacro("FP_FAST_FMAF");
   if (hasLDEXPF())
     Builder.defineMacro("__HAS_LDEXPF__");

clang/test/Driver/amdgpu-macros.cl

 // RUN: %clang -E -dM -target amdgcn -mcpu=tongapro %s 2>&1 | FileCheck --check-prefix=ARCH-GCN %s -DWAVEFRONT_SIZE=64 -DCPU=gfx805
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx810 %s 2>&1 | FileCheck --check-prefix=ARCH-GCN %s -DWAVEFRONT_SIZE=64 -DCPU=gfx810
 // RUN: %clang -E -dM -target amdgcn -mcpu=stoney %s 2>&1 | FileCheck --check-prefix=ARCH-GCN %s -DWAVEFRONT_SIZE=64 -DCPU=gfx810
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx900 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx900
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx902 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx902
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx904 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx904
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx906 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx906
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx908 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx908
+// RUN: %clang -E -dM -target amdgcn -mcpu=gfx908 -munsafe-fp-atomics %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,UNSAFEFPATOMIC %s -DWAVEFRONT_SIZE=64 -DCPU=gfx908
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx909 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx909
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx90a %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx90a
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx90c %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx90c
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx940 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=64 -DCPU=gfx940
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx1010 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=32 -DCPU=gfx1010
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx1011 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=32 -DCPU=gfx1011
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx1012 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=32 -DCPU=gfx1012
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx1013 %s 2>&1 | FileCheck --check-prefixes=ARCH-GCN,FAST_FMAF %s -DWAVEFRONT_SIZE=32 -DCPU=gfx1013

 // ARCH-GCN-DAG: #define __AMDGPU__ 1
 // ARCH-GCN-DAG: #define __AMD__ 1
 // ARCH-GCN-DAG: #define __HAS_FMAF__ 1
 // ARCH-GCN-DAG: #define __HAS_FP64__ 1
 // ARCH-GCN-DAG: #define __HAS_LDEXPF__ 1
 // ARCH-GCN-DAG: #define __[[CPU]]__ 1
 // ARCH-GCN-DAG: #define __amdgcn_processor__ "[[CPU]]"
 // ARCH-GCN-DAG: #define __AMDGCN_WAVEFRONT_SIZE [[WAVEFRONT_SIZE]]
+// UNSAFEFPATOMIC-DAG: #define __AMDGCN_UNSAFE_FP_ATOMICS__ 1
 
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx906 -mwavefrontsize64 \
 // RUN:   %s 2>&1 | FileCheck --check-prefix=WAVE64 %s
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx1010 -mwavefrontsize64 \
 // RUN:   %s 2>&1 | FileCheck --check-prefix=WAVE64 %s
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx906 -mwavefrontsize64 \
 // RUN:   -mno-wavefrontsize64 %s 2>&1 | FileCheck --check-prefix=WAVE64 %s
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx1010 -mwavefrontsize64 \
 // RUN:   -mno-wavefrontsize64 %s 2>&1 | FileCheck --check-prefix=WAVE32 %s
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx906 -mno-wavefrontsize64 \
 // RUN:   -mwavefrontsize64 %s 2>&1 | FileCheck --check-prefix=WAVE64 %s
 // RUN: %clang -E -dM -target amdgcn -mcpu=gfx1010 -mno-wavefrontsize64 \
 // RUN:   -mwavefrontsize64 %s 2>&1 | FileCheck --check-prefix=WAVE64 %s
 // WAVE64-DAG: #define __AMDGCN_WAVEFRONT_SIZE 64
 // WAVE32-DAG: #define __AMDGCN_WAVEFRONT_SIZE 32