[clang] db49231 - [clang][BFloat] Avoid redefining bfloat16_t in arm_neon.h

[Dimitry Andric via cfe-commits]

Author: Dimitry Andric
Date: 2023-05-03T17:54:58+02:00
New Revision: db492316399a0edc26788265c7fce78c63a0f838

URL: https://github.com/llvm/llvm-project/commit/db492316399a0edc26788265c7fce78c63a0f838
DIFF: https://github.com/llvm/llvm-project/commit/db492316399a0edc26788265c7fce78c63a0f838.diff

LOG: [clang][BFloat] Avoid redefining bfloat16_t in arm_neon.h

As of https://reviews.llvm.org/D79708, clang-tblgen generates `arm_neon.h`,
`arm_sve.h` and `arm_bf16.h`, and all those generated files will contain a
typedef of `bfloat16_t`. However, `arm_neon.h` and `arm_sve.h` include
`arm_bf16.h` immediately before their own typedef:

    #include <arm_bf16.h>
    typedef __bf16 bfloat16_t;

With a recent version of clang (I used 16.0.1) this results in warnings:

    /usr/lib/clang/16/include/arm_neon.h:38:16: error: redefinition of typedef 'bfloat16_t' is a C11 feature [-Werror,-Wtypedef-redefinition]

Since `arm_bf16.h` is very likely supposed to be the one true place where
`bfloat16_t` is defined, I propose to delete the duplicate typedefs from the
generated `arm_neon.h` and `arm_sve.h`.

Reviewed By: sdesmalen, simonbutcher

Differential Revision: https://reviews.llvm.org/D148822

Added: 
    

Modified: 
    clang/utils/TableGen/NeonEmitter.cpp
    clang/utils/TableGen/SveEmitter.cpp

Removed: 
    


################################################################################
diff  --git a/clang/utils/TableGen/NeonEmitter.cpp b/clang/utils/TableGen/NeonEmitter.cpp
index 51bb774c6da99..6ef5790731a6b 100644
--- a/clang/utils/TableGen/NeonEmitter.cpp
+++ b/clang/utils/TableGen/NeonEmitter.cpp
@@ -2353,7 +2353,6 @@ void NeonEmitter::run(raw_ostream &OS) {
   OS << "#include <stdint.h>\n\n";
 
   OS << "#include <arm_bf16.h>\n";
-  OS << "typedef __bf16 bfloat16_t;\n";
 
   // Emit NEON-specific scalar typedefs.
   OS << "typedef float float32_t;\n";

diff  --git a/clang/utils/TableGen/SveEmitter.cpp b/clang/utils/TableGen/SveEmitter.cpp
index bc50cbad4b541..d5d3f5fe558a8 100644
--- a/clang/utils/TableGen/SveEmitter.cpp
+++ b/clang/utils/TableGen/SveEmitter.cpp
@@ -1103,7 +1103,6 @@ void SVEEmitter::createHeader(raw_ostream &OS) {
   OS << "typedef __SVBFloat16_t svbfloat16_t;\n";
 
   OS << "#include <arm_bf16.h>\n";
-  OS << "typedef __bf16 bfloat16_t;\n";
 
   OS << "typedef __SVFloat32_t svfloat32_t;\n";
   OS << "typedef __SVFloat64_t svfloat64_t;\n";