AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

Implement V8_ASSUME via __builtin_unreachable for GCC

Browse Source 
Provide a V8_ASSUME implementation for GCC which has the same effect as
using __builtin_assume on clang.

R=cbruni@chromium.org

Change-Id: Ia6ab56995d9ecac1015eab8bacc7e3115da7004f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3779691
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81901}
This commit is contained in:
Clemens Backes 2022-07-21 15:09:00 +02:00 committed by V8 LUCI CQ
parent 594d229872
commit 0998bbe6fb
1 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
include/v8config.h
View File

@ -357,6 +357,7 @@ path. Add it with -I<path> to the command line
# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
# define V8_HAS_BUILTIN_UNREACHABLE (__has_builtin(__builtin_unreachable))
// Clang has no __has_feature for computed gotos.
// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
@ -395,6 +396,7 @@ path. Add it with -I<path> to the command line
# define V8_HAS_BUILTIN_EXPECT 1
# define V8_HAS_BUILTIN_FRAME_ADDRESS 1
# define V8_HAS_BUILTIN_POPCOUNT 1
# define V8_HAS_BUILTIN_UNREACHABLE 1
// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
#define V8_HAS_COMPUTED_GOTO 1
@ -431,6 +433,9 @@ path. Add it with -I<path> to the command line
# define V8_ASSUME(condition) DCHECK(condition)
#elif V8_HAS_BUILTIN_ASSUME
# define V8_ASSUME(condition) __builtin_assume(condition)
#elif V8_HAS_BUILTIN_UNREACHABLE
# define V8_ASSUME(condition) \
do { if (!(condition)) __builtin_unreachable(); } while (false)
#else
# define V8_ASSUME(condition)
#endif