Export of internal Abseil changes.
--
6258612abc571fa7f51f34046b410c73486505fe by Derek Mauro <dmauro@google.com>:
Rollback checking the return value of pthread functions in thread_identity.cc.
PiperOrigin-RevId: 248381230
--
fda6acddab04fc53eeb84ec253de4a9655bf9a36 by CJ Johnson <johnsoncj@google.com>:
Removes too-restrictive benchmark abstraction in inlined_vector_benchmark
PiperOrigin-RevId: 248366325
--
68674991e63c919de8a3eebced5adec6466ec8fe by Abseil Team <absl-team@google.com>:
Check for pthread_setmask() failure.
Log a fatal error message if pthread_setmask() fails.
PiperOrigin-RevId: 248347115
--
45389e44c0d1badafb6b560cae3df99fc8bd16ac by Derek Mauro <dmauro@google.com>:
Fix a -Wredundant-move warning in GCC 9.
PiperOrigin-RevId: 248338682
--
12cfbacf599084a8ac6bf4395026cbf193c85a26 by Derek Mauro <dmauro@google.com>:
Check the return value of pthread functions in thread_identity.cc.
PiperOrigin-RevId: 248327118
--
2bc69998e68cfee96e812ce800e83cce7a715091 by Benjamin Barenblat <bbaren@google.com>:
Encourage judicious use of ABSL_PREDICT_{TRUE,FALSE}
Recommend that users use branch prediction annotations only on hot,
consistently mispredicted branches.
PiperOrigin-RevId: 248222450
GitOrigin-RevId: 6258612abc571fa7f51f34046b410c73486505fe
Change-Id: I09d409f9a3941ee926b8476b5473f9c4899cc3ff
This commit is contained in:
parent
436ba6c4a0
commit
fa00c32107
4 changed files with 19 additions and 11 deletions
|
|
@ -163,6 +163,12 @@
|
|||
// Compilers can use the information that a certain branch is not likely to be
|
||||
// taken (for instance, a CHECK failure) to optimize for the common case in
|
||||
// the absence of better information (ie. compiling gcc with `-fprofile-arcs`).
|
||||
//
|
||||
// Recommendation: Modern CPUs dynamically predict branch execution paths,
|
||||
// typically with accuracy greater than 97%. As a result, annotating every
|
||||
// branch in a codebase is likely counterproductive; however, annotating
|
||||
// specific branches that are both hot and consistently mispredicted is likely
|
||||
// to yield performance improvements.
|
||||
#if ABSL_HAVE_BUILTIN(__builtin_expect) || \
|
||||
(defined(__GNUC__) && !defined(__clang__))
|
||||
#define ABSL_PREDICT_FALSE(x) (__builtin_expect(x, 0))
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue