From: Jonathan Wakely <jwakely@redhat.com>
Date: Fri, 5 Nov 2021 12:18:52 +0000 (+0000)
Subject: libstdc++: Add [[unlikely]] attributes to std::random_device routines
X-Git-Tag: basepoints/gcc-13~3360
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2627e3b7fd820876bc45c99be48aea05351d210a;p=thirdparty%2Fgcc.git

libstdc++: Add [[unlikely]] attributes to std::random_device routines

libstdc++-v3/ChangeLog:

	* src/c++11/random.cc (__x86_rdrand, __x86_rdseed): Add
	[[unlikely]] attribute.
---

diff --git a/libstdc++-v3/src/c++11/random.cc b/libstdc++-v3/src/c++11/random.cc
index 55a73c51fcaa..4b88818646f1 100644
--- a/libstdc++-v3/src/c++11/random.cc
+++ b/libstdc++-v3/src/c++11/random.cc
@@ -97,7 +97,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
       unsigned int retries = 100;
       unsigned int val;
 
-      while (__builtin_ia32_rdrand32_step(&val) == 0)
+      while (__builtin_ia32_rdrand32_step(&val) == 0) [[__unlikely__]]
 	if (--retries == 0)
 	  std::__throw_runtime_error(__N("random_device: rdrand failed"));
 
@@ -113,7 +113,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
       unsigned int retries = 100;
       unsigned int val;
 
-      while (__builtin_ia32_rdseed_si_step(&val) == 0)
+      while (__builtin_ia32_rdseed_si_step(&val) == 0) [[__unlikely__]]
 	{
 	  if (--retries == 0)
 	    {