From: Ulrich Drepper <drepper@gmail.com>
Date: Wed, 5 Sep 2012 13:54:57 +0000 (+0000)
Subject: random.cc (random_device::_M_init): Check whether cpuid instruction is available... 
X-Git-Tag: misc/gccgo-go1_1_2~1030
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=efc622f843e3db6a4da4112ef411abf935048438;p=thirdparty%2Fgcc.git

random.cc (random_device::_M_init): Check whether cpuid instruction is available by using __get_cpuid_max.


	* src/c++11/random.cc (random_device::_M_init): Check whether cpuid
	instruction is available by using __get_cpuid_max.

From-SVN: r190982
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index b7fb7956c1c3..fa11b3404b1e 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,8 @@
 2012-09-05  Ulrich Drepper  <drepper@gmail.com>
 
+	* src/c++11/random.cc (random_device::_M_init): Check whether cpuid
+	instruction is available by using __get_cpuid_max.
+
 	* include/ext/random.tcc (__gnu_cxx:normal_mv_distribution<>)
 	(operator()): Use __generate() function of _M_nd.
 
diff --git a/libstdc++-v3/src/c++11/random.cc b/libstdc++-v3/src/c++11/random.cc
index cabc388760b4..f5ee9f4fa610 100644
--- a/libstdc++-v3/src/c++11/random.cc
+++ b/libstdc++-v3/src/c++11/random.cc
@@ -77,9 +77,9 @@ namespace std _GLIBCXX_VISIBILITY(default)
       {
 #if defined __i386__ || defined __x86_64__
 	unsigned int eax, ebx, ecx, edx;
-	__cpuid(0, eax, ebx, ecx, edx);
-	// Check for "GenuineIntel"
-	if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
+	// Check availability of cpuid and, for now at least, also the
+	// CPU signature for Intel's
+	if (__get_cpuid_max(0, &ebx) > 0 && ebx == 0x756e6547)
 	  {
 	    __cpuid(1, eax, ebx, ecx, edx);
 	    if (ecx & bit_RDRND)
@@ -104,7 +104,6 @@ namespace std _GLIBCXX_VISIBILITY(default)
 
   void
   random_device::_M_init_pretr1(const std::string& token)
-
   {
     _M_mt.seed(_M_strtoul(token));
   }