Message ID | 20120906192210.GA17313@bromo.med.uc.edu |
---|---|
State | New |
Headers | show |
On Thu, Sep 06, 2012 at 03:22:10PM -0400, Jack Howarth wrote: > The attached patch eliminates the bootstrap failures in libstdc++-v3 > of PR 54419 by having configure check for assembler support of the new > rdrand opcode and defining _GLIBCXX_X86_RDRAND in config.h if supported. > Tested on x86_64-apple-darwin12 against the assembler from Xcode 4.4.1. > Okay for gcc trunk? Paolo requested in the PR that instead we define a new AC_DEFUN([GLIBCXX_CHECK_X86_RDRAND], [ ... ]) (or similar) in libstdc++-v3/acinclude.m4 and add just GLIBCXX_CHECK_X86_RDRAND (or similar) line to libstdc++-v3/configure.ac. Jakub
On Thu, Sep 06, 2012 at 03:22:10PM -0400, Jack Howarth wrote: > The attached patch eliminates the bootstrap failures in libstdc++-v3 > of PR 54419 by having configure check for assembler support of the new > rdrand opcode and defining _GLIBCXX_X86_RDRAND in config.h if supported. > Tested on x86_64-apple-darwin12 against the assembler from Xcode 4.4.1. > Okay for gcc trunk? Paolo requested in the PR that instead we define a new AC_DEFUN([GLIBCXX_CHECK_X86_RDRAND], [ ... ]) (or similar) in libstdc++-v3/acinclude.m4 and add just GLIBCXX_CHECK_X86_RDRAND (or similar) line to libstdc++-v3/configure.ac. Jakub
Index: libstdc++-v3/src/c++11/random.cc =================================================================== --- libstdc++-v3/src/c++11/random.cc (revision 191031) +++ libstdc++-v3/src/c++11/random.cc (working copy) @@ -50,7 +50,7 @@ namespace std _GLIBCXX_VISIBILITY(defaul return __ret; } -#if defined __i386__ || defined __x86_64__ +#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND unsigned int __attribute__ ((target("rdrnd"))) __x86_rdrand(void) @@ -75,7 +75,7 @@ namespace std _GLIBCXX_VISIBILITY(defaul if (token == "default") { -#if defined __i386__ || defined __x86_64__ +#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND unsigned int eax, ebx, ecx, edx; // Check availability of cpuid and, for now at least, also the // CPU signature for Intel's @@ -118,7 +118,7 @@ namespace std _GLIBCXX_VISIBILITY(defaul random_device::result_type random_device::_M_getval() { -#if (defined __i386__ || defined __x86_64__) +#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND if (! _M_file) return __x86_rdrand(); #endif Index: libstdc++-v3/configure.ac =================================================================== --- libstdc++-v3/configure.ac (revision 191031) +++ libstdc++-v3/configure.ac (working copy) @@ -330,6 +330,18 @@ case "$target" in esac GLIBCXX_CONDITIONAL(GLIBCXX_LDBL_COMPAT, test $ac_ldbl_compat = yes) +ac_cv_x86_rdrand=no +case "$target" in + i?86-*-* | \ + x86_64-*-*) + AC_TRY_COMPILE(, [asm("rdrand %eax");], + [ac_cv_x86_rdrand=yes], [ac_cv_x86_rdrand=no]) +esac +if test $ac_cv_x86_rdrand = yes; then + AC_DEFINE(_GLIBCXX_X86_RDRAND, 1, + [ Defined if as can handle rdrand. ]) +fi + # This depends on GLIBCXX_ENABLE_SYMVERS and GLIBCXX_IS_NATIVE. GLIBCXX_CONFIGURE_TESTSUITE