diff options
| author | Paul Davis <paul@linuxaudiosystems.com> | 2009-12-31 17:51:27 +0000 |
|---|---|---|
| committer | Paul Davis <paul@linuxaudiosystems.com> | 2009-12-31 17:51:27 +0000 |
| commit | 53b0b4d114b82434e99e88cd7147014c29368d02 (patch) | |
| tree | 6dc0fab170b3fb91f6297e590f5f8ffa6247bcab /libs/pbd/fpu.cc | |
| parent | 019100470ab662d2390ad3d10bedf7088fc87e94 (diff) | |
add some asm notes, some more registers back to the clobber list, and memset the fxsave area in FPU::FPU()
git-svn-id: svn://localhost/ardour2/branches/3.0@6420 d708f5d6-7413-0410-9779-e7cbd77b26cf
Diffstat (limited to 'libs/pbd/fpu.cc')
| -rw-r--r-- | libs/pbd/fpu.cc | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/libs/pbd/fpu.cc b/libs/pbd/fpu.cc index 0eab7a93cb..12400221cc 100644 --- a/libs/pbd/fpu.cc +++ b/libs/pbd/fpu.cc @@ -1,4 +1,5 @@ #define _XOPEN_SOURCE 600 +#include <cstring> // for memset #include <cstdlib> #include <stdint.h> @@ -19,6 +20,12 @@ FPU::FPU () #ifndef ARCH_X86 return; #endif + + /* asm notes: although we explicitly save&restore ebx/rbx (stack pointer), we must tell + gcc that ebx,rbx is clobbered so that it doesn't try to use it as an intermediate + register when storing edx/rdx. gcc 4.3 didn't make this "mistake", but gcc 4.4 + does, at least on x86_64. + */ #ifndef USE_X86_64_ASM asm volatile ( @@ -29,7 +36,7 @@ FPU::FPU () "popl %%ebx\n" : "=r" (cpuflags) : - : "%eax", "%ebx", "%edx" + : "%eax", "%ebx", "%ecx", "%edx" ); #else @@ -42,11 +49,11 @@ FPU::FPU () "popq %%rbx\n" : "=r" (cpuflags) : - : "%rax", "%rbx", "%rdx" + : "%rax", "%rbx", "%rcx", "%rdx" ); #endif /* USE_X86_64_ASM */ - + if (cpuflags & (1<<25)) { _flags = Flags (_flags | (HasSSE|HasFlushToZero)); } @@ -68,6 +75,8 @@ FPU::FPU () error << _("cannot allocate 16 byte aligned buffer for h/w feature detection") << endmsg; } else { + memset (fxbuf, 0, 512); + asm volatile ( "fxsave (%0)" : |