http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53190
--- Comment #6 from rguenther at suse dot de <rguenther at suse dot de> 2012-05-03 08:19:17 UTC --- On Thu, 3 May 2012, ubizjak at gmail dot com wrote: > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53190 > > --- Comment #5 from Uros Bizjak <ubizjak at gmail dot com> 2012-05-03 > 08:15:00 UTC --- > (In reply to comment #4) > > > So you say that it's correct for CSE to CSE asm()s if they have the same > > asm string and the same asm operands in case the asm is not volatile? I was > > not aware we would do that ;) (but yes, it sounds like a reasonable thing) > > There is nothing that prevents gcc from doing this... > > BTW: fpsr is FP *status* register, an x87 CC-like internal register. This asm > should probably depend on fpcr, a FP *control* register. > > In fact, there are two FP control registers, x87 and SSE one. The later is not > handled at all. Well, the asm in glibc is simply extern __inline __attribute__ ((__always_inline__)) long int __attribute__ ((__nothrow__ )) lrintf (float __x) { long int __res; __asm ("cvtss2si %1, %0" : "=r" (__res) : "xm" (__x)); return __res; } thus the CLOBBERs somehow magically appear anyways it seems.
