On 2012-02-16 14:51:26 +0000, Andrew Haley wrote: > Ah, I see. So, we could bring gcc+glibc into compliance by not > defining the rounding mode macros.
Yes, but... Directed rounding modes can also be used with the arithmetic operations only, on which there are no problems at the implementation level (well, there's still bug 34678: Optimization generates incorrect code with -frounding-math option (#pragma STDC FENV_ACCESS not implemented)). They could be defined only by some option, and this could be related to -frounding-math. In particular, the fact that directed rounding modes are affected by optimization bugs may be another reason not to define these macros by default. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <http://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
