[arch-dev-public] [arch-general] [signoff] gcc-4.5 toolchain rebuild

Allan McRae allan at archlinux.org
Sat Apr 17 00:30:25 CEST 2010


On 17/04/10 00:03, Emmanuel Benisty wrote:
> Just out of curiosity, what is the plan regarding this issue (quoted
> from the gcc changelog):
>
> On x86 targets, code containing floating-point calculations may run
> significantly slower when compiled with GCC 4.5 in strict C99
> conformance mode than they did with earlier GCC versions. This is due
> to stricter standard conformance of the compiler and can be avoided by
> using the option -fexcess-precision=fast;
>

 From what I understand, this requires passing -std=c99 (or equivalent) 
to the compiler for it to use strict C99 mode.  So most software will 
not be affected.  Of course, the maintainer of any software the does set 
C99 mode should consider this.

Allan


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