This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: soft-fp: Adjust call to abort for kernel use [committed]

On Fri, 20 Feb 2015, Rich Felker wrote:

> Could these be replaced by __builtin_trap() or similar? I'm not clear
> on whether this code is purely glibc+kernel or also used by gcc, but
> if it's used by gcc too it would be very much preferable not to have
> libgcc pulling in a reference to abort (this affects -ffreestanding,
> etc.).

This code is used by libgcc as well.  The particular case in this patch is 
one that could become a call to a nonexistent __softfp_link_failure or 
similar.  The ones that may sometimes end up as abort calls could be 
__builtin_unreachable.  There is never a need for an actual abort.

(Actually the aborts from _FP_CLS_COMBINE switches seem to get optimized 
out by current GCC anyway - I don't see them in the TFmode functions in 
libgcc from a recent x86_64 build, for example; looking at some old 
powerpc libraries I have to hand, I see them from GCC 4.3 but not 4.4.  
The ones in those switches are the only ones needing more than simple 
constant folding to optimize away.)

Joseph S. Myers

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]