[PATCH][4.3] Deprecate -ftrapv
Ken Raeburn
raeburn@raeburn.org
Wed Mar 5 22:46:00 GMT 2008
On Feb 29, 2008, at 19:13, Richard Guenther wrote:
> We wrap the libcalls inside libcall notes using REG_EQUAL notes
> which indicate the libcalls compute non-trapping +-* (there's no
> RTX code for the trappingness), so we combine and simplify the
> operations making the libcall possibly dead and remove it again.
My patch from September (http://gcc.gnu.org/ml/gcc-patches/2007-09/
msg01351.html) should help with the libcall issue a bit, by making
the trapping libcalls not be considered dead, even if optimizations
make the results not get used. (Was I supposed to re-submit the
patch in non-unidiff format? I've had a couple of machine die on me
recently, I might have to reconstruct the source tree.) Of course,
if the trapping math is optimized away before you get to emitting
libcalls, that's a different bug.
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