------- Comment #2 from pinskia at gcc dot gnu dot org 2008-11-23 18:55 -------
This happens on i386-darwin also (-m64 -O2 -fomit-frame-pointer):
movl %edi, %edx
testb %dil, %dil
movl $-1, %eax
notl %edx
cmovne %edx, %eax
Using the following source:
unsigned char negate(unsigned char val)
{
if (val)
val = ~val;
else
val = ~val;
return val;
}
We should be able to just do ~val but this comes down to hoisting before
applying VRP/DOM.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
GCC build triplet|i386-linux-gnu |
GCC host triplet|i386-linux-gnu |
GCC target triplet|avr-*-* |
Last reconfirmed|0000-00-00 00:00:00 |2008-11-23 18:55:59
date| |
Summary|[avr] branch optimisation |branch optimisation
|generates worse code |generates worse code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38209
