------- Comment #5 from rguenth at gcc dot gnu dot org 2008-03-05 10:27 -------
With -O we even have
movl $0, %edx
movl a, %ecx
imull %edx, %ecx
I wonder why we do not constant-propagate / simplify here?
Note that with 4.2 and 4.1 mul16 is also bad. Setting milestone to 4.3.1,
only mul32 is a regression.
Steven, shouldn't rtl const-prop catch this?
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |stevenb dot gcc at gmail dot
| |com
GCC build triplet|i386-apple-darwin9.2.0 |
GCC host triplet|i386-apple-darwin9.2.0 |
GCC target triplet|i386-apple-darwin9.2.0 |i?86-*-*
Keywords| |missed-optimization
Priority|P3 |P2
Summary|[4.3 regression] multiply |[4.3/4.4 Regression]
|with 0 generated for 64*32- |multiply with 0 generated
|>64 |for 64*32->64
Target Milestone|4.3.0 |4.3.1
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35281
