[Bug c/55299] missed optimization: ASR idiom

2012-11-13 Thread hjl.tools at gmail dot com 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55299



H.J. Lu hjl.tools at gmail dot com changed:



   What|Removed |Added



 Status|UNCONFIRMED |NEW

   Last reconfirmed||2012-11-13

 CC||areg.melikadamyan at gmail

   ||dot com, hjl.tools at gmail

   ||dot com

 Ever Confirmed|0   |1



--- Comment #1 from H.J. Lu hjl.tools at gmail dot com 2012-11-13 14:58:03 
UTC ---

clang generates:



movb%sil, %cl

sarl%cl, %edi

movl%edi, %eax

ret

[Bug c/55299] missed optimization: ASR idiom

2012-11-13 Thread olly at survex dot com 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55299



--- Comment #2 from olly at survex dot com 2012-11-13 20:40:06 UTC ---

Interestingly clang (at least 3.0-6 from Debian testing) fails to optimise the

same testcase but shifting by a constant.  For that variant case clang

generates essentially the same code as GCC currently does.