[Bug rtl-optimization/55583] Extended shift instruction on x86-64 is not used, producing unoptimal code

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55583



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



           What    |Removed                     |Added

----------------------------------------------------------------------------

             Status|UNCONFIRMED                 |NEW

   Last reconfirmed|                            |2012-12-04

                 CC|                            |areg.melikadamyan at gmail

                   |                            |dot com, hjl.tools at gmail

                   |                            |dot com, ubizjak at gmail

                   |                            |dot com

     Ever Confirmed|0                           |1



--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2012-12-04 00:21:02 
UTC ---

Clang generates:



    movl    a(%rip), %eax

    shldl    $2, %eax, b(%rip)

    ret



at -O2.