target/8871: Inefficient zero_extendsidi2 for MMX

[bangerth@dealii.org]

Synopsis: Inefficient zero_extendsidi2 for MMX

Responsible-Changed-From-To: unassigned->hubicka
Responsible-Changed-By: bangerth
Responsible-Changed-When: Fri Dec 20 21:04:29 2002
Responsible-Changed-Why:
    Jan, you are probably best acquainted with the MMX patterns

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8871