[Bug middle-end/33349] Redundant zero-extension of registers

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33349

Jeffrey A. Law  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 CC||law at redhat dot com
 Resolution|--- |FIXED

--- Comment #3 from Jeffrey A. Law  ---
Fixed on the trunk.  Not sure when and given the age of the BZ I didn't bisect
to find out.

[Bug middle-end/33349] Redundant zero-extension of registers

[gcc.hall at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33349

Jeremy  changed:

   What|Removed |Added

 CC||gcc.hall at gmail dot com

--- Comment #2 from Jeremy  2011-06-16 11:27:24 UTC 
---

Another example I came across ...

  unsigned short sw;
  asm( "fnstsw %0" : "=a" (sw) );

  if( sw & FE_DIVBYZERO )
...   
  if( sw & FE_OVERFLOW )
...  
  if( sw & FE_UNDERFLOW )
...

generates:

movzx   eax, ax # D.14460, sw

testal, 1   # D.14460,

testal, 4   # D.14460,

testal, 8   # D.14460,

[Bug middle-end/33349] Redundant zero-extension of registers

[steven at gcc dot gnu dot org]

--- Comment #1 from steven at gcc dot gnu dot org  2009-02-06 21:45 ---
This would be fixed if someone would fix the Sign Extension Elimination pass
(yes, it also handles zero extensions).  But that pass is probably broken
beyond repair at this point, and likely needs a rewrite instead of just a fix.


-- 

steven at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
 Ever Confirmed|0   |1
   Last reconfirmed|-00-00 00:00:00 |2009-02-06 21:45:16
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33349