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* [Bug middle-end/35288] Expression reassociation problem
       [not found] <bug-35288-4@http.gcc.gnu.org/bugzilla/>
@ 2010-11-02 23:40 ` xinliangli at gmail dot com
  2021-12-23  8:14 ` [Bug tree-optimization/35288] " pinskia at gcc dot gnu.org
  1 sibling, 0 replies; 3+ messages in thread
From: xinliangli at gmail dot com @ 2010-11-02 23:40 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35288

--- Comment #2 from davidxl <xinliangli at gmail dot com> 2010-11-02 23:40:15 UTC ---
LLVM got it right:


    addl    %esi, %edi
    leal    (%rdx,%rdi,2), %eax

vs gcc:


    addl    %esi, %edx
    leal    (%rsi,%rdi,2), %edi
    leal    (%rdi,%rdx), %eax

vs open64:


    leal 0(%rdi,%rsi,1), %eax         # [0] 
    addl %esi,%edx                    # [0] 
    addl %edx,%edi                    # [1] 
    addl %edi,%eax                    # [2] 

David


^ permalink raw reply	[flat|nested] 3+ messages in thread
* [Bug tree-optimization/35288] Expression reassociation problem
       [not found] <bug-35288-4@http.gcc.gnu.org/bugzilla/>
  2010-11-02 23:40 ` [Bug middle-end/35288] Expression reassociation problem xinliangli at gmail dot com
@ 2021-12-23  8:14 ` pinskia at gcc dot gnu.org
  1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-12-23  8:14 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=35288

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
          Component|middle-end                  |tree-optimization
           Keywords|                            |missed-optimization

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
If we use -fwrapv, then GCC is able to get it. THere might be a dup of this bug
already too.

^ permalink raw reply	[flat|nested] 3+ messages in thread
* [Bug middle-end/35288] Expression reassociation problem
  2008-02-22  6:36 [Bug middle-end/35288] New: " xinliangli at gmail dot com
@ 2008-02-22 10:56 ` rguenth at gcc dot gnu dot org
  0 siblings, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2008-02-22 10:56 UTC (permalink / raw)
  To: gcc-bugs



------- Comment #1 from rguenth at gcc dot gnu dot org  2008-02-22 10:55 -------
Confirmed.  Re-association generates

  D.1548_3 = a1_4(D) + a1_4(D);
  b1_5 = D.1548_3 + a2_2(D);
  b2_6 = b1_5 + a2_2(D);
  D.1549_7 = b2_6 + a3_1(D);

but that does not expose SSA_NAMEs with the same value.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-02-22 10:55:53
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35288


^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-12-23  8:14 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <bug-35288-4@http.gcc.gnu.org/bugzilla/>
2010-11-02 23:40 ` [Bug middle-end/35288] Expression reassociation problem xinliangli at gmail dot com
2021-12-23  8:14 ` [Bug tree-optimization/35288] " pinskia at gcc dot gnu.org
2008-02-22  6:36 [Bug middle-end/35288] New: " xinliangli at gmail dot com
2008-02-22 10:56 ` [Bug middle-end/35288] " rguenth at gcc dot gnu dot org

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