[Bug optimization/15348] New: [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[Bug optimization/15348] New: [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[kazu at cs dot umass dot edu]

Convert foo() into baz().

void bar (void);

int
foo (int x, int y)
{
  int t1 = x < 0;
  int t2 = y < 0;
  return t1 || t2;
}

int
baz (int x, int y)
{
  return (x | y) < 0;
}

Needless to mention, we should do this fairly late in SSA optimizations.

-- 
           Summary: [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Keywords: pessimizes-code
          Severity: enhancement
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

[Bug optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[kazu at cs dot umass dot edu]

------- Additional Comments From kazu at cs dot umass dot edu  2004-05-09 19:32 -------
Another one just like above:

void bar (void);

void
foo (int a, int b)
{
  if (a != 0)
    return;
  if (b != 0)
    return;
  bar ();
}

void
baz (int a, int b)
{
  if ((a | b) == 0)
    bar ();
}

See also PR 15241.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

[Bug optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-09 19:41 -------
Confirmed.  

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-05-09 19:41:56
               date|                            |
   Target Milestone|---                         |tree-ssa


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

[Bug optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |15357


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

[Bug tree-optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

[Bug tree-optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

Jeffrey A. Law <law at redhat dot com> changed:

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

--- Comment #5 from Jeffrey A. Law <law at redhat dot com> ---
Resolved at some point in the past.  Not worth the trouble to bisect.

[Bug tree-optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[dimhen at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

Dmitry G. Dyachenko <dimhen at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dimhen at gmail dot com

--- Comment #4 from Dmitry G. Dyachenko <dimhen at gmail dot com> ---
x86_64 r10-7080 for me produce identical code
-- c#0 with -O2
-- c#1 with -O

[Bug tree-optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348
Bug 15348 depends on bug 15459, which changed state.

Bug 15459 Summary: [meta-bug] there should be a tree combiner like the rtl one
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=15459

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

[Bug tree-optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348

Bug 15348 depends on bug 15357, which changed state.

Bug 15357 Summary: [tree-ssa] combing if statements
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15357

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

[Bug tree-optimization/15348] [tree-ssa] Convert (x < 0) || (y < 0) into (x | y) < 0.

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-09-30 22:29 -------
For AMD64, the functions from the first test case don't produce the 
same code either, so combine is not catching this either. 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15348