[Bug rtl-optimization/52082] Memory loads not rematerialized

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52082

Andrew Pinski  changed:

   What|Removed |Added

   Severity|normal  |enhancement

--- Comment #3 from Andrew Pinski  ---
One thing I noticed that LLVM does to reduce the register pressure is:
(z ? v4 [k] : v3 [k])

Gets pulled out of the loop such that it is:
tmpaddr = z ? v4 : v3;

and then inside the loop it does:
(tempaddr)[k]

GCC still has (I changed the bb order just so it is easier to see what is going
on):
  if (z_39(D) != 0)
goto ; [50.00%]
  else
goto ; [50.00%]

   [local count: 5427362]:
  _21 = v3.3_18 + _157;
  iftmp.1_40 = *_21;
  goto ; [100.00%]

   [local count: 5427362]:
  _17 = v4.2_14 + _157;
  iftmp.1_41 = *_17;

   [local count: 10854724]:
  # m_8 = PHI 
  if (m_8 != 0B)
goto ; [94.50%]
  else
goto ; [5.50%]

we should able to do the similar it seems and need two less registers; one to
hold z and one to hold either v3 or v4.  This won't be enough for this testcase
but it will be something.

[Bug rtl-optimization/52082] Memory loads not rematerialized

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52082

Eric Gallager  changed:

   What|Removed |Added

 CC||egallager at gcc dot gnu.org

--- Comment #2 from Eric Gallager  ---
(In reply to Jakub Jelinek from comment #0)
> On the following testcase at -O2 (distilled from genautomata.c):

Missed optimizations for genautomata.c should get a higher priority, IMO, given
how slowly the genautomata executable runs...

[Bug rtl-optimization/52082] Memory loads not rematerialized

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52082

Andrew Pinski pinskia at gcc dot gnu.org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
   Last reconfirmed||2012-02-03
  Component|middle-end  |rtl-optimization
 Ever Confirmed|0   |1

--- Comment #1 from Andrew Pinski pinskia at gcc dot gnu.org 2012-02-03 
02:29:47 UTC ---
Confirmed.