[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[wschmidt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44214

William J. Schmidt <wschmidt at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bergner at vnet dot
                   |                            |ibm.com, wschmidt at gcc
                   |                            |dot gnu.org
         AssignedTo|unassigned at gcc dot       |wschmidt at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #4 from William J. Schmidt <wschmidt at gcc dot gnu.org> 2012-04-19 15:20:21 UTC ---
I'll take this one.

[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[wschmidt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44214

William J. Schmidt <wschmidt at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.0

[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[wschmidt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44214

--- Comment #5 from William J. Schmidt <wschmidt at gcc dot gnu.org> 2012-04-20 14:19:23 UTC ---
Author: wschmidt
Date: Fri Apr 20 14:19:13 2012
New Revision: 186625

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=186625
Log:
gcc:

2012-04-20  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

    PR rtl-optimization/44214
    * fold-const.c (exact_inverse): New function.
    (fold_binary_loc): Fold vector and complex division by constant into
    multiply by recripocal with flag_reciprocal_math; fold vector division
    by constant into multiply by reciprocal with exact inverse.

gcc/testsuite:

2012-04-20  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

    PR rtl-optimization/44214
    * gcc.dg/pr44214-1.c: New test.
    * gcc.dg/pr44214-2.c: Likewise.
    * gcc.dg/pr44214-3.c: Likewise.



Added:
    trunk/gcc/testsuite/gcc.dg/pr44214-1.c
    trunk/gcc/testsuite/gcc.dg/pr44214-2.c
    trunk/gcc/testsuite/gcc.dg/pr44214-3.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/testsuite/ChangeLog

[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[wschmidt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44214

William J. Schmidt <wschmidt at gcc dot gnu.org> changed:

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

--- Comment #6 from William J. Schmidt <wschmidt at gcc dot gnu.org> 2012-04-20 14:21:09 UTC ---
Fixed.

[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2010-05-21 09:47 -------
The fold code should probably simply use fold_binary to do the constant
folding (which already should handle 1/x for x vector and complex.  There
is a build_one_cst to build the constant 1 for any type).  The exact
result check would need to use mpc (and I'm not sure its correct for
-frounding-math anyway).


-- 

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         |2010-05-21 09:47:56
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44214

[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[meissner at gcc dot gnu dot org]

------- Comment #2 from meissner at gcc dot gnu dot org  2010-05-20 18:02 -------
Created an attachment (id=20712)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20712&action=view)
Example program that shows the issue on powerpc.

Compile with -mcpu=power7 on powerpc.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44214

[Bug rtl-optimization/44214] Compiler does not optimize vector divide with -freciprocal-math (or -ffast-math)

[meissner at gcc dot gnu dot org]

------- Comment #1 from meissner at gcc dot gnu dot org  2010-05-20 18:00 -------
Actually in looking at it further, I was wrong in the initial claim.  Auto
vectorization now handles division by a constant.  Explicit vectors like
PowerPC (and probably SPU) do show the problem.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44214