[Bug target/56843] PowerPC Newton-Raphson reciprocal estimates can be improved

[wschmidt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56843

--- Comment #6 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Author: wschmidt
Date: Fri Apr  4 14:29:23 2014
New Revision: 209104

URL: http://gcc.gnu.org/viewcvs?rev=209104&root=gcc&view=rev
Log:
[gcc]

2014-04-04  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

    Backport from mainline
    2013-04-05  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

    PR target/56843
    * config/rs6000/rs6000.c (rs6000_emit_swdiv_high_precision): Remove.
    (rs6000_emit_swdiv_low_precision): Remove.
    (rs6000_emit_swdiv): Rewrite to handle between one and four
    iterations of Newton-Raphson generally; modify required number of
    iterations for some cases.
    * config/rs6000/rs6000.h (RS6000_RECIP_HIGH_PRECISION_P): Remove.

[gcc/testsuite]

2014-04-04  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

    Backport from mainline
    2013-04-05  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

    PR target/56843
    * gcc.target/powerpc/recip-1.c: Modify expected output.
    * gcc.target/powerpc/recip-3.c: Likewise.
    * gcc.target/powerpc/recip-4.c: Likewise.
    * gcc.target/powerpc/recip-5.c: Add expected output for iterations.


Modified:
    branches/gcc-4_8-branch/gcc/ChangeLog
    branches/gcc-4_8-branch/gcc/config/rs6000/rs6000.c
    branches/gcc-4_8-branch/gcc/config/rs6000/rs6000.h
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_8-branch/gcc/testsuite/gcc.target/powerpc/recip-1.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.target/powerpc/recip-3.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.target/powerpc/recip-4.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.target/powerpc/recip-5.c