[Bug rtl-optimization/68920] [6 Regression] Undesirable if-conversion for a rarely taken branch

[ienkovich at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68920

--- Comment #7 from Ilya Enkovich <ienkovich at gcc dot gnu.org> ---
Author: ienkovich
Date: Mon Jan 11 12:07:31 2016
New Revision: 232220

URL: https://gcc.gnu.org/viewcvs?rev=232220&root=gcc&view=rev
Log:
gcc/

2016-01-11  Yuri Rumyantsev  <ysrum...@gmail.com>

        PR rtl-optimization/68920
        * config/i386/i386.c (ix86_option_override_internal): Restrict number
        of conditional moves for  RTL if-conversion to 1 for
        TARGET_ONE_IF_CONV_INSN.
        * config/i386/i386.h (TARGET_ONE_IF_CONV_INSN): New macros.
        * config/i386/x86-tune.def (X86_TUNE_ONE_IF_CONV_INSN): New macros.
        * params.def (PARAM_MAX_RTL_IF_CONVERSION_INSNS) : Introduce new
        parameter to restirct number of conditional moves for
        RTL if-conversion.
        * doc/invoke.texi (max-rtl-if-conversion-insns): Document it.
        * ifcvt.c (bb_ok_for_noce_convert_multiple_sets): Limit number of
        conditionl moves.

gcc/testsuite/

2016-01-11  Yuri Rumyantsev  <ysrum...@gmail.com>

        PR rtl-optimization/68920
        * gcc.dg/ifcvt-4.c: Add "--param max-rtl-if-conversion-insns=3" option
        for ix86 targets.
        * gcc.dg/ifcvt-5.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/ifcvt-5.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/config/i386/i386.h
    trunk/gcc/config/i386/x86-tune.def
    trunk/gcc/doc/invoke.texi
    trunk/gcc/ifcvt.c
    trunk/gcc/params.def
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/ifcvt-4.c