[Bug tree-optimization/85466] Performance is slow when doing 'branchless' conditional style math operations

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85466

--- Comment #23 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Fri May  4 07:19:45 2018
New Revision: 259921

URL: https://gcc.gnu.org/viewcvs?rev=259921&root=gcc&view=rev
Log:
        PR libstdc++/85466
        * real.h (real_nextafter): Declare.
        * real.c (real_nextafter): New function.
        * fold-const-call.c (fold_const_nextafter): New function.
        (fold_const_call_sss): Call it for CASE_CFN_NEXTAFTER and
        CASE_CFN_NEXTTOWARD.
        (fold_const_call_1): For CASE_CFN_NEXTTOWARD call fold_const_call_sss
        even when arg1_mode is different from arg0_mode.

        * gcc.dg/nextafter-1.c: New test.
        * gcc.dg/nextafter-2.c: New test.
        * gcc.dg/nextafter-3.c: New test.
        * gcc.dg/nextafter-4.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/nextafter-1.c
    trunk/gcc/testsuite/gcc.dg/nextafter-2.c
    trunk/gcc/testsuite/gcc.dg/nextafter-3.c
    trunk/gcc/testsuite/gcc.dg/nextafter-4.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const-call.c
    trunk/gcc/real.c
    trunk/gcc/real.h
    trunk/gcc/testsuite/ChangeLog