[Bug rtl-optimization/85925] [7/8/9 regression] compilation of masking with 257 goes wrong in combine at -02

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85925

--- Comment #22 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Author: ebotcazou
Date: Tue Nov 20 09:04:12 2018
New Revision: 266304

URL: https://gcc.gnu.org/viewcvs?rev=266304&root=gcc&view=rev
Log:
2018-11-20  Eric Botcazou  <ebotcazou@adacore.com>

        PR rtl-optimization/85925
        * rtl.h (word_register_operation_p): New predicate.
        * combine.c (record_dead_and_set_regs_1): Only apply specific handling
        for WORD_REGISTER_OPERATIONS targets to word_register_operation_p RTX.
        * rtlanal.c (nonzero_bits1): Likewise.  Adjust couple of comments.
        (num_sign_bit_copies1): Likewise.

Added:
    branches/gcc-7-branch/gcc/testsuite/gcc.c-torture/execute/20181120-1.c
      - copied unchanged from r266302,
trunk/gcc/testsuite/gcc.c-torture/execute/20181120-1.c
Modified:
    branches/gcc-7-branch/gcc/ChangeLog
    branches/gcc-7-branch/gcc/combine.c
    branches/gcc-7-branch/gcc/rtl.h
    branches/gcc-7-branch/gcc/rtlanal.c
    branches/gcc-7-branch/gcc/testsuite/ChangeLog