[Bug target/84899] [6 Regression] ICE: in final_scan_insn_1, at final.c:3139 (error: could not split insn)

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84899

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Mon Jun 25 17:34:55 2018
New Revision: 262079

URL: https://gcc.gnu.org/viewcvs?rev=262079&root=gcc&view=rev
Log:
        Backported from mainline
        2018-03-16  Jakub Jelinek  <jakub@redhat.com>

        PR target/84899
        * postreload.c (reload_combine_recognize_pattern): Perform
        INTVAL addition in unsigned HOST_WIDE_INT type to avoid UB and
        truncate_int_for_mode the result for the destination's mode.

        * gcc.dg/pr84899.c: New test.

Added:
    branches/gcc-6-branch/gcc/testsuite/gcc.dg/pr84899.c
Modified:
    branches/gcc-6-branch/gcc/ChangeLog
    branches/gcc-6-branch/gcc/postreload.c
    branches/gcc-6-branch/gcc/testsuite/ChangeLog