[Bug c/82413] [8 Regression] -O0 crash (ICE in decompose, at tree.h:5179)

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82413

--- Comment #5 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Author: rsandifo
Date: Wed Oct  4 10:50:19 2017
New Revision: 253401

URL: https://gcc.gnu.org/viewcvs?rev=253401&root=gcc&view=rev
Log:
PR82413: Mismatched precisions in build_range_check

build_range_check explicitly allows LOW and HIGH to be a different type
from EXP, so we need to use w::to_widest when comparing a value based on
HIGH with a value based on EXP's type.

2017-10-04  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
        PR tree-optimization/82413
        * fold-const.c (build_range_check): Use widest_int when comparing
        the maximum ETYPE value with HIGH.

gcc/testsuite/
        PR tree-optimization/82413
        * g++.dg/pr82413.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/pr82413.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/testsuite/ChangeLog