[Bug rtl-optimization/75964] insn combiner removes comparison after ABS

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=75964

--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Author: rsandifo
Date: Sat May  6 07:44:13 2017
New Revision: 247719

URL: https://gcc.gnu.org/viewcvs?rev=247719&root=gcc&view=rev
Log:
PR 75964: Invalid integer ABS handling in simplify-rtx.c

RTL has no distinction between signed and unsigned values, so it
doesn't make sense to test for signed overflow.

2017-05-06  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
        PR rtl-optimization/75964
        * simplify-rtx.c (simplify_const_relational_operation): Remove
        invalid handling of comparisons of integer ABS.

gcc/testsuite/
        PR rtl-optimization/75964
        * gcc.dg/torture/pr75964.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr75964.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/simplify-rtx.c
    trunk/gcc/testsuite/ChangeLog