[Bug tree-optimization/71631] [7 Regression] Wrong constant folding

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71631

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Sat Jun 25 17:20:15 2016
New Revision: 237782

URL: https://gcc.gnu.org/viewcvs?rev=237782&root=gcc&view=rev
Log:
        PR tree-optimization/71631
        * tree-ssa-reassoc.c (reassociate_bb): Pass true as last argument
        to rewrite_expr_tree even if negate_result, move new_lhs var
        declaration and initialization earlier, for powi_result set afterwards
        new_lhs to lhs.  For negate_result, use new_lhs instead of tmp
        if new_lhs != lhs, and don't shadow gsi var.

        * gcc.c-torture/execute/pr71631.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr71631.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-reassoc.c