[Bug tree-optimization/71026] Missing division optimizations

[wilco at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71026

--- Comment #8 from Wilco <wilco at gcc dot gnu.org> ---
Author: wilco
Date: Tue Nov  7 12:38:55 2017
New Revision: 254497

URL: https://gcc.gnu.org/viewcvs?rev=254497&root=gcc&view=rev
Log:
PR71026: Canonicalize negates in division

Canonicalize x / (- y) into (-x) / y.

This moves negates out of the RHS of a division in order to
allow further simplifications and potentially more reciprocal CSEs.

2017-11-07  Wilco Dijkstra  <wdijkstr@arm.com>
            Jackson Woodruff  <jackson.woodruff@arm.com>

    gcc/
        PR tree-optimization/71026
        * match.pd: Canonicalize negate in division.

    testsuite/
        PR 71026/tree-optimization/71026
        * gcc.dg/div_neg: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/div_neg.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/match.pd
    trunk/gcc/testsuite/ChangeLog