r254497 - in /trunk/gcc: ChangeLog match.pd tes...

[wilco@gcc.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