From: Richard Biener <rguenther@suse.de>
Date: Mon, 25 Apr 2022 08:55:21 +0000 (+0200)
Subject: tree-optimization/105368 - avoid overflow in powi_cost
X-Git-Tag: upstream/12.2.0~455
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f0e170f72f8bfaa2a64e1d09ebdfd48f917420f1;p=platform%2Fupstream%2Fgcc.git

tree-optimization/105368 - avoid overflow in powi_cost

The following avoids undefined signed overflow when computing
the absolute of the exponent in powi_cost.

2022-04-25  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/105368
	* tree-ssa-math-opts.cc (powi_cost): Use absu_hwi.
---

diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
index 102b7a2..7555793 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -1462,7 +1462,7 @@ powi_cost (HOST_WIDE_INT n)
     return 0;
 
   /* Ignore the reciprocal when calculating the cost.  */
-  val = (n < 0) ? -n : n;
+  val = absu_hwi (n);
 
   /* Initialize the exponent cache.  */
   memset (cache, 0, POWI_TABLE_SIZE * sizeof (bool));