From: liuhongt <hongtao.liu@intel.com>
Date: Mon, 8 Nov 2021 01:32:17 +0000 (+0800)
Subject: Add !HONOR_SNANS to simplifcation: (trunc)copysign((extend)a, (extend)b) to copysign... 
X-Git-Tag: basepoints/gcc-13~3328
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a1f7ead09cd41d32e2feffff902eb32e587c36e7;p=thirdparty%2Fgcc.git

Add !HONOR_SNANS to simplifcation: (trunc)copysign((extend)a, (extend)b) to copysign (a, b).

> Note that this is not safe with -fsignaling-nans, so needs to be disabled
> for that option (if there isn't already logic somewhere with that effect),
> because the extend will convert a signaling NaN to quiet (raising
> "invalid"), but copysign won't, so this transformation could result in a
> signaling NaN being wrongly returned when the original code would never
> have returned a signaling NaN.
>
> --
> Joseph S. Myers
> joseph@codesourcery.com

gcc/ChangeLog

	PR target/102464
	* match.pd (Simplifcation (trunc)copysign((extend)a, (extend)b)
	to .COPYSIGN (a, b)): Add !HONOR_SNANS.
---

diff --git a/gcc/match.pd b/gcc/match.pd
index 869b26d16a0c..71cf6f9df0ac 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -6210,6 +6210,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  (simplify
   (convert (copysigns (convert@2 @0) (convert @1)))
    (if (optimize
+       && !HONOR_SNANS (@2)
        && types_match (type, TREE_TYPE (@0))
        && types_match (type, TREE_TYPE (@1))
        && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@2))