From: Xi Ruoyao <xry111@xry111.site>
Date: Sun, 12 Nov 2023 14:16:20 +0000 (+0000)
Subject: Fix (fcopysign x, NEGATIVE_CONST) -> (fneg (fabs x)) simplification [PR112483]
X-Git-Tag: basepoints/gcc-15~4762
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ba7529ee3974667a8e68d089b606ac2fb159415;p=thirdparty%2Fgcc.git

Fix (fcopysign x, NEGATIVE_CONST) -> (fneg (fabs x)) simplification [PR112483]

(fcopysign x, NEGATIVE_CONST) can be simplified to (fneg (fabs x)), but
a logic error in the code caused it mistakenly simplified to (fneg x)
instead.

gcc/ChangeLog:

	PR rtl-optimization/112483
	* simplify-rtx.cc (simplify_binary_operation_1) <case COPYSIGN>:
	Fix the simplification of (fcopysign x, NEGATIVE_CONST).
---

diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index 69d87579d9c8..2d2e5a3c1ca6 100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -4392,7 +4392,7 @@ simplify_ashift:
 	  real_convert (&f1, mode, CONST_DOUBLE_REAL_VALUE (trueop1));
 	  rtx tmp = simplify_gen_unary (ABS, mode, op0, mode);
 	  if (REAL_VALUE_NEGATIVE (f1))
-	    tmp = simplify_gen_unary (NEG, mode, op0, mode);
+	    tmp = simplify_gen_unary (NEG, mode, tmp, mode);
 	  return tmp;
 	}
       if (GET_CODE (op0) == NEG || GET_CODE (op0) == ABS)