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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/110755] [13/14 Regression] Wrong optimization of fabs on ppc64el at -O1 Date: Mon, 24 Jul 2023 07:12:12 +0000 [thread overview] Message-ID: <bug-110755-4-cdXXtvtp4f@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-110755-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110755 --- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Actually looking at IEEE754, the fix should be limited to +- operations, not +-*/. Because only for +- IEEE754 has: "When the sum of two operands with opposite signs (or the difference of two operands with like signs) is exactly zero, the sign of that sum (or difference) shall be +0 in all rounding direction modes except roundTowardNegative; in that mode, the sign of an exact zero sum (or difference) shall be –0. However, x+x = x–(–x) retains the same sign as x even when x is zero."
next prev parent reply other threads:[~2023-07-24 7:12 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-07-20 20:18 [Bug target/110755] New: " aurelien at aurel32 dot net 2023-07-20 20:25 ` [Bug target/110755] " pinskia at gcc dot gnu.org 2023-07-20 20:28 ` aurelien at aurel32 dot net 2023-07-20 20:31 ` [Bug tree-optimization/110755] [13/14 Regression] " pinskia at gcc dot gnu.org 2023-07-21 6:56 ` rguenth at gcc dot gnu.org 2023-07-21 8:11 ` jakub at gcc dot gnu.org 2023-07-21 8:38 ` jakub at gcc dot gnu.org 2023-07-22 20:20 ` aurelien at aurel32 dot net 2023-07-24 7:12 ` jakub at gcc dot gnu.org [this message] 2023-07-24 7:47 ` jakub at gcc dot gnu.org 2023-07-24 18:31 ` aurelien at aurel32 dot net 2023-07-26 8:52 ` cvs-commit at gcc dot gnu.org 2023-07-26 10:00 ` [Bug tree-optimization/110755] [13 " jakub at gcc dot gnu.org 2023-07-27 9:27 ` rguenth at gcc dot gnu.org 2023-07-27 17:53 ` cvs-commit at gcc dot gnu.org 2023-08-30 22:21 ` jakub at gcc dot gnu.org 2023-11-06 2:38 ` hp at gcc dot gnu.org
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