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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/114902] [14/15 Regression] wrong code at -O3 with "-fno-tree-vrp -fno-expensive-optimizations -fno-tree-dominator-opts" on x86_64-linux-gnu Date: Wed, 01 May 2024 02:06:36 +0000 [thread overview] Message-ID: <bug-114902-4-8To5RdilCJ@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-114902-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114902 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |14.0 Summary|wrong code at -O3 with |[14/15 Regression] wrong |"-fno-tree-vrp |code at -O3 with |-fno-expensive-optimization |"-fno-tree-vrp |s -fno-tree-dominator-opts" |-fno-expensive-optimization |on x86_64-linux-gnu |s -fno-tree-dominator-opts" | |on x86_64-linux-gnu Component|tree-optimization |target Status|UNCONFIRMED |NEW Last reconfirmed| |2024-05-01 Ever confirmed|0 |1 Target| |x86_64-linux-gnu --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. Here is a testcase which does not depedent on division by zero trapping: ``` volatile int a, c; unsigned b = 1; int main() { a = 1; for (; c < 2; c++) { unsigned t = 1 & ~b; int e = -t; int f = -~(!!(1 % a)); if (a == 0) __builtin_trap(); if (e >= -1) e = 1; a = e; } return 0; } ``` The testcase works on aarch64-linux-gnu with no issues. The difference between GCC 13 and 14 is on the gimple level but the code looks correct there. In GCC 13 .optimized has: ``` b.0_1 = b; _2 = b.0_1 & 1; _3 = _2 + 4294967295; e_16 = (int) _3; _13 = e_16 >= -1; e_11 = _13 ? 1 : e_16; ``` While in 14 .optimized has: ``` b.0_1 = b; _2 = ~b.0_1; t_13 = _2 & 1; _3 = -t_13; e_14 = (int) _3; _10 = e_14 >= -1; e_9 = _10 ? 1 : e_14; ``` Both are valid and correct. But then it goes wrong after that. I have not looked where though.
next prev parent reply other threads:[~2024-05-01 2:06 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-04-30 22:13 [Bug tree-optimization/114902] New: " zhendong.su at inf dot ethz.ch 2024-05-01 2:06 ` pinskia at gcc dot gnu.org [this message] 2024-05-01 2:22 ` [Bug rtl-optimization/114902] [14/15 Regression] " pinskia at gcc dot gnu.org 2024-05-01 2:34 ` pinskia at gcc dot gnu.org 2024-05-01 5:12 ` pinskia at gcc dot gnu.org 2024-05-01 5:29 ` pinskia at gcc dot gnu.org 2024-05-03 8:14 ` segher at gcc dot gnu.org 2024-05-03 8:38 ` pinskia at gcc dot gnu.org 2024-05-07 7:45 ` rguenth at gcc dot gnu.org 2024-05-09 9:48 ` segher at gcc dot gnu.org 2024-05-09 9:49 ` segher at gcc dot gnu.org 2024-05-14 20:09 ` segher at gcc dot gnu.org 2024-05-14 22:04 ` pinskia at gcc dot gnu.org 2024-05-15 16:44 ` cvs-commit at gcc dot gnu.org 2024-05-15 16:54 ` [Bug rtl-optimization/114902] [14 " jakub at gcc dot gnu.org 2024-06-04 14:26 ` cvs-commit at gcc dot gnu.org 2024-06-04 14:28 ` jakub at gcc dot gnu.org 2024-06-11 6:17 ` cvs-commit at gcc dot gnu.org 2024-06-11 10:38 ` cvs-commit at gcc dot gnu.org 2024-06-20 13:23 ` cvs-commit at gcc dot gnu.org
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