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From: "theodort at inf dot ethz.ch" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/110503] New: [13/14 Regression] Dead Code Elimination Regression at -O3 since r13-322-g7f04b0d786e Date: Fri, 30 Jun 2023 16:34:39 +0000 [thread overview] Message-ID: <bug-110503-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110503 Bug ID: 110503 Summary: [13/14 Regression] Dead Code Elimination Regression at -O3 since r13-322-g7f04b0d786e Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: theodort at inf dot ethz.ch Target Milestone: --- https://godbolt.org/z/h3G76EEW5 Given the following code: void foo(void); static int f = 10, g, h; static int *i = &g, *j = &f, *k = &h; static char(a)(int b) { if (!(((b) >= 1) && ((b) <= 3))) { __builtin_unreachable(); } return 0; } static char(c)(char d, char e) { return d % e; } static void l() { char m, n; unsigned o; int *p = &g; o = -19; for (; o > 22; o = o + 8) { int *q = &g; g = 30; unsigned char d = 60, e = o; m = d / e; if ((0 || *q) & m == 0) ; else { foo(); n = c(0 != p, *p); a(n); *q = 0; } } *i = a(3); *k = 0 != *j; } int main() { l(); a(h); } gcc-trunk -O3 does not eliminate the call to foo: main: pushq %rbx movl $-19, %ebx jmp .L5 .p2align 4,,10 .p2align 3 .L8: call foo addl $8, %ebx .L5: movl $30, g(%rip) cmpb $60, %bl jbe .L8 addl $8, %ebx cmpl $5, %ebx jne .L5 movl f(%rip), %edx xorl %eax, %eax popq %rbx movl $0, g(%rip) testl %edx, %edx setne %al movl %eax, h(%rip) xorl %eax, %eax ret gcc-12.3.0 -O3 eliminates the call to foo: main: movl f(%rip), %edx xorl %eax, %eax movl $0, g(%rip) testl %edx, %edx setne %al movl %eax, h(%rip) xorl %eax, %eax ret Bisects to r13-322-g7f04b0d786e
next reply other threads:[~2023-06-30 16:34 UTC|newest] Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-06-30 16:34 theodort at inf dot ethz.ch [this message] 2023-06-30 21:21 ` [Bug tree-optimization/110503] " pinskia at gcc dot gnu.org 2023-06-30 21:42 ` pinskia at gcc dot gnu.org 2023-06-30 21:47 ` pinskia at gcc dot gnu.org 2023-06-30 22:29 ` pinskia at gcc dot gnu.org 2023-07-27 9:27 ` rguenth at gcc dot gnu.org 2023-08-07 9:08 ` pinskia at gcc dot gnu.org 2023-08-26 0:13 ` pinskia at gcc dot gnu.org 2024-03-08 15:28 ` law at gcc dot gnu.org 2024-03-09 7:16 ` law at gcc dot gnu.org 2024-05-21 9:16 ` [Bug tree-optimization/110503] [13/14/15 " jakub at gcc dot gnu.org
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