public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "theodort at inf dot ethz.ch" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/111293] New: [14 Regression] Missed Dead Code Elimination since r14-3414-g0cfc9c953d0 Date: Tue, 05 Sep 2023 15:01:10 +0000 [thread overview] Message-ID: <bug-111293-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111293 Bug ID: 111293 Summary: [14 Regression] Missed Dead Code Elimination since r14-3414-g0cfc9c953d0 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/9aj7sr5d6 Given the following code: void foo(void); static int a, d; static short e; static int(f)(int b, int c) { return c == 0 ? b : b / c; } static char g(char h) { char i = 1; int j = 8; e = 3; for (; d; ++d) { if (f(0 == j, e)) return a; for (; i; i--) { if (j) { if (e) ; else if (a) continue; else foo(); j = -h; break; } __builtin_unreachable(); break; } } return 1; } int main() { g(-1); a = e; } gcc-trunk -O2 does not eliminate the call to foo: main: subq $8, %rsp movl d(%rip), %ecx movl $3, %edx movw %dx, e(%rip) testl %ecx, %ecx je .L6 movl $3, %edx .p2align 4,,10 .p2align 3 .L2: testw %dx, %dx jne .L3 movl a(%rip), %eax testl %eax, %eax je .L18 .L5: addl $1, d(%rip) jne .L5 .L6: movswl e(%rip), %eax movl %eax, a(%rip) xorl %eax, %eax addq $8, %rsp ret .p2align 4,,10 .p2align 3 .L18: call foo .L3: addl $1, d(%rip) movzwl e(%rip), %edx jne .L2 jmp .L6 gcc-13.2.0 -O2 eliminates the call to foo: main: movl d(%rip), %edx movl $3, %eax movw %ax, e(%rip) testl %edx, %edx je .L3 movl $0, d(%rip) .L3: movl $3, a(%rip) xorl %eax, %eax ret Bisects to r14-3414-g0cfc9c953d0
next reply other threads:[~2023-09-05 15:01 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-09-05 15:01 theodort at inf dot ethz.ch [this message] 2023-09-05 17:25 ` [Bug tree-optimization/111293] " pinskia at gcc dot gnu.org 2023-09-05 17:40 ` pinskia at gcc dot gnu.org 2023-09-05 17:40 ` pinskia at gcc dot gnu.org 2023-11-24 15:56 ` amacleod at redhat dot com 2024-03-07 23:21 ` law at gcc dot gnu.org 2024-04-09 9:38 ` mikael at gcc dot gnu.org 2024-04-09 9:47 ` mikael at gcc dot gnu.org 2024-05-07 7:41 ` [Bug tree-optimization/111293] [14/15 " rguenth at gcc dot gnu.org
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-111293-4@http.gcc.gnu.org/bugzilla/ \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).