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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/109866] New: Sometimes using sub/test instead just test Date: Mon, 15 May 2023 18:44:19 +0000 [thread overview] Message-ID: <bug-109866-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109866 Bug ID: 109866 Summary: Sometimes using sub/test instead just test Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: pinskia at gcc dot gnu.org Target Milestone: --- Take: ``` int g(void); int h(void); int t(void); int f(int a, int b) { int c = a - b; if(c == 0) return g(); if (c > 0) return h(); return t(); } ``` This is reduced from bzip2 in spec 2006, though I am not so sure any more. On x86_64 GCC produces: ``` subl %esi, %edi testl %edi, %edi je .L5 jle .L3 jmp h() .L3: jmp t() .L5: jmp g() ``` But GCC should produce (likes clang/LLVM does): ``` cmpl %esi, %edi je .L5 jle .L3 jmp h() .L3: jmp t() .L5: jmp g() ``` Note a similar thing happens with aarch64 target too.
next reply other threads:[~2023-05-15 18:44 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-05-15 18:44 pinskia at gcc dot gnu.org [this message] 2023-05-16 8:07 ` [Bug rtl-optimization/109866] " ubizjak at gmail dot com 2023-05-16 8:19 ` ubizjak at gmail dot com 2023-05-16 10:24 ` pinskia at gcc dot gnu.org 2023-05-16 15:50 ` [Bug tree-optimization/109866] " pinskia at gcc dot gnu.org 2023-05-17 6:56 ` rguenth at gcc dot gnu.org
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