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From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/94838] Failure to optimize out useless zero-ing after register was already zero-ed Date: Wed, 29 Apr 2020 06:51:31 +0000 [thread overview] Message-ID: <bug-94838-4-t0OerwxCMU@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-94838-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94838 --- Comment #3 from Gabriel Ravier <gabravier at gmail dot com> --- This also occurs on i68* : f(bool, int*): xor eax, eax ; Already 0 cmp BYTE PTR [esp+4], 0 je .L1 mov eax, DWORD PTR [esp+8] ; Could use different caller-saved register such as ecx or edx mov eax, DWORD PTR [eax] test eax, eax setne al movzx eax, al ; This could then be avoided since eax would already be 0 .L1: ret
next prev parent reply other threads:[~2020-04-29 6:51 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-29 1:32 [Bug rtl-optimization/94838] New: " gabravier at gmail dot com 2020-04-29 2:06 ` [Bug target/94838] " pinskia at gcc dot gnu.org 2020-04-29 6:50 ` gabravier at gmail dot com 2020-04-29 6:51 ` gabravier at gmail dot com [this message] 2020-04-29 6:53 ` gabravier at gmail dot com 2020-04-29 7:13 ` rguenth at gcc dot gnu.org 2020-04-29 9:00 ` [Bug rtl-optimization/94838] " ubizjak at gmail dot com
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