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From: "cassio.neri at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/104539] New: Failed to inline a very simple template function when it's explicit instantiated. Date: Tue, 15 Feb 2022 04:34:33 +0000 [thread overview] Message-ID: <bug-104539-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104539 Bug ID: 104539 Summary: Failed to inline a very simple template function when it's explicit instantiated. Product: gcc Version: 11.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: cassio.neri at gmail dot com Target Milestone: --- Consider: template <int> //inline int f() { return 0; } int g() { return f<0>() + 1; } Using -O3, I'd expect f to be inlined in g and this is indeed the case: g(): mov eax, 1 ret However, if f is explicit instantiated: template unsigned f<0>(); then we get a function call (or a jmp if tail call optimisation is possible) g(): sub rsp, 8 call int f<0>() add rsp, 8 add eax, 1 ret A (quite unusual, IMHO) workaround is declaring f as inline: template <unsigned n> inline unsigned f() { return n; } https://godbolt.org/z/TarsTY3zb
next reply other threads:[~2022-02-15 4:34 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-02-15 4:34 cassio.neri at gmail dot com [this message] 2022-02-15 4:35 ` [Bug tree-optimization/104539] " cassio.neri at gmail dot com 2022-02-15 8:13 ` [Bug c++/104539] " rguenth at gcc dot gnu.org 2022-02-17 5:11 ` jason at gcc dot gnu.org 2022-02-17 18:29 ` jason at gcc dot gnu.org 2022-02-17 22:51 ` cvs-commit at gcc dot gnu.org 2022-02-17 22:52 ` jason at gcc dot gnu.org 2024-03-18 7:08 ` pinskia at gcc dot gnu.org
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