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From: "dg at cowlark dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/52670] New: -mabi=ms generates bad code Date: Thu, 22 Mar 2012 15:52:00 -0000 [thread overview] Message-ID: <bug-52670-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52670 Bug #: 52670 Summary: -mabi=ms generates bad code Classification: Unclassified Product: gcc Version: 4.6.3 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target AssignedTo: unassigned@gcc.gnu.org ReportedBy: dg@cowlark.com If I take this test case: int z(int i) { return i; } ...and compile it with: gcc-4.6 -Os -m32 -mabi=sysv -o test.s -c test.c -S -fomit-frame-pointer ...I get this (trimmed): movl 4(%esp), %eax ret However, if I compile it with this: gcc-4.6 -Os -m32 -mabi=ms -o test.s -c test.c -S -fomit-frame-pointer ...then I get this, which is wrong: movl 36(%esp), %eax ret Compiling with a copy of the Mingw compiler or with Visual C produces (the equivalent of) the 4 result. The -fomit-frame-pointer is there purely to reduce the size of the output; the bug persists without it. This appears to affect all stack accesses. It *seems* to only apply to ia32 code. amd64 code appears to be fine, but my target environment is ia32 only so I haven't looked into amd64 much. This was discussed on gcc-help here: http://gcc.gnu.org/ml/gcc-help/2012-03/msg00281.html This patch appears to fix the issue: http://gcc.gnu.org/ml/gcc-patches/2011-03/txt00118.txt (although the patch needs a bit of work to apply).
next reply other threads:[~2012-03-22 15:45 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-03-22 15:52 dg at cowlark dot com [this message] 2023-12-17 7:12 ` [Bug target/52670] " pinskia at gcc dot gnu.org
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