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From: "su at cs dot ucdavis.edu" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/64007] New: wrong code at -O3 on x86_64-linux-gnu Date: Fri, 21 Nov 2014 01:01:00 -0000 [thread overview] Message-ID: <bug-64007-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64007 Bug ID: 64007 Summary: wrong code at -O3 on x86_64-linux-gnu Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: su at cs dot ucdavis.edu The current gcc trunk miscompiles the following code on x86_64-linux at -O3 in both 32-bit and 64-bit modes. This is a regression from 4.9.x. $ gcc-trunk -v Using built-in specs. COLLECT_GCC=gcc-trunk COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk --enable-languages=c,c++ --disable-werror --enable-multilib Thread model: posix gcc version 5.0.0 20141119 (experimental) [trunk revision 217800] (GCC) $ $ gcc-trunk -O2 small.c; a.out $ gcc-4.9 -O3 small.c; a.out $ $ gcc-trunk -O3 small.c $ ./a.out Aborted (core dumped) $ ---------------------------- #include <assert.h> int d, i; struct S { int f0; } *b, c, e, h, **g = &b; static struct S *f = &e; int fn1 (int p) { int a = 0; return a || p < 0 || p >= 2 || 1 >> p; } int main () { int k = 1, l, *m = &c.f0; for (;;) { l = fn1 (i); *m = k && i; if (l) { int n[1] = {0}; } break; } *g = &h; assert (b); if (d) (*m)--; d = (f != 0) | (i >= 0); if (c.f0 != 0) __builtin_abort (); return 0; }
next reply other threads:[~2014-11-21 1:01 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-11-21 1:01 su at cs dot ucdavis.edu [this message] 2014-11-21 1:28 ` [Bug tree-optimization/64007] " hjl.tools at gmail dot com
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