http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58227
Bug ID: 58227 Summary: wrong code (hangs) at -O3 on x86_64-linux-gnu Product: gcc Version: unknown 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 produces wrong code (that hangs) for the following testcase on x86_64-linux when compiled at -O3 in both 32-bit and 64-bit modes. This is a regression from 4.8.x. It might be related to 58143, but 58143 also fails for 4.8. $ gcc-trunk -v gcc version 4.9.0 20130822 (experimental) [trunk revision 201915] (GCC) $ gcc-4.8 -O3 reduced.c $ a.out $ gcc-trunk -O2 reduced.c $ a.out $ gcc-trunk -O3 reduced.c $ a.out ^C $ ------------------------------------------ int a, b, d, e, f, *g, h, i; volatile int c; char foo (unsigned char p) { return p + 1; } int bar () { for (h = 0; h < 3; h = foo (h)) { c; for (f = 0; f < 1; f++) { i = a && 0 < -2147483647 - h ? 0 : 1; if (e) for (; d;) b = 0; else g = 0; } } return 0; } int main () { bar (); return 0; }