https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79088
Bug ID: 79088 Summary: wrong code at -O2 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 Target Milestone: --- It seems to be a recent regression. $ gcc-trunk -v Using built-in specs. COLLECT_GCC=gcc-trunk COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto --prefix=/usr/local/gcc-trunk --disable-bootstrap Thread model: posix gcc version 7.0.0 20170113 (experimental) [trunk revision 244397] (GCC) $ $ gcc-trunk -Os small.c $ ./a.out $ $ gcc-trunk -O2 small.c $ timeout -s 9 5 ./a.out Killed $ -------------------------------------------- int a, b, c, d, e = 1; int main () { int f; if (a) goto L; for (f = 0; f < e; e++) { L: if (d) continue; if (c) goto L; for (a = 0; a < 6; a++) for (f = 0; f < 3; f++) while (b) c++; } return 0; }