https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87176
Bug ID: 87176 Summary: wrong code at -Os and above 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 is a recent regression. $ gcctk -v Using built-in specs. COLLECT_GCC=gcctk COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/9.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto --prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap Thread model: posix gcc version 9.0.0 20180831 (experimental) [trunk revision 264021] (GCC) $ $ gcctk -O1 small.c; ./a.out $ gcc-8.1.0 -Os small.c; ./a.out $ $ gcctk -Os small.c $ timeout -s 9 5 ./a.out Killed $ ------------------------------------------ int a, b, c; int main () { int d = a = 0; while (1) { a = a ^ 6; if (!a) break; if (d) goto L; d = a; for (b = 0; b < 2; b++) { const int *f[3] = { &c }; const int **g[] = { &f[2] }; int h = ~d; if (d) L: if (h > 1) continue; } } return 0; }