http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55838
Bug #: 55838 Summary: ICE in extract_insn (unrecognizable insn) with -O -funroll-loops Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassig...@gcc.gnu.org ReportedBy: antoine.balest...@gmail.com Hi ! This very simple testcase makes GCC 4.8.0 as of 20121231 (and 4.7.2 as well) crash with -O -funroll-loops. I hope this is not a dup. $ cat insn.c int a; unsigned char c; void f(void) { while(c++ < 2) c = a += 129; } $ xgcc -O -funroll-loops -w insn.c insn.c: In function âfâ: insn.c:8:1: error: unrecognizable insn: } ^ (insn 93 92 94 3 (set (reg:QI 127) (const_int 129 [0x81])) -1 (nil)) insn.c:8:1: internal compiler error: in extract_insn, at recog.c:2152 Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. I wish you a happy new year !