https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86850
--- Comment #4 from David Binderman <dcb314 at hotmail dot com> --- I tried out your suggestion and got this: $ ~/gcc/results.264011.dcb.ubsan/bin/gcc -c -O3 -std=c89 -w bug453.c during GIMPLE pass: slp src/rate.c: In function ‘od_enc_rc_reset’: src/rate.c:365:13: internal compiler error: in vect_build_slp_tree_2, at tree-vect-slp.c:1492 0x676275 vect_build_slp_tree_2 ../../trunk/gcc/tree-vect-slp.c:1492 0x2c3a7d6 vect_build_slp_tree ../../trunk/gcc/tree-vect-slp.c:1105 0x2c3e793 vect_build_slp_tree_2 ../../trunk/gcc/tree-vect-slp.c:1257 0x2c3a7d6 vect_build_slp_tree ../../trunk/gcc/tree-vect-slp.c:1105 I used revision 264011 as a baseline.