https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66779
David Malcolm <dmalcolm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |ASSIGNED Last reconfirmed| |2015-07-06 Ever confirmed|0 |1 --- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> --- Root cause is here (in expr.c): 11035 tree type = lang_hooks.types.type_for_mode (mode, unsignedp); where the langhook returns NULL, leading to a segfault. 11034 enum tree_code tcode = code == NE ? NE_EXPR : EQ_EXPR; 11035 tree type = lang_hooks.types.type_for_mode (mode, unsignedp); 11036 tree temp = fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE (arg1), 11037 gimple_assign_rhs1 (srcstmt), 11038 gimple_assign_rhs2 (srcstmt)); 11039 temp = fold_single_bit_test (loc, tcode, temp, arg1, type); (gdb) p mode $2 = QImode (gdb) p unsignedp $3 = 0 Guarded by: 11031 if (srcstmt 11032 && integer_pow2p (gimple_assign_rhs2 (srcstmt))) Fix is to handle the missing modes in jit_langhook_type_for_mode.