https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52478
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> --- It seems that the libgcc functions for SImode are present (at least on x86_64), so sth like Index: gcc/optabs.c =================================================================== --- gcc/optabs.c (revision 212970) +++ gcc/optabs.c (working copy) @@ -5559,13 +5559,17 @@ gen_int_libfunc (optab optable, const ch enum machine_mode mode) { int maxsize = 2 * BITS_PER_WORD; + int minsize = BITS_PER_WORD; if (GET_MODE_CLASS (mode) != MODE_INT) return; if (maxsize < LONG_LONG_TYPE_SIZE) maxsize = LONG_LONG_TYPE_SIZE; - if (GET_MODE_CLASS (mode) != MODE_INT - || GET_MODE_BITSIZE (mode) < BITS_PER_WORD + if (minsize > INT_TYPE_SIZE + && (trapv_binoptab_p (optable) + || trapv_unoptab_p (optable))) + minsize = INT_TYPE_SIZE; + if (GET_MODE_BITSIZE (mode) < minsize || GET_MODE_BITSIZE (mode) > maxsize) return; gen_libfunc (optable, opname, suffix, mode); Index: gcc/expr.c =================================================================== --- gcc/expr.c (revision 212970) +++ gcc/expr.c (working copy) @@ -9212,7 +9212,9 @@ expand_expr_real_2 (sepops ops, rtx targ if (modifier == EXPAND_STACK_PARM) target = 0; temp = expand_binop (mode, this_optab, op0, op1, target, - unsignedp, OPTAB_LIB_WIDEN); + unsignedp, + trapv_binoptab_p (this_optab) + ? OPTAB_LIB : OPTAB_LIB_WIDEN); gcc_assert (temp); /* Bitwise operations do not need bitfield reduction as we expect their operands being properly truncated. */ makes the testcase pass.