diff options
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 28 |
1 files changed, 28 insertions, 0 deletions
@@ -8809,6 +8809,34 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode, where some terms of the dividend have coeffs divisible by it. */ expand_operands (treeop0, treeop1, subtarget, &op0, &op1, EXPAND_NORMAL); + if (SCALAR_INT_MODE_P (mode) + && optimize >= 2 + && get_range_pos_neg (treeop0) == 1 + && get_range_pos_neg (treeop1) == 1) + { + /* If both arguments are known to be positive when interpreted + as signed, we can expand it as both signed and unsigned + division or modulo. Choose the cheaper sequence in that case. */ + bool speed_p = optimize_insn_for_speed_p (); + do_pending_stack_adjust (); + start_sequence (); + rtx uns_ret = expand_divmod (0, code, mode, op0, op1, target, 1); + rtx_insn *uns_insns = get_insns (); + end_sequence (); + start_sequence (); + rtx sgn_ret = expand_divmod (0, code, mode, op0, op1, target, 0); + rtx_insn *sgn_insns = get_insns (); + end_sequence (); + unsigned uns_cost = seq_cost (uns_insns, speed_p); + unsigned sgn_cost = seq_cost (sgn_insns, speed_p); + if (uns_cost < sgn_cost || (uns_cost == sgn_cost && unsignedp)) + { + emit_insn (uns_insns); + return uns_ret; + } + emit_insn (sgn_insns); + return sgn_ret; + } return expand_divmod (0, code, mode, op0, op1, target, unsignedp); case RDIV_EXPR: |