+ switch ((ir_opcode)get_irn_opcode(node)) {
+ case iro_And:
+ if (!mode_is_signed(mode)) {
+ return upper_bits_clean(get_And_left(node), mode)
+ || upper_bits_clean(get_And_right(node), mode);
+ }
+ /* FALLTHROUGH */
+ case iro_Or:
+ case iro_Eor:
+ return upper_bits_clean(get_binop_left(node), mode)
+ && upper_bits_clean(get_binop_right(node), mode);
+
+ case iro_Shr:
+ if (mode_is_signed(mode)) {
+ return false; /* TODO */
+ } else {
+ ir_node *right = get_Shr_right(node);
+ if (is_Const(right)) {
+ ir_tarval *tv = get_Const_tarval(right);
+ long val = get_tarval_long(tv);
+ if (val >= 32 - (long)get_mode_size_bits(mode))
+ return true;
+ }
+ return upper_bits_clean(get_Shr_left(node), mode);
+ }
+
+ case iro_Shrs:
+ return upper_bits_clean(get_Shrs_left(node), mode);
+
+ case iro_Const: {
+ ir_tarval *tv = get_Const_tarval(node);
+ long val = get_tarval_long(tv);
+ if (mode_is_signed(mode)) {
+ long shifted = val >> (get_mode_size_bits(mode)-1);
+ return shifted == 0 || shifted == -1;
+ } else {
+ unsigned long shifted = (unsigned long)val;
+ shifted >>= get_mode_size_bits(mode)-1;
+ shifted >>= 1;
+ return shifted == 0;
+ }
+ }
+
+ case iro_Conv: {
+ ir_mode *dest_mode = get_irn_mode(node);
+ ir_node *op = get_Conv_op(node);
+ ir_mode *src_mode = get_irn_mode(op);
+ unsigned src_bits = get_mode_size_bits(src_mode);
+ unsigned dest_bits = get_mode_size_bits(dest_mode);
+ /* downconvs are a nop */
+ if (src_bits <= dest_bits)
+ return upper_bits_clean(op, mode);
+ if (dest_bits <= get_mode_size_bits(mode)
+ && mode_is_signed(dest_mode) == mode_is_signed(mode))
+ return true;
+ return false;
+ }
+
+ case iro_Proj: {
+ ir_node *pred = get_Proj_pred(node);
+ switch (get_irn_opcode(pred)) {
+ case iro_Load: {
+ ir_mode *load_mode = get_Load_mode(pred);
+ unsigned load_bits = get_mode_size_bits(load_mode);
+ unsigned bits = get_mode_size_bits(mode);
+ if (load_bits > bits)
+ return false;
+ if (mode_is_signed(mode) != mode_is_signed(load_mode))
+ return false;
+ return true;
+ }
+ default:
+ break;
+ }
+ }
+ default:
+ break;
+ }