diff options
Diffstat (limited to 'gcc/stmt.c')
| -rw-r--r-- | gcc/stmt.c | 24 |
1 files changed, 22 insertions, 2 deletions
@@ -6293,8 +6293,10 @@ emit_case_nodes (index, node, default_label, index_type) /* Node has no children so we check low and high bounds to remove redundant tests. Only one of the bounds can exist, since otherwise this node is bounded--a case tested already. */ + int high_bound = node_has_high_bound (node, index_type); + int low_bound = node_has_low_bound (node, index_type); - if (!node_has_high_bound (node, index_type)) + if (!high_bound && low_bound) { emit_cmp_and_jump_insns (index, convert_modes @@ -6306,7 +6308,7 @@ emit_case_nodes (index, node, default_label, index_type) default_label); } - if (!node_has_low_bound (node, index_type)) + else if (!low_bound && high_bound) { emit_cmp_and_jump_insns (index, convert_modes @@ -6317,6 +6319,24 @@ emit_case_nodes (index, node, default_label, index_type) LT, NULL_RTX, mode, unsignedp, 0, default_label); } + else if (!low_bound && !high_bound) + { + /* Instead of doing two branches emit test (index-low) <= (high-low). */ + tree new_bound = fold (build (MINUS_EXPR, index_type, node->high, + node->low)); + rtx new_index; + + new_index = expand_binop (mode, sub_optab, index, + expand_expr (node->low, NULL_RTX, + VOIDmode, 0), + NULL_RTX, 0, OPTAB_WIDEN); + + emit_cmp_and_jump_insns (new_index, + expand_expr (new_bound, NULL_RTX, + VOIDmode, 0), + GT, NULL_RTX, mode, 1, 0, + default_label); + } emit_jump (label_rtx (node->code_label)); } |