Add more special cases for Shift operations

[r7790]

diff --git a/ir/lower/lower_dw.c b/ir/lower/lower_dw.c
index d9fdcd8..1c4644a 100644 (file)
--- a/ir/lower/lower_dw.c
+++ b/ir/lower/lower_dw.c
@@ -906,15 +906,22 @@ static void lower_Shr(ir_node *node, ir_mode *mode, lower_env_t *env) {
                tarval *tv = get_Const_tarval(right);
 
                if (tarval_is_long(tv) &&
-                       get_tarval_long(tv) == get_mode_size_bits(env->params->low_signed)) {
+                       get_tarval_long(tv) >= get_mode_size_bits(mode)) {
                        ir_node *block = get_nodes_block(node);
                        ir_node *left = get_Shr_left(node);
+                       ir_node *c;
+                       long shf_cnt = get_tarval_long(tv) - get_mode_size_bits(mode);
                        int idx = get_irn_idx(left);
 
                        left = env->entries[idx]->high_word;
                        idx = get_irn_idx(node);
 
-                       env->entries[idx]->low_word  = left;
+                       if (shf_cnt > 0) {
+                               c = new_r_Const_long(current_ir_graph, block, mode_Iu, shf_cnt);
+                               env->entries[idx]->low_word = new_r_Shr(current_ir_graph, block, left, c, mode);
+                       }
+                       else
+                               env->entries[idx]->low_word = left;
                        env->entries[idx]->high_word = new_r_Const(current_ir_graph, block, mode, get_mode_null(mode));
 
                        return;
@@ -933,16 +940,23 @@ static void lower_Shl(ir_node *node, ir_mode *mode, lower_env_t *env) {
                tarval *tv = get_Const_tarval(right);
 
                if (tarval_is_long(tv) &&
-                       get_tarval_long(tv) == get_mode_size_bits(env->params->low_signed)) {
+                       get_tarval_long(tv) >= get_mode_size_bits(mode)) {
                        ir_node *block = get_nodes_block(node);
                        ir_node *left = get_Shl_left(node);
+                       ir_node *c;
+                       long shf_cnt = get_tarval_long(tv) - get_mode_size_bits(mode);
                        int idx = get_irn_idx(left);
 
                        left = env->entries[idx]->low_word;
                        idx = get_irn_idx(node);
 
+                       if (shf_cnt > 0) {
+                               c = new_r_Const_long(current_ir_graph, block, mode_Iu, shf_cnt);
+                               env->entries[idx]->high_word = new_r_Shl(current_ir_graph, block, left, c, mode);
+                       }
+                       else
+                               env->entries[idx]->high_word = left;
                        env->entries[idx]->low_word  = new_r_Const(current_ir_graph, block, mode, get_mode_null(mode));
-                       env->entries[idx]->high_word = left;
 
                        return;
                }
@@ -960,17 +974,24 @@ static void lower_Shrs(ir_node *node, ir_mode *mode, lower_env_t *env) {
                tarval *tv = get_Const_tarval(right);
 
                if (tarval_is_long(tv) &&
-                       get_tarval_long(tv) == get_mode_size_bits(env->params->low_signed)) {
+                       get_tarval_long(tv) >= get_mode_size_bits(mode)) {
                        ir_node *block = get_nodes_block(node);
                        ir_node *left = get_Shrs_left(node);
+                       long shf_cnt = get_tarval_long(tv) - get_mode_size_bits(mode);
                        ir_node *c;
                        int idx = get_irn_idx(left);
 
                        left = env->entries[idx]->high_word;
                        idx = get_irn_idx(node);
 
+                       if (shf_cnt > 0) {
+                               c = new_r_Const_long(current_ir_graph, block, mode_Iu, shf_cnt);
+                               env->entries[idx]->low_word = new_r_Shrs(current_ir_graph, block, left, c, mode);
+                       }
+                       else
+                               env->entries[idx]->low_word = left;
+
                        c = new_r_Const_long(current_ir_graph, block, mode_Iu, get_mode_size_bits(mode) - 1);
-                       env->entries[idx]->low_word  = left;
                        env->entries[idx]->high_word = new_r_Shrs(current_ir_graph, block, left, c, mode);
 
                        return;
@@ -989,7 +1010,7 @@ static void lower_Rot(ir_node *node, ir_mode *mode, lower_env_t *env) {
                tarval *tv = get_Const_tarval(right);
 
                if (tarval_is_long(tv) &&
-                       get_tarval_long(tv) == get_mode_size_bits(env->params->low_signed)) {
+                       get_tarval_long(tv) == get_mode_size_bits(mode)) {
                        ir_node *block = get_nodes_block(node);
                        ir_node *left = get_Rot_left(node);
                        ir_node *h, *l;