fixed bitfield loads: mode must be adjustedir/lower/lower_hl.c

run lowering in the post phase or a node may be lowered twice

[r15254]

diff --git a/ir/lower/lower_hl.c b/ir/lower/lower_hl.c
index 9dcb6b8..0dc8eb0 100644 (file)
--- a/ir/lower/lower_hl.c
+++ b/ir/lower/lower_hl.c
@@ -39,7 +39,7 @@
 #include "irgwalk.h"
 
 /**
- * Lower a Sel node. Do not touch Sels accessing entities on teh frame type.
+ * Lower a Sel node. Do not touch Sels accessing entities on the frame type.
  */
 static void lower_sel(ir_node *sel) {
        ir_graph *irg = current_ir_graph;
@@ -355,15 +355,26 @@ static void lower_bitfields_loads(ir_node *proj, ir_node *load) {
        if (! bf_mode)
                return;
 
+       mode       = get_irn_mode(proj);
+       block      = get_nodes_block(proj);
        bf_bits    = get_mode_size_bits(bf_mode);
        bit_offset = get_entity_offset_bits_remainder(ent);
-       if (bit_offset == 0 && is_integral_size(bf_bits))
+       if (bit_offset == 0 && is_integral_size(bf_bits)) {
+               if (mode != bf_mode) {
+                       /* we have an integral size and can replace the load by a load
+                          of a smaller mode */
+                       set_Load_mode(load, bf_mode);
+                       db    = get_irn_dbg_info(load);
+                       res   = new_rd_Proj(get_irn_dbg_info(proj), current_ir_graph, block, load, bf_mode, pn_Load_res);
+                       res   = new_rd_Conv(db, current_ir_graph, block, res, mode);
+
+                       exchange(proj, res);
+               }
                return;
+       }
 
-       mode   = get_irn_mode(proj);
        bits   = get_mode_size_bits(mode);
        offset = get_entity_offset(ent);
-       block  = get_nodes_block(proj);
 
        /*
         * ok, here we are: now convert the Proj_mode_bf(Load) into And(Shr(Proj_mode(Load)) for unsigned
@@ -549,10 +560,10 @@ void lower_highlevel(void) {
                ir_graph *irg = get_irp_irg(i);
 
                /* First step: lower bitfield access: must be run as long as Sels still exists. */
-               irg_walk_graph(irg, lower_bf_access, NULL, NULL);
+               irg_walk_graph(irg, NULL, lower_bf_access, NULL);
 
                /* Finally: lower SymConst-Size and Sel nodes. */
-               irg_walk_graph(irg, lower_irnode, NULL, NULL);
+               irg_walk_graph(irg, NULL, lower_irnode, NULL);
 
                set_irg_phase_low(irg);
        }