Make the conv opt analysis and transformation code symmetrical.

[r14051]

diff --git a/ir/opt/convopt.c b/ir/opt/convopt.c
index 9eacd79..b775570 100644 (file)
--- a/ir/opt/convopt.c
+++ b/ir/opt/convopt.c
@@ -45,6 +45,7 @@
 #include "debug.h"
 #include "ircons.h"
 #include "irgmod.h"
+#include "irgopt.h"
 #include "irnode_t.h"
 #include "iredges_t.h"
 #include "irgwalk.h"
@@ -55,48 +56,62 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg);
 static
 int is_optimizable_node(const ir_node *node)
 {
-       if(is_Const(node)) {
-               ir_mode *mode = get_irn_mode(node);
-               /* tarval module is incomplete and can't convert floats to ints */
-               if(!mode_is_int(mode))
-                       return 0;
-               return 1;
-       }
-       return is_Add(node) || is_Sub(node) || is_Mul(node) || is_Phi(node);
+       return
+               is_Add(node) ||
+               is_Sub(node) ||
+               is_Mul(node) ||
+               is_Phi(node);
+}
+
+static tarval* conv_const_tv(const ir_node* cnst, ir_mode* dest_mode)
+{
+       return tarval_convert_to(get_Const_tarval(cnst), dest_mode);
 }
 
 static
 int get_conv_costs(const ir_node *node, ir_mode *dest_mode)
 {
        ir_mode *mode = get_irn_mode(node);
+       size_t arity;
+       size_t i;
+       int costs;
 
-       if(mode == dest_mode)
+       if (mode == dest_mode)
                return 0;
 
-       /* TODO... */
-       if(!is_Const(node) && get_irn_n_edges(node) > 1) {
+       if (is_Const(node)) {
+               /* TODO tarval module is incomplete and can't convert floats to ints */
+               return conv_const_tv(node, dest_mode) == tarval_bad ? 1 : 0;
+       }
+
+       if (get_irn_n_edges(node) > 1) {
                DB((dbg, LEVEL_3, "multi outs at %+F\n", node));
                return 1;
        }
 
-       if(is_Conv(node)) {
+       if (is_Conv(node)) {
                return get_conv_costs(get_Conv_op(node), dest_mode) - 1;
        }
 
-       if(is_optimizable_node(node)) {
-               int i;
-               int arity = get_irn_arity(node);
-               int costs = 0;
-
-               for(i = 0; i < arity; ++i) {
-                       ir_node *pred = get_irn_n(node, i);
-                       costs += get_conv_costs(pred, dest_mode);
-               }
+       if (!is_optimizable_node(node)) {
+               return 1;
+       }
 
-               return costs;
+       costs = 0;
+       arity = get_irn_arity(node);
+       for (i = 0; i < arity; ++i) {
+               ir_node *pred = get_irn_n(node, i);
+               costs += get_conv_costs(pred, dest_mode);
        }
 
-       return 1;
+       return costs;
+}
+
+static ir_node *place_conv(ir_node *node, ir_mode *dest_mode)
+{
+       ir_node *block = get_nodes_block(node);
+       ir_node *conv = new_r_Conv(current_ir_graph, block, node, dest_mode);
+       return conv;
 }
 
 static
@@ -109,19 +124,25 @@ ir_node *conv_transform(ir_node *node, ir_mode *dest_mode)
                return node;
 
        if (is_Const(node)) {
-               tarval *tv = tarval_convert_to(get_Const_tarval(node), dest_mode);
-               assert(get_tarval_mode(tv) == dest_mode);
-               return new_Const(dest_mode, tv);
+               /* TODO tarval module is incomplete and can't convert floats to ints */
+               tarval *tv = conv_const_tv(node, dest_mode);
+               if (tv == tarval_bad) {
+                       return place_conv(node, dest_mode);
+               } else {
+                       return new_Const(dest_mode, tv);
+               }
+       }
+
+       if (get_irn_n_edges(node) > 1) {
+               return place_conv(node, dest_mode);
        }
 
        if (is_Conv(node)) {
                return conv_transform(get_Conv_op(node), dest_mode);
        }
 
-       if (!is_optimizable_node(node) || get_irn_n_edges(node) > 1) {
-               ir_node *block = get_nodes_block(node);
-               ir_node *conv = new_r_Conv(current_ir_graph, block, node, dest_mode);
-               return conv;
+       if (!is_optimizable_node(node)) {
+               return place_conv(node, dest_mode);
        }
 
        arity = get_irn_arity(node);
@@ -137,12 +158,10 @@ ir_node *conv_transform(ir_node *node, ir_mode *dest_mode)
 static
 int is_downconv(ir_mode *src_mode, ir_mode *dest_mode)
 {
-       if(!mode_is_int(src_mode) || !mode_is_int(dest_mode))
-               return 0;
-       if(get_mode_size_bits(dest_mode) >= get_mode_size_bits(src_mode))
-               return 0;
-
-       return 1;
+       return
+               mode_is_int(src_mode) &&
+               mode_is_int(dest_mode) &&
+               get_mode_size_bits(dest_mode) < get_mode_size_bits(src_mode);
 }
 
 /* TODO, backends can't handle and it's probably not more efficient on most
@@ -177,7 +196,7 @@ void conv_opt_walker(ir_node *node, void *data)
        }
 #endif
 
-       if(!is_Conv(node))
+       if (!is_Conv(node))
                return;
 
        pred      = get_Conv_op(node);
@@ -187,9 +206,10 @@ void conv_opt_walker(ir_node *node, void *data)
        if (!is_Phi(pred) && !is_downconv(pred_mode, mode))
                return;
 
-       costs = get_conv_costs(pred, mode);
+       /* - 1 for the initial conv */
+       costs = get_conv_costs(pred, mode) - 1;
        DB((dbg, LEVEL_2, "Costs for %+F -> %+F: %d\n", node, pred, costs));
-       if (costs > 0) return;
+       if (costs >= 0) return;
 
        transformed = conv_transform(pred, mode);
        exchange(node, transformed);