- more work on the Unknown problems: the only

[libfirm] / ir / opt / convopt.c

diff --git a/ir/opt/convopt.c b/ir/opt/convopt.c
index 3ee9687..0ec6243 100644 (file)
--- a/ir/opt/convopt.c
+++ b/ir/opt/convopt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -36,9 +36,7 @@
  * TODO: * try to optimize cmp modes
  *       * decide when it is useful to move the convs through phis
  */
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
 
 #include "iroptimize.h"
 
@@ -54,7 +52,7 @@
 
 DEBUG_ONLY(static firm_dbg_module_t *dbg);
 
-static INLINE int imin(int a, int b) { return a < b ? a : b; }
+static inline int imin(int a, int b) { return a < b ? a : b; }
 
 static
 int is_optimizable_node(const ir_node *node)
@@ -87,7 +85,7 @@ int is_downconv(ir_mode *src_mode, ir_mode *dest_mode)
        return
                mode_is_int(src_mode) &&
                mode_is_int(dest_mode) &&
-               get_mode_size_bits(dest_mode) < get_mode_size_bits(src_mode);
+               get_mode_size_bits(dest_mode) <= get_mode_size_bits(src_mode);
 }
 
 static
@@ -106,15 +104,18 @@ int get_conv_costs(const ir_node *node, ir_mode *dest_mode)
                return conv_const_tv(node, dest_mode) == tarval_bad ? 1 : 0;
        }
 
+       if (is_Conv(node) &&
+                       is_downconv(mode, dest_mode) &&
+                       get_irn_mode(get_Conv_op(node)) == dest_mode) {
+               return -1;
+       }
+
        if (get_irn_n_edges(node) > 1) {
-               if (is_Conv(node) && is_downconv(get_irn_mode(node), dest_mode)) {
-                       return get_conv_costs(get_Conv_op(node), dest_mode) - 1;
-               }
                DB((dbg, LEVEL_3, "multi outs at %+F\n", node));
                return 1;
        }
 
-       if (is_Conv(node) && is_downconv(get_irn_mode(node), dest_mode)) {
+       if (is_Conv(node) && is_downconv(mode, dest_mode)) {
                return get_conv_costs(get_Conv_op(node), dest_mode) - 1;
        }
 
@@ -137,12 +138,13 @@ int get_conv_costs(const ir_node *node, ir_mode *dest_mode)
        }
 #endif
 
-       if (!is_optimizable_node(node)) {
+       if (!mode_is_int(mode) || !is_optimizable_node(node)) {
                return 1;
        }
 
        costs = 0;
-       arity = get_irn_arity(node);
+       // The shift count does not participate in the conv optimisation
+       arity = is_Shl(node) ? 1 : get_irn_arity(node);
        for (i = 0; i < arity; ++i) {
                ir_node *pred = get_irn_n(node, i);
                costs += imin(get_conv_costs(pred, dest_mode), 1);
@@ -161,10 +163,11 @@ static ir_node *place_conv(ir_node *node, ir_mode *dest_mode)
 static
 ir_node *conv_transform(ir_node *node, ir_mode *dest_mode)
 {
-       size_t arity;
-       size_t i;
+       ir_mode *mode = get_irn_mode(node);
+       size_t   arity;
+       size_t   i;
 
-       if (get_irn_mode(node) == dest_mode)
+       if (mode == dest_mode)
                return node;
 
        if (is_Const(node)) {
@@ -177,22 +180,26 @@ ir_node *conv_transform(ir_node *node, ir_mode *dest_mode)
                }
        }
 
+       if (is_Conv(node) &&
+                       is_downconv(mode, dest_mode) &&
+                       get_irn_mode(get_Conv_op(node)) == dest_mode) {
+               return get_Conv_op(node);
+       }
+
        if (get_irn_n_edges(node) > 1) {
-               if (is_Conv(node) && is_downconv(get_irn_mode(node), dest_mode)) {
-                       return conv_transform(get_Conv_op(node), dest_mode);
-               }
                return place_conv(node, dest_mode);
        }
 
-       if (is_Conv(node) && is_downconv(get_irn_mode(node), dest_mode)) {
+       if (is_Conv(node) && is_downconv(mode, dest_mode)) {
                return conv_transform(get_Conv_op(node), dest_mode);
        }
 
-       if (!is_optimizable_node(node)) {
+       if (!mode_is_int(mode) || !is_optimizable_node(node)) {
                return place_conv(node, dest_mode);
        }
 
-       arity = get_irn_arity(node);
+       // The shift count does not participate in the conv optimisation
+       arity = is_Shl(node) ? 1 : get_irn_arity(node);
        for (i = 0; i < arity; i++) {
                ir_node *pred = get_irn_n(node, i);
                ir_node *transformed;
@@ -247,6 +254,9 @@ void conv_opt_walker(ir_node *node, void *data)
        mode      = get_irn_mode(node);
        pred_mode = get_irn_mode(pred);
 
+       if (mode_is_reference(mode) || mode_is_reference(pred_mode))
+               return;
+
        if (!is_Phi(pred) && !is_downconv(pred_mode, mode))
                return;
 
@@ -262,7 +272,7 @@ void conv_opt_walker(ir_node *node, void *data)
        }
 }
 
-void conv_opt(ir_graph *irg)
+int conv_opt(ir_graph *irg)
 {
        char invalidate = 0;
        FIRM_DBG_REGISTER(dbg, "firm.opt.conv");
@@ -280,4 +290,5 @@ void conv_opt(ir_graph *irg)
        if (invalidate) {
                set_irg_outs_inconsistent(irg);
        }
+       return invalidate;
 }