Some cleanup of cfopt.

[libfirm] / ir / opt / convopt.c

diff --git a/ir/opt/convopt.c b/ir/opt/convopt.c
index 9785dea..7ea1e3a 100644 (file)
--- a/ir/opt/convopt.c
+++ b/ir/opt/convopt.c
@@ -47,6 +47,7 @@
 #include "irgmod.h"
 #include "irgopt.h"
 #include "irnode_t.h"
+#include "iropt_t.h"
 #include "iredges_t.h"
 #include "irgwalk.h"
 #include "irprintf.h"
@@ -58,7 +59,7 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg);
 
 static inline int imin(int a, int b) { return a < b ? a : b; }
 
-static bool is_optimizable_node(const ir_node *node)
+static bool is_optimizable_node(const ir_node *node, ir_mode *dest_mode)
 {
        switch (get_irn_opcode(node)) {
        case iro_Add:
@@ -69,9 +70,17 @@ static bool is_optimizable_node(const ir_node *node)
        case iro_Not:
        case iro_Or:
        case iro_Phi:
-       case iro_Shl:
        case iro_Sub:
                return true;
+       case iro_Shl: {
+               int modulo_shift = get_mode_modulo_shift(dest_mode);
+               int old_shift    = get_mode_modulo_shift(get_irn_mode(node));
+               /* bail out if modulo shift changes */
+               if (modulo_shift != old_shift)
+                       return false;
+               return true;
+       }
+
        default:
                return false;
        }
@@ -116,6 +125,10 @@ static int get_conv_costs(const ir_node *node, ir_mode *dest_mode)
                return 1;
        }
 
+       if (ir_zero_when_converted(node, dest_mode)) {
+               return -1;
+       }
+
 #if 0 // TODO
        /* Take the minimum of the conversion costs for Phi predecessors as only one
         * branch is actually executed at a time */
@@ -149,7 +162,7 @@ static int get_conv_costs(const ir_node *node, ir_mode *dest_mode)
                return get_conv_costs(get_Conv_op(node), dest_mode) - 1;
        }
 
-       if (!is_optimizable_node(node)) {
+       if (!is_optimizable_node(node, dest_mode)) {
                return 1;
        }
 
@@ -218,7 +231,7 @@ static ir_node *conv_transform(ir_node *node, ir_mode *dest_mode)
                return conv_transform(get_Conv_op(node), dest_mode);
        }
 
-       if (!is_optimizable_node(node)) {
+       if (!is_optimizable_node(node, dest_mode)) {
                return place_conv(node, dest_mode);
        }
 
@@ -315,9 +328,6 @@ int conv_opt(ir_graph *irg)
                invalidate |= changed;
        } while (changed);
 
-       if (invalidate) {
-               set_irg_outs_inconsistent(irg);
-       }
        return invalidate;
 }