Optimize SubInt(ConvInt(aP), ConvInt(bP)) into SubInt(aP,bP)

[r14466]

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index fb966c0..3bd393c 100644 (file)
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -962,6 +962,7 @@ static ir_node *equivalent_node_Sub(ir_node *n) {
 
        a = get_Sub_left(n);
        b = get_Sub_right(n);
+restart:
 
        /* Beware: modes might be different */
        if (classify_tarval(value_of(b)) == TV_CLASSIFY_NULL) {
@@ -970,7 +971,7 @@ static ir_node *equivalent_node_Sub(ir_node *n) {
 
                        DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_0);
                }
-       } else if (get_irn_op(a) == op_Add) {
+       } else if (is_Add(a)) {
                if (mode_wrap_around(mode)) {
                        ir_node *left  = get_Add_left(a);
                        ir_node *right = get_Add_right(a);
@@ -987,6 +988,27 @@ static ir_node *equivalent_node_Sub(ir_node *n) {
                                }
                        }
                }
+       } else if (mode_is_int(mode) && is_Conv(a) && is_Conv(b)) {
+               ir_mode *mode = get_irn_mode(a);
+
+               if (mode == get_irn_mode(b)) {
+                       ir_mode *ma, *mb;
+
+                       a = get_Conv_op(a);
+                       b = get_Conv_op(b);
+
+                       /* check if it's allowed to skip the conv */
+                       ma = get_irn_mode(a);
+                       mb = get_irn_mode(b);
+
+                       if (mode_is_reference(ma) && mode_is_reference(mb)) {
+                               /* SubInt(ConvInt(aP), ConvInt(bP)) -> SubInt(aP,bP) */
+                               set_Sub_left(n, a);
+                               set_Sub_right(n, b);
+
+                               goto restart;
+                       }
+               }
        }
        return n;
 }  /* equivalent_node_Sub */