Moved the Sub Optimization into transform (changes the graph!) and made it more agressive

[r14467]

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index 3bd393c..fa9f83a 100644 (file)
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -953,62 +953,23 @@ static ir_node *equivalent_node_left_zero(ir_node *n) {
  */
 static ir_node *equivalent_node_Sub(ir_node *n) {
        ir_node *oldn = n;
-       ir_node *a, *b;
+       ir_node *b;
        ir_mode *mode = get_irn_mode(n);
 
        /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
        if (mode_is_float(mode) && (get_irg_fp_model(current_ir_graph) & fp_strict_algebraic))
                return 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) {
+               ir_node *a = get_Sub_left(n);
                if (mode == get_irn_mode(a)) {
                        n = a;
 
                        DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_0);
                }
-       } else if (is_Add(a)) {
-               if (mode_wrap_around(mode)) {
-                       ir_node *left  = get_Add_left(a);
-                       ir_node *right = get_Add_right(a);
-
-                       if (left == b) {
-                               if (mode == get_irn_mode(right)) {
-                                       n = right;
-                                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
-                               }
-                       } else if (right == b) {
-                               if (mode == get_irn_mode(left)) {
-                                       n = left;
-                                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
-                               }
-                       }
-               }
-       } 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 */
@@ -2053,16 +2014,61 @@ static ir_node *transform_node_Sub(ir_node *n) {
        a = get_Sub_left(n);
        b = get_Sub_right(n);
 
-       HANDLE_BINOP_PHI(tarval_sub, a,b,c);
-
        mode = get_irn_mode(n);
 
+restart:
+       HANDLE_BINOP_PHI(tarval_sub, a,b,c);
+
        /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
        if (mode_is_float(mode) && (get_irg_fp_model(current_ir_graph) & fp_strict_algebraic))
                return n;
 
+       if (is_Add(a)) {
+               if (mode_wrap_around(mode)) {
+                       ir_node *left  = get_Add_left(a);
+                       ir_node *right = get_Add_right(a);
+
+                       /* FIXME: Does the Conv's word only for two complement or generally? */
+                       if (left == b) {
+                               if (mode != get_irn_mode(right)) {
+                                       /* This Sub is an effective Cast */
+                                       right = new_r_Conv(get_irn_irg(n), get_irn_n(n, -1), right, mode);
+                               }
+                               n = right;
+                               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+                       } else if (right == b) {
+                               if (mode != get_irn_mode(left)) {
+                                       /* This Sub is an effective Cast */
+                                       left = new_r_Conv(get_irn_irg(n), get_irn_n(n, -1), left, mode);
+                               }
+                               n = left;
+                               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+                       }
+               }
+       } 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;
+                       }
+               }
+       }
        /* Beware of Sub(P, P) which cannot be optimized into a simple Minus ... */
-       if (mode_is_num(mode) && mode == get_irn_mode(a) && (classify_Const(a) == CNST_NULL)) {
+       else if (mode_is_num(mode) && mode == get_irn_mode(a) && (classify_Const(a) == CNST_NULL)) {
                n = new_rd_Minus(
                                get_irn_dbg_info(n),
                                current_ir_graph,
@@ -2136,7 +2142,6 @@ static ir_node *transform_node_Sub(ir_node *n) {
                set_Sub_right(n, add);
                DBG_OPT_ALGSIM0(n, n, FS_OPT_SUB_SUB_X_Y_Z);
        }
-
        return n;
 }  /* transform_node_Sub */