added -(x >>u 31) and -(x >>s 31)

[r15795]

diff --git a/include/libfirm/firmstat.h b/include/libfirm/firmstat.h
index e909a0a..568cc6d 100644 (file)
--- a/include/libfirm/firmstat.h
+++ b/include/libfirm/firmstat.h
@@ -88,6 +88,7 @@ enum firmstat_optimizations_t {
        FS_OPT_ADD_X_NOT_X,                       /**< ~x + x = -1 */
        FS_OPT_FP_INV_MUL,                        /**< x / y = x * (1.0/y) */
        FS_OPT_CONST_PHI,                         /**< Constant evaluation on Phi */
+       FS_OPT_PREDICATE,                         /**< Predicate optimization */
        FS_BE_IA32_LEA,                           /**< Lea was created */
        FS_BE_IA32_LOAD_LEA,                      /**< Load merged with a Lea */
        FS_BE_IA32_STORE_LEA,                     /**< Store merged with a Lea */

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index c1a40dd..02ed4e8 100644 (file)
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -3041,6 +3041,7 @@ static ir_node *transform_node_Not(ir_node *n) {
  * Transform a Minus.
  * Optimize:
  *   -(~x) = x + 1
+ *   -(a-b) = b - a
  */
 static ir_node *transform_node_Minus(ir_node *n) {
        ir_node *c, *oldn = n;
@@ -3050,15 +3051,52 @@ static ir_node *transform_node_Minus(ir_node *n) {
        HANDLE_UNOP_PHI(tarval_neg,a,c);
 
        mode = get_irn_mode(a);
-       if (get_mode_arithmetic(mode) == irma_twos_complement && is_Not(a)) {
-               /* -(~x) = x + 1 */
-               ir_node *op   = get_Not_op(a);
-               tarval *tv    = get_mode_one(mode);
-               ir_node *blk  = get_irn_n(n, -1);
-               ir_node *c    = new_r_Const(current_ir_graph, blk, mode, tv);
-               n = new_rd_Add(get_irn_dbg_info(n), current_ir_graph, blk, op, c, mode);
-               DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_MINUS_NOT);
-       } else if (is_Sub(a)) {
+       if (get_mode_arithmetic(mode) == irma_twos_complement) {
+               /* the following rules are only to twos-complement */
+               if (is_Not(a)) {
+                       /* -(~x) = x + 1 */
+                       ir_node *op   = get_Not_op(a);
+                       tarval *tv    = get_mode_one(mode);
+                       ir_node *blk  = get_irn_n(n, -1);
+                       ir_node *c    = new_r_Const(current_ir_graph, blk, mode, tv);
+                       n = new_rd_Add(get_irn_dbg_info(n), current_ir_graph, blk, op, c, mode);
+                       DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_MINUS_NOT);
+                       return n;
+               }
+               if (is_Shr(a)) {
+                       ir_node *c = get_Shr_right(a);
+
+                       if (is_Const(c)) {
+                               tarval *tv = get_Const_tarval(c);
+
+                               if (tarval_is_long(tv) && get_tarval_long(tv) == get_mode_size_bits(mode) - 1) {
+                                       /* -(a >>u (size-1)) = a >>s (size-1) */
+                                       ir_node *v = get_Shr_left(a);
+
+                                       n = new_rd_Shrs(get_irn_dbg_info(n), current_ir_graph, get_irn_n(n, -1), v, c, mode);
+                                       DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_PREDICATE);
+                                       return n;
+                               }
+                       }
+               }
+               if (is_Shrs(a)) {
+                       ir_node *c = get_Shrs_right(a);
+
+                       if (is_Const(c)) {
+                               tarval *tv = get_Const_tarval(c);
+
+                               if (tarval_is_long(tv) && get_tarval_long(tv) == get_mode_size_bits(mode) - 1) {
+                                       /* -(a >>s (size-1)) = a >>u (size-1) */
+                                       ir_node *v = get_Shrs_left(a);
+
+                                       n = new_rd_Shr(get_irn_dbg_info(n), current_ir_graph, get_irn_n(n, -1), v, c, mode);
+                                       DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_PREDICATE);
+                                       return n;
+                               }
+                       }
+               }
+       }
+       if (is_Sub(a)) {
                /* - (a-b) = b - a */
                ir_node *la  = get_Sub_left(a);
                ir_node *ra  = get_Sub_right(a);
@@ -3066,6 +3104,7 @@ static ir_node *transform_node_Minus(ir_node *n) {
 
                n = new_rd_Sub(get_irn_dbg_info(n), current_ir_graph, blk, ra, la, mode);
                DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_MINUS_SUB);
+               return n;
        }
 
        return n;

diff --git a/ir/stat/stat_dmp.c b/ir/stat/stat_dmp.c
index 944f3e8..a9e9e77 100644 (file)
--- a/ir/stat/stat_dmp.c
+++ b/ir/stat/stat_dmp.c
@@ -106,6 +106,7 @@ static const struct {
        { FS_OPT_ADD_X_NOT_X,    "algebraic simplification: ~x + x = -1" },
        { FS_OPT_FP_INV_MUL,     "algebraic simplification:  x / y = x * (1.0/y)" },
        { FS_OPT_CONST_PHI,      "constant evaluation on Phi node" },
+       { FS_OPT_PREDICATE,      "predicate optimization" },
        { FS_BE_IA32_LEA,        "ia32 Backend transformation: Lea was created" },
        { FS_BE_IA32_LOAD_LEA,   "ia32 Backend transformation: Load merged with a Lea" },
        { FS_BE_IA32_STORE_LEA,  "ia32 Backend transformation: Store merged with a Lea" },