fold-const.c (fold_binary_loc): Move ~x & ~y -> ~(x | y) and ~x | ~y -> ~(x & y)...

2015-06-30  Richard Biener  <rguenther@suse.de>

	* fold-const.c (fold_binary_loc): Move ~x & ~y -> ~(x | y) and
	~x | ~y -> ~(x & y), (x & CST) ^ (x & CST2) -> (x & CST) | (x & CST2),
	(X | Y) ^ X -> Y & ~ X, ~X ^ ~Y to X ^ Y and ~X ^ C to X ^ ~C ...
	* match.pd: ... to patterns here.

From-SVN: r225184

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 59d3052da9d823d5040d2b980df4e02bc76b999b..8ac39dc1930d7169c79baf2e42fba43b10d7d8d0 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2015-06-30  Richard Biener  <rguenther@suse.de>
+
+       * fold-const.c (fold_binary_loc): Move ~x & ~y -> ~(x | y) and
+       ~x | ~y -> ~(x & y), (x & CST) ^ (x & CST2) -> (x & CST) | (x & CST2),
+       (X | Y) ^ X -> Y & ~ X, ~X ^ ~Y to X ^ Y and ~X ^ C to X ^ ~C ...
+       * match.pd: ... to patterns here.
+
 2015-06-30  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/66704

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 67115d2377eb001a7b715a1317e9699fe78113d0..7e30002122037e5d8914fc457bdb6d27febabdd6 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -10974,24 +10974,6 @@ fold_binary_loc (location_t loc,
       if (t1 != NULL_TREE)
        return t1;
 
-      /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
-
-        This results in more efficient code for machines without a NAND
-        instruction.  Combine will canonicalize to the first form
-        which will allow use of NAND instructions provided by the
-        backend if they exist.  */
-      if (TREE_CODE (arg0) == BIT_NOT_EXPR
-         && TREE_CODE (arg1) == BIT_NOT_EXPR)
-       {
-         return
-           fold_build1_loc (loc, BIT_NOT_EXPR, type,
-                        build2 (BIT_AND_EXPR, type,
-                                fold_convert_loc (loc, type,
-                                                  TREE_OPERAND (arg0, 0)),
-                                fold_convert_loc (loc, type,
-                                                  TREE_OPERAND (arg1, 0))));
-       }
-
       /* See if this can be simplified into a rotate first.  If that
         is unsuccessful continue in the association code.  */
       goto bit_rotate;
@@ -11015,90 +10997,6 @@ fold_binary_loc (location_t loc,
          return omit_one_operand_loc (loc, type, t1, arg0);
        }
 
-      /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
-         with a constant, and the two constants have no bits in common,
-        we should treat this as a BIT_IOR_EXPR since this may produce more
-        simplifications.  */
-      if (TREE_CODE (arg0) == BIT_AND_EXPR
-         && TREE_CODE (arg1) == BIT_AND_EXPR
-         && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
-         && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
-         && wi::bit_and (TREE_OPERAND (arg0, 1),
-                         TREE_OPERAND (arg1, 1)) == 0)
-       {
-         code = BIT_IOR_EXPR;
-         goto bit_ior;
-       }
-
-      /* (X | Y) ^ X -> Y & ~ X*/
-      if (TREE_CODE (arg0) == BIT_IOR_EXPR
-          && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
-        {
-         tree t2 = TREE_OPERAND (arg0, 1);
-         t1 = fold_build1_loc (loc, BIT_NOT_EXPR, TREE_TYPE (arg1),
-                           arg1);
-         t1 = fold_build2_loc (loc, BIT_AND_EXPR, type,
-                           fold_convert_loc (loc, type, t2),
-                           fold_convert_loc (loc, type, t1));
-         return t1;
-       }
-
-      /* (Y | X) ^ X -> Y & ~ X*/
-      if (TREE_CODE (arg0) == BIT_IOR_EXPR
-          && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
-        {
-         tree t2 = TREE_OPERAND (arg0, 0);
-         t1 = fold_build1_loc (loc, BIT_NOT_EXPR, TREE_TYPE (arg1),
-                           arg1);
-         t1 = fold_build2_loc (loc, BIT_AND_EXPR, type,
-                           fold_convert_loc (loc, type, t2),
-                           fold_convert_loc (loc, type, t1));
-         return t1;
-       }
-
-      /* X ^ (X | Y) -> Y & ~ X*/
-      if (TREE_CODE (arg1) == BIT_IOR_EXPR
-          && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
-        {
-         tree t2 = TREE_OPERAND (arg1, 1);
-         t1 = fold_build1_loc (loc, BIT_NOT_EXPR, TREE_TYPE (arg0),
-                           arg0);
-         t1 = fold_build2_loc (loc, BIT_AND_EXPR, type,
-                           fold_convert_loc (loc, type, t2),
-                           fold_convert_loc (loc, type, t1));
-         return t1;
-       }
-
-      /* X ^ (Y | X) -> Y & ~ X*/
-      if (TREE_CODE (arg1) == BIT_IOR_EXPR
-          && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
-        {
-         tree t2 = TREE_OPERAND (arg1, 0);
-         t1 = fold_build1_loc (loc, BIT_NOT_EXPR, TREE_TYPE (arg0),
-                           arg0);
-         t1 = fold_build2_loc (loc, BIT_AND_EXPR, type,
-                           fold_convert_loc (loc, type, t2),
-                           fold_convert_loc (loc, type, t1));
-         return t1;
-       }
-
-      /* Convert ~X ^ ~Y to X ^ Y.  */
-      if (TREE_CODE (arg0) == BIT_NOT_EXPR
-         && TREE_CODE (arg1) == BIT_NOT_EXPR)
-       return fold_build2_loc (loc, code, type,
-                           fold_convert_loc (loc, type,
-                                             TREE_OPERAND (arg0, 0)),
-                           fold_convert_loc (loc, type,
-                                             TREE_OPERAND (arg1, 0)));
-
-      /* Convert ~X ^ C to X ^ ~C.  */
-      if (TREE_CODE (arg0) == BIT_NOT_EXPR
-         && TREE_CODE (arg1) == INTEGER_CST)
-       return fold_build2_loc (loc, code, type,
-                           fold_convert_loc (loc, type,
-                                             TREE_OPERAND (arg0, 0)),
-                           fold_build1_loc (loc, BIT_NOT_EXPR, type, arg1));
-
       /* Fold (X & 1) ^ 1 as (X & 1) == 0.  */
       if (TREE_CODE (arg0) == BIT_AND_EXPR
          && INTEGRAL_TYPE_P (type)
@@ -11410,23 +11308,6 @@ fold_binary_loc (location_t loc,
              fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
        }
 
-      /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
-
-        This results in more efficient code for machines without a NOR
-        instruction.  Combine will canonicalize to the first form
-        which will allow use of NOR instructions provided by the
-        backend if they exist.  */
-      if (TREE_CODE (arg0) == BIT_NOT_EXPR
-         && TREE_CODE (arg1) == BIT_NOT_EXPR)
-       {
-         return fold_build1_loc (loc, BIT_NOT_EXPR, type,
-                             build2 (BIT_IOR_EXPR, type,
-                                     fold_convert_loc (loc, type,
-                                                       TREE_OPERAND (arg0, 0)),
-                                     fold_convert_loc (loc, type,
-                                                       TREE_OPERAND (arg1, 0))));
-       }
-
       /* If arg0 is derived from the address of an object or function, we may
         be able to fold this expression using the object or function's
         alignment.  */

diff --git a/gcc/match.pd b/gcc/match.pd
index d81ea53dae406b1b90b27c5750fae2634c6d3a64..682784b094b5e7b45b4bd6fe5396ef3af0888b74 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -389,6 +389,47 @@ along with GCC; see the file COPYING3.  If not see
  (bit_and:c (bit_ior:c @0 @1) (bit_xor:c @1 (bit_not @0)))
  (bit_and @0 @1))
 
+/* ~x & ~y -> ~(x | y)
+   ~x | ~y -> ~(x & y) */
+(for op (bit_and bit_ior)
+     rop (bit_ior bit_and)
+ (simplify
+  (op (convert1? (bit_not @0)) (convert2? (bit_not @1)))
+  (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
+       && tree_nop_conversion_p (type, TREE_TYPE (@1)))
+   (bit_not (rop (convert @0) (convert @1))))))
+
+/* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
+   with a constant, and the two constants have no bits in common,
+   we should treat this as a BIT_IOR_EXPR since this may produce more
+   simplifications.  */
+(simplify
+ (bit_xor (convert1? (bit_and@4 @0 INTEGER_CST@1))
+          (convert2? (bit_and@5 @2 INTEGER_CST@3)))
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
+      && tree_nop_conversion_p (type, TREE_TYPE (@2))
+      && wi::bit_and (@1, @3) == 0)
+  (bit_ior (convert @4) (convert @5))))
+
+/* (X | Y) ^ X -> Y & ~ X*/
+(simplify
+ (bit_xor:c (convert? (bit_ior:c @0 @1)) (convert? @0))
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
+  (convert (bit_and @1 (bit_not @0)))))
+
+/* Convert ~X ^ ~Y to X ^ Y.  */
+(simplify
+ (bit_xor (convert1? (bit_not @0)) (convert2? (bit_not @1)))
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
+      && tree_nop_conversion_p (type, TREE_TYPE (@1)))
+  (bit_xor (convert @0) (convert @1))))
+
+/* Convert ~X ^ C to X ^ ~C.  */
+(simplify
+ (bit_xor (convert? (bit_not @0)) INTEGER_CST@1)
+ (bit_xor (convert @0) (bit_not @1)))
+
+
 (simplify
  (abs (abs@1 @0))
  @1)