The following moves some bitwise patterns from the match-and-simplify
branch, extending them with proper conditional converts and removing
the corresponding patterns from fold-const.c
Bootstrap & regtest in progress on x86_64-unknown-linux-gnu.
Richard.
2015-06-30 Richard Biener <rguent...@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.
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c (revision 225164)
+++ gcc/fold-const.c (working copy)
@@ -10996,24 +10996,6 @@ 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;
@@ -11037,90 +11019,6 @@ 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)
@@ -11432,23 +11330,6 @@ 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. */
Index: gcc/match.pd
===================================================================
--- gcc/match.pd (revision 225164)
+++ gcc/match.pd (working copy)
@@ -389,6 +389,47 @@ (define_operator_list swapped_tcc_compar
(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 (negate @0))
(abs @0))
