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fold-const.c (fold_binary_loc): Move ~X ^ X -> -1 and (X & Y) ^ Y -> ~X & Y transforms to ...

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2015-07-01  Richard Biener  <rguenther@suse.de>

	* fold-const.c (fold_binary_loc): Move ~X ^ X -> -1 and
	(X & Y) ^ Y -> ~X & Y transforms to ...
	* match.pd: ... here.

From-SVN: r225225
This commit is contained in:
Richard Biener 2015-07-01 07:42:10 +00:00 committed by Richard Biener
parent a64be36b47
commit 97e7739106
3 changed files with 16 additions and 57 deletions
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6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2015-07-01 Richard Biener <rguenther@suse.de>
* fold-const.c (fold_binary_loc): Move ~X ^ X -> -1 and
(X & Y) ^ Y -> ~X & Y transforms to ...
* match.pd: ... here.
2015-07-01 Richard Biener <rguenther@suse.de>
* genmatch.c (expr::gen_transform): Shortcut re-simplifying

57
gcc/fold-const.c
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@ -10979,24 +10979,6 @@ fold_binary_loc (location_t loc,
goto bit_rotate;
case BIT_XOR_EXPR:
/* ~X ^ X is -1. */
if (TREE_CODE (arg0) == BIT_NOT_EXPR
&& operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
{
t1 = build_zero_cst (type);
t1 = fold_unary_loc (loc, BIT_NOT_EXPR, type, t1);
return omit_one_operand_loc (loc, type, t1, arg1);
}
/* X ^ ~X is -1. */
if (TREE_CODE (arg1) == BIT_NOT_EXPR
&& operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
{
t1 = build_zero_cst (type);
t1 = fold_unary_loc (loc, BIT_NOT_EXPR, type, t1);
return omit_one_operand_loc (loc, type, t1, arg0);
}
/* Fold (X & 1) ^ 1 as (X & 1) == 0. */
if (TREE_CODE (arg0) == BIT_AND_EXPR
&& INTEGRAL_TYPE_P (type)
@ -11005,45 +10987,6 @@ fold_binary_loc (location_t loc,
return fold_build2_loc (loc, EQ_EXPR, type, arg0,
build_zero_cst (TREE_TYPE (arg0)));
/* Fold (X & Y) ^ Y as ~X & Y. */
if (TREE_CODE (arg0) == BIT_AND_EXPR
&& operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
{
tem = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
return fold_build2_loc (loc, BIT_AND_EXPR, type,
fold_build1_loc (loc, BIT_NOT_EXPR, type, tem),
fold_convert_loc (loc, type, arg1));
}
/* Fold (X & Y) ^ X as ~Y & X. */
if (TREE_CODE (arg0) == BIT_AND_EXPR
&& operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
&& reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
{
tem = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 1));
return fold_build2_loc (loc, BIT_AND_EXPR, type,
fold_build1_loc (loc, BIT_NOT_EXPR, type, tem),
fold_convert_loc (loc, type, arg1));
}
/* Fold X ^ (X & Y) as X & ~Y. */
if (TREE_CODE (arg1) == BIT_AND_EXPR
&& operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
{
tem = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 1));
return fold_build2_loc (loc, BIT_AND_EXPR, type,
fold_convert_loc (loc, type, arg0),
fold_build1_loc (loc, BIT_NOT_EXPR, type, tem));
}
/* Fold X ^ (Y & X) as ~Y & X. */
if (TREE_CODE (arg1) == BIT_AND_EXPR
&& operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
&& reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
{
tem = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 0));
return fold_build2_loc (loc, BIT_AND_EXPR, type,
fold_build1_loc (loc, BIT_NOT_EXPR, type, tem),
fold_convert_loc (loc, type, arg0));
}
/* See if this can be simplified into a rotate first. If that
is unsuccessful continue in the association code. */
goto bit_rotate;

10
gcc/match.pd
View File

@ -298,6 +298,11 @@ along with GCC; see the file COPYING3. If not see
(bit_xor @0 integer_all_onesp@1)
(bit_not @0))
/* ~X ^ X is -1. */
(simplify
(bit_xor:c (bit_not @0) @0)
{ build_all_ones_cst (type); })
/* x & ~0 -> x */
(simplify
(bit_and @0 integer_all_onesp)
@ -428,6 +433,11 @@ along with GCC; see the file COPYING3. If not see
(bit_xor (convert? (bit_not @0)) INTEGER_CST@1)
(bit_xor (convert @0) (bit_not @1)))
/* Fold (X & Y) ^ Y as ~X & Y. */
(simplify
(bit_xor:c (bit_and:c @0 @1) @1)
(bit_and (bit_not @0) @1))
(simplify
(abs (abs@1 @0))