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fold-const.c (fold_unary): Fold (T1)(~(T2)X) as ~(T1)X...

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* fold-const.c (fold_unary) <NOP_EXPR>: Fold (T1)(~(T2)X) as
	~(T1)X, when T1 and T2 are integer types of the same precision
	and (T2)X isn't an extension.

	* gcc.dg/fold-convnotconv-1.c: New test case.

From-SVN: r112455
This commit is contained in:
Roger Sayle 2006-03-28 17:06:19 +00:00 • committed by Roger Sayle
parent 792617a52a
commit e8206491f0
4 changed files with 43 additions and 0 deletions
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6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2006-03-28 Roger Sayle <roger@eyesopen.com>
* fold-const.c (fold_unary) <NOP_EXPR>: Fold (T1)(~(T2)X) as
~(T1)X, when T1 and T2 are integer types of the same precision
and (T2)X isn't an extension.
2006-03-28 Jeff Law <law@redhat.com>
PR tree-optimization/26796

16
gcc/fold-const.c
View file

@ -7074,6 +7074,22 @@ fold_unary (enum tree_code code, tree type, tree op0)
TREE_OPERAND (arg0, 1));
}
/* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
of the same precision, and X is a integer type not narrower than
types T1 or T2, i.e. the cast (T2)X isn't an extension. */
if (INTEGRAL_TYPE_P (type)
&& TREE_CODE (op0) == BIT_NOT_EXPR
&& INTEGRAL_TYPE_P (TREE_TYPE (op0))
&& (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
|| TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
&& TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
{
tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
&& TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
}
tem = fold_convert_const (code, type, arg0);
return tem ? tem : NULL_TREE;

4
gcc/testsuite/ChangeLog
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@ -1,3 +1,7 @@
2006-03-28 Roger Sayle <roger@eyesopen.com>
* gcc.dg/fold-convnotconv-1.c: New test case.
2006-03-28 Paul Thomas <pault@gcc.gnu.org>
PR fortran/26779

17
gcc/testsuite/gcc.dg/fold-convnotconv-1.c Normal file
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@ -0,0 +1,17 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-original" } */
int test1(int a)
{
return ~(unsigned int)a;
}
unsigned int test2(unsigned int b)
{
return ~(int)b;
}
/* { dg-final { scan-tree-dump-times "~a" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "~b" 1 "original" } } */
/* { dg-final { cleanup-tree-dump "original" } } */