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re PR middle-end/29695 (Folding breaks (a & 0x80) ? 0x80 : 0 for unsigned char or unsigned short a)

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PR middle-end/29695
	* fold-const.c (fold_ternary): Fix A < 0 ? <sign bit of A> : 0
	simplification.

	* gcc.c-torture/execute/pr29695-1.c: New test.
	* gcc.c-torture/execute/pr29695-2.c: New test.

From-SVN: r118497
This commit is contained in:
Jakub Jelinek 2006-11-05 13:13:46 +01:00 • committed by Jakub Jelinek
parent 75c0ed055f
commit 789e604dfa
5 changed files with 245 additions and 7 deletions
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6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2006-11-05 Jakub Jelinek <jakub@redhat.com>
PR middle-end/29695
* fold-const.c (fold_ternary): Fix A < 0 ? <sign bit of A> : 0
simplification.
2006-11-04 Uros Bizjak <ubizjak@gmail.com>
PR target/26915

77
gcc/fold-const.c
View file

@ -11380,13 +11380,76 @@ fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
/* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
if (TREE_CODE (arg0) == LT_EXPR
&& integer_zerop (TREE_OPERAND (arg0, 1))
&& integer_zerop (op2)
&& (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
return fold_convert (type,
fold_build2 (BIT_AND_EXPR,
TREE_TYPE (tem), tem,
fold_convert (TREE_TYPE (tem), arg1)));
&& integer_zerop (TREE_OPERAND (arg0, 1))
&& integer_zerop (op2)
&& (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
{
/* sign_bit_p only checks ARG1 bits within A's precision.
If <sign bit of A> has wider type than A, bits outside
of A's precision in <sign bit of A> need to be checked.
If they are all 0, this optimization needs to be done
in unsigned A's type, if they are all 1 in signed A's type,
otherwise this can't be done. */
if (TYPE_PRECISION (TREE_TYPE (tem))
< TYPE_PRECISION (TREE_TYPE (arg1))
&& TYPE_PRECISION (TREE_TYPE (tem))
< TYPE_PRECISION (type))
{
unsigned HOST_WIDE_INT mask_lo;
HOST_WIDE_INT mask_hi;
int inner_width, outer_width;
tree tem_type;
inner_width = TYPE_PRECISION (TREE_TYPE (tem));
outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
if (outer_width > TYPE_PRECISION (type))
outer_width = TYPE_PRECISION (type);
if (outer_width > HOST_BITS_PER_WIDE_INT)
{
mask_hi = ((unsigned HOST_WIDE_INT) -1
>> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
mask_lo = -1;
}
else
{
mask_hi = 0;
mask_lo = ((unsigned HOST_WIDE_INT) -1
>> (HOST_BITS_PER_WIDE_INT - outer_width));
}
if (inner_width > HOST_BITS_PER_WIDE_INT)
{
mask_hi &= ~((unsigned HOST_WIDE_INT) -1
>> (HOST_BITS_PER_WIDE_INT - inner_width));
mask_lo = 0;
}
else
mask_lo &= ~((unsigned HOST_WIDE_INT) -1
>> (HOST_BITS_PER_WIDE_INT - inner_width));
if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
&& (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
{
tem_type = lang_hooks.types.signed_type (TREE_TYPE (tem));
tem = fold_convert (tem_type, tem);
}
else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
&& (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
{
tem_type = lang_hooks.types.unsigned_type (TREE_TYPE (tem));
tem = fold_convert (tem_type, tem);
}
else
tem = NULL;
}
if (tem)
return fold_convert (type,
fold_build2 (BIT_AND_EXPR,
TREE_TYPE (tem), tem,
fold_convert (TREE_TYPE (tem),
arg1)));
}
/* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
already handled above. */

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2006-11-05 Jakub Jelinek <jakub@redhat.com>
PR middle-end/29695
* gcc.c-torture/execute/pr29695-1.c: New test.
* gcc.c-torture/execute/pr29695-2.c: New test.
2006-11-05 Paul Thomas <pault@gcc.gnu.org>
PR fortran/29565

83
gcc/testsuite/gcc.c-torture/execute/pr29695-1.c Normal file
View file

@ -0,0 +1,83 @@
/* PR middle-end/29695 */
extern void abort (void);
int
f1 (void)
{
int a = 128;
return (a & 0x80) ? 0x80 : 0;
}
int
f2 (void)
{
unsigned char a = 128;
return (a & 0x80) ? 0x80 : 0;
}
int
f3 (void)
{
unsigned char a = 128;
return (a & 0x80) ? 0x380 : 0;
}
int
f4 (void)
{
unsigned char a = 128;
return (a & 0x80) ? -128 : 0;
}
long long
f5 (void)
{
long long a = 0x80000000LL;
return (a & 0x80000000) ? 0x80000000LL : 0LL;
}
long long
f6 (void)
{
unsigned int a = 0x80000000;
return (a & 0x80000000) ? 0x80000000LL : 0LL;
}
long long
f7 (void)
{
unsigned int a = 0x80000000;
return (a & 0x80000000) ? 0x380000000LL : 0LL;
}
long long
f8 (void)
{
unsigned int a = 0x80000000;
return (a & 0x80000000) ? -2147483648LL : 0LL;
}
int
main (void)
{
if ((char) 128 != -128 || (int) 0x80000000 != -2147483648)
return 0;
if (f1 () != 128)
abort ();
if (f2 () != 128)
abort ();
if (f3 () != 896)
abort ();
if (f4 () != -128)
abort ();
if (f5 () != 0x80000000LL)
abort ();
if (f6 () != 0x80000000LL)
abort ();
if (f7 () != 0x380000000LL)
abort ();
if (f8 () != -2147483648LL)
abort ();
return 0;
}

80
gcc/testsuite/gcc.c-torture/execute/pr29695-2.c Normal file
View file

@ -0,0 +1,80 @@
/* PR middle-end/29695 */
extern void abort (void);
int a = 128;
unsigned char b = 128;
long long c = 0x80000000LL;
unsigned int d = 0x80000000;
int
f1 (void)
{
return (a & 0x80) ? 0x80 : 0;
}
int
f2 (void)
{
return (b & 0x80) ? 0x80 : 0;
}
int
f3 (void)
{
return (b & 0x80) ? 0x380 : 0;
}
int
f4 (void)
{
return (b & 0x80) ? -128 : 0;
}
long long
f5 (void)
{
return (c & 0x80000000) ? 0x80000000LL : 0LL;
}
long long
f6 (void)
{
return (d & 0x80000000) ? 0x80000000LL : 0LL;
}
long long
f7 (void)
{
return (d & 0x80000000) ? 0x380000000LL : 0LL;
}
long long
f8 (void)
{
return (d & 0x80000000) ? -2147483648LL : 0LL;
}
int
main (void)
{
if ((char) 128 != -128 || (int) 0x80000000 != -2147483648)
return 0;
if (f1 () != 128)
abort ();
if (f2 () != 128)
abort ();
if (f3 () != 896)
abort ();
if (f4 () != -128)
abort ();
if (f5 () != 0x80000000LL)
abort ();
if (f6 () != 0x80000000LL)
abort ();
if (f7 () != 0x380000000LL)
abort ();
if (f8 () != -2147483648LL)
abort ();
return 0;
}