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re PR tree-optimization/22360 (upper_bound_in_type and lower_bound_in_type are buggy)

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PR tree-optimization/22360
	* tree.c (upper_bound_in_type): Fix calculations for casting
	to a non-wider signed type and casting a signed value to a
	wider unsigned type.
	(lower_bound_in_type): Fix calculations for casting to a
	non-wider signed type.

From-SVN: r101785
This commit is contained in:
Kazu Hirata 2005-07-08 18:49:05 +00:00 • committed by Kazu Hirata
parent d5c7794157
commit ea9a5df4c2
2 changed files with 87 additions and 41 deletions
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9
gcc/ChangeLog
View file

@ -1,3 +1,12 @@
2005-07-08 Kazu Hirata <kazu@codesourcery.com>
PR tree-optimization/22360
* tree.c (upper_bound_in_type): Fix calculations for casting
to a non-wider signed type and casting a signed value to a
wider unsigned type.
(lower_bound_in_type): Fix calculations for casting to a
non-wider signed type.
2005-07-08 Andrew Pinski <pinskia@physics.uc.edu>
PR tree-opt/22356

119
gcc/tree.c
View file

@ -6417,43 +6417,64 @@ tree
upper_bound_in_type (tree outer, tree inner)
{
unsigned HOST_WIDE_INT lo, hi;
unsigned bits = TYPE_PRECISION (inner);
unsigned int det = 0;
unsigned oprec = TYPE_PRECISION (outer);
unsigned iprec = TYPE_PRECISION (inner);
unsigned prec;
if (TYPE_UNSIGNED (outer) || TYPE_UNSIGNED (inner))
/* Compute a unique number for every combination. */
det |= (oprec > iprec) ? 4 : 0;
det |= TYPE_UNSIGNED (outer) ? 2 : 0;
det |= TYPE_UNSIGNED (inner) ? 1 : 0;
/* Determine the exponent to use. */
switch (det)
{
/* Zero extending in these cases. */
if (bits <= HOST_BITS_PER_WIDE_INT)
{
hi = 0;
lo = (~(unsigned HOST_WIDE_INT) 0)
>> (HOST_BITS_PER_WIDE_INT - bits);
}
else
{
hi = (~(unsigned HOST_WIDE_INT) 0)
>> (2 * HOST_BITS_PER_WIDE_INT - bits);
lo = ~(unsigned HOST_WIDE_INT) 0;
}
case 0:
case 1:
/* oprec <= iprec, outer: signed, inner: don't care. */
prec = oprec - 1;
break;
case 2:
case 3:
/* oprec <= iprec, outer: unsigned, inner: don't care. */
prec = oprec;
break;
case 4:
/* oprec > iprec, outer: signed, inner: signed. */
prec = iprec - 1;
break;
case 5:
/* oprec > iprec, outer: signed, inner: unsigned. */
prec = iprec;
break;
case 6:
/* oprec > iprec, outer: unsigned, inner: signed. */
prec = oprec;
break;
case 7:
/* oprec > iprec, outer: unsigned, inner: unsigned. */
prec = iprec;
break;
default:
gcc_unreachable ();
}
/* Compute 2^^prec - 1. */
if (prec <= HOST_BITS_PER_WIDE_INT)
{
hi = 0;
lo = ((~(unsigned HOST_WIDE_INT) 0)
>> (HOST_BITS_PER_WIDE_INT - prec));
}
else
{
/* Sign extending in these cases. */
if (bits <= HOST_BITS_PER_WIDE_INT)
{
hi = 0;
lo = (~(unsigned HOST_WIDE_INT) 0)
>> (HOST_BITS_PER_WIDE_INT - bits) >> 1;
}
else
{
hi = (~(unsigned HOST_WIDE_INT) 0)
>> (2 * HOST_BITS_PER_WIDE_INT - bits) >> 1;
lo = ~(unsigned HOST_WIDE_INT) 0;
}
hi = ((~(unsigned HOST_WIDE_INT) 0)
>> (2 * HOST_BITS_PER_WIDE_INT - prec));
lo = ~(unsigned HOST_WIDE_INT) 0;
}
return fold_convert (outer,
build_int_cst_wide (inner, lo, hi));
return build_int_cst_wide (outer, lo, hi);
}
/* Returns the smallest value obtainable by casting something in INNER type to
@ -6463,23 +6484,39 @@ tree
lower_bound_in_type (tree outer, tree inner)
{
unsigned HOST_WIDE_INT lo, hi;
unsigned bits = TYPE_PRECISION (inner);
unsigned oprec = TYPE_PRECISION (outer);
unsigned iprec = TYPE_PRECISION (inner);
if (TYPE_UNSIGNED (outer) || TYPE_UNSIGNED (inner))
/* If OUTER type is unsigned, we can definitely cast 0 to OUTER type
and obtain 0. */
if (TYPE_UNSIGNED (outer)
/* If we are widening something of an unsigned type, OUTER type
contains all values of INNER type. In particular, both INNER
and OUTER types have zero in common. */
|| (oprec > iprec && TYPE_UNSIGNED (inner)))
lo = hi = 0;
else if (bits <= HOST_BITS_PER_WIDE_INT)
{
hi = ~(unsigned HOST_WIDE_INT) 0;
lo = (~(unsigned HOST_WIDE_INT) 0) << (bits - 1);
}
else
{
hi = (~(unsigned HOST_WIDE_INT) 0) << (bits - HOST_BITS_PER_WIDE_INT - 1);
lo = 0;
/* If we are widening a signed type to another signed type, we
want to obtain -2^^(iprec-1). If we are keeping the
precision or narrowing to a signed type, we want to obtain
-2^(oprec-1). */
unsigned prec = oprec > iprec ? iprec : oprec;
if (prec <= HOST_BITS_PER_WIDE_INT)
{
hi = ~(unsigned HOST_WIDE_INT) 0;
lo = (~(unsigned HOST_WIDE_INT) 0) << (prec - 1);
}
else
{
hi = ((~(unsigned HOST_WIDE_INT) 0)
<< (prec - HOST_BITS_PER_WIDE_INT - 1));
lo = 0;
}
}
return fold_convert (outer,
build_int_cst_wide (inner, lo, hi));
return build_int_cst_wide (outer, lo, hi);
}
/* Return nonzero if two operands that are suitable for PHI nodes are