static tree
chrec_convert_1 (tree type, tree chrec, tree at_stmt,
bool use_overflow_semantics)
{
tree ct, res;
tree base, step;
struct loop *loop;
if (automatically_generated_chrec_p (chrec))
return chrec;
ct = chrec_type (chrec);
if (ct == type)
return chrec;
if (!evolution_function_is_affine_p (chrec))
goto keep_cast;
loop = current_loops->parray[CHREC_VARIABLE (chrec)];
base = CHREC_LEFT (chrec);
step = CHREC_RIGHT (chrec);
if (convert_affine_scev (loop, type, &base, &step, at_stmt,
use_overflow_semantics))
return build_polynomial_chrec (loop->num, base, step);
/* If we cannot propagate the cast inside the chrec, just keep the cast. */
keep_cast:
res = fold_convert (type, chrec);
/* Don't propagate overflows. */
if (CONSTANT_CLASS_P (res))
{
TREE_CONSTANT_OVERFLOW (res) = 0;
TREE_OVERFLOW (res) = 0;
}
/* But reject constants that don't fit in their type after conversion.
This can happen if TYPE_MIN_VALUE or TYPE_MAX_VALUE are not the
natural values associated with TYPE_PRECISION and TYPE_UNSIGNED,
and can cause problems later when computing niters of loops. Note
that we don't do the check before converting because we don't want
to reject conversions of negative chrecs to unsigned types. */
if (TREE_CODE (res) == INTEGER_CST
&& TREE_CODE (type) == INTEGER_TYPE
&& !int_fits_type_p (res, type))
res = chrec_dont_know;
return res;
}
tree
chrec_convert_aggressive (tree type, tree chrec, bool *fold_conversions)
{
tree inner_type, left, right, lc, rc, rtype;
gcc_assert (fold_conversions != NULL);
if (automatically_generated_chrec_p (chrec)
|| TREE_CODE (chrec) != POLYNOMIAL_CHREC)
return NULL_TREE;
inner_type = TREE_TYPE (chrec);
if (TYPE_PRECISION (type) > TYPE_PRECISION (inner_type))
return NULL_TREE;
if (useless_type_conversion_p (type, inner_type))
return NULL_TREE;
if (!*fold_conversions && evolution_function_is_affine_p (chrec))
{
tree base, step;
struct loop *loop;
loop = get_chrec_loop (chrec);
base = CHREC_LEFT (chrec);
step = CHREC_RIGHT (chrec);
if (convert_affine_scev (loop, type, &base, &step, NULL, true))
return build_polynomial_chrec (loop->num, base, step);
}
rtype = POINTER_TYPE_P (type) ? sizetype : type;
left = CHREC_LEFT (chrec);
right = CHREC_RIGHT (chrec);
lc = chrec_convert_aggressive (type, left, fold_conversions);
if (!lc)
lc = chrec_convert (type, left, NULL);
rc = chrec_convert_aggressive (rtype, right, fold_conversions);
if (!rc)
rc = chrec_convert (rtype, right, NULL);
*fold_conversions = true;
return build_polynomial_chrec (CHREC_VARIABLE (chrec), lc, rc);
}
static tree
chrec_convert_1 (tree type, tree chrec, gimple *at_stmt,
bool use_overflow_semantics)
{
tree ct, res;
tree base, step;
struct loop *loop;
if (automatically_generated_chrec_p (chrec))
return chrec;
ct = chrec_type (chrec);
if (useless_type_conversion_p (type, ct))
return chrec;
if (!evolution_function_is_affine_p (chrec))
goto keep_cast;
loop = get_chrec_loop (chrec);
base = CHREC_LEFT (chrec);
step = CHREC_RIGHT (chrec);
if (convert_affine_scev (loop, type, &base, &step, at_stmt,
use_overflow_semantics))
return build_polynomial_chrec (loop->num, base, step);
/* If we cannot propagate the cast inside the chrec, just keep the cast. */
keep_cast:
/* Fold will not canonicalize (long)(i - 1) to (long)i - 1 because that
may be more expensive. We do want to perform this optimization here
though for canonicalization reasons. */
if (use_overflow_semantics
&& (TREE_CODE (chrec) == PLUS_EXPR
|| TREE_CODE (chrec) == MINUS_EXPR)
&& TREE_CODE (type) == INTEGER_TYPE
&& TREE_CODE (ct) == INTEGER_TYPE
&& TYPE_PRECISION (type) > TYPE_PRECISION (ct)
&& TYPE_OVERFLOW_UNDEFINED (ct))
res = fold_build2 (TREE_CODE (chrec), type,
fold_convert (type, TREE_OPERAND (chrec, 0)),
fold_convert (type, TREE_OPERAND (chrec, 1)));
/* Similar perform the trick that (signed char)((int)x + 2) can be
narrowed to (signed char)((unsigned char)x + 2). */
else if (use_overflow_semantics
&& TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& TREE_CODE (ct) == INTEGER_TYPE
&& TREE_CODE (type) == INTEGER_TYPE
&& TYPE_OVERFLOW_UNDEFINED (type)
&& TYPE_PRECISION (type) < TYPE_PRECISION (ct))
{
tree utype = unsigned_type_for (type);
res = build_polynomial_chrec (CHREC_VARIABLE (chrec),
fold_convert (utype,
CHREC_LEFT (chrec)),
fold_convert (utype,
CHREC_RIGHT (chrec)));
res = chrec_convert_1 (type, res, at_stmt, use_overflow_semantics);
}
else
res = fold_convert (type, chrec);
/* Don't propagate overflows. */
if (CONSTANT_CLASS_P (res))
TREE_OVERFLOW (res) = 0;
/* But reject constants that don't fit in their type after conversion.
This can happen if TYPE_MIN_VALUE or TYPE_MAX_VALUE are not the
natural values associated with TYPE_PRECISION and TYPE_UNSIGNED,
and can cause problems later when computing niters of loops. Note
that we don't do the check before converting because we don't want
to reject conversions of negative chrecs to unsigned types. */
if (TREE_CODE (res) == INTEGER_CST
&& TREE_CODE (type) == INTEGER_TYPE
&& !int_fits_type_p (res, type))
res = chrec_dont_know;
return res;
}
