tree
chrec_apply (unsigned var,
tree chrec,
tree x)
{
tree type = chrec_type (chrec);
tree res = chrec_dont_know;
if (automatically_generated_chrec_p (chrec)
|| automatically_generated_chrec_p (x)
/* When the symbols are defined in an outer loop, it is possible
to symbolically compute the apply, since the symbols are
constants with respect to the varying loop. */
|| chrec_contains_symbols_defined_in_loop (chrec, var)
|| chrec_contains_symbols (x))
return chrec_dont_know;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(chrec_apply \n");
if (evolution_function_is_affine_p (chrec))
{
/* "{a, +, b} (x)" -> "a + b*x". */
if (TREE_CODE (CHREC_LEFT (chrec)) == INTEGER_CST
&& integer_zerop (CHREC_LEFT (chrec)))
res = chrec_fold_multiply (type, CHREC_RIGHT (chrec), x);
else
res = chrec_fold_plus (type, CHREC_LEFT (chrec),
chrec_fold_multiply (type,
CHREC_RIGHT (chrec), x));
}
else if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
res = chrec;
else if (TREE_CODE (x) == INTEGER_CST
&& tree_int_cst_sgn (x) == 1)
/* testsuite/.../ssa-chrec-38.c. */
res = chrec_evaluate (var, chrec, x, 0);
else
res = chrec_dont_know;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " (varying_loop = %d\n", var);
fprintf (dump_file, ")\n (chrec = ");
print_generic_expr (dump_file, chrec, 0);
fprintf (dump_file, ")\n (x = ");
print_generic_expr (dump_file, x, 0);
fprintf (dump_file, ")\n (res = ");
print_generic_expr (dump_file, res, 0);
fprintf (dump_file, "))\n");
}
return res;
}
tree
chrec_fold_multiply (tree type,
tree op0,
tree op1)
{
if (automatically_generated_chrec_p (op0)
|| automatically_generated_chrec_p (op1))
return chrec_fold_automatically_generated_operands (op0, op1);
switch (TREE_CODE (op0))
{
case POLYNOMIAL_CHREC:
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
return chrec_fold_multiply_poly_poly (type, op0, op1);
default:
if (integer_onep (op1))
return op0;
if (integer_zerop (op1))
return build_int_cst (type, 0);
return build_polynomial_chrec
(CHREC_VARIABLE (op0),
chrec_fold_multiply (type, CHREC_LEFT (op0), op1),
chrec_fold_multiply (type, CHREC_RIGHT (op0), op1));
}
default:
if (integer_onep (op0))
return op1;
if (integer_zerop (op0))
return build_int_cst (type, 0);
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
return build_polynomial_chrec
(CHREC_VARIABLE (op1),
chrec_fold_multiply (type, CHREC_LEFT (op1), op0),
chrec_fold_multiply (type, CHREC_RIGHT (op1), op0));
default:
if (integer_onep (op1))
return op0;
if (integer_zerop (op1))
return build_int_cst (type, 0);
return fold_build2 (MULT_EXPR, type, op0, op1);
}
}
}
tree
chrec_fold_minus (tree type,
tree op0,
tree op1)
{
if (automatically_generated_chrec_p (op0)
|| automatically_generated_chrec_p (op1))
return chrec_fold_automatically_generated_operands (op0, op1);
if (integer_zerop (op1))
return op0;
return chrec_fold_plus_1 (MINUS_EXPR, type, op0, op1);
}
tree
chrec_convert_aggressive (tree type, tree chrec)
{
tree inner_type, left, right, lc, rc, rtype;
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 we cannot perform arithmetic in TYPE, avoid creating an scev. */
if (avoid_arithmetics_in_type_p (type))
return NULL_TREE;
rtype = POINTER_TYPE_P (type) ? sizetype : type;
left = CHREC_LEFT (chrec);
right = CHREC_RIGHT (chrec);
lc = chrec_convert_aggressive (type, left);
if (!lc)
lc = chrec_convert (type, left, NULL);
rc = chrec_convert_aggressive (rtype, right);
if (!rc)
rc = chrec_convert (rtype, right, NULL);
return build_polynomial_chrec (CHREC_VARIABLE (chrec), lc, rc);
}
tree
hide_evolution_in_other_loops_than_loop (tree chrec,
unsigned loop_num)
{
if (automatically_generated_chrec_p (chrec))
return chrec;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
if (CHREC_VARIABLE (chrec) == loop_num)
return build_polynomial_chrec
(loop_num,
hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
loop_num),
CHREC_RIGHT (chrec));
else if (CHREC_VARIABLE (chrec) < loop_num)
/* There is no evolution in this loop. */
return initial_condition (chrec);
else
return hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
loop_num);
default:
return chrec;
}
}
tree
hide_evolution_in_other_loops_than_loop (tree chrec,
unsigned loop_num)
{
struct loop *loop = get_loop (cfun, loop_num), *chloop;
if (automatically_generated_chrec_p (chrec))
return chrec;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
chloop = get_chrec_loop (chrec);
if (chloop == loop)
return build_polynomial_chrec
(loop_num,
hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
loop_num),
CHREC_RIGHT (chrec));
else if (flow_loop_nested_p (chloop, loop))
/* There is no evolution in this loop. */
return initial_condition (chrec);
else
{
gcc_assert (flow_loop_nested_p (loop, chloop));
return hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
loop_num);
}
default:
return chrec;
}
}
tree
chrec_type (tree chrec)
{
if (automatically_generated_chrec_p (chrec))
return NULL_TREE;
return TREE_TYPE (chrec);
}
static tree
chrec_component_in_loop_num (tree chrec,
unsigned loop_num,
bool right)
{
tree component;
struct loop *loop = get_loop (cfun, loop_num), *chloop;
if (automatically_generated_chrec_p (chrec))
return chrec;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
chloop = get_chrec_loop (chrec);
if (chloop == loop)
{
if (right)
component = CHREC_RIGHT (chrec);
else
component = CHREC_LEFT (chrec);
if (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC
|| CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec))
return component;
else
return build_polynomial_chrec
(loop_num,
chrec_component_in_loop_num (CHREC_LEFT (chrec),
loop_num,
right),
component);
}
else if (flow_loop_nested_p (chloop, loop))
/* There is no evolution part in this loop. */
return NULL_TREE;
else
{
gcc_assert (flow_loop_nested_p (loop, chloop));
return chrec_component_in_loop_num (CHREC_LEFT (chrec),
loop_num,
right);
}
default:
if (right)
return NULL_TREE;
else
return chrec;
}
}
tree
initial_condition (tree chrec)
{
if (automatically_generated_chrec_p (chrec))
return chrec;
if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
return initial_condition (CHREC_LEFT (chrec));
else
return chrec;
}
tree
chrec_fold_plus (tree type,
tree op0,
tree op1)
{
enum tree_code code;
if (automatically_generated_chrec_p (op0)
|| automatically_generated_chrec_p (op1))
return chrec_fold_automatically_generated_operands (op0, op1);
if (integer_zerop (op0))
return chrec_convert (type, op1, NULL);
if (integer_zerop (op1))
return chrec_convert (type, op0, NULL);
if (POINTER_TYPE_P (type))
code = POINTER_PLUS_EXPR;
else
code = PLUS_EXPR;
return chrec_fold_plus_1 (code, type, op0, op1);
}
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;
}
static tree
chrec_component_in_loop_num (tree chrec,
unsigned loop_num,
bool right)
{
tree component;
if (automatically_generated_chrec_p (chrec))
return chrec;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
if (CHREC_VARIABLE (chrec) == loop_num)
{
if (right)
component = CHREC_RIGHT (chrec);
else
component = CHREC_LEFT (chrec);
if (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC
|| CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec))
return component;
else
return build_polynomial_chrec
(loop_num,
chrec_component_in_loop_num (CHREC_LEFT (chrec),
loop_num,
right),
component);
}
else if (CHREC_VARIABLE (chrec) < loop_num)
/* There is no evolution part in this loop. */
return NULL_TREE;
else
return chrec_component_in_loop_num (CHREC_LEFT (chrec),
loop_num,
right);
default:
if (right)
return NULL_TREE;
else
return chrec;
}
}
tree
chrec_convert (tree type,
tree chrec)
{
tree ct;
if (automatically_generated_chrec_p (chrec))
return chrec;
ct = chrec_type (chrec);
if (ct == type)
return chrec;
if (TYPE_PRECISION (ct) < TYPE_PRECISION (type))
return count_ev_in_wider_type (type, chrec);
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
return build_polynomial_chrec (CHREC_VARIABLE (chrec),
chrec_convert (type,
CHREC_LEFT (chrec)),
chrec_convert (type,
CHREC_RIGHT (chrec)));
default:
{
tree res = fold_convert (type, chrec);
/* Don't propagate overflows. */
TREE_OVERFLOW (res) = 0;
if (CONSTANT_CLASS_P (res))
TREE_CONSTANT_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);
}
tree
chrec_replace_initial_condition (tree chrec,
tree init_cond)
{
if (automatically_generated_chrec_p (chrec))
return chrec;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
return build_polynomial_chrec
(CHREC_VARIABLE (chrec),
chrec_replace_initial_condition (CHREC_LEFT (chrec), init_cond),
CHREC_RIGHT (chrec));
default:
return init_cond;
}
}
bool
convert_affine_scev (struct loop *loop, tree type,
tree *base, tree *step, gimple *at_stmt,
bool use_overflow_semantics)
{
tree ct = TREE_TYPE (*step);
bool enforce_overflow_semantics;
bool must_check_src_overflow, must_check_rslt_overflow;
tree new_base, new_step;
tree step_type = POINTER_TYPE_P (type) ? sizetype : type;
/* In general,
(TYPE) (BASE + STEP * i) = (TYPE) BASE + (TYPE -- sign extend) STEP * i,
but we must check some assumptions.
1) If [BASE, +, STEP] wraps, the equation is not valid when precision
of CT is smaller than the precision of TYPE. For example, when we
cast unsigned char [254, +, 1] to unsigned, the values on left side
are 254, 255, 0, 1, ..., but those on the right side are
254, 255, 256, 257, ...
2) In case that we must also preserve the fact that signed ivs do not
overflow, we must additionally check that the new iv does not wrap.
For example, unsigned char [125, +, 1] casted to signed char could
become a wrapping variable with values 125, 126, 127, -128, -127, ...,
which would confuse optimizers that assume that this does not
happen. */
must_check_src_overflow = TYPE_PRECISION (ct) < TYPE_PRECISION (type);
enforce_overflow_semantics = (use_overflow_semantics
&& nowrap_type_p (type));
if (enforce_overflow_semantics)
{
/* We can avoid checking whether the result overflows in the following
cases:
-- must_check_src_overflow is true, and the range of TYPE is superset
of the range of CT -- i.e., in all cases except if CT signed and
TYPE unsigned.
-- both CT and TYPE have the same precision and signedness, and we
verify instead that the source does not overflow (this may be
easier than verifying it for the result, as we may use the
information about the semantics of overflow in CT). */
if (must_check_src_overflow)
{
if (TYPE_UNSIGNED (type) && !TYPE_UNSIGNED (ct))
must_check_rslt_overflow = true;
else
must_check_rslt_overflow = false;
}
else if (TYPE_UNSIGNED (ct) == TYPE_UNSIGNED (type)
&& TYPE_PRECISION (ct) == TYPE_PRECISION (type))
{
must_check_rslt_overflow = false;
must_check_src_overflow = true;
}
else
must_check_rslt_overflow = true;
}
else
must_check_rslt_overflow = false;
if (must_check_src_overflow
&& scev_probably_wraps_p (*base, *step, at_stmt, loop,
use_overflow_semantics))
return false;
new_base = chrec_convert (type, *base, at_stmt, use_overflow_semantics);
/* The step must be sign extended, regardless of the signedness
of CT and TYPE. This only needs to be handled specially when
CT is unsigned -- to avoid e.g. unsigned char [100, +, 255]
(with values 100, 99, 98, ...) from becoming signed or unsigned
[100, +, 255] with values 100, 355, ...; the sign-extension is
performed by default when CT is signed. */
new_step = *step;
if (TYPE_PRECISION (step_type) > TYPE_PRECISION (ct) && TYPE_UNSIGNED (ct))
{
tree signed_ct = build_nonstandard_integer_type (TYPE_PRECISION (ct), 0);
new_step = chrec_convert (signed_ct, new_step, at_stmt,
use_overflow_semantics);
}
new_step = chrec_convert (step_type, new_step, at_stmt,
use_overflow_semantics);
if (automatically_generated_chrec_p (new_base)
|| automatically_generated_chrec_p (new_step))
return false;
if (must_check_rslt_overflow
/* Note that in this case we cannot use the fact that signed variables
do not overflow, as this is what we are verifying for the new iv. */
&& scev_probably_wraps_p (new_base, new_step, at_stmt, loop, false))
return false;
*base = new_base;
*step = new_step;
return true;
}
static tree
chrec_fold_plus_1 (enum tree_code code,
tree type,
tree op0,
tree op1)
{
if (automatically_generated_chrec_p (op0)
|| automatically_generated_chrec_p (op1))
return chrec_fold_automatically_generated_operands (op0, op1);
switch (TREE_CODE (op0))
{
case POLYNOMIAL_CHREC:
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
return chrec_fold_plus_poly_poly (code, type, op0, op1);
default:
if (code == PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (op0),
chrec_fold_plus (type, CHREC_LEFT (op0), op1),
CHREC_RIGHT (op0));
else
return build_polynomial_chrec
(CHREC_VARIABLE (op0),
chrec_fold_minus (type, CHREC_LEFT (op0), op1),
CHREC_RIGHT (op0));
}
default:
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
if (code == PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (op1),
chrec_fold_plus (type, op0, CHREC_LEFT (op1)),
CHREC_RIGHT (op1));
else
return build_polynomial_chrec
(CHREC_VARIABLE (op1),
chrec_fold_minus (type, op0, CHREC_LEFT (op1)),
chrec_fold_multiply (type, CHREC_RIGHT (op1),
build_int_cst_type (type, -1)));
default:
{
int size = 0;
if ((tree_contains_chrecs (op0, &size)
|| tree_contains_chrecs (op1, &size))
&& size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
return build2 (code, type, op0, op1);
else if (size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
return fold (build2 (code, type, op0, op1));
else
return chrec_dont_know;
}
}
}
}
tree
chrec_apply (unsigned var,
tree chrec,
tree x)
{
tree type = chrec_type (chrec);
tree res = chrec_dont_know;
if (automatically_generated_chrec_p (chrec)
|| automatically_generated_chrec_p (x)
/* When the symbols are defined in an outer loop, it is possible
to symbolically compute the apply, since the symbols are
constants with respect to the varying loop. */
|| chrec_contains_symbols_defined_in_loop (chrec, var))
return chrec_dont_know;
if (dump_file && (dump_flags & TDF_SCEV))
fprintf (dump_file, "(chrec_apply \n");
if (TREE_CODE (x) == INTEGER_CST && SCALAR_FLOAT_TYPE_P (type))
x = build_real_from_int_cst (type, x);
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
if (evolution_function_is_affine_p (chrec))
{
if (CHREC_VARIABLE (chrec) != var)
return build_polynomial_chrec
(CHREC_VARIABLE (chrec),
chrec_apply (var, CHREC_LEFT (chrec), x),
chrec_apply (var, CHREC_RIGHT (chrec), x));
/* "{a, +, b} (x)" -> "a + b*x". */
x = chrec_convert_rhs (type, x, NULL);
res = chrec_fold_multiply (TREE_TYPE (x), CHREC_RIGHT (chrec), x);
res = chrec_fold_plus (type, CHREC_LEFT (chrec), res);
}
else if (TREE_CODE (x) == INTEGER_CST
&& tree_int_cst_sgn (x) == 1)
/* testsuite/.../ssa-chrec-38.c. */
res = chrec_evaluate (var, chrec, x, 0);
else
res = chrec_dont_know;
break;
CASE_CONVERT:
res = chrec_convert (TREE_TYPE (chrec),
chrec_apply (var, TREE_OPERAND (chrec, 0), x),
NULL);
break;
default:
res = chrec;
break;
}
if (dump_file && (dump_flags & TDF_SCEV))
{
fprintf (dump_file, " (varying_loop = %d\n", var);
fprintf (dump_file, ")\n (chrec = ");
print_generic_expr (dump_file, chrec, 0);
fprintf (dump_file, ")\n (x = ");
print_generic_expr (dump_file, x, 0);
fprintf (dump_file, ")\n (res = ");
print_generic_expr (dump_file, res, 0);
fprintf (dump_file, "))\n");
}
return res;
}
tree
chrec_fold_multiply (tree type,
tree op0,
tree op1)
{
if (automatically_generated_chrec_p (op0)
|| automatically_generated_chrec_p (op1))
return chrec_fold_automatically_generated_operands (op0, op1);
switch (TREE_CODE (op0))
{
case POLYNOMIAL_CHREC:
gcc_checking_assert
(!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0)));
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
gcc_checking_assert
(!chrec_contains_symbols_defined_in_loop (op1,
CHREC_VARIABLE (op1)));
return chrec_fold_multiply_poly_poly (type, op0, op1);
CASE_CONVERT:
if (tree_contains_chrecs (op1, NULL))
return chrec_dont_know;
default:
if (integer_onep (op1))
return op0;
if (integer_zerop (op1))
return build_int_cst (type, 0);
return build_polynomial_chrec
(CHREC_VARIABLE (op0),
chrec_fold_multiply (type, CHREC_LEFT (op0), op1),
chrec_fold_multiply (type, CHREC_RIGHT (op0), op1));
}
CASE_CONVERT:
if (tree_contains_chrecs (op0, NULL))
return chrec_dont_know;
default:
if (integer_onep (op0))
return op1;
if (integer_zerop (op0))
return build_int_cst (type, 0);
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
gcc_checking_assert
(!chrec_contains_symbols_defined_in_loop (op1,
CHREC_VARIABLE (op1)));
return build_polynomial_chrec
(CHREC_VARIABLE (op1),
chrec_fold_multiply (type, CHREC_LEFT (op1), op0),
chrec_fold_multiply (type, CHREC_RIGHT (op1), op0));
CASE_CONVERT:
if (tree_contains_chrecs (op1, NULL))
return chrec_dont_know;
default:
if (integer_onep (op1))
return op0;
if (integer_zerop (op1))
return build_int_cst (type, 0);
return fold_build2 (MULT_EXPR, type, op0, op1);
}
}
}
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;
}
static tree
chrec_fold_plus_1 (enum tree_code code, tree type,
tree op0, tree op1)
{
if (automatically_generated_chrec_p (op0)
|| automatically_generated_chrec_p (op1))
return chrec_fold_automatically_generated_operands (op0, op1);
switch (TREE_CODE (op0))
{
case POLYNOMIAL_CHREC:
gcc_checking_assert
(!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0)));
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
gcc_checking_assert
(!chrec_contains_symbols_defined_in_loop (op1,
CHREC_VARIABLE (op1)));
return chrec_fold_plus_poly_poly (code, type, op0, op1);
CASE_CONVERT:
if (tree_contains_chrecs (op1, NULL))
return chrec_dont_know;
default:
if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (op0),
chrec_fold_plus (type, CHREC_LEFT (op0), op1),
CHREC_RIGHT (op0));
else
return build_polynomial_chrec
(CHREC_VARIABLE (op0),
chrec_fold_minus (type, CHREC_LEFT (op0), op1),
CHREC_RIGHT (op0));
}
CASE_CONVERT:
if (tree_contains_chrecs (op0, NULL))
return chrec_dont_know;
default:
switch (TREE_CODE (op1))
{
case POLYNOMIAL_CHREC:
gcc_checking_assert
(!chrec_contains_symbols_defined_in_loop (op1,
CHREC_VARIABLE (op1)));
if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (op1),
chrec_fold_plus (type, op0, CHREC_LEFT (op1)),
CHREC_RIGHT (op1));
else
return build_polynomial_chrec
(CHREC_VARIABLE (op1),
chrec_fold_minus (type, op0, CHREC_LEFT (op1)),
chrec_fold_multiply (type, CHREC_RIGHT (op1),
SCALAR_FLOAT_TYPE_P (type)
? build_real (type, dconstm1)
: build_int_cst_type (type, -1)));
CASE_CONVERT:
if (tree_contains_chrecs (op1, NULL))
return chrec_dont_know;
default:
{
int size = 0;
if ((tree_contains_chrecs (op0, &size)
|| tree_contains_chrecs (op1, &size))
&& size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
return build2 (code, type, op0, op1);
else if (size < PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
{
if (code == POINTER_PLUS_EXPR)
return fold_build_pointer_plus (fold_convert (type, op0),
op1);
else
return fold_build2 (code, type,
fold_convert (type, op0),
fold_convert (type, op1));
}
else
return chrec_dont_know;
}
}
}
}
