tree
reset_evolution_in_loop (unsigned loop_num,
tree chrec,
tree new_evol)
{
struct loop *loop = get_loop (cfun, loop_num);
if (POINTER_TYPE_P (chrec_type (chrec)))
gcc_assert (ptrofftype_p (chrec_type (new_evol)));
else
gcc_assert (chrec_type (chrec) == chrec_type (new_evol));
if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& flow_loop_nested_p (loop, get_chrec_loop (chrec)))
{
tree left = reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec),
new_evol);
tree right = reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec),
new_evol);
return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
CHREC_VAR (chrec), left, right);
}
while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& CHREC_VARIABLE (chrec) == loop_num)
chrec = CHREC_LEFT (chrec);
return build_polynomial_chrec (loop_num, chrec, new_evol);
}
static inline tree
chrec_fold_multiply_poly_poly (tree type,
tree poly0,
tree poly1)
{
tree t0, t1, t2;
int var;
struct loop *loop0 = get_chrec_loop (poly0);
struct loop *loop1 = get_chrec_loop (poly1);
gcc_assert (poly0);
gcc_assert (poly1);
gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC);
gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly0))
&& useless_type_conversion_p (type, chrec_type (poly1)));
/* {a, +, b}_1 * {c, +, d}_2 -> {c*{a, +, b}_1, +, d}_2,
{a, +, b}_2 * {c, +, d}_1 -> {a*{c, +, d}_1, +, b}_2,
{a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */
if (flow_loop_nested_p (loop0, loop1))
/* poly0 is a constant wrt. poly1. */
return build_polynomial_chrec
(CHREC_VARIABLE (poly1),
chrec_fold_multiply (type, CHREC_LEFT (poly1), poly0),
CHREC_RIGHT (poly1));
if (flow_loop_nested_p (loop1, loop0))
/* poly1 is a constant wrt. poly0. */
return build_polynomial_chrec
(CHREC_VARIABLE (poly0),
chrec_fold_multiply (type, CHREC_LEFT (poly0), poly1),
CHREC_RIGHT (poly0));
gcc_assert (loop0 == loop1);
/* poly0 and poly1 are two polynomials in the same variable,
{a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */
/* "a*c". */
t0 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
/* "a*d + b*c". */
t1 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1));
t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type,
CHREC_RIGHT (poly0),
CHREC_LEFT (poly1)));
/* "b*d". */
t2 = chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
/* "a*d + b*c + b*d". */
t1 = chrec_fold_plus (type, t1, t2);
/* "2*b*d". */
t2 = chrec_fold_multiply (type, SCALAR_FLOAT_TYPE_P (type)
? build_real (type, dconst2)
: build_int_cst (type, 2), t2);
var = CHREC_VARIABLE (poly0);
return build_polynomial_chrec (var, t0,
build_polynomial_chrec (var, t1, t2));
}
tree
reset_evolution_in_loop (unsigned loop_num,
tree chrec,
tree new_evol)
{
gcc_assert (chrec_type (chrec) == chrec_type (new_evol));
if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& CHREC_VARIABLE (chrec) > loop_num)
{
tree left = reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec),
new_evol);
tree right = reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec),
new_evol);
return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
build_int_cst (NULL_TREE, CHREC_VARIABLE (chrec)),
left, right);
}
while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
&& CHREC_VARIABLE (chrec) == loop_num)
chrec = CHREC_LEFT (chrec);
return build_polynomial_chrec (loop_num, chrec, new_evol);
}
static inline tree
chrec_fold_multiply_poly_poly (tree type,
tree poly0,
tree poly1)
{
tree t0, t1, t2;
int var;
gcc_assert (poly0);
gcc_assert (poly1);
gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC);
gcc_assert (chrec_type (poly0) == chrec_type (poly1));
gcc_assert (type == chrec_type (poly0));
/* {a, +, b}_1 * {c, +, d}_2 -> {c*{a, +, b}_1, +, d}_2,
{a, +, b}_2 * {c, +, d}_1 -> {a*{c, +, d}_1, +, b}_2,
{a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */
if (CHREC_VARIABLE (poly0) < CHREC_VARIABLE (poly1))
/* poly0 is a constant wrt. poly1. */
return build_polynomial_chrec
(CHREC_VARIABLE (poly1),
chrec_fold_multiply (type, CHREC_LEFT (poly1), poly0),
CHREC_RIGHT (poly1));
if (CHREC_VARIABLE (poly1) < CHREC_VARIABLE (poly0))
/* poly1 is a constant wrt. poly0. */
return build_polynomial_chrec
(CHREC_VARIABLE (poly0),
chrec_fold_multiply (type, CHREC_LEFT (poly0), poly1),
CHREC_RIGHT (poly0));
/* poly0 and poly1 are two polynomials in the same variable,
{a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */
/* "a*c". */
t0 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
/* "a*d + b*c + b*d". */
t1 = chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1));
t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type,
CHREC_RIGHT (poly0),
CHREC_LEFT (poly1)));
t1 = chrec_fold_plus (type, t1, chrec_fold_multiply (type,
CHREC_RIGHT (poly0),
CHREC_RIGHT (poly1)));
/* "2*b*d". */
t2 = chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
t2 = chrec_fold_multiply (type, SCALAR_FLOAT_TYPE_P (type)
? build_real (type, dconst2)
: build_int_cst (type, 2), t2);
var = CHREC_VARIABLE (poly0);
return build_polynomial_chrec (var, t0,
build_polynomial_chrec (var, t1, t2));
}
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_replace_initial_condition (tree chrec,
tree init_cond)
{
if (automatically_generated_chrec_p (chrec))
return chrec;
gcc_assert (chrec_type (chrec) == chrec_type (init_cond));
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;
}
}
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 (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;
}
}
}
static inline tree
chrec_fold_poly_cst (enum tree_code code,
tree type,
tree poly,
tree cst)
{
gcc_assert (poly);
gcc_assert (cst);
gcc_assert (TREE_CODE (poly) == POLYNOMIAL_CHREC);
gcc_checking_assert (!is_not_constant_evolution (cst));
gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly)));
switch (code)
{
case PLUS_EXPR:
return build_polynomial_chrec
(CHREC_VARIABLE (poly),
chrec_fold_plus (type, CHREC_LEFT (poly), cst),
CHREC_RIGHT (poly));
case MINUS_EXPR:
return build_polynomial_chrec
(CHREC_VARIABLE (poly),
chrec_fold_minus (type, CHREC_LEFT (poly), cst),
CHREC_RIGHT (poly));
case MULT_EXPR:
return build_polynomial_chrec
(CHREC_VARIABLE (poly),
chrec_fold_multiply (type, CHREC_LEFT (poly), cst),
chrec_fold_multiply (type, CHREC_RIGHT (poly), cst));
default:
return chrec_dont_know;
}
}
static inline tree
chrec_fold_plus_poly_poly (enum tree_code code,
tree type,
tree poly0,
tree poly1)
{
tree left, right;
struct loop *loop0 = get_chrec_loop (poly0);
struct loop *loop1 = get_chrec_loop (poly1);
tree rtype = code == POINTER_PLUS_EXPR ? chrec_type (poly1) : type;
gcc_assert (poly0);
gcc_assert (poly1);
gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC);
if (POINTER_TYPE_P (chrec_type (poly0)))
gcc_checking_assert (ptrofftype_p (chrec_type (poly1))
&& useless_type_conversion_p (type, chrec_type (poly0)));
else
gcc_checking_assert (useless_type_conversion_p (type, chrec_type (poly0))
&& useless_type_conversion_p (type, chrec_type (poly1)));
/*
{a, +, b}_1 + {c, +, d}_2 -> {{a, +, b}_1 + c, +, d}_2,
{a, +, b}_2 + {c, +, d}_1 -> {{c, +, d}_1 + a, +, b}_2,
{a, +, b}_x + {c, +, d}_x -> {a+c, +, b+d}_x. */
if (flow_loop_nested_p (loop0, loop1))
{
if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (poly1),
chrec_fold_plus (type, poly0, CHREC_LEFT (poly1)),
CHREC_RIGHT (poly1));
else
return build_polynomial_chrec
(CHREC_VARIABLE (poly1),
chrec_fold_minus (type, poly0, CHREC_LEFT (poly1)),
chrec_fold_multiply (type, CHREC_RIGHT (poly1),
SCALAR_FLOAT_TYPE_P (type)
? build_real (type, dconstm1)
: build_int_cst_type (type, -1)));
}
if (flow_loop_nested_p (loop1, loop0))
{
if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (poly0),
chrec_fold_plus (type, CHREC_LEFT (poly0), poly1),
CHREC_RIGHT (poly0));
else
return build_polynomial_chrec
(CHREC_VARIABLE (poly0),
chrec_fold_minus (type, CHREC_LEFT (poly0), poly1),
CHREC_RIGHT (poly0));
}
/* This function should never be called for chrecs of loops that
do not belong to the same loop nest. */
gcc_assert (loop0 == loop1);
if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR)
{
left = chrec_fold_plus
(type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
right = chrec_fold_plus
(rtype, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
}
else
{
left = chrec_fold_minus
(type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
right = chrec_fold_minus
(type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
}
if (chrec_zerop (right))
return left;
else
return build_polynomial_chrec
(CHREC_VARIABLE (poly0), left, right);
}
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;
}
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 inline tree
chrec_fold_plus_poly_poly (enum tree_code code,
tree type,
tree poly0,
tree poly1)
{
tree left, right;
gcc_assert (poly0);
gcc_assert (poly1);
gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC);
gcc_assert (chrec_type (poly0) == chrec_type (poly1));
gcc_assert (type == chrec_type (poly0));
/*
{a, +, b}_1 + {c, +, d}_2 -> {{a, +, b}_1 + c, +, d}_2,
{a, +, b}_2 + {c, +, d}_1 -> {{c, +, d}_1 + a, +, b}_2,
{a, +, b}_x + {c, +, d}_x -> {a+c, +, b+d}_x. */
if (CHREC_VARIABLE (poly0) < CHREC_VARIABLE (poly1))
{
if (code == PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (poly1),
chrec_fold_plus (type, poly0, CHREC_LEFT (poly1)),
CHREC_RIGHT (poly1));
else
return build_polynomial_chrec
(CHREC_VARIABLE (poly1),
chrec_fold_minus (type, poly0, CHREC_LEFT (poly1)),
chrec_fold_multiply (type, CHREC_RIGHT (poly1),
SCALAR_FLOAT_TYPE_P (type)
? build_real (type, dconstm1)
: build_int_cst_type (type, -1)));
}
if (CHREC_VARIABLE (poly0) > CHREC_VARIABLE (poly1))
{
if (code == PLUS_EXPR)
return build_polynomial_chrec
(CHREC_VARIABLE (poly0),
chrec_fold_plus (type, CHREC_LEFT (poly0), poly1),
CHREC_RIGHT (poly0));
else
return build_polynomial_chrec
(CHREC_VARIABLE (poly0),
chrec_fold_minus (type, CHREC_LEFT (poly0), poly1),
CHREC_RIGHT (poly0));
}
if (code == PLUS_EXPR)
{
left = chrec_fold_plus
(type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
right = chrec_fold_plus
(type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
}
else
{
left = chrec_fold_minus
(type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
right = chrec_fold_minus
(type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
}
if (chrec_zerop (right))
return left;
else
return build_polynomial_chrec
(CHREC_VARIABLE (poly0), left, right);
}
