bool
chrec_contains_undetermined (tree chrec)
{
if (chrec == chrec_dont_know
|| chrec == chrec_not_analyzed_yet
|| chrec == NULL_TREE)
return true;
switch (TREE_CODE_LENGTH (TREE_CODE (chrec)))
{
case 3:
if (chrec_contains_undetermined (TREE_OPERAND (chrec, 2)))
return true;
case 2:
if (chrec_contains_undetermined (TREE_OPERAND (chrec, 1)))
return true;
case 1:
if (chrec_contains_undetermined (TREE_OPERAND (chrec, 0)))
return true;
default:
return false;
}
}
static bool
graphite_can_represent_scev (tree scev)
{
if (chrec_contains_undetermined (scev))
return false;
/* We disable the handling of pointer types, because it’s currently not
supported by Graphite with the ISL AST generator. SSA_NAME nodes are
the only nodes, which are disabled in case they are pointers to object
types, but this can be changed. */
if (POINTER_TYPE_P (TREE_TYPE (scev)) && TREE_CODE (scev) == SSA_NAME)
return false;
switch (TREE_CODE (scev))
{
case NEGATE_EXPR:
case BIT_NOT_EXPR:
CASE_CONVERT:
case NON_LVALUE_EXPR:
return graphite_can_represent_scev (TREE_OPERAND (scev, 0));
case PLUS_EXPR:
case POINTER_PLUS_EXPR:
case MINUS_EXPR:
return graphite_can_represent_scev (TREE_OPERAND (scev, 0))
&& graphite_can_represent_scev (TREE_OPERAND (scev, 1));
case MULT_EXPR:
return !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 0)))
&& !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 1)))
&& !(chrec_contains_symbols (TREE_OPERAND (scev, 0))
&& chrec_contains_symbols (TREE_OPERAND (scev, 1)))
&& graphite_can_represent_init (scev)
&& graphite_can_represent_scev (TREE_OPERAND (scev, 0))
&& graphite_can_represent_scev (TREE_OPERAND (scev, 1));
case POLYNOMIAL_CHREC:
/* Check for constant strides. With a non constant stride of
'n' we would have a value of 'iv * n'. Also check that the
initial value can represented: for example 'n * m' cannot be
represented. */
if (!evolution_function_right_is_integer_cst (scev)
|| !graphite_can_represent_init (scev))
return false;
return graphite_can_represent_scev (CHREC_LEFT (scev));
default:
break;
}
/* Only affine functions can be represented. */
if (tree_contains_chrecs (scev, NULL)
|| !scev_is_linear_expression (scev))
return false;
return true;
}
static bool
graphite_can_represent_scev (tree scev)
{
if (chrec_contains_undetermined (scev))
return false;
switch (TREE_CODE (scev))
{
case NEGATE_EXPR:
case BIT_NOT_EXPR:
CASE_CONVERT:
case NON_LVALUE_EXPR:
return graphite_can_represent_scev (TREE_OPERAND (scev, 0));
case PLUS_EXPR:
case POINTER_PLUS_EXPR:
case MINUS_EXPR:
return graphite_can_represent_scev (TREE_OPERAND (scev, 0))
&& graphite_can_represent_scev (TREE_OPERAND (scev, 1));
case MULT_EXPR:
return !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 0)))
&& !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 1)))
&& !(chrec_contains_symbols (TREE_OPERAND (scev, 0))
&& chrec_contains_symbols (TREE_OPERAND (scev, 1)))
&& graphite_can_represent_init (scev)
&& graphite_can_represent_scev (TREE_OPERAND (scev, 0))
&& graphite_can_represent_scev (TREE_OPERAND (scev, 1));
case POLYNOMIAL_CHREC:
/* Check for constant strides. With a non constant stride of
'n' we would have a value of 'iv * n'. Also check that the
initial value can represented: for example 'n * m' cannot be
represented. */
if (!evolution_function_right_is_integer_cst (scev)
|| !graphite_can_represent_init (scev))
return false;
return graphite_can_represent_scev (CHREC_LEFT (scev));
default:
break;
}
/* Only affine functions can be represented. */
if (tree_contains_chrecs (scev, NULL)
|| !scev_is_linear_expression (scev))
return false;
return true;
}
static bool
graphite_can_represent_loop (basic_block scop_entry, loop_p loop)
{
tree niter;
struct tree_niter_desc niter_desc;
/* FIXME: For the moment, graphite cannot be used on loops that
iterate using induction variables that wrap. */
return number_of_iterations_exit (loop, single_exit (loop), &niter_desc, false)
&& niter_desc.control.no_overflow
&& (niter = number_of_latch_executions (loop))
&& !chrec_contains_undetermined (niter)
&& graphite_can_represent_expr (scop_entry, loop, niter);
}
bool
chrec_contains_undetermined (const_tree chrec)
{
int i, n;
if (chrec == chrec_dont_know)
return true;
if (chrec == NULL_TREE)
return false;
n = TREE_OPERAND_LENGTH (chrec);
for (i = 0; i < n; i++)
if (chrec_contains_undetermined (TREE_OPERAND (chrec, i)))
return true;
return false;
}