Local Optimizations

Functions
ir_tarval *	computed_value (const ir_node *n)
	If the expression referenced can be evaluated statically computed_value returns a tarval representing the result, tarval_bad if operation will throw an exception/produce undefined behaviour, otherwise tarval_unknown. More...
ir_node *	optimize_in_place (ir_node *n)
	Applies all optimizations to n that are expressible as a pattern in Firm, i.e., they need not a walk of the graph. More...
int	ir_is_negated_value (const ir_node *a, const ir_node *b)
	checks whether 1 value is the negated other value More...
ir_relation	ir_get_possible_cmp_relations (const ir_node *left, const ir_node *right)
	(conservatively) approximates all possible relations when comparing the value left and right More...
void	ir_allow_imprecise_float_transforms (int enable)
	enable/disable imprecise floatingpoint optimizations. More...
int	ir_imprecise_float_transforms_allowed (void)
	return 1 if imprecise float transformations are allowed. More...

Detailed Description

Function Documentation

ir_tarval* computed_value

(

const ir_node *

n

)

If the expression referenced can be evaluated statically computed_value returns a tarval representing the result, tarval_bad if operation will throw an exception/produce undefined behaviour, otherwise tarval_unknown.

void ir_allow_imprecise_float_transforms

(

int

enable

)

enable/disable imprecise floatingpoint optimizations.

These include rules like (a - x) + x = a, or a-0=a. They are wrong in several corner cases but may still be fine for some applications.

ir_relation ir_get_possible_cmp_relations	(	const ir_node *	left,
		const ir_node *	right
	)

(conservatively) approximates all possible relations when comparing the value left and right

int ir_imprecise_float_transforms_allowed

(

void

)

return 1 if imprecise float transformations are allowed.

int ir_is_negated_value	(	const ir_node *	a,
		const ir_node *	b
	)

checks whether 1 value is the negated other value

ir_node* optimize_in_place

(

ir_node *

n

)

Applies all optimizations to n that are expressible as a pattern in Firm, i.e., they need not a walk of the graph.

Returns a better node for n. Does not free n – other nodes could reference n.

An equivalent optimization is applied in the constructors defined in ircons.ch. There n is freed if a better node could be found.