ExtCons : External Constraint Format

This kinb of file contains constraints that may be added to an IPET computation performed in OTAWA (using the otawa::ipet::ConstraintLoader processor). More...

Classes
class	otawa::ipet::ConstraintLoader
	This code processor allows loading IPET constraint from an external file. More...

Variables
static Identifier< String >	otawa::ipet::ConstraintLoader::PATH
	This property identifier is used for passing specific file to load to the ConstraintLoader (argument of type elm::String). More...

Detailed Description

This kinb of file contains constraints that may be added to an IPET computation performed in OTAWA (using the otawa::ipet::ConstraintLoader processor).

This features may be used to insert hand-written constraints or constraints generated by external tool.

The format of this file is simple text possibly containing comments starting from '#' symbol to the end of the file.

The constraints are written as usual inequalities with comparators : '<', '>', '=', '<=', or '>='. The expressions may contain:

• variable names,
• numeric constants,
• '+' expression : prefixed plus,
• '-' expression : prefixed minus,
• expression '+' expression : addition,
• expression '-' expression : subtraction,
• expression '*' expression : multiplication,
• expression '/' expression : division,
• '(' expression ')' : parentheses,

To be consistent with the current ILP constraint system in OTAWA, links must be done with the variables associated with nodes and edges. This is performed by the following commands:

• 'bb' id address – name id the variable identifying occurrences of BB at given address,
• 'bb' id '$' index – name id the variable identifying occurrences of BB with given index,
• 'edge' id address address – name id the variable identifying occurrences edge whose source and target BB are at given address.

The identifier id are name of variable that may be then used in the constraint description.

Below is displayed a simple example of mutual exclusive execution:

# variable identification
bb      x_1     0x125C
bb      x_2     $11

# constraints
x_1 + x_2 <= 1

Variable Documentation

Identifier< string > otawa::ipet::ConstraintLoader::PATH

static

This property identifier is used for passing specific file to load to the ConstraintLoader (argument of type elm::String).

Referenced by otawa::ipet::ConstraintLoader::configure().