DPDK::ElimHeaderCopy Class Reference

Inheritance diagram for DPDK::ElimHeaderCopy:

Public Member Functions
	ElimHeaderCopy (P4::TypeMap *typeMap)
bool	isHeader (const IR::Expression *e)
const IR::Node *	postorder (IR::Member *m) override
const IR::Node *	preorder (IR::AssignmentStatement *as) override
const IR::Node *	preorder (IR::MethodCallStatement *mcs) override

Detailed Description

Eliminate temporary copies of header, which generally populated after inlining, if it's not temporary copy then transform direct header copy to element wise copy i.e. case 1) when header copied to temporary eth_0 = hdr.ethernet eth_1 = hdr.outer_ethernet eth_0.srcAddr = eth_1.srcAddr eth_0.dstAddr = eth_1.dstAddr eth_0.etherType = eth_1.etherType hdr.ethernet = eth_0 above block will be transformed into hdr.ethernet.srcAddr = hdr.outer_ethernet.srcAddr hdr.ethernet.dstAddr = hdr.outer_ethernet.dstAddr hdr.ethernet.etherType = hdr.outer_ethernet.etherType

case 2) when header copied to non temporary hdr.ethernet = hdr.outer_ethernet it will be transformed into below memberwise copy hdr.ethernet.srcAddr = hdr.outer_ethernet.srcAddr hdr.ethernet.dstAddr = hdr.outer_ethernet.dstAddr hdr.ethernet.etherType = hdr.outer_ethernet.etherType

Member Function Documentation

preorder()

const IR::Node * DPDK::ElimHeaderCopy::preorder ( IR::MethodCallStatement * mcs )

override

Replace method call expression with temporary instances like eth_0.setInvalid() with empty statement as all uses of eth_0 already replaced