GCC Middle and Back End API Reference

#include <expmed.h>
Data Fields  
short  cost 
short  latency 
This structure holds the "cost" of a multiply sequence. The "cost" field holds the total rtx_cost of every operator in the synthetic multiplication sequence, hence cost(a op b) is defined as rtx_cost(op) + cost(a) + cost(b), where cost(leaf) is zero. The "latency" field holds the minimum possible latency of the synthetic multiply, on a hypothetical infinitely parallel CPU. This is the critical path, or the maximum height, of the expression tree which is the sum of rtx_costs on the most expensive path from any leaf to the root. Hence latency(a op b) is defined as zero for leaves and rtx_cost(op) + max(latency(a), latency(b)) otherwise.
short mult_cost::cost 
Referenced by choose_mult_variant(), expmed_mult_highpart(), and mult_by_coeff_cost().
short mult_cost::latency 
Referenced by choose_mult_variant().