mult_cost Struct Reference

#include <expmed.h>

Data Fields
short	cost
short	latency

Detailed Description

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.   

Field Documentation

cost

short mult_cost::cost

Referenced by choose_mult_variant(), expmed_mult_highpart(), and mult_by_coeff_cost().

latency

short mult_cost::latency

Referenced by choose_mult_variant().

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The documentation for this struct was generated from the following file:

• expmed.h