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Package pgo

Variables

LookupFunc looks up a function or method in export data. It is expected to be overridden by package noder, to break a dependency cycle.

var LookupFunc = func(fullName string) (*ir.Func, error) {
    base.Fatalf("pgo.LookupMethodFunc not overridden")
    panic("unreachable")
}

func DirectCallee ¶

func DirectCallee(fn ir.Node) *ir.Func

DirectCallee takes a function-typed expression and returns the underlying function that it refers to if statically known. Otherwise, it returns nil.

Equivalent to inline.inlCallee without calling CanInline on closures.

func NodeLineOffset ¶

func NodeLineOffset(n ir.Node, fn *ir.Func) int

NodeLineOffset returns the line offset of n in fn.

func WeightInPercentage ¶

func WeightInPercentage(value int64, total int64) float64

WeightInPercentage converts profile weights to a percentage.

type CallSiteInfo ¶

CallSiteInfo captures call-site information and its caller/callee.

type CallSiteInfo struct {
    LineOffset int // Line offset from function start line.
    Caller     *ir.Func
    Callee     *ir.Func
}

type IREdge ¶

IREdge represents a call edge in the IRGraph with source, destination, weight, callsite, and line number information.

type IREdge struct {
    // Source and destination of the edge in IRNode.
    Src, Dst       *IRNode
    Weight         int64
    CallSiteOffset int // Line offset from function start line.
}

type IRGraph ¶

IRGraph is a call graph with nodes pointing to IRs of functions and edges carrying weights and callsite information.

Nodes for indirect calls may have missing IR (IRNode.AST == nil) if the node is not visible from this package (e.g., not in the transitive deps). Keeping these nodes allows determining the hottest edge from a call even if that callee is not available.

TODO(prattmic): Consider merging this data structure with Graph. This is effectively a copy of Graph aggregated to line number and pointing to IR.

type IRGraph struct {
    // Nodes of the graph. Each node represents a function, keyed by linker
    // symbol name.
    IRNodes map[string]*IRNode
}

type IRNode ¶

IRNode represents a node (function) in the IRGraph.

type IRNode struct {
    // Pointer to the IR of the Function represented by this node.
    AST *ir.Func
    // Linker symbol name of the Function represented by this node.
    // Populated only if AST == nil.
    LinkerSymbolName string

    // Set of out-edges in the callgraph. The map uniquely identifies each
    // edge based on the callsite and callee, for fast lookup.
    OutEdges map[NamedCallEdge]*IREdge
}

func (*IRNode) Name ¶

func (i *IRNode) Name() string

Name returns the symbol name of this function.

type NamedCallEdge ¶

NamedCallEdge identifies a call edge by linker symbol names and call site offset.

type NamedCallEdge struct {
    CallerName     string
    CalleeName     string
    CallSiteOffset int // Line offset from function start line.
}

type NamedEdgeMap ¶

NamedEdgeMap contains all unique call edges in the profile and their edge weight.

type NamedEdgeMap struct {
    Weight map[NamedCallEdge]int64

    // ByWeight lists all keys in Weight, sorted by edge weight.
    ByWeight []NamedCallEdge
}

type Profile ¶

Profile contains the processed PGO profile and weighted call graph used for PGO optimizations.

type Profile struct {
    // Aggregated edge weights across the profile. This helps us determine
    // the percentage threshold for hot/cold partitioning.
    TotalWeight int64

    // NamedEdgeMap contains all unique call edges in the profile and their
    // edge weight.
    NamedEdgeMap NamedEdgeMap

    // WeightedCG represents the IRGraph built from profile, which we will
    // update as part of inlining.
    WeightedCG *IRGraph
}

func New ¶

func New(profileFile string) (*Profile, error)

New generates a profile-graph from the profile.

func (*Profile) PrintWeightedCallGraphDOT ¶

func (p *Profile) PrintWeightedCallGraphDOT(edgeThreshold float64)

PrintWeightedCallGraphDOT prints IRGraph in DOT format.

Subdirectories