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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ssa
import "testing"
type lca interface {
find(a, b *Block) *Block
}
func lcaEqual(f *Func, lca1, lca2 lca) bool {
for _, b := range f.Blocks {
for _, c := range f.Blocks {
if lca1.find(b, c) != lca2.find(b, c) {
return false
}
}
}
return true
}
func testLCAgen(t *testing.T, bg blockGen, size int) {
c := NewConfig("amd64", DummyFrontend{t}, nil, true)
fun := Fun(c, "entry", bg(size)...)
CheckFunc(fun.f)
if size == 4 {
t.Logf(fun.f.String())
}
lca1 := makeLCArange(fun.f)
lca2 := makeLCAeasy(fun.f)
for _, b := range fun.f.Blocks {
for _, c := range fun.f.Blocks {
l1 := lca1.find(b, c)
l2 := lca2.find(b, c)
if l1 != l2 {
t.Errorf("lca(%s,%s)=%s, want %s", b, c, l1, l2)
}
}
}
}
func TestLCALinear(t *testing.T) {
testLCAgen(t, genLinear, 10)
testLCAgen(t, genLinear, 100)
}
func TestLCAFwdBack(t *testing.T) {
testLCAgen(t, genFwdBack, 10)
testLCAgen(t, genFwdBack, 100)
}
func TestLCAManyPred(t *testing.T) {
testLCAgen(t, genManyPred, 10)
testLCAgen(t, genManyPred, 100)
}
func TestLCAMaxPred(t *testing.T) {
testLCAgen(t, genMaxPred, 10)
testLCAgen(t, genMaxPred, 100)
}
func TestLCAMaxPredValue(t *testing.T) {
testLCAgen(t, genMaxPredValue, 10)
testLCAgen(t, genMaxPredValue, 100)
}
// Simple implementation of LCA to compare against.
type lcaEasy struct {
parent []*Block
}
func makeLCAeasy(f *Func) *lcaEasy {
return &lcaEasy{parent: dominators(f)}
}
func (lca *lcaEasy) find(a, b *Block) *Block {
da := lca.depth(a)
db := lca.depth(b)
for da > db {
da--
a = lca.parent[a.ID]
}
for da < db {
db--
b = lca.parent[b.ID]
}
for a != b {
a = lca.parent[a.ID]
b = lca.parent[b.ID]
}
return a
}
func (lca *lcaEasy) depth(b *Block) int {
n := 0
for b != nil {
b = lca.parent[b.ID]
n++
}
return n
}