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