Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 832 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/abt/avlint32.go b/src/cmd/compile/internal/abt/avlint32.go
new file mode 100644
index 0000000..28c1642
--- /dev/null
+++ b/src/cmd/compile/internal/abt/avlint32.go
@@ -0,0 +1,832 @@
+// Copyright 2022 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 abt
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+const (
+	LEAF_HEIGHT = 1
+	ZERO_HEIGHT = 0
+	NOT_KEY32   = int32(-0x80000000)
+)
+
+// T is the exported applicative balanced tree data type.
+// A T can be used as a value; updates to one copy of the value
+// do not change other copies.
+type T struct {
+	root *node32
+	size int
+}
+
+// node32 is the internal tree node data type
+type node32 struct {
+	// Standard conventions hold for left = smaller, right = larger
+	left, right *node32
+	data        interface{}
+	key         int32
+	height_     int8
+}
+
+func makeNode(key int32) *node32 {
+	return &node32{key: key, height_: LEAF_HEIGHT}
+}
+
+// IsEmpty returns true iff t is empty.
+func (t *T) IsEmpty() bool {
+	return t.root == nil
+}
+
+// IsSingle returns true iff t is a singleton (leaf).
+func (t *T) IsSingle() bool {
+	return t.root != nil && t.root.isLeaf()
+}
+
+// VisitInOrder applies f to the key and data pairs in t,
+// with keys ordered from smallest to largest.
+func (t *T) VisitInOrder(f func(int32, interface{})) {
+	if t.root == nil {
+		return
+	}
+	t.root.visitInOrder(f)
+}
+
+func (n *node32) nilOrData() interface{} {
+	if n == nil {
+		return nil
+	}
+	return n.data
+}
+
+func (n *node32) nilOrKeyAndData() (k int32, d interface{}) {
+	if n == nil {
+		k = NOT_KEY32
+		d = nil
+	} else {
+		k = n.key
+		d = n.data
+	}
+	return
+}
+
+func (n *node32) height() int8 {
+	if n == nil {
+		return 0
+	}
+	return n.height_
+}
+
+// Find returns the data associated with x in the tree, or
+// nil if x is not in the tree.
+func (t *T) Find(x int32) interface{} {
+	return t.root.find(x).nilOrData()
+}
+
+// Insert either adds x to the tree if x was not previously
+// a key in the tree, or updates the data for x in the tree if
+// x was already a key in the tree.  The previous data associated
+// with x is returned, and is nil if x was not previously a
+// key in the tree.
+func (t *T) Insert(x int32, data interface{}) interface{} {
+	if x == NOT_KEY32 {
+		panic("Cannot use sentinel value -0x80000000 as key")
+	}
+	n := t.root
+	var newroot *node32
+	var o *node32
+	if n == nil {
+		n = makeNode(x)
+		newroot = n
+	} else {
+		newroot, n, o = n.aInsert(x)
+	}
+	var r interface{}
+	if o != nil {
+		r = o.data
+	} else {
+		t.size++
+	}
+	n.data = data
+	t.root = newroot
+	return r
+}
+
+func (t *T) Copy() *T {
+	u := *t
+	return &u
+}
+
+func (t *T) Delete(x int32) interface{} {
+	n := t.root
+	if n == nil {
+		return nil
+	}
+	d, s := n.aDelete(x)
+	if d == nil {
+		return nil
+	}
+	t.root = s
+	t.size--
+	return d.data
+}
+
+func (t *T) DeleteMin() (int32, interface{}) {
+	n := t.root
+	if n == nil {
+		return NOT_KEY32, nil
+	}
+	d, s := n.aDeleteMin()
+	if d == nil {
+		return NOT_KEY32, nil
+	}
+	t.root = s
+	t.size--
+	return d.key, d.data
+}
+
+func (t *T) DeleteMax() (int32, interface{}) {
+	n := t.root
+	if n == nil {
+		return NOT_KEY32, nil
+	}
+	d, s := n.aDeleteMax()
+	if d == nil {
+		return NOT_KEY32, nil
+	}
+	t.root = s
+	t.size--
+	return d.key, d.data
+}
+
+func (t *T) Size() int {
+	return t.size
+}
+
+// Intersection returns the intersection of t and u, where the result
+// data for any common keys is given by f(t's data, u's data) -- f need
+// not be symmetric.  If f returns nil, then the key and data are not
+// added to the result.  If f itself is nil, then whatever value was
+// already present in the smaller set is used.
+func (t *T) Intersection(u *T, f func(x, y interface{}) interface{}) *T {
+	if t.Size() == 0 || u.Size() == 0 {
+		return &T{}
+	}
+
+	// For faster execution and less allocation, prefer t smaller, iterate over t.
+	if t.Size() <= u.Size() {
+		v := t.Copy()
+		for it := t.Iterator(); !it.Done(); {
+			k, d := it.Next()
+			e := u.Find(k)
+			if e == nil {
+				v.Delete(k)
+				continue
+			}
+			if f == nil {
+				continue
+			}
+			if c := f(d, e); c != d {
+				if c == nil {
+					v.Delete(k)
+				} else {
+					v.Insert(k, c)
+				}
+			}
+		}
+		return v
+	}
+	v := u.Copy()
+	for it := u.Iterator(); !it.Done(); {
+		k, e := it.Next()
+		d := t.Find(k)
+		if d == nil {
+			v.Delete(k)
+			continue
+		}
+		if f == nil {
+			continue
+		}
+		if c := f(d, e); c != d {
+			if c == nil {
+				v.Delete(k)
+			} else {
+				v.Insert(k, c)
+			}
+		}
+	}
+
+	return v
+}
+
+// Union returns the union of t and u, where the result data for any common keys
+// is given by f(t's data, u's data) -- f need not be symmetric.  If f returns nil,
+// then the key and data are not added to the result.  If f itself is nil, then
+// whatever value was already present in the larger set is used.
+func (t *T) Union(u *T, f func(x, y interface{}) interface{}) *T {
+	if t.Size() == 0 {
+		return u
+	}
+	if u.Size() == 0 {
+		return t
+	}
+
+	if t.Size() >= u.Size() {
+		v := t.Copy()
+		for it := u.Iterator(); !it.Done(); {
+			k, e := it.Next()
+			d := t.Find(k)
+			if d == nil {
+				v.Insert(k, e)
+				continue
+			}
+			if f == nil {
+				continue
+			}
+			if c := f(d, e); c != d {
+				if c == nil {
+					v.Delete(k)
+				} else {
+					v.Insert(k, c)
+				}
+			}
+		}
+		return v
+	}
+
+	v := u.Copy()
+	for it := t.Iterator(); !it.Done(); {
+		k, d := it.Next()
+		e := u.Find(k)
+		if e == nil {
+			v.Insert(k, d)
+			continue
+		}
+		if f == nil {
+			continue
+		}
+		if c := f(d, e); c != d {
+			if c == nil {
+				v.Delete(k)
+			} else {
+				v.Insert(k, c)
+			}
+		}
+	}
+	return v
+}
+
+// Difference returns the difference of t and u, subject to the result
+// of f applied to data corresponding to equal keys.  If f returns nil
+// (or if f is nil) then the key+data are excluded, as usual.  If f
+// returns not-nil, then that key+data pair is inserted. instead.
+func (t *T) Difference(u *T, f func(x, y interface{}) interface{}) *T {
+	if t.Size() == 0 {
+		return &T{}
+	}
+	if u.Size() == 0 {
+		return t
+	}
+	v := t.Copy()
+	for it := t.Iterator(); !it.Done(); {
+		k, d := it.Next()
+		e := u.Find(k)
+		if e != nil {
+			if f == nil {
+				v.Delete(k)
+				continue
+			}
+			c := f(d, e)
+			if c == nil {
+				v.Delete(k)
+				continue
+			}
+			if c != d {
+				v.Insert(k, c)
+			}
+		}
+	}
+	return v
+}
+
+func (t *T) Iterator() Iterator {
+	return Iterator{it: t.root.iterator()}
+}
+
+func (t *T) Equals(u *T) bool {
+	if t == u {
+		return true
+	}
+	if t.Size() != u.Size() {
+		return false
+	}
+	return t.root.equals(u.root)
+}
+
+func (t *T) String() string {
+	var b strings.Builder
+	first := true
+	for it := t.Iterator(); !it.Done(); {
+		k, v := it.Next()
+		if first {
+			first = false
+		} else {
+			b.WriteString("; ")
+		}
+		b.WriteString(strconv.FormatInt(int64(k), 10))
+		b.WriteString(":")
+		fmt.Fprint(&b, v)
+	}
+	return b.String()
+}
+
+func (t *node32) equals(u *node32) bool {
+	if t == u {
+		return true
+	}
+	it, iu := t.iterator(), u.iterator()
+	for !it.done() && !iu.done() {
+		nt := it.next()
+		nu := iu.next()
+		if nt == nu {
+			continue
+		}
+		if nt.key != nu.key {
+			return false
+		}
+		if nt.data != nu.data {
+			return false
+		}
+	}
+	return it.done() == iu.done()
+}
+
+func (t *T) Equiv(u *T, eqv func(x, y interface{}) bool) bool {
+	if t == u {
+		return true
+	}
+	if t.Size() != u.Size() {
+		return false
+	}
+	return t.root.equiv(u.root, eqv)
+}
+
+func (t *node32) equiv(u *node32, eqv func(x, y interface{}) bool) bool {
+	if t == u {
+		return true
+	}
+	it, iu := t.iterator(), u.iterator()
+	for !it.done() && !iu.done() {
+		nt := it.next()
+		nu := iu.next()
+		if nt == nu {
+			continue
+		}
+		if nt.key != nu.key {
+			return false
+		}
+		if !eqv(nt.data, nu.data) {
+			return false
+		}
+	}
+	return it.done() == iu.done()
+}
+
+type iterator struct {
+	parents []*node32
+}
+
+type Iterator struct {
+	it iterator
+}
+
+func (it *Iterator) Next() (int32, interface{}) {
+	x := it.it.next()
+	if x == nil {
+		return NOT_KEY32, nil
+	}
+	return x.key, x.data
+}
+
+func (it *Iterator) Done() bool {
+	return len(it.it.parents) == 0
+}
+
+func (t *node32) iterator() iterator {
+	if t == nil {
+		return iterator{}
+	}
+	it := iterator{parents: make([]*node32, 0, int(t.height()))}
+	it.leftmost(t)
+	return it
+}
+
+func (it *iterator) leftmost(t *node32) {
+	for t != nil {
+		it.parents = append(it.parents, t)
+		t = t.left
+	}
+}
+
+func (it *iterator) done() bool {
+	return len(it.parents) == 0
+}
+
+func (it *iterator) next() *node32 {
+	l := len(it.parents)
+	if l == 0 {
+		return nil
+	}
+	x := it.parents[l-1] // return value
+	if x.right != nil {
+		it.leftmost(x.right)
+		return x
+	}
+	// discard visited top of parents
+	l--
+	it.parents = it.parents[:l]
+	y := x // y is known visited/returned
+	for l > 0 && y == it.parents[l-1].right {
+		y = it.parents[l-1]
+		l--
+		it.parents = it.parents[:l]
+	}
+
+	return x
+}
+
+// Min returns the minimum element of t.
+// If t is empty, then (NOT_KEY32, nil) is returned.
+func (t *T) Min() (k int32, d interface{}) {
+	return t.root.min().nilOrKeyAndData()
+}
+
+// Max returns the maximum element of t.
+// If t is empty, then (NOT_KEY32, nil) is returned.
+func (t *T) Max() (k int32, d interface{}) {
+	return t.root.max().nilOrKeyAndData()
+}
+
+// Glb returns the greatest-lower-bound-exclusive of x and the associated
+// data.  If x has no glb in the tree, then (NOT_KEY32, nil) is returned.
+func (t *T) Glb(x int32) (k int32, d interface{}) {
+	return t.root.glb(x, false).nilOrKeyAndData()
+}
+
+// GlbEq returns the greatest-lower-bound-inclusive of x and the associated
+// data.  If x has no glbEQ in the tree, then (NOT_KEY32, nil) is returned.
+func (t *T) GlbEq(x int32) (k int32, d interface{}) {
+	return t.root.glb(x, true).nilOrKeyAndData()
+}
+
+// Lub returns the least-upper-bound-exclusive of x and the associated
+// data.  If x has no lub in the tree, then (NOT_KEY32, nil) is returned.
+func (t *T) Lub(x int32) (k int32, d interface{}) {
+	return t.root.lub(x, false).nilOrKeyAndData()
+}
+
+// LubEq returns the least-upper-bound-inclusive of x and the associated
+// data.  If x has no lubEq in the tree, then (NOT_KEY32, nil) is returned.
+func (t *T) LubEq(x int32) (k int32, d interface{}) {
+	return t.root.lub(x, true).nilOrKeyAndData()
+}
+
+func (t *node32) isLeaf() bool {
+	return t.left == nil && t.right == nil && t.height_ == LEAF_HEIGHT
+}
+
+func (t *node32) visitInOrder(f func(int32, interface{})) {
+	if t.left != nil {
+		t.left.visitInOrder(f)
+	}
+	f(t.key, t.data)
+	if t.right != nil {
+		t.right.visitInOrder(f)
+	}
+}
+
+func (t *node32) find(key int32) *node32 {
+	for t != nil {
+		if key < t.key {
+			t = t.left
+		} else if key > t.key {
+			t = t.right
+		} else {
+			return t
+		}
+	}
+	return nil
+}
+
+func (t *node32) min() *node32 {
+	if t == nil {
+		return t
+	}
+	for t.left != nil {
+		t = t.left
+	}
+	return t
+}
+
+func (t *node32) max() *node32 {
+	if t == nil {
+		return t
+	}
+	for t.right != nil {
+		t = t.right
+	}
+	return t
+}
+
+func (t *node32) glb(key int32, allow_eq bool) *node32 {
+	var best *node32 = nil
+	for t != nil {
+		if key <= t.key {
+			if allow_eq && key == t.key {
+				return t
+			}
+			// t is too big, glb is to left.
+			t = t.left
+		} else {
+			// t is a lower bound, record it and seek a better one.
+			best = t
+			t = t.right
+		}
+	}
+	return best
+}
+
+func (t *node32) lub(key int32, allow_eq bool) *node32 {
+	var best *node32 = nil
+	for t != nil {
+		if key >= t.key {
+			if allow_eq && key == t.key {
+				return t
+			}
+			// t is too small, lub is to right.
+			t = t.right
+		} else {
+			// t is an upper bound, record it and seek a better one.
+			best = t
+			t = t.left
+		}
+	}
+	return best
+}
+
+func (t *node32) aInsert(x int32) (newroot, newnode, oldnode *node32) {
+	// oldnode default of nil is good, others should be assigned.
+	if x == t.key {
+		oldnode = t
+		newt := *t
+		newnode = &newt
+		newroot = newnode
+		return
+	}
+	if x < t.key {
+		if t.left == nil {
+			t = t.copy()
+			n := makeNode(x)
+			t.left = n
+			newnode = n
+			newroot = t
+			t.height_ = 2 // was balanced w/ 0, sibling is height 0 or 1
+			return
+		}
+		var new_l *node32
+		new_l, newnode, oldnode = t.left.aInsert(x)
+		t = t.copy()
+		t.left = new_l
+		if new_l.height() > 1+t.right.height() {
+			newroot = t.aLeftIsHigh(newnode)
+		} else {
+			t.height_ = 1 + max(t.left.height(), t.right.height())
+			newroot = t
+		}
+	} else { // x > t.key
+		if t.right == nil {
+			t = t.copy()
+			n := makeNode(x)
+			t.right = n
+			newnode = n
+			newroot = t
+			t.height_ = 2 // was balanced w/ 0, sibling is height 0 or 1
+			return
+		}
+		var new_r *node32
+		new_r, newnode, oldnode = t.right.aInsert(x)
+		t = t.copy()
+		t.right = new_r
+		if new_r.height() > 1+t.left.height() {
+			newroot = t.aRightIsHigh(newnode)
+		} else {
+			t.height_ = 1 + max(t.left.height(), t.right.height())
+			newroot = t
+		}
+	}
+	return
+}
+
+func (t *node32) aDelete(key int32) (deleted, newSubTree *node32) {
+	if t == nil {
+		return nil, nil
+	}
+
+	if key < t.key {
+		oh := t.left.height()
+		d, tleft := t.left.aDelete(key)
+		if tleft == t.left {
+			return d, t
+		}
+		return d, t.copy().aRebalanceAfterLeftDeletion(oh, tleft)
+	} else if key > t.key {
+		oh := t.right.height()
+		d, tright := t.right.aDelete(key)
+		if tright == t.right {
+			return d, t
+		}
+		return d, t.copy().aRebalanceAfterRightDeletion(oh, tright)
+	}
+
+	if t.height() == LEAF_HEIGHT {
+		return t, nil
+	}
+
+	// Interior delete by removing left.Max or right.Min,
+	// then swapping contents
+	if t.left.height() > t.right.height() {
+		oh := t.left.height()
+		d, tleft := t.left.aDeleteMax()
+		r := t
+		t = t.copy()
+		t.data, t.key = d.data, d.key
+		return r, t.aRebalanceAfterLeftDeletion(oh, tleft)
+	}
+
+	oh := t.right.height()
+	d, tright := t.right.aDeleteMin()
+	r := t
+	t = t.copy()
+	t.data, t.key = d.data, d.key
+	return r, t.aRebalanceAfterRightDeletion(oh, tright)
+}
+
+func (t *node32) aDeleteMin() (deleted, newSubTree *node32) {
+	if t == nil {
+		return nil, nil
+	}
+	if t.left == nil { // leaf or left-most
+		return t, t.right
+	}
+	oh := t.left.height()
+	d, tleft := t.left.aDeleteMin()
+	if tleft == t.left {
+		return d, t
+	}
+	return d, t.copy().aRebalanceAfterLeftDeletion(oh, tleft)
+}
+
+func (t *node32) aDeleteMax() (deleted, newSubTree *node32) {
+	if t == nil {
+		return nil, nil
+	}
+
+	if t.right == nil { // leaf or right-most
+		return t, t.left
+	}
+
+	oh := t.right.height()
+	d, tright := t.right.aDeleteMax()
+	if tright == t.right {
+		return d, t
+	}
+	return d, t.copy().aRebalanceAfterRightDeletion(oh, tright)
+}
+
+func (t *node32) aRebalanceAfterLeftDeletion(oldLeftHeight int8, tleft *node32) *node32 {
+	t.left = tleft
+
+	if oldLeftHeight == tleft.height() || oldLeftHeight == t.right.height() {
+		// this node is still balanced and its height is unchanged
+		return t
+	}
+
+	if oldLeftHeight > t.right.height() {
+		// left was larger
+		t.height_--
+		return t
+	}
+
+	// left height fell by 1 and it was already less than right height
+	t.right = t.right.copy()
+	return t.aRightIsHigh(nil)
+}
+
+func (t *node32) aRebalanceAfterRightDeletion(oldRightHeight int8, tright *node32) *node32 {
+	t.right = tright
+
+	if oldRightHeight == tright.height() || oldRightHeight == t.left.height() {
+		// this node is still balanced and its height is unchanged
+		return t
+	}
+
+	if oldRightHeight > t.left.height() {
+		// left was larger
+		t.height_--
+		return t
+	}
+
+	// right height fell by 1 and it was already less than left height
+	t.left = t.left.copy()
+	return t.aLeftIsHigh(nil)
+}
+
+// aRightIsHigh does rotations necessary to fix a high right child
+// assume that t and t.right are already fresh copies.
+func (t *node32) aRightIsHigh(newnode *node32) *node32 {
+	right := t.right
+	if right.right.height() < right.left.height() {
+		// double rotation
+		if newnode != right.left {
+			right.left = right.left.copy()
+		}
+		t.right = right.leftToRoot()
+	}
+	t = t.rightToRoot()
+	return t
+}
+
+// aLeftIsHigh does rotations necessary to fix a high left child
+// assume that t and t.left are already fresh copies.
+func (t *node32) aLeftIsHigh(newnode *node32) *node32 {
+	left := t.left
+	if left.left.height() < left.right.height() {
+		// double rotation
+		if newnode != left.right {
+			left.right = left.right.copy()
+		}
+		t.left = left.rightToRoot()
+	}
+	t = t.leftToRoot()
+	return t
+}
+
+// rightToRoot does that rotation, modifying t and t.right in the process.
+func (t *node32) rightToRoot() *node32 {
+	//    this
+	// left  right
+	//      rl   rr
+	//
+	// becomes
+	//
+	//       right
+	//    this   rr
+	// left  rl
+	//
+	right := t.right
+	rl := right.left
+	right.left = t
+	// parent's child ptr fixed in caller
+	t.right = rl
+	t.height_ = 1 + max(rl.height(), t.left.height())
+	right.height_ = 1 + max(t.height(), right.right.height())
+	return right
+}
+
+// leftToRoot does that rotation, modifying t and t.left in the process.
+func (t *node32) leftToRoot() *node32 {
+	//     this
+	//  left  right
+	// ll  lr
+	//
+	// becomes
+	//
+	//    left
+	//   ll  this
+	//      lr  right
+	//
+	left := t.left
+	lr := left.right
+	left.right = t
+	// parent's child ptr fixed in caller
+	t.left = lr
+	t.height_ = 1 + max(lr.height(), t.right.height())
+	left.height_ = 1 + max(t.height(), left.left.height())
+	return left
+}
+
+func max(a, b int8) int8 {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func (t *node32) copy() *node32 {
+	u := *t
+	return &u
+}