From 73df946d56c74384511a194dd01dbe099584fd1a Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 28 Apr 2024 15:14:23 +0200
Subject: Adding upstream version 1.16.10.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/runtime/map_fast64.go | 469 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 469 insertions(+)
 create mode 100644 src/runtime/map_fast64.go

(limited to 'src/runtime/map_fast64.go')

diff --git a/src/runtime/map_fast64.go b/src/runtime/map_fast64.go
new file mode 100644
index 0000000..f1368dc
--- /dev/null
+++ b/src/runtime/map_fast64.go
@@ -0,0 +1,469 @@
+// Copyright 2018 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 runtime
+
+import (
+	"runtime/internal/sys"
+	"unsafe"
+)
+
+func mapaccess1_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
+	if raceenabled && h != nil {
+		callerpc := getcallerpc()
+		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_fast64))
+	}
+	if h == nil || h.count == 0 {
+		return unsafe.Pointer(&zeroVal[0])
+	}
+	if h.flags&hashWriting != 0 {
+		throw("concurrent map read and map write")
+	}
+	var b *bmap
+	if h.B == 0 {
+		// One-bucket table. No need to hash.
+		b = (*bmap)(h.buckets)
+	} else {
+		hash := t.hasher(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
+		m := bucketMask(h.B)
+		b = (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
+		if c := h.oldbuckets; c != nil {
+			if !h.sameSizeGrow() {
+				// There used to be half as many buckets; mask down one more power of two.
+				m >>= 1
+			}
+			oldb := (*bmap)(add(c, (hash&m)*uintptr(t.bucketsize)))
+			if !evacuated(oldb) {
+				b = oldb
+			}
+		}
+	}
+	for ; b != nil; b = b.overflow(t) {
+		for i, k := uintptr(0), b.keys(); i < bucketCnt; i, k = i+1, add(k, 8) {
+			if *(*uint64)(k) == key && !isEmpty(b.tophash[i]) {
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*8+i*uintptr(t.elemsize))
+			}
+		}
+	}
+	return unsafe.Pointer(&zeroVal[0])
+}
+
+func mapaccess2_fast64(t *maptype, h *hmap, key uint64) (unsafe.Pointer, bool) {
+	if raceenabled && h != nil {
+		callerpc := getcallerpc()
+		racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_fast64))
+	}
+	if h == nil || h.count == 0 {
+		return unsafe.Pointer(&zeroVal[0]), false
+	}
+	if h.flags&hashWriting != 0 {
+		throw("concurrent map read and map write")
+	}
+	var b *bmap
+	if h.B == 0 {
+		// One-bucket table. No need to hash.
+		b = (*bmap)(h.buckets)
+	} else {
+		hash := t.hasher(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
+		m := bucketMask(h.B)
+		b = (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
+		if c := h.oldbuckets; c != nil {
+			if !h.sameSizeGrow() {
+				// There used to be half as many buckets; mask down one more power of two.
+				m >>= 1
+			}
+			oldb := (*bmap)(add(c, (hash&m)*uintptr(t.bucketsize)))
+			if !evacuated(oldb) {
+				b = oldb
+			}
+		}
+	}
+	for ; b != nil; b = b.overflow(t) {
+		for i, k := uintptr(0), b.keys(); i < bucketCnt; i, k = i+1, add(k, 8) {
+			if *(*uint64)(k) == key && !isEmpty(b.tophash[i]) {
+				return add(unsafe.Pointer(b), dataOffset+bucketCnt*8+i*uintptr(t.elemsize)), true
+			}
+		}
+	}
+	return unsafe.Pointer(&zeroVal[0]), false
+}
+
+func mapassign_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
+	if h == nil {
+		panic(plainError("assignment to entry in nil map"))
+	}
+	if raceenabled {
+		callerpc := getcallerpc()
+		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapassign_fast64))
+	}
+	if h.flags&hashWriting != 0 {
+		throw("concurrent map writes")
+	}
+	hash := t.hasher(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
+
+	// Set hashWriting after calling t.hasher for consistency with mapassign.
+	h.flags ^= hashWriting
+
+	if h.buckets == nil {
+		h.buckets = newobject(t.bucket) // newarray(t.bucket, 1)
+	}
+
+again:
+	bucket := hash & bucketMask(h.B)
+	if h.growing() {
+		growWork_fast64(t, h, bucket)
+	}
+	b := (*bmap)(add(h.buckets, bucket*uintptr(t.bucketsize)))
+
+	var insertb *bmap
+	var inserti uintptr
+	var insertk unsafe.Pointer
+
+bucketloop:
+	for {
+		for i := uintptr(0); i < bucketCnt; i++ {
+			if isEmpty(b.tophash[i]) {
+				if insertb == nil {
+					insertb = b
+					inserti = i
+				}
+				if b.tophash[i] == emptyRest {
+					break bucketloop
+				}
+				continue
+			}
+			k := *((*uint64)(add(unsafe.Pointer(b), dataOffset+i*8)))
+			if k != key {
+				continue
+			}
+			insertb = b
+			inserti = i
+			goto done
+		}
+		ovf := b.overflow(t)
+		if ovf == nil {
+			break
+		}
+		b = ovf
+	}
+
+	// Did not find mapping for key. Allocate new cell & add entry.
+
+	// If we hit the max load factor or we have too many overflow buckets,
+	// and we're not already in the middle of growing, start growing.
+	if !h.growing() && (overLoadFactor(h.count+1, h.B) || tooManyOverflowBuckets(h.noverflow, h.B)) {
+		hashGrow(t, h)
+		goto again // Growing the table invalidates everything, so try again
+	}
+
+	if insertb == nil {
+		// The current bucket and all the overflow buckets connected to it are full, allocate a new one.
+		insertb = h.newoverflow(t, b)
+		inserti = 0 // not necessary, but avoids needlessly spilling inserti
+	}
+	insertb.tophash[inserti&(bucketCnt-1)] = tophash(hash) // mask inserti to avoid bounds checks
+
+	insertk = add(unsafe.Pointer(insertb), dataOffset+inserti*8)
+	// store new key at insert position
+	*(*uint64)(insertk) = key
+
+	h.count++
+
+done:
+	elem := add(unsafe.Pointer(insertb), dataOffset+bucketCnt*8+inserti*uintptr(t.elemsize))
+	if h.flags&hashWriting == 0 {
+		throw("concurrent map writes")
+	}
+	h.flags &^= hashWriting
+	return elem
+}
+
+func mapassign_fast64ptr(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer {
+	if h == nil {
+		panic(plainError("assignment to entry in nil map"))
+	}
+	if raceenabled {
+		callerpc := getcallerpc()
+		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapassign_fast64))
+	}
+	if h.flags&hashWriting != 0 {
+		throw("concurrent map writes")
+	}
+	hash := t.hasher(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
+
+	// Set hashWriting after calling t.hasher for consistency with mapassign.
+	h.flags ^= hashWriting
+
+	if h.buckets == nil {
+		h.buckets = newobject(t.bucket) // newarray(t.bucket, 1)
+	}
+
+again:
+	bucket := hash & bucketMask(h.B)
+	if h.growing() {
+		growWork_fast64(t, h, bucket)
+	}
+	b := (*bmap)(add(h.buckets, bucket*uintptr(t.bucketsize)))
+
+	var insertb *bmap
+	var inserti uintptr
+	var insertk unsafe.Pointer
+
+bucketloop:
+	for {
+		for i := uintptr(0); i < bucketCnt; i++ {
+			if isEmpty(b.tophash[i]) {
+				if insertb == nil {
+					insertb = b
+					inserti = i
+				}
+				if b.tophash[i] == emptyRest {
+					break bucketloop
+				}
+				continue
+			}
+			k := *((*unsafe.Pointer)(add(unsafe.Pointer(b), dataOffset+i*8)))
+			if k != key {
+				continue
+			}
+			insertb = b
+			inserti = i
+			goto done
+		}
+		ovf := b.overflow(t)
+		if ovf == nil {
+			break
+		}
+		b = ovf
+	}
+
+	// Did not find mapping for key. Allocate new cell & add entry.
+
+	// If we hit the max load factor or we have too many overflow buckets,
+	// and we're not already in the middle of growing, start growing.
+	if !h.growing() && (overLoadFactor(h.count+1, h.B) || tooManyOverflowBuckets(h.noverflow, h.B)) {
+		hashGrow(t, h)
+		goto again // Growing the table invalidates everything, so try again
+	}
+
+	if insertb == nil {
+		// The current bucket and all the overflow buckets connected to it are full, allocate a new one.
+		insertb = h.newoverflow(t, b)
+		inserti = 0 // not necessary, but avoids needlessly spilling inserti
+	}
+	insertb.tophash[inserti&(bucketCnt-1)] = tophash(hash) // mask inserti to avoid bounds checks
+
+	insertk = add(unsafe.Pointer(insertb), dataOffset+inserti*8)
+	// store new key at insert position
+	*(*unsafe.Pointer)(insertk) = key
+
+	h.count++
+
+done:
+	elem := add(unsafe.Pointer(insertb), dataOffset+bucketCnt*8+inserti*uintptr(t.elemsize))
+	if h.flags&hashWriting == 0 {
+		throw("concurrent map writes")
+	}
+	h.flags &^= hashWriting
+	return elem
+}
+
+func mapdelete_fast64(t *maptype, h *hmap, key uint64) {
+	if raceenabled && h != nil {
+		callerpc := getcallerpc()
+		racewritepc(unsafe.Pointer(h), callerpc, funcPC(mapdelete_fast64))
+	}
+	if h == nil || h.count == 0 {
+		return
+	}
+	if h.flags&hashWriting != 0 {
+		throw("concurrent map writes")
+	}
+
+	hash := t.hasher(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
+
+	// Set hashWriting after calling t.hasher for consistency with mapdelete
+	h.flags ^= hashWriting
+
+	bucket := hash & bucketMask(h.B)
+	if h.growing() {
+		growWork_fast64(t, h, bucket)
+	}
+	b := (*bmap)(add(h.buckets, bucket*uintptr(t.bucketsize)))
+	bOrig := b
+search:
+	for ; b != nil; b = b.overflow(t) {
+		for i, k := uintptr(0), b.keys(); i < bucketCnt; i, k = i+1, add(k, 8) {
+			if key != *(*uint64)(k) || isEmpty(b.tophash[i]) {
+				continue
+			}
+			// Only clear key if there are pointers in it.
+			if t.key.ptrdata != 0 {
+				if sys.PtrSize == 8 {
+					*(*unsafe.Pointer)(k) = nil
+				} else {
+					// There are three ways to squeeze at one ore more 32 bit pointers into 64 bits.
+					// Just call memclrHasPointers instead of trying to handle all cases here.
+					memclrHasPointers(k, 8)
+				}
+			}
+			e := add(unsafe.Pointer(b), dataOffset+bucketCnt*8+i*uintptr(t.elemsize))
+			if t.elem.ptrdata != 0 {
+				memclrHasPointers(e, t.elem.size)
+			} else {
+				memclrNoHeapPointers(e, t.elem.size)
+			}
+			b.tophash[i] = emptyOne
+			// If the bucket now ends in a bunch of emptyOne states,
+			// change those to emptyRest states.
+			if i == bucketCnt-1 {
+				if b.overflow(t) != nil && b.overflow(t).tophash[0] != emptyRest {
+					goto notLast
+				}
+			} else {
+				if b.tophash[i+1] != emptyRest {
+					goto notLast
+				}
+			}
+			for {
+				b.tophash[i] = emptyRest
+				if i == 0 {
+					if b == bOrig {
+						break // beginning of initial bucket, we're done.
+					}
+					// Find previous bucket, continue at its last entry.
+					c := b
+					for b = bOrig; b.overflow(t) != c; b = b.overflow(t) {
+					}
+					i = bucketCnt - 1
+				} else {
+					i--
+				}
+				if b.tophash[i] != emptyOne {
+					break
+				}
+			}
+		notLast:
+			h.count--
+			// Reset the hash seed to make it more difficult for attackers to
+			// repeatedly trigger hash collisions. See issue 25237.
+			if h.count == 0 {
+				h.hash0 = fastrand()
+			}
+			break search
+		}
+	}
+
+	if h.flags&hashWriting == 0 {
+		throw("concurrent map writes")
+	}
+	h.flags &^= hashWriting
+}
+
+func growWork_fast64(t *maptype, h *hmap, bucket uintptr) {
+	// make sure we evacuate the oldbucket corresponding
+	// to the bucket we're about to use
+	evacuate_fast64(t, h, bucket&h.oldbucketmask())
+
+	// evacuate one more oldbucket to make progress on growing
+	if h.growing() {
+		evacuate_fast64(t, h, h.nevacuate)
+	}
+}
+
+func evacuate_fast64(t *maptype, h *hmap, oldbucket uintptr) {
+	b := (*bmap)(add(h.oldbuckets, oldbucket*uintptr(t.bucketsize)))
+	newbit := h.noldbuckets()
+	if !evacuated(b) {
+		// TODO: reuse overflow buckets instead of using new ones, if there
+		// is no iterator using the old buckets.  (If !oldIterator.)
+
+		// xy contains the x and y (low and high) evacuation destinations.
+		var xy [2]evacDst
+		x := &xy[0]
+		x.b = (*bmap)(add(h.buckets, oldbucket*uintptr(t.bucketsize)))
+		x.k = add(unsafe.Pointer(x.b), dataOffset)
+		x.e = add(x.k, bucketCnt*8)
+
+		if !h.sameSizeGrow() {
+			// Only calculate y pointers if we're growing bigger.
+			// Otherwise GC can see bad pointers.
+			y := &xy[1]
+			y.b = (*bmap)(add(h.buckets, (oldbucket+newbit)*uintptr(t.bucketsize)))
+			y.k = add(unsafe.Pointer(y.b), dataOffset)
+			y.e = add(y.k, bucketCnt*8)
+		}
+
+		for ; b != nil; b = b.overflow(t) {
+			k := add(unsafe.Pointer(b), dataOffset)
+			e := add(k, bucketCnt*8)
+			for i := 0; i < bucketCnt; i, k, e = i+1, add(k, 8), add(e, uintptr(t.elemsize)) {
+				top := b.tophash[i]
+				if isEmpty(top) {
+					b.tophash[i] = evacuatedEmpty
+					continue
+				}
+				if top < minTopHash {
+					throw("bad map state")
+				}
+				var useY uint8
+				if !h.sameSizeGrow() {
+					// Compute hash to make our evacuation decision (whether we need
+					// to send this key/elem to bucket x or bucket y).
+					hash := t.hasher(k, uintptr(h.hash0))
+					if hash&newbit != 0 {
+						useY = 1
+					}
+				}
+
+				b.tophash[i] = evacuatedX + useY // evacuatedX + 1 == evacuatedY, enforced in makemap
+				dst := &xy[useY]                 // evacuation destination
+
+				if dst.i == bucketCnt {
+					dst.b = h.newoverflow(t, dst.b)
+					dst.i = 0
+					dst.k = add(unsafe.Pointer(dst.b), dataOffset)
+					dst.e = add(dst.k, bucketCnt*8)
+				}
+				dst.b.tophash[dst.i&(bucketCnt-1)] = top // mask dst.i as an optimization, to avoid a bounds check
+
+				// Copy key.
+				if t.key.ptrdata != 0 && writeBarrier.enabled {
+					if sys.PtrSize == 8 {
+						// Write with a write barrier.
+						*(*unsafe.Pointer)(dst.k) = *(*unsafe.Pointer)(k)
+					} else {
+						// There are three ways to squeeze at least one 32 bit pointer into 64 bits.
+						// Give up and call typedmemmove.
+						typedmemmove(t.key, dst.k, k)
+					}
+				} else {
+					*(*uint64)(dst.k) = *(*uint64)(k)
+				}
+
+				typedmemmove(t.elem, dst.e, e)
+				dst.i++
+				// These updates might push these pointers past the end of the
+				// key or elem arrays.  That's ok, as we have the overflow pointer
+				// at the end of the bucket to protect against pointing past the
+				// end of the bucket.
+				dst.k = add(dst.k, 8)
+				dst.e = add(dst.e, uintptr(t.elemsize))
+			}
+		}
+		// Unlink the overflow buckets & clear key/elem to help GC.
+		if h.flags&oldIterator == 0 && t.bucket.ptrdata != 0 {
+			b := add(h.oldbuckets, oldbucket*uintptr(t.bucketsize))
+			// Preserve b.tophash because the evacuation
+			// state is maintained there.
+			ptr := add(b, dataOffset)
+			n := uintptr(t.bucketsize) - dataOffset
+			memclrHasPointers(ptr, n)
+		}
+	}
+
+	if oldbucket == h.nevacuate {
+		advanceEvacuationMark(h, t, newbit)
+	}
+}
-- 
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