mirror of
https://github.com/golang/go
synced 2024-11-20 02:54:39 -07:00
d5e4c4061b
The equal algorithm used to take the size equal(p, q *T, size uintptr) bool With this change, it does not equal(p, q *T) bool Similarly for the hash algorithm. The size is rarely used, as most equal functions know the size of the thing they are comparing. For instance f32equal already knows its inputs are 4 bytes in size. For cases where the size is not known, we allocate a closure (one for each size needed) that points to an assembly stub that reads the size out of the closure and calls generic code that has a size argument. Reduces the size of the go binary by 0.07%. Performance impact is not measurable. Change-Id: I6e00adf3dde7ad2974adbcff0ee91e86d2194fec Reviewed-on: https://go-review.googlesource.com/2392 Reviewed-by: Russ Cox <rsc@golang.org>
380 lines
11 KiB
Go
380 lines
11 KiB
Go
// Copyright 2014 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 runtime
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import (
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"unsafe"
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)
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func mapaccess1_fast32(t *maptype, h *hmap, key uint32) unsafe.Pointer {
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if raceenabled && h != nil {
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callerpc := getcallerpc(unsafe.Pointer(&t))
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racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_fast32))
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}
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if h == nil || h.count == 0 {
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return unsafe.Pointer(t.elem.zero)
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}
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var b *bmap
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if h.B == 0 {
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// One-bucket table. No need to hash.
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b = (*bmap)(h.buckets)
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} else {
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hash := t.key.alg.hash(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
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m := uintptr(1)<<h.B - 1
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b = (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
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if c := h.oldbuckets; c != nil {
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oldb := (*bmap)(add(c, (hash&(m>>1))*uintptr(t.bucketsize)))
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if !evacuated(oldb) {
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b = oldb
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}
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}
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}
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for {
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for i := uintptr(0); i < bucketCnt; i++ {
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k := *((*uint32)(add(unsafe.Pointer(b), dataOffset+i*4)))
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if k != key {
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continue
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}
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*4+i*uintptr(t.valuesize))
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}
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b = b.overflow(t)
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if b == nil {
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return unsafe.Pointer(t.elem.zero)
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}
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}
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}
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func mapaccess2_fast32(t *maptype, h *hmap, key uint32) (unsafe.Pointer, bool) {
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if raceenabled && h != nil {
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callerpc := getcallerpc(unsafe.Pointer(&t))
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racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_fast32))
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}
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if h == nil || h.count == 0 {
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return unsafe.Pointer(t.elem.zero), false
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}
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var b *bmap
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if h.B == 0 {
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// One-bucket table. No need to hash.
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b = (*bmap)(h.buckets)
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} else {
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hash := t.key.alg.hash(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
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m := uintptr(1)<<h.B - 1
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b = (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
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if c := h.oldbuckets; c != nil {
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oldb := (*bmap)(add(c, (hash&(m>>1))*uintptr(t.bucketsize)))
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if !evacuated(oldb) {
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b = oldb
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}
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}
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}
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for {
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for i := uintptr(0); i < bucketCnt; i++ {
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k := *((*uint32)(add(unsafe.Pointer(b), dataOffset+i*4)))
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if k != key {
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continue
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}
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*4+i*uintptr(t.valuesize)), true
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}
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b = b.overflow(t)
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if b == nil {
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return unsafe.Pointer(t.elem.zero), false
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}
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}
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}
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func mapaccess1_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
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if raceenabled && h != nil {
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callerpc := getcallerpc(unsafe.Pointer(&t))
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racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_fast64))
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}
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if h == nil || h.count == 0 {
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return unsafe.Pointer(t.elem.zero)
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}
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var b *bmap
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if h.B == 0 {
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// One-bucket table. No need to hash.
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b = (*bmap)(h.buckets)
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} else {
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hash := t.key.alg.hash(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
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m := uintptr(1)<<h.B - 1
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b = (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
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if c := h.oldbuckets; c != nil {
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oldb := (*bmap)(add(c, (hash&(m>>1))*uintptr(t.bucketsize)))
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if !evacuated(oldb) {
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b = oldb
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}
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}
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}
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for {
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for i := uintptr(0); i < bucketCnt; i++ {
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k := *((*uint64)(add(unsafe.Pointer(b), dataOffset+i*8)))
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if k != key {
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continue
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}
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*8+i*uintptr(t.valuesize))
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}
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b = b.overflow(t)
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if b == nil {
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return unsafe.Pointer(t.elem.zero)
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}
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}
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}
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func mapaccess2_fast64(t *maptype, h *hmap, key uint64) (unsafe.Pointer, bool) {
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if raceenabled && h != nil {
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callerpc := getcallerpc(unsafe.Pointer(&t))
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racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_fast64))
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}
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if h == nil || h.count == 0 {
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return unsafe.Pointer(t.elem.zero), false
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}
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var b *bmap
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if h.B == 0 {
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// One-bucket table. No need to hash.
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b = (*bmap)(h.buckets)
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} else {
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hash := t.key.alg.hash(noescape(unsafe.Pointer(&key)), uintptr(h.hash0))
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m := uintptr(1)<<h.B - 1
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b = (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
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if c := h.oldbuckets; c != nil {
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oldb := (*bmap)(add(c, (hash&(m>>1))*uintptr(t.bucketsize)))
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if !evacuated(oldb) {
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b = oldb
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}
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}
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}
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for {
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for i := uintptr(0); i < bucketCnt; i++ {
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k := *((*uint64)(add(unsafe.Pointer(b), dataOffset+i*8)))
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if k != key {
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continue
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}
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*8+i*uintptr(t.valuesize)), true
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}
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b = b.overflow(t)
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if b == nil {
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return unsafe.Pointer(t.elem.zero), false
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}
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}
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}
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func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
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if raceenabled && h != nil {
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callerpc := getcallerpc(unsafe.Pointer(&t))
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racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_faststr))
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}
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if h == nil || h.count == 0 {
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return unsafe.Pointer(t.elem.zero)
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}
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key := (*stringStruct)(unsafe.Pointer(&ky))
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if h.B == 0 {
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// One-bucket table.
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b := (*bmap)(h.buckets)
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if key.len < 32 {
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// short key, doing lots of comparisons is ok
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for i := uintptr(0); i < bucketCnt; i++ {
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*ptrSize))
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if k.len != key.len {
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continue
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}
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if k.str == key.str || memeq(k.str, key.str, uintptr(key.len)) {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+i*uintptr(t.valuesize))
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}
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}
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return unsafe.Pointer(t.elem.zero)
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}
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// long key, try not to do more comparisons than necessary
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keymaybe := uintptr(bucketCnt)
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for i := uintptr(0); i < bucketCnt; i++ {
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*ptrSize))
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if k.len != key.len {
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continue
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}
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if k.str == key.str {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+i*uintptr(t.valuesize))
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}
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// check first 4 bytes
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// TODO: on amd64/386 at least, make this compile to one 4-byte comparison instead of
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// four 1-byte comparisons.
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if *((*[4]byte)(key.str)) != *((*[4]byte)(k.str)) {
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continue
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}
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// check last 4 bytes
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if *((*[4]byte)(add(key.str, uintptr(key.len)-4))) != *((*[4]byte)(add(k.str, uintptr(key.len)-4))) {
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continue
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}
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if keymaybe != bucketCnt {
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// Two keys are potential matches. Use hash to distinguish them.
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goto dohash
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}
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keymaybe = i
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}
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if keymaybe != bucketCnt {
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+keymaybe*2*ptrSize))
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if memeq(k.str, key.str, uintptr(key.len)) {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+keymaybe*uintptr(t.valuesize))
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}
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}
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return unsafe.Pointer(t.elem.zero)
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}
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dohash:
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hash := t.key.alg.hash(noescape(unsafe.Pointer(&ky)), uintptr(h.hash0))
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m := uintptr(1)<<h.B - 1
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b := (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
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if c := h.oldbuckets; c != nil {
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oldb := (*bmap)(add(c, (hash&(m>>1))*uintptr(t.bucketsize)))
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if !evacuated(oldb) {
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b = oldb
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}
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}
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top := uint8(hash >> (ptrSize*8 - 8))
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if top < minTopHash {
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top += minTopHash
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}
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for {
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for i := uintptr(0); i < bucketCnt; i++ {
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x != top {
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continue
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}
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*ptrSize))
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if k.len != key.len {
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continue
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}
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if k.str == key.str || memeq(k.str, key.str, uintptr(key.len)) {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+i*uintptr(t.valuesize))
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}
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}
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b = b.overflow(t)
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if b == nil {
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return unsafe.Pointer(t.elem.zero)
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}
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}
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}
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func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
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if raceenabled && h != nil {
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callerpc := getcallerpc(unsafe.Pointer(&t))
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racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_faststr))
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}
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if h == nil || h.count == 0 {
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return unsafe.Pointer(t.elem.zero), false
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}
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key := (*stringStruct)(unsafe.Pointer(&ky))
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if h.B == 0 {
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// One-bucket table.
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b := (*bmap)(h.buckets)
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if key.len < 32 {
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// short key, doing lots of comparisons is ok
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for i := uintptr(0); i < bucketCnt; i++ {
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*ptrSize))
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if k.len != key.len {
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continue
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}
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if k.str == key.str || memeq(k.str, key.str, uintptr(key.len)) {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+i*uintptr(t.valuesize)), true
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}
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}
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return unsafe.Pointer(t.elem.zero), false
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}
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// long key, try not to do more comparisons than necessary
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keymaybe := uintptr(bucketCnt)
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for i := uintptr(0); i < bucketCnt; i++ {
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x == empty {
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continue
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}
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*ptrSize))
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if k.len != key.len {
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continue
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}
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if k.str == key.str {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+i*uintptr(t.valuesize)), true
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}
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// check first 4 bytes
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if *((*[4]byte)(key.str)) != *((*[4]byte)(k.str)) {
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continue
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}
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// check last 4 bytes
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if *((*[4]byte)(add(key.str, uintptr(key.len)-4))) != *((*[4]byte)(add(k.str, uintptr(key.len)-4))) {
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continue
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}
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if keymaybe != bucketCnt {
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// Two keys are potential matches. Use hash to distinguish them.
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goto dohash
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}
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keymaybe = i
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}
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if keymaybe != bucketCnt {
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+keymaybe*2*ptrSize))
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if memeq(k.str, key.str, uintptr(key.len)) {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+keymaybe*uintptr(t.valuesize)), true
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}
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}
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return unsafe.Pointer(t.elem.zero), false
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}
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dohash:
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hash := t.key.alg.hash(noescape(unsafe.Pointer(&ky)), uintptr(h.hash0))
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m := uintptr(1)<<h.B - 1
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b := (*bmap)(add(h.buckets, (hash&m)*uintptr(t.bucketsize)))
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if c := h.oldbuckets; c != nil {
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oldb := (*bmap)(add(c, (hash&(m>>1))*uintptr(t.bucketsize)))
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if !evacuated(oldb) {
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b = oldb
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}
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}
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top := uint8(hash >> (ptrSize*8 - 8))
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if top < minTopHash {
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top += minTopHash
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}
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for {
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for i := uintptr(0); i < bucketCnt; i++ {
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x := *((*uint8)(add(unsafe.Pointer(b), i))) // b.topbits[i] without the bounds check
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if x != top {
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continue
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}
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k := (*stringStruct)(add(unsafe.Pointer(b), dataOffset+i*2*ptrSize))
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if k.len != key.len {
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continue
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}
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if k.str == key.str || memeq(k.str, key.str, uintptr(key.len)) {
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return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*ptrSize+i*uintptr(t.valuesize)), true
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}
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}
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b = b.overflow(t)
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if b == nil {
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return unsafe.Pointer(t.elem.zero), false
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}
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}
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}
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