Commit 06a78b57 authored by Martin Möhrmann's avatar Martin Möhrmann

cmd/compile: pass stack allocated bucket to makemap inside hmap

name         old time/op    new time/op    delta
NewEmptyMap    53.2ns ± 7%    48.0ns ± 5%  -9.77%  (p=0.000 n=20+20)
NewSmallMap     111ns ± 1%     106ns ± 2%  -3.78%  (p=0.000 n=20+19)

Change-Id: I979d21ab16eae9f6893873becca517db57e054b5
Reviewed-on: https://go-review.googlesource.com/56290
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarJosh Bleecher Snyder <josharian@gmail.com>
parent 1a2ac46e
......@@ -211,7 +211,7 @@ func runtimeTypes() []*types.Type {
typs[58] = types.Types[TUNSAFEPTR]
typs[59] = functype(nil, []*Node{anonfield(typs[57]), anonfield(typs[58]), anonfield(typs[58])}, []*Node{anonfield(typs[11])})
typs[60] = types.NewMap(typs[2], typs[2])
typs[61] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[15]), anonfield(typs[3]), anonfield(typs[3])}, []*Node{anonfield(typs[60])})
typs[61] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[15]), anonfield(typs[3])}, []*Node{anonfield(typs[60])})
typs[62] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[60]), anonfield(typs[3])}, []*Node{anonfield(typs[3])})
typs[63] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[60]), anonfield(typs[2])}, []*Node{anonfield(typs[3])})
typs[64] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[60]), anonfield(typs[3]), anonfield(typs[1])}, []*Node{anonfield(typs[3])})
......
......@@ -93,7 +93,7 @@ func ifaceeq(tab *uintptr, x, y unsafe.Pointer) (ret bool)
func efaceeq(typ *uintptr, x, y unsafe.Pointer) (ret bool)
// *byte is really *runtime.Type
func makemap(mapType *byte, hint int64, mapbuf *any, bucketbuf *any) (hmap map[any]any)
func makemap(mapType *byte, hint int64, mapbuf *any) (hmap map[any]any)
func mapaccess1(mapType *byte, hmap map[any]any, key *any) (val *any)
func mapaccess1_fast32(mapType *byte, hmap map[any]any, key any) (val *any)
func mapaccess1_fast64(mapType *byte, hmap map[any]any, key any) (val *any)
......
......@@ -1435,32 +1435,49 @@ opswitch:
case OMAKEMAP:
t := n.Type
hmapType := hmap(t)
a := nodnil() // hmap buffer
r := nodnil() // bucket buffer
// var h *hmap
var h *Node
if n.Esc == EscNone {
// Allocate hmap buffer on stack.
var_ := temp(hmap(t))
// Allocate hmap and one bucket on stack.
a = nod(OAS, var_, nil) // zero temp
a = typecheck(a, Etop)
init.Append(a)
a = nod(OADDR, var_, nil)
// var hv hmap
hv := temp(hmapType)
zero := nod(OAS, hv, nil)
zero = typecheck(zero, Etop)
init.Append(zero)
// h = &hv
h = nod(OADDR, hv, nil)
// Allocate one bucket on stack.
// Allocate one bucket pointed to by hmap.buckets on stack.
// Maximum key/value size is 128 bytes, larger objects
// are stored with an indirection. So max bucket size is 2048+eps.
var_ = temp(mapbucket(t))
r = nod(OAS, var_, nil) // zero temp
r = typecheck(r, Etop)
init.Append(r)
r = nod(OADDR, var_, nil)
// var bv bmap
bv := temp(mapbucket(t))
zero = nod(OAS, bv, nil)
zero = typecheck(zero, Etop)
init.Append(zero)
// b = &bv
b := nod(OADDR, bv, nil)
// h.buckets = b
bsym := hmapType.Field(5).Sym // hmap.buckets see reflect.go:hmap
na := nod(OAS, nodSym(ODOT, h, bsym), b)
na = typecheck(na, Etop)
init.Append(na)
} else {
// h = nil
h = nodnil()
}
fn := syslook("makemap")
fn = substArgTypes(fn, hmap(t), mapbucket(t), t.Key(), t.Val())
n = mkcall1(fn, n.Type, init, typename(n.Type), conv(n.Left, types.Types[TINT64]), a, r)
fn = substArgTypes(fn, hmapType, t.Key(), t.Val())
n = mkcall1(fn, n.Type, init, typename(n.Type), conv(n.Left, types.Types[TINT64]), h)
case OMAKESLICE:
l := n.Left
......
......@@ -259,8 +259,8 @@ func (h *hmap) createOverflow() {
// If the compiler has determined that the map or the first bucket
// can be created on the stack, h and/or bucket may be non-nil.
// If h != nil, the map can be created directly in h.
// If bucket != nil, bucket can be used as the first bucket.
func makemap(t *maptype, hint int64, h *hmap, bucket unsafe.Pointer) *hmap {
// If h.buckets != nil, bucket pointed to can be used as the first bucket.
func makemap(t *maptype, hint int64, h *hmap) *hmap {
if sz := unsafe.Sizeof(hmap{}); sz > 48 || sz != t.hmap.size {
println("runtime: sizeof(hmap) =", sz, ", t.hmap.size =", t.hmap.size)
throw("bad hmap size")
......@@ -312,34 +312,31 @@ func makemap(t *maptype, hint int64, h *hmap, bucket unsafe.Pointer) *hmap {
throw("bad evacuatedN")
}
// initialize Hmap
if h == nil {
h = (*hmap)(newobject(t.hmap))
}
h.hash0 = fastrand()
// find size parameter which will hold the requested # of elements
B := uint8(0)
for ; overLoadFactor(hint, B); B++ {
for overLoadFactor(hint, B) {
B++
}
h.B = B
// allocate initial hash table
// if B == 0, the buckets field is allocated lazily later (in mapassign)
// If hint is large zeroing this memory could take a while.
buckets := bucket
var extra *mapextra
if B != 0 {
if h.B != 0 {
var nextOverflow *bmap
buckets, nextOverflow = makeBucketArray(t, B)
h.buckets, nextOverflow = makeBucketArray(t, h.B)
if nextOverflow != nil {
extra = new(mapextra)
extra.nextOverflow = nextOverflow
h.extra = new(mapextra)
h.extra.nextOverflow = nextOverflow
}
}
// initialize Hmap
if h == nil {
h = (*hmap)(newobject(t.hmap))
}
h.B = B
h.extra = extra
h.hash0 = fastrand()
h.buckets = buckets
return h
}
......@@ -1171,7 +1168,7 @@ func ismapkey(t *_type) bool {
//go:linkname reflect_makemap reflect.makemap
func reflect_makemap(t *maptype, cap int) *hmap {
return makemap(t, int64(cap), nil, nil)
return makemap(t, int64(cap), nil)
}
//go:linkname reflect_mapaccess reflect.mapaccess
......
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