aboutsummaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/cmd/compile/internal/gc/builtin.go2
-rw-r--r--src/cmd/compile/internal/gc/builtin/runtime.go2
-rw-r--r--src/cmd/compile/internal/gc/go.go3
-rw-r--r--src/cmd/compile/internal/gc/main.go5
-rw-r--r--src/cmd/compile/internal/gc/obj.go5
-rw-r--r--src/cmd/compile/internal/gc/reflect.go24
-rw-r--r--src/cmd/compile/internal/gc/walk.go18
-rw-r--r--src/runtime/hashmap.go65
-rw-r--r--src/runtime/hashmap_fast.go33
-rw-r--r--src/runtime/map_test.go16
10 files changed, 110 insertions, 63 deletions
diff --git a/src/cmd/compile/internal/gc/builtin.go b/src/cmd/compile/internal/gc/builtin.go
index 411c7b8605..b593d11296 100644
--- a/src/cmd/compile/internal/gc/builtin.go
+++ b/src/cmd/compile/internal/gc/builtin.go
@@ -70,10 +70,12 @@ const runtimeimport = "" +
"func @\"\".mapaccess1_fast32 (@\"\".mapType·2 *byte, @\"\".hmap·3 map[any]any, @\"\".key·4 any) (@\"\".val·1 *any)\n" +
"func @\"\".mapaccess1_fast64 (@\"\".mapType·2 *byte, @\"\".hmap·3 map[any]any, @\"\".key·4 any) (@\"\".val·1 *any)\n" +
"func @\"\".mapaccess1_faststr (@\"\".mapType·2 *byte, @\"\".hmap·3 map[any]any, @\"\".key·4 any) (@\"\".val·1 *any)\n" +
+ "func @\"\".mapaccess1_fat (@\"\".mapType·2 *byte, @\"\".hmap·3 map[any]any, @\"\".key·4 *any, @\"\".zero·5 *byte) (@\"\".val·1 *any)\n" +
"func @\"\".mapaccess2 (@\"\".mapType·3 *byte, @\"\".hmap·4 map[any]any, @\"\".key·5 *any) (@\"\".val·1 *any, @\"\".pres·2 bool)\n" +
"func @\"\".mapaccess2_fast32 (@\"\".mapType·3 *byte, @\"\".hmap·4 map[any]any, @\"\".key·5 any) (@\"\".val·1 *any, @\"\".pres·2 bool)\n" +
"func @\"\".mapaccess2_fast64 (@\"\".mapType·3 *byte, @\"\".hmap·4 map[any]any, @\"\".key·5 any) (@\"\".val·1 *any, @\"\".pres·2 bool)\n" +
"func @\"\".mapaccess2_faststr (@\"\".mapType·3 *byte, @\"\".hmap·4 map[any]any, @\"\".key·5 any) (@\"\".val·1 *any, @\"\".pres·2 bool)\n" +
+ "func @\"\".mapaccess2_fat (@\"\".mapType·3 *byte, @\"\".hmap·4 map[any]any, @\"\".key·5 *any, @\"\".zero·6 *byte) (@\"\".val·1 *any, @\"\".pres·2 bool)\n" +
"func @\"\".mapassign1 (@\"\".mapType·1 *byte, @\"\".hmap·2 map[any]any, @\"\".key·3 *any, @\"\".val·4 *any)\n" +
"func @\"\".mapiterinit (@\"\".mapType·1 *byte, @\"\".hmap·2 map[any]any, @\"\".hiter·3 *any)\n" +
"func @\"\".mapdelete (@\"\".mapType·1 *byte, @\"\".hmap·2 map[any]any, @\"\".key·3 *any)\n" +
diff --git a/src/cmd/compile/internal/gc/builtin/runtime.go b/src/cmd/compile/internal/gc/builtin/runtime.go
index 584368a144..e9316cb313 100644
--- a/src/cmd/compile/internal/gc/builtin/runtime.go
+++ b/src/cmd/compile/internal/gc/builtin/runtime.go
@@ -89,10 +89,12 @@ 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)
func mapaccess1_faststr(mapType *byte, hmap map[any]any, key any) (val *any)
+func mapaccess1_fat(mapType *byte, hmap map[any]any, key *any, zero *byte) (val *any)
func mapaccess2(mapType *byte, hmap map[any]any, key *any) (val *any, pres bool)
func mapaccess2_fast32(mapType *byte, hmap map[any]any, key any) (val *any, pres bool)
func mapaccess2_fast64(mapType *byte, hmap map[any]any, key any) (val *any, pres bool)
func mapaccess2_faststr(mapType *byte, hmap map[any]any, key any) (val *any, pres bool)
+func mapaccess2_fat(mapType *byte, hmap map[any]any, key *any, zero *byte) (val *any, pres bool)
func mapassign1(mapType *byte, hmap map[any]any, key *any, val *any)
func mapiterinit(mapType *byte, hmap map[any]any, hiter *any)
func mapdelete(mapType *byte, hmap map[any]any, key *any)
diff --git a/src/cmd/compile/internal/gc/go.go b/src/cmd/compile/internal/gc/go.go
index af9aaf0dae..87b6121c8e 100644
--- a/src/cmd/compile/internal/gc/go.go
+++ b/src/cmd/compile/internal/gc/go.go
@@ -175,6 +175,9 @@ var unsafepkg *Pkg // package unsafe
var trackpkg *Pkg // fake package for field tracking
+var mappkg *Pkg // fake package for map zero value
+var zerosize int64
+
var Tptr EType // either TPTR32 or TPTR64
var myimportpath string
diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index 37e8a17886..2afd262fed 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -137,6 +137,11 @@ func Main() {
typepkg = mkpkg("type")
typepkg.Name = "type"
+ // pseudo-package used for map zero values
+ mappkg = mkpkg("go.map")
+ mappkg.Name = "go.map"
+ mappkg.Prefix = "go.map"
+
goroot = obj.Getgoroot()
goos = obj.Getgoos()
diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go
index b60f78f638..fab611fdb5 100644
--- a/src/cmd/compile/internal/gc/obj.go
+++ b/src/cmd/compile/internal/gc/obj.go
@@ -87,6 +87,11 @@ func dumpobj() {
dumpglobls()
externdcl = tmp
+ if zerosize > 0 {
+ zero := Pkglookup("zero", mappkg)
+ ggloblsym(zero, int32(zerosize), obj.DUPOK|obj.RODATA)
+ }
+
dumpdata()
obj.Writeobjdirect(Ctxt, bout.Writer)
diff --git a/src/cmd/compile/internal/gc/reflect.go b/src/cmd/compile/internal/gc/reflect.go
index 5031045c64..4792f88abe 100644
--- a/src/cmd/compile/internal/gc/reflect.go
+++ b/src/cmd/compile/internal/gc/reflect.go
@@ -1689,3 +1689,27 @@ func (p *GCProg) emit(t *Type, offset int64) {
}
}
}
+
+// zeroaddr returns the address of a symbol with at least
+// size bytes of zeros.
+func zeroaddr(size int64) *Node {
+ if size >= 1<<31 {
+ Fatalf("map value too big %d", size)
+ }
+ if zerosize < size {
+ zerosize = size
+ }
+ s := Pkglookup("zero", mappkg)
+ if s.Def == nil {
+ x := newname(s)
+ x.Type = Types[TUINT8]
+ x.Class = PEXTERN
+ x.Typecheck = 1
+ s.Def = x
+ }
+ z := Nod(OADDR, s.Def, nil)
+ z.Type = Ptrto(Types[TUINT8])
+ z.Addable = true
+ z.Typecheck = 1
+ return z
+}
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index 82ac74ae33..8cce85de9a 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -864,8 +864,14 @@ opswitch:
// a = *var
a := n.List.First()
- fn := mapfn(p, t)
- r = mkcall1(fn, fn.Type.Results(), init, typename(t), r.Left, key)
+ if w := t.Val().Width; w <= 1024 { // 1024 must match ../../../../runtime/hashmap.go:maxZero
+ fn := mapfn(p, t)
+ r = mkcall1(fn, fn.Type.Results(), init, typename(t), r.Left, key)
+ } else {
+ fn := mapfn("mapaccess2_fat", t)
+ z := zeroaddr(w)
+ r = mkcall1(fn, fn.Type.Results(), init, typename(t), r.Left, key, z)
+ }
// mapaccess2* returns a typed bool, but due to spec changes,
// the boolean result of i.(T) is now untyped so we make it the
@@ -1222,7 +1228,13 @@ opswitch:
p = "mapaccess1"
}
- n = mkcall1(mapfn(p, t), Ptrto(t.Val()), init, typename(t), n.Left, key)
+ if w := t.Val().Width; w <= 1024 { // 1024 must match ../../../../runtime/hashmap.go:maxZero
+ n = mkcall1(mapfn(p, t), Ptrto(t.Val()), init, typename(t), n.Left, key)
+ } else {
+ p = "mapaccess1_fat"
+ z := zeroaddr(w)
+ n = mkcall1(mapfn(p, t), Ptrto(t.Val()), init, typename(t), n.Left, key, z)
+ }
n = Nod(OIND, n, nil)
n.Type = t.Val()
n.Typecheck = 1
diff --git a/src/runtime/hashmap.go b/src/runtime/hashmap.go
index 4f5d03d983..ff59faab5d 100644
--- a/src/runtime/hashmap.go
+++ b/src/runtime/hashmap.go
@@ -236,9 +236,6 @@ func makemap(t *maptype, hint int64, h *hmap, bucket unsafe.Pointer) *hmap {
throw("need padding in bucket (value)")
}
- // make sure zeroptr is large enough
- mapzero(t.elem)
-
// find size parameter which will hold the requested # of elements
B := uint8(0)
for ; hint > bucketCnt && float32(hint) > loadFactor*float32(uintptr(1)<<B); B++ {
@@ -283,7 +280,7 @@ func mapaccess1(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer {
msanread(key, t.key.size)
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -321,7 +318,7 @@ func mapaccess1(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer {
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
}
}
@@ -337,7 +334,7 @@ func mapaccess2(t *maptype, h *hmap, key unsafe.Pointer) (unsafe.Pointer, bool)
msanread(key, t.key.size)
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -375,7 +372,7 @@ func mapaccess2(t *maptype, h *hmap, key unsafe.Pointer) (unsafe.Pointer, bool)
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
}
}
@@ -426,6 +423,22 @@ func mapaccessK(t *maptype, h *hmap, key unsafe.Pointer) (unsafe.Pointer, unsafe
}
}
+func mapaccess1_fat(t *maptype, h *hmap, key, zero unsafe.Pointer) unsafe.Pointer {
+ v := mapaccess1(t, h, key)
+ if v == unsafe.Pointer(&zeroVal[0]) {
+ return zero
+ }
+ return v
+}
+
+func mapaccess2_fat(t *maptype, h *hmap, key, zero unsafe.Pointer) (unsafe.Pointer, bool) {
+ v := mapaccess1(t, h, key)
+ if v == unsafe.Pointer(&zeroVal[0]) {
+ return zero, false
+ }
+ return v, true
+}
+
func mapassign1(t *maptype, h *hmap, key unsafe.Pointer, val unsafe.Pointer) {
if h == nil {
panic(plainError("assignment to entry in nil map"))
@@ -1044,39 +1057,5 @@ func reflect_ismapkey(t *_type) bool {
return ismapkey(t)
}
-var zerolock mutex
-
-const initialZeroSize = 1024
-
-var zeroinitial [initialZeroSize]byte
-
-// All accesses to zeroptr and zerosize must be atomic so that they
-// can be accessed without locks in the common case.
-var zeroptr unsafe.Pointer = unsafe.Pointer(&zeroinitial)
-var zerosize uintptr = initialZeroSize
-
-// mapzero ensures that zeroptr points to a buffer large enough to
-// serve as the zero value for t.
-func mapzero(t *_type) {
- // Is the type small enough for existing buffer?
- cursize := uintptr(atomic.Loadp(unsafe.Pointer(&zerosize)))
- if t.size <= cursize {
- return
- }
-
- // Allocate a new buffer.
- lock(&zerolock)
- cursize = uintptr(atomic.Loadp(unsafe.Pointer(&zerosize)))
- if cursize < t.size {
- for cursize < t.size {
- cursize *= 2
- if cursize == 0 {
- // need >2GB zero on 32-bit machine
- throw("map element too large")
- }
- }
- atomic.StorepNoWB(unsafe.Pointer(&zeroptr), persistentalloc(cursize, 64, &memstats.other_sys))
- atomic.StorepNoWB(unsafe.Pointer(&zerosize), unsafe.Pointer(zerosize))
- }
- unlock(&zerolock)
-}
+const maxZero = 1024 // must match value in ../cmd/compile/internal/gc/walk.go
+var zeroVal [maxZero]byte
diff --git a/src/runtime/hashmap_fast.go b/src/runtime/hashmap_fast.go
index 6a5484edee..8f9bb5a6fc 100644
--- a/src/runtime/hashmap_fast.go
+++ b/src/runtime/hashmap_fast.go
@@ -5,7 +5,6 @@
package runtime
import (
- "runtime/internal/atomic"
"runtime/internal/sys"
"unsafe"
)
@@ -16,7 +15,7 @@ func mapaccess1_fast32(t *maptype, h *hmap, key uint32) unsafe.Pointer {
racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_fast32))
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -50,7 +49,7 @@ func mapaccess1_fast32(t *maptype, h *hmap, key uint32) unsafe.Pointer {
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
}
}
@@ -61,7 +60,7 @@ func mapaccess2_fast32(t *maptype, h *hmap, key uint32) (unsafe.Pointer, bool) {
racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_fast32))
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -95,7 +94,7 @@ func mapaccess2_fast32(t *maptype, h *hmap, key uint32) (unsafe.Pointer, bool) {
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
}
}
@@ -106,7 +105,7 @@ func mapaccess1_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_fast64))
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -140,7 +139,7 @@ func mapaccess1_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
}
}
@@ -151,7 +150,7 @@ func mapaccess2_fast64(t *maptype, h *hmap, key uint64) (unsafe.Pointer, bool) {
racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_fast64))
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -185,7 +184,7 @@ func mapaccess2_fast64(t *maptype, h *hmap, key uint64) (unsafe.Pointer, bool) {
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
}
}
@@ -196,7 +195,7 @@ func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess1_faststr))
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -220,7 +219,7 @@ func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.valuesize))
}
}
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
// long key, try not to do more comparisons than necessary
keymaybe := uintptr(bucketCnt)
@@ -258,7 +257,7 @@ func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+keymaybe*uintptr(t.valuesize))
}
}
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
dohash:
hash := t.key.alg.hash(noescape(unsafe.Pointer(&ky)), uintptr(h.hash0))
@@ -290,7 +289,7 @@ dohash:
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr))
+ return unsafe.Pointer(&zeroVal[0])
}
}
}
@@ -301,7 +300,7 @@ func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
racereadpc(unsafe.Pointer(h), callerpc, funcPC(mapaccess2_faststr))
}
if h == nil || h.count == 0 {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
if h.flags&hashWriting != 0 {
throw("concurrent map read and map write")
@@ -325,7 +324,7 @@ func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.valuesize)), true
}
}
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
// long key, try not to do more comparisons than necessary
keymaybe := uintptr(bucketCnt)
@@ -361,7 +360,7 @@ func mapaccess2_faststr(t *maptype, h *hmap, ky string) (unsafe.Pointer, bool) {
return add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+keymaybe*uintptr(t.valuesize)), true
}
}
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
dohash:
hash := t.key.alg.hash(noescape(unsafe.Pointer(&ky)), uintptr(h.hash0))
@@ -393,7 +392,7 @@ dohash:
}
b = b.overflow(t)
if b == nil {
- return atomic.Loadp(unsafe.Pointer(&zeroptr)), false
+ return unsafe.Pointer(&zeroVal[0]), false
}
}
}
diff --git a/src/runtime/map_test.go b/src/runtime/map_test.go
index 9d2894cb6f..496f8e8868 100644
--- a/src/runtime/map_test.go
+++ b/src/runtime/map_test.go
@@ -317,6 +317,22 @@ func TestBigItems(t *testing.T) {
}
}
+func TestMapHugeZero(t *testing.T) {
+ type T [4000]byte
+ m := map[int]T{}
+ x := m[0]
+ if x != (T{}) {
+ t.Errorf("map value not zero")
+ }
+ y, ok := m[0]
+ if ok {
+ t.Errorf("map value should be missing")
+ }
+ if y != (T{}) {
+ t.Errorf("map value not zero")
+ }
+}
+
type empty struct {
}
generated by cgit v1.3 (git 2.53.0) at 2026-04-15 19:28:51 +0000