all: split old and swiss map abi and compiler integration

The two map implementations are still identical, but now the compiler
targets the appropriate ABI depending on GOEXPERIMENT.

For #54766.

Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest,gotip-linux-amd64-longtest-swissmap
Change-Id: I8438f64f044ba9de30ddbf2b8ceb9b4edd2d5614
Reviewed-on: https://go-review.googlesource.com/c/go/+/580779
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Pratt <mpratt@google.com>

3 files changed, 91 insertions, 44 deletions

diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go
index 277c703edd..2870a0adef 100644
--- a/src/reflect/all_test.go
+++ b/src/reflect/all_test.go
@@ -12,6 +12,7 @@ import (
 	"go/token"
 	"internal/abi"
 	"internal/goarch"
+	"internal/goexperiment"
 	"internal/testenv"
 	"io"
 	"math"
@@ -32,8 +33,6 @@ import (
 	"unsafe"
 )
 
-const bucketCount = abi.MapBucketCount
-
 var sink any
 
 func TestBool(t *testing.T) {
@@ -7277,47 +7276,95 @@ func TestGCBits(t *testing.T) {
 	verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1))
 	verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1))
 
-	hdr := make([]byte, bucketCount/goarch.PtrSize)
+	if goexperiment.SwissMap {
+		const bucketCount = abi.SwissMapBucketCount
 
-	verifyMapBucket := func(t *testing.T, k, e Type, m any, want []byte) {
-		verifyGCBits(t, MapBucketOf(k, e), want)
-		verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
-	}
-	verifyMapBucket(t,
+		hdr := make([]byte, bucketCount/goarch.PtrSize)
+
+		verifyMapBucket := func(t *testing.T, k, e Type, m any, want []byte) {
+			verifyGCBits(t, MapBucketOf(k, e), want)
+			verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
+		}
+		verifyMapBucket(t,
 		Tscalar, Tptr,
 		map[Xscalar]Xptr(nil),
 		join(hdr, rep(bucketCount, lit(0)), rep(bucketCount, lit(1)), lit(1)))
-	verifyMapBucket(t,
+		verifyMapBucket(t,
 		Tscalarptr, Tptr,
 		map[Xscalarptr]Xptr(nil),
 		join(hdr, rep(bucketCount, lit(0, 1)), rep(bucketCount, lit(1)), lit(1)))
-	verifyMapBucket(t, Tint64, Tptr,
+		verifyMapBucket(t, Tint64, Tptr,
 		map[int64]Xptr(nil),
 		join(hdr, rep(bucketCount, rep(8/goarch.PtrSize, lit(0))), rep(bucketCount, lit(1)), lit(1)))
-	verifyMapBucket(t,
+		verifyMapBucket(t,
 		Tscalar, Tscalar,
 		map[Xscalar]Xscalar(nil),
 		empty)
-	verifyMapBucket(t,
+		verifyMapBucket(t,
 		ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar),
 		map[[2]Xscalarptr][3]Xptrscalar(nil),
 		join(hdr, rep(bucketCount*2, lit(0, 1)), rep(bucketCount*3, lit(1, 0)), lit(1)))
-	verifyMapBucket(t,
+		verifyMapBucket(t,
 		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
 		map[[64 / goarch.PtrSize]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
 		join(hdr, rep(bucketCount*64/goarch.PtrSize, lit(0, 1)), rep(bucketCount*64/goarch.PtrSize, lit(1, 0)), lit(1)))
-	verifyMapBucket(t,
+		verifyMapBucket(t,
 		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
 		map[[64/goarch.PtrSize + 1]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
 		join(hdr, rep(bucketCount, lit(1)), rep(bucketCount*64/goarch.PtrSize, lit(1, 0)), lit(1)))
-	verifyMapBucket(t,
+		verifyMapBucket(t,
 		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
 		map[[64 / goarch.PtrSize]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
 		join(hdr, rep(bucketCount*64/goarch.PtrSize, lit(0, 1)), rep(bucketCount, lit(1)), lit(1)))
-	verifyMapBucket(t,
+		verifyMapBucket(t,
 		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
 		map[[64/goarch.PtrSize + 1]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
 		join(hdr, rep(bucketCount, lit(1)), rep(bucketCount, lit(1)), lit(1)))
+	} else {
+		const bucketCount = abi.OldMapBucketCount
+
+		hdr := make([]byte, bucketCount/goarch.PtrSize)
+
+		verifyMapBucket := func(t *testing.T, k, e Type, m any, want []byte) {
+			verifyGCBits(t, MapBucketOf(k, e), want)
+			verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
+		}
+		verifyMapBucket(t,
+		Tscalar, Tptr,
+		map[Xscalar]Xptr(nil),
+		join(hdr, rep(bucketCount, lit(0)), rep(bucketCount, lit(1)), lit(1)))
+		verifyMapBucket(t,
+		Tscalarptr, Tptr,
+		map[Xscalarptr]Xptr(nil),
+		join(hdr, rep(bucketCount, lit(0, 1)), rep(bucketCount, lit(1)), lit(1)))
+		verifyMapBucket(t, Tint64, Tptr,
+		map[int64]Xptr(nil),
+		join(hdr, rep(bucketCount, rep(8/goarch.PtrSize, lit(0))), rep(bucketCount, lit(1)), lit(1)))
+		verifyMapBucket(t,
+		Tscalar, Tscalar,
+		map[Xscalar]Xscalar(nil),
+		empty)
+		verifyMapBucket(t,
+		ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar),
+		map[[2]Xscalarptr][3]Xptrscalar(nil),
+		join(hdr, rep(bucketCount*2, lit(0, 1)), rep(bucketCount*3, lit(1, 0)), lit(1)))
+		verifyMapBucket(t,
+		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
+		map[[64 / goarch.PtrSize]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
+		join(hdr, rep(bucketCount*64/goarch.PtrSize, lit(0, 1)), rep(bucketCount*64/goarch.PtrSize, lit(1, 0)), lit(1)))
+		verifyMapBucket(t,
+		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize, Tptrscalar),
+		map[[64/goarch.PtrSize + 1]Xscalarptr][64 / goarch.PtrSize]Xptrscalar(nil),
+		join(hdr, rep(bucketCount, lit(1)), rep(bucketCount*64/goarch.PtrSize, lit(1, 0)), lit(1)))
+		verifyMapBucket(t,
+		ArrayOf(64/goarch.PtrSize, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
+		map[[64 / goarch.PtrSize]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
+		join(hdr, rep(bucketCount*64/goarch.PtrSize, lit(0, 1)), rep(bucketCount, lit(1)), lit(1)))
+		verifyMapBucket(t,
+		ArrayOf(64/goarch.PtrSize+1, Tscalarptr), ArrayOf(64/goarch.PtrSize+1, Tptrscalar),
+		map[[64/goarch.PtrSize + 1]Xscalarptr][64/goarch.PtrSize + 1]Xptrscalar(nil),
+		join(hdr, rep(bucketCount, lit(1)), rep(bucketCount, lit(1)), lit(1)))
+	}
 }
 
 func rep(n int, b []byte) []byte { return bytes.Repeat(b, n) }
diff --git a/src/reflect/map_noswiss.go b/src/reflect/map_noswiss.go
index de92e76df0..5af50ac779 100644
--- a/src/reflect/map_noswiss.go
+++ b/src/reflect/map_noswiss.go
@@ -14,7 +14,7 @@ import (
 
 // mapType represents a map type.
 type mapType struct {
-	abi.MapType
+	abi.OldMapType
 }
 
 func (t *rtype) Key() Type {
@@ -70,13 +70,13 @@ func MapOf(key, elem Type) Type {
 		return typehash(ktyp, p, seed)
 	}
 	mt.Flags = 0
-	if ktyp.Size_ > abi.MapMaxKeyBytes {
+	if ktyp.Size_ > abi.OldMapMaxKeyBytes {
 		mt.KeySize = uint8(goarch.PtrSize)
 		mt.Flags |= 1 // indirect key
 	} else {
 		mt.KeySize = uint8(ktyp.Size_)
 	}
-	if etyp.Size_ > abi.MapMaxElemBytes {
+	if etyp.Size_ > abi.OldMapMaxElemBytes {
 		mt.ValueSize = uint8(goarch.PtrSize)
 		mt.Flags |= 2 // indirect value
 	} else {
@@ -99,10 +99,10 @@ func MapOf(key, elem Type) Type {
 }
 
 func bucketOf(ktyp, etyp *abi.Type) *abi.Type {
-	if ktyp.Size_ > abi.MapMaxKeyBytes {
+	if ktyp.Size_ > abi.OldMapMaxKeyBytes {
 		ktyp = ptrTo(ktyp)
 	}
-	if etyp.Size_ > abi.MapMaxElemBytes {
+	if etyp.Size_ > abi.OldMapMaxElemBytes {
 		etyp = ptrTo(etyp)
 	}
 
@@ -114,29 +114,29 @@ func bucketOf(ktyp, etyp *abi.Type) *abi.Type {
 	var gcdata *byte
 	var ptrdata uintptr
 
-	size := abi.MapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize
+	size := abi.OldMapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize
 	if size&uintptr(ktyp.Align_-1) != 0 || size&uintptr(etyp.Align_-1) != 0 {
 		panic("reflect: bad size computation in MapOf")
 	}
 
 	if ktyp.Pointers() || etyp.Pointers() {
-		nptr := (abi.MapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize) / goarch.PtrSize
+		nptr := (abi.OldMapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize) / goarch.PtrSize
 		n := (nptr + 7) / 8
 
 		// Runtime needs pointer masks to be a multiple of uintptr in size.
 		n = (n + goarch.PtrSize - 1) &^ (goarch.PtrSize - 1)
 		mask := make([]byte, n)
-		base := uintptr(abi.MapBucketCount / goarch.PtrSize)
+		base := uintptr(abi.OldMapBucketCount / goarch.PtrSize)
 
 		if ktyp.Pointers() {
-			emitGCMask(mask, base, ktyp, abi.MapBucketCount)
+			emitGCMask(mask, base, ktyp, abi.OldMapBucketCount)
 		}
-		base += abi.MapBucketCount * ktyp.Size_ / goarch.PtrSize
+		base += abi.OldMapBucketCount * ktyp.Size_ / goarch.PtrSize
 
 		if etyp.Pointers() {
-			emitGCMask(mask, base, etyp, abi.MapBucketCount)
+			emitGCMask(mask, base, etyp, abi.OldMapBucketCount)
 		}
-		base += abi.MapBucketCount * etyp.Size_ / goarch.PtrSize
+		base += abi.OldMapBucketCount * etyp.Size_ / goarch.PtrSize
 
 		word := base
 		mask[word/8] |= 1 << (word % 8)
@@ -180,7 +180,7 @@ func (v Value) MapIndex(key Value) Value {
 	// of unexported fields.
 
 	var e unsafe.Pointer
-	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.MapMaxElemBytes {
+	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.OldMapMaxElemBytes {
 		k := *(*string)(key.ptr)
 		e = mapaccess_faststr(v.typ(), v.pointer(), k)
 	} else {
@@ -423,7 +423,7 @@ func (v Value) SetMapIndex(key, elem Value) {
 	key.mustBeExported()
 	tt := (*mapType)(unsafe.Pointer(v.typ()))
 
-	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.MapMaxElemBytes {
+	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.OldMapMaxElemBytes {
 		k := *(*string)(key.ptr)
 		if elem.typ() == nil {
 			mapdelete_faststr(v.typ(), v.pointer(), k)
diff --git a/src/reflect/map_swiss.go b/src/reflect/map_swiss.go
index a42a9d6f89..39f799c9b2 100644
--- a/src/reflect/map_swiss.go
+++ b/src/reflect/map_swiss.go
@@ -14,7 +14,7 @@ import (
 
 // mapType represents a map type.
 type mapType struct {
-	abi.MapType
+	abi.SwissMapType
 }
 
 func (t *rtype) Key() Type {
@@ -70,13 +70,13 @@ func MapOf(key, elem Type) Type {
 		return typehash(ktyp, p, seed)
 	}
 	mt.Flags = 0
-	if ktyp.Size_ > abi.MapMaxKeyBytes {
+	if ktyp.Size_ > abi.SwissMapMaxKeyBytes {
 		mt.KeySize = uint8(goarch.PtrSize)
 		mt.Flags |= 1 // indirect key
 	} else {
 		mt.KeySize = uint8(ktyp.Size_)
 	}
-	if etyp.Size_ > abi.MapMaxElemBytes {
+	if etyp.Size_ > abi.SwissMapMaxElemBytes {
 		mt.ValueSize = uint8(goarch.PtrSize)
 		mt.Flags |= 2 // indirect value
 	} else {
@@ -99,10 +99,10 @@ func MapOf(key, elem Type) Type {
 }
 
 func bucketOf(ktyp, etyp *abi.Type) *abi.Type {
-	if ktyp.Size_ > abi.MapMaxKeyBytes {
+	if ktyp.Size_ > abi.SwissMapMaxKeyBytes {
 		ktyp = ptrTo(ktyp)
 	}
-	if etyp.Size_ > abi.MapMaxElemBytes {
+	if etyp.Size_ > abi.SwissMapMaxElemBytes {
 		etyp = ptrTo(etyp)
 	}
 
@@ -114,29 +114,29 @@ func bucketOf(ktyp, etyp *abi.Type) *abi.Type {
 	var gcdata *byte
 	var ptrdata uintptr
 
-	size := abi.MapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize
+	size := abi.SwissMapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize
 	if size&uintptr(ktyp.Align_-1) != 0 || size&uintptr(etyp.Align_-1) != 0 {
 		panic("reflect: bad size computation in MapOf")
 	}
 
 	if ktyp.Pointers() || etyp.Pointers() {
-		nptr := (abi.MapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize) / goarch.PtrSize
+		nptr := (abi.SwissMapBucketCount*(1+ktyp.Size_+etyp.Size_) + goarch.PtrSize) / goarch.PtrSize
 		n := (nptr + 7) / 8
 
 		// Runtime needs pointer masks to be a multiple of uintptr in size.
 		n = (n + goarch.PtrSize - 1) &^ (goarch.PtrSize - 1)
 		mask := make([]byte, n)
-		base := uintptr(abi.MapBucketCount / goarch.PtrSize)
+		base := uintptr(abi.SwissMapBucketCount / goarch.PtrSize)
 
 		if ktyp.Pointers() {
-			emitGCMask(mask, base, ktyp, abi.MapBucketCount)
+			emitGCMask(mask, base, ktyp, abi.SwissMapBucketCount)
 		}
-		base += abi.MapBucketCount * ktyp.Size_ / goarch.PtrSize
+		base += abi.SwissMapBucketCount * ktyp.Size_ / goarch.PtrSize
 
 		if etyp.Pointers() {
-			emitGCMask(mask, base, etyp, abi.MapBucketCount)
+			emitGCMask(mask, base, etyp, abi.SwissMapBucketCount)
 		}
-		base += abi.MapBucketCount * etyp.Size_ / goarch.PtrSize
+		base += abi.SwissMapBucketCount * etyp.Size_ / goarch.PtrSize
 
 		word := base
 		mask[word/8] |= 1 << (word % 8)
@@ -180,7 +180,7 @@ func (v Value) MapIndex(key Value) Value {
 	// of unexported fields.
 
 	var e unsafe.Pointer
-	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.MapMaxElemBytes {
+	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.SwissMapMaxElemBytes {
 		k := *(*string)(key.ptr)
 		e = mapaccess_faststr(v.typ(), v.pointer(), k)
 	} else {
@@ -423,7 +423,7 @@ func (v Value) SetMapIndex(key, elem Value) {
 	key.mustBeExported()
 	tt := (*mapType)(unsafe.Pointer(v.typ()))
 
-	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.MapMaxElemBytes {
+	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.SwissMapMaxElemBytes {
 		k := *(*string)(key.ptr)
 		if elem.typ() == nil {
 			mapdelete_faststr(v.typ(), v.pointer(), k)