runtime: move sizeclass defs to new package internal/runtime/gc

We will want to reference these definitions from new generator programs,
and this is a good opportunity to cleanup all these old C-style names.

Change-Id: Ifb06f0afc381e2697e7877f038eca786610c96de
Reviewed-on: https://go-review.googlesource.com/c/go/+/655275
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>

1 files changed, 20 insertions, 22 deletions

diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 0a48f8bc61..554cfa6fcf 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -104,6 +104,7 @@ import (
 	"internal/goarch"
 	"internal/goos"
 	"internal/runtime/atomic"
+	"internal/runtime/gc"
 	"internal/runtime/math"
 	"internal/runtime/sys"
 	"unsafe"
@@ -112,13 +113,10 @@ import (
 const (
 	maxTinySize   = _TinySize
 	tinySizeClass = _TinySizeClass
-	maxSmallSize  = _MaxSmallSize
-
-	pageShift = _PageShift
-	pageSize  = _PageSize
-
-	_PageSize = 1 << _PageShift
-	_PageMask = _PageSize - 1
+	maxSmallSize  = gc.MaxSmallSize
+	pageSize      = 1 << gc.PageShift
+	pageMask      = pageSize - 1
+	_PageSize     = pageSize // Unused. Left for viewcore.
 
 	// _64bit = 1 on 64-bit systems, 0 on 32-bit systems
 	_64bit = 1 << (^uintptr(0) >> 63) / 2
@@ -371,7 +369,7 @@ var (
 )
 
 func mallocinit() {
-	if class_to_size[_TinySizeClass] != _TinySize {
+	if gc.SizeClassToSize[tinySizeClass] != maxTinySize {
 		throw("bad TinySizeClass")
 	}
 
@@ -432,11 +430,11 @@ func mallocinit() {
 	// span sizes are one page. Some code relies on this.
 	minSizeForMallocHeaderIsSizeClass := false
 	sizeClassesUpToMinSizeForMallocHeaderAreOnePage := true
-	for i := 0; i < len(class_to_size); i++ {
-		if class_to_allocnpages[i] > 1 {
+	for i := 0; i < len(gc.SizeClassToSize); i++ {
+		if gc.SizeClassToNPages[i] > 1 {
 			sizeClassesUpToMinSizeForMallocHeaderAreOnePage = false
 		}
-		if minSizeForMallocHeader == uintptr(class_to_size[i]) {
+		if minSizeForMallocHeader == uintptr(gc.SizeClassToSize[i]) {
 			minSizeForMallocHeaderIsSizeClass = true
 			break
 		}
@@ -1272,12 +1270,12 @@ func mallocgcSmallNoscan(size uintptr, typ *_type, needzero bool) (unsafe.Pointe
 	checkGCTrigger := false
 	c := getMCache(mp)
 	var sizeclass uint8
-	if size <= smallSizeMax-8 {
-		sizeclass = size_to_class8[divRoundUp(size, smallSizeDiv)]
+	if size <= gc.SmallSizeMax-8 {
+		sizeclass = gc.SizeToSizeClass8[divRoundUp(size, gc.SmallSizeDiv)]
 	} else {
-		sizeclass = size_to_class128[divRoundUp(size-smallSizeMax, largeSizeDiv)]
+		sizeclass = gc.SizeToSizeClass128[divRoundUp(size-gc.SmallSizeMax, gc.LargeSizeDiv)]
 	}
-	size = uintptr(class_to_size[sizeclass])
+	size = uintptr(gc.SizeClassToSize[sizeclass])
 	spc := makeSpanClass(sizeclass, true)
 	span := c.alloc[spc]
 	v := nextFreeFast(span)
@@ -1360,7 +1358,7 @@ func mallocgcSmallScanNoHeader(size uintptr, typ *_type) (unsafe.Pointer, uintpt
 
 	checkGCTrigger := false
 	c := getMCache(mp)
-	sizeclass := size_to_class8[divRoundUp(size, smallSizeDiv)]
+	sizeclass := gc.SizeToSizeClass8[divRoundUp(size, gc.SmallSizeDiv)]
 	spc := makeSpanClass(sizeclass, false)
 	span := c.alloc[spc]
 	v := nextFreeFast(span)
@@ -1378,7 +1376,7 @@ func mallocgcSmallScanNoHeader(size uintptr, typ *_type) (unsafe.Pointer, uintpt
 	} else {
 		c.scanAlloc += heapSetTypeNoHeader(uintptr(x), size, typ, span)
 	}
-	size = uintptr(class_to_size[sizeclass])
+	size = uintptr(gc.SizeClassToSize[sizeclass])
 
 	// Ensure that the stores above that initialize x to
 	// type-safe memory and set the heap bits occur before
@@ -1453,12 +1451,12 @@ func mallocgcSmallScanHeader(size uintptr, typ *_type) (unsafe.Pointer, uintptr)
 	c := getMCache(mp)
 	size += mallocHeaderSize
 	var sizeclass uint8
-	if size <= smallSizeMax-8 {
-		sizeclass = size_to_class8[divRoundUp(size, smallSizeDiv)]
+	if size <= gc.SmallSizeMax-8 {
+		sizeclass = gc.SizeToSizeClass8[divRoundUp(size, gc.SmallSizeDiv)]
 	} else {
-		sizeclass = size_to_class128[divRoundUp(size-smallSizeMax, largeSizeDiv)]
+		sizeclass = gc.SizeToSizeClass128[divRoundUp(size-gc.SmallSizeMax, gc.LargeSizeDiv)]
 	}
-	size = uintptr(class_to_size[sizeclass])
+	size = uintptr(gc.SizeClassToSize[sizeclass])
 	spc := makeSpanClass(sizeclass, false)
 	span := c.alloc[spc]
 	v := nextFreeFast(span)
@@ -1909,7 +1907,7 @@ func persistentalloc1(size, align uintptr, sysStat *sysMemStat) *notInHeap {
 		if align&(align-1) != 0 {
 			throw("persistentalloc: align is not a power of 2")
 		}
-		if align > _PageSize {
+		if align > pageSize {
 			throw("persistentalloc: align is too large")
 		}
 	} else {