1 // Copyright 2009 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 //go:build goexperiment.allocheaders
7 // Malloc small size classes.
9 // See malloc.go for overview.
10 // See also mksizeclasses.go for how we decide what size classes to use.
14 // Returns size of the memory block that mallocgc will allocate if you ask for the size.
15 func roundupsize(size uintptr) uintptr {
16 if size < _MaxSmallSize {
17 if size <= smallSizeMax-8 {
18 return uintptr(class_to_size[size_to_class8[divRoundUp(size, smallSizeDiv)]])
20 return uintptr(class_to_size[size_to_class128[divRoundUp(size-smallSizeMax, largeSizeDiv)]])
23 if size+_PageSize < size {
26 return alignUp(size, _PageSize)