libgo/go/runtime/msize.go

   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.
   4
   5 // Malloc small size classes.
   6 //
   7 // See malloc.go for overview.
   8 // See also mksizeclasses.go for how we decide what size classes to use.
   9
  10 package runtime
  11
  12 // Returns size of the memory block that mallocgc will allocate if you ask for the size.
  13 func roundupsize(size uintptr) uintptr {
  14         if size < _MaxSmallSize {
  15                 if size <= smallSizeMax-8 {
  16                         return uintptr(class_to_size[size_to_class8[(size+smallSizeDiv-1)/smallSizeDiv]])
  17                 } else {
  18                         return uintptr(class_to_size[size_to_class128[(size-smallSizeMax+largeSizeDiv-1)/largeSizeDiv]])
  19                 }
  20         }
  21         if size+_PageSize < size {
  22                 return size
  23         }
  24         return round(size, _PageSize)
  25 }