From: Russ Cox <rsc@golang.org>
Date: Fri, 14 Nov 2014 16:37:54 +0000 (-0500)
Subject: [dev.garbage] all: merge default (f38460037b72) into dev.garbage
X-Git-Tag: go1.5beta1~2684^2~12
X-Git-Url: http://www.git.cypherpunks.ru/?a=commitdiff_plain;h=3dcc62e1dad3c62a1c8df1b6f613f93521124764;p=gostls13.git

[dev.garbage] all: merge default (f38460037b72) into dev.garbage

This is the revision that dev.cc is branched from.

LGTM=austin
R=austin
CC=golang-codereviews
https://golang.org/cl/169590043
---

3dcc62e1dad3c62a1c8df1b6f613f93521124764
diff --cc src/runtime/malloc.go
index a18e77421e,8cf1c3d342..fab8cf2695
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@@ -358,40 -344,9 +358,40 @@@ marked
  	return x
  }
  
 +func loadPtrMask(typ *_type) []uint8 {
 +	var ptrmask *uint8
 +	nptr := (uintptr(typ.size) + ptrSize - 1) / ptrSize
 +	if typ.kind&kindGCProg != 0 {
 +		masksize := nptr
 +		if masksize%2 != 0 {
 +			masksize *= 2 // repeated
 +		}
 +		masksize = masksize * pointersPerByte / 8 // 4 bits per word
 +		masksize++                                // unroll flag in the beginning
 +		if masksize > maxGCMask && typ.gc[1] != 0 {
 +			// write barriers have not been updated to deal with this case yet.
 +			gothrow("maxGCMask too small for now")
 +		}
 +		ptrmask = (*uint8)(unsafe.Pointer(uintptr(typ.gc[0])))
 +		// Check whether the program is already unrolled
 +		// by checking if the unroll flag byte is set
 +		maskword := uintptr(atomicloadp(unsafe.Pointer(ptrmask)))
 +		if *(*uint8)(unsafe.Pointer(&maskword)) == 0 {
 +			mp := acquirem()
 +			mp.ptrarg[0] = unsafe.Pointer(typ)
 +			onM(unrollgcprog_m)
 +			releasem(mp)
 +		}
 +		ptrmask = (*uint8)(add(unsafe.Pointer(ptrmask), 1)) // skip the unroll flag byte
 +	} else {
 +		ptrmask = (*uint8)(unsafe.Pointer(typ.gc[0])) // pointer to unrolled mask
 +	}
 +	return (*[1 << 30]byte)(unsafe.Pointer(ptrmask))[:(nptr+1)/2]
 +}
 +
  // implementation of new builtin
  func newobject(typ *_type) unsafe.Pointer {
- 	flags := 0
+ 	flags := uint32(0)
  	if typ.kind&kindNoPointers != 0 {
  		flags |= flagNoScan
  	}