From 3b02c5b1b66df9cdb23d5a3243bb37b2c312ea1b Mon Sep 17 00:00:00 2001 From: Dave Cheney Date: Thu, 7 Apr 2016 07:29:22 +1000 Subject: runtime: merge lfstack{Pack,Unpack} into one file Merge the remaining lfstack{Pack,Unpack} implemetations into one file. unsafe.Sizeof(uintptr(0)) == 4 is a constant comparison so this branch folds away at compile time. Dmitry confirmed that the upper 17 bits of an address will be zero for a user mode pointer, so there is no need to sign extend on amd64 during unpack, so we can reuse the same implementation as all othe 64 bit archs. Change-Id: I99f589416d8b181ccde5364c9c2e78e4a5efc7f1 Reviewed-on: https://go-review.googlesource.com/21597 Run-TryBot: Dave Cheney TryBot-Result: Gobot Gobot Reviewed-by: Minux Ma --- src/runtime/lfstack_amd64.go | 22 ---------------------- 1 file changed, 22 deletions(-) delete mode 100644 src/runtime/lfstack_amd64.go (limited to 'src/runtime/lfstack_amd64.go') diff --git a/src/runtime/lfstack_amd64.go b/src/runtime/lfstack_amd64.go deleted file mode 100644 index 6397e1d47f..0000000000 --- a/src/runtime/lfstack_amd64.go +++ /dev/null @@ -1,22 +0,0 @@ -// Copyright 2014 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package runtime - -import "unsafe" - -// On AMD64, virtual addresses are 48-bit numbers sign extended to 64. -// We shift the address left 16 to eliminate the sign extended part and make -// room in the bottom for the count. -// In addition to the 16 bits taken from the top, we can take 3 from the -// bottom, because node must be pointer-aligned, giving a total of 19 bits -// of count. - -func lfstackPack(node *lfnode, cnt uintptr) uint64 { - return uint64(uintptr(unsafe.Pointer(node)))<<16 | uint64(cnt&(1<<19-1)) -} - -func lfstackUnpack(val uint64) *lfnode { - return (*lfnode)(unsafe.Pointer(uintptr(int64(val) >> 19 << 3))) -} -- cgit v1.3