Revert "runtime: merge lfstack{Pack,Unpack} into one file"

This broke solaris, which apparently does use the upper 17 bits of the address space.

This reverts commit 3b02c5b1b66df9cdb23d5a3243bb37b2c312ea1b.

Change-Id: Iedfe54abd0384960845468205f20191a97751c0b
Reviewed-on: https://go-review.googlesource.com/21652
Reviewed-by: Dave Cheney <dave@cheney.net>

diff --git a/src/runtime/lfstack.go b/src/runtime/lfstack.go
index 8a2d519402c065f9b4d7e1acfaeff43030e9f932..1261f54d9727c85fc625dc08ad8710c43247ab70 100644 (file)
--- a/src/runtime/lfstack.go
+++ b/src/runtime/lfstack.go
@@ -41,38 +41,3 @@ func lfstackpop(head *uint64) unsafe.Pointer {
                }
        }
 }
-
-const (
-       addrBits = 48
-       cntBits  = 64 - addrBits + 3
-)
-
-func lfstackPack(node *lfnode, cnt uintptr) uint64 {
-       if unsafe.Sizeof(uintptr(0)) == 4 {
-               // On 32-bit systems, the stored uint64 has a 32-bit pointer and 32-bit count.
-               return uint64(uintptr(unsafe.Pointer(node)))<<32 | uint64(cnt)
-       }
-       // On ppc64, Linux limits the user address space to 46 bits (see
-       // TASK_SIZE_USER64 in the Linux kernel).  This has grown over time,
-       // so here we allow 48 bit addresses.
-       //
-       // On mips64, Linux limits the user address space to 40 bits (see
-       // TASK_SIZE64 in the Linux kernel).  This has grown over time,
-       // so here we allow 48 bit addresses.
-       //
-       // 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.
-       return uint64(uintptr(unsafe.Pointer(node)))<<(64-addrBits) | uint64(cnt&(1<<cntBits-1))
-}
-
-func lfstackUnpack(val uint64) *lfnode {
-       if unsafe.Sizeof(uintptr(0)) == 4 {
-               return (*lfnode)(unsafe.Pointer(uintptr(val >> 32)))
-       }
-       return (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3)))
-}

diff --git a/src/runtime/lfstack_32bit.go b/src/runtime/lfstack_32bit.go
new file mode 100644 (file)
index 0000000..2f59e02
--- /dev/null
+++ b/src/runtime/lfstack_32bit.go
@@ -0,0 +1,19 @@
+// 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.
+
+// +build 386 arm nacl
+
+package runtime
+
+import "unsafe"
+
+// On 32-bit systems, the stored uint64 has a 32-bit pointer and 32-bit count.
+
+func lfstackPack(node *lfnode, cnt uintptr) uint64 {
+       return uint64(uintptr(unsafe.Pointer(node)))<<32 | uint64(cnt)
+}
+
+func lfstackUnpack(val uint64) *lfnode {
+       return (*lfnode)(unsafe.Pointer(uintptr(val >> 32)))
+}

diff --git a/src/runtime/lfstack_64bit.go b/src/runtime/lfstack_64bit.go
new file mode 100644 (file)
index 0000000..07c2a14
--- /dev/null
+++ b/src/runtime/lfstack_64bit.go
@@ -0,0 +1,33 @@
+// 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.
+
+// +build arm64 mips64 mips64le ppc64 ppc64le
+
+package runtime
+
+import "unsafe"
+
+// On ppc64, Linux limits the user address space to 46 bits (see
+// TASK_SIZE_USER64 in the Linux kernel).  This has grown over time,
+// so here we allow 48 bit addresses.
+//
+// On mips64, Linux limits the user address space to 40 bits (see
+// TASK_SIZE64 in the Linux kernel).  This has grown over time,
+// so here we allow 48 bit addresses.
+//
+// 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.
+const (
+       addrBits = 48
+       cntBits  = 64 - addrBits + 3
+)
+
+func lfstackPack(node *lfnode, cnt uintptr) uint64 {
+       return uint64(uintptr(unsafe.Pointer(node)))<<(64-addrBits) | uint64(cnt&(1<<cntBits-1))
+}
+
+func lfstackUnpack(val uint64) *lfnode {
+       return (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3)))
+}

diff --git a/src/runtime/lfstack_amd64.go b/src/runtime/lfstack_amd64.go
new file mode 100644 (file)
index 0000000..6397e1d
--- /dev/null
+++ b/src/runtime/lfstack_amd64.go
@@ -0,0 +1,22 @@
+// 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)))
+}