[PATCH] libgo: fix support for ia64

[Andreas Schwab]

This adds support for ia64 in lfstack.

Andreas.

diff --git a/libgo/go/runtime/lfstack_64bit.go 
b/libgo/go/runtime/lfstack_64bit.go
index b314a3ba21..99dcec02de 100644
--- a/libgo/go/runtime/lfstack_64bit.go
+++ b/libgo/go/runtime/lfstack_64bit.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64 arm64 mips64 mips64le ppc64 ppc64le s390x arm64be alpha 
mipsn64 sparc64
+// +build amd64 arm64 mips64 mips64le ppc64 ppc64le s390x arm64be alpha 
mipsn64 sparc64 ia64
 
 package runtime
 
@@ -38,12 +38,22 @@ const (
        // room in the bottom for the count.
        sparcLinuxAddrBits = 52
        sparcLinuxCntBits  = 64 - sparcLinuxAddrBits + 3
+
+       // On IA64, the virtual address space is devided into 8 regions, with
+       // 52 address bits each (with 64k page size).
+       ia64AddrBits = 55
+       ia64CntBits = 64 - ia64AddrBits + 3
 )
 
 func lfstackPack(node *lfnode, cnt uintptr) uint64 {
        if GOARCH == "sparc64" && GOOS == "linux" {
                return 
uint64(uintptr(unsafe.Pointer(node)))<<(64-sparcLinuxAddrBits) | 
uint64(cnt&(1<<sparcLinuxCntBits-1))
        }
+       if GOARCH == "ia64" {
+               // Top three bits are the region number
+               val := uint64(uintptr(unsafe.Pointer(node)))
+               return (val<<(64-ia64AddrBits))&(1<<(64-3)-1) | 
val&^(1<<(64-3)-1) | uint64(cnt&(1<<ia64CntBits-1))
+       }
        return uint64(uintptr(unsafe.Pointer(node)))<<(64-addrBits) | 
uint64(cnt&(1<<cntBits-1))
 }
 
@@ -56,5 +66,8 @@ func lfstackUnpack(val uint64) *lfnode {
        if GOARCH == "sparc64" && GOOS == "linux" {
                return (*lfnode)(unsafe.Pointer(uintptr(int64(val) >> 
sparcLinuxCntBits << 3)))
        }
+       if GOARCH == "ia64" {
+               return (*lfnode)(unsafe.Pointer(uintptr((val >> ia64CntBits << 
3)&(1<<(64-3)-1) | val&^(1<<(64-3)-1))))
+       }
        return (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3)))
 }
-- 
2.13.1


-- 
Andreas Schwab, SUSE Labs, sch...@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."