diff options
Diffstat (limited to 'src/runtime/lfstack.go')
| -rw-r--r-- | src/runtime/lfstack.go | 35 |
1 files changed, 0 insertions, 35 deletions
diff --git a/src/runtime/lfstack.go b/src/runtime/lfstack.go index 8a2d519402..1261f54d97 100644 --- 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))) -} |