1 files changed, 204 insertions, 0 deletions
diff --git a/libgo/go/runtime/alg.go b/libgo/go/runtime/alg.go
new file mode 100644
index 0000000..8f7c3c0
--- /dev/null
+++ b/libgo/go/runtime/alg.go
@@ -0,0 +1,204 @@
+// 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 (
+	"runtime/internal/sys"
+	"unsafe"
+)
+
+// For gccgo, use go:linkname to rename compiler-called functions to
+// themselves, so that the compiler will export them.
+//
+//go:linkname interhash runtime.interhash
+//go:linkname nilinterhash runtime.nilinterhash
+//go:linkname interequal runtime.interequal
+//go:linkname nilinterequal runtime.nilinterequal
+//go:linkname efaceeq runtime.efaceeq
+//go:linkname ifaceeq runtime.ifaceeq
+//go:linkname ifacevaleq runtime.ifacevaleq
+//go:linkname ifaceefaceeq runtime.ifaceefaceeq
+//go:linkname efacevaleq runtime.efacevaleq
+//go:linkname eqstring runtime.eqstring
+//go:linkname cmpstring runtime.cmpstring
+
+const (
+	c0 = uintptr((8-sys.PtrSize)/4*2860486313 + (sys.PtrSize-4)/4*33054211828000289)
+	c1 = uintptr((8-sys.PtrSize)/4*3267000013 + (sys.PtrSize-4)/4*23344194077549503)
+)
+
+func interhash(p unsafe.Pointer, h uintptr, size uintptr) uintptr {
+	a := (*iface)(p)
+	tab := a.tab
+	if tab == nil {
+		return h
+	}
+	t := *(**_type)(tab)
+	fn := t.hashfn
+	if fn == nil {
+		panic(errorString("hash of unhashable type " + *t.string))
+	}
+	if isDirectIface(t) {
+		return c1 * fn(unsafe.Pointer(&a.data), h^c0, t.size)
+	} else {
+		return c1 * fn(a.data, h^c0, t.size)
+	}
+}
+
+func nilinterhash(p unsafe.Pointer, h uintptr, size uintptr) uintptr {
+	a := (*eface)(p)
+	t := a._type
+	if t == nil {
+		return h
+	}
+	fn := t.hashfn
+	if fn == nil {
+		panic(errorString("hash of unhashable type " + *t.string))
+	}
+	if isDirectIface(t) {
+		return c1 * fn(unsafe.Pointer(&a.data), h^c0, t.size)
+	} else {
+		return c1 * fn(a.data, h^c0, t.size)
+	}
+}
+
+func interequal(p, q unsafe.Pointer, size uintptr) bool {
+	return ifaceeq(*(*iface)(p), *(*iface)(q))
+}
+
+func nilinterequal(p, q unsafe.Pointer, size uintptr) bool {
+	return efaceeq(*(*eface)(p), *(*eface)(q))
+}
+
+func efaceeq(x, y eface) bool {
+	t := x._type
+	if !eqtype(t, y._type) {
+		return false
+	}
+	if t == nil {
+		return true
+	}
+	eq := t.equalfn
+	if eq == nil {
+		panic(errorString("comparing uncomparable type " + *t.string))
+	}
+	if isDirectIface(t) {
+		return x.data == y.data
+	}
+	return eq(x.data, y.data, t.size)
+}
+
+func ifaceeq(x, y iface) bool {
+	xtab := x.tab
+	if xtab == nil && y.tab == nil {
+		return true
+	}
+	if xtab == nil || y.tab == nil {
+		return false
+	}
+	t := *(**_type)(xtab)
+	if !eqtype(t, *(**_type)(y.tab)) {
+		return false
+	}
+	eq := t.equalfn
+	if eq == nil {
+		panic(errorString("comparing uncomparable type " + *t.string))
+	}
+	if isDirectIface(t) {
+		return x.data == y.data
+	}
+	return eq(x.data, y.data, t.size)
+}
+
+func ifacevaleq(x iface, t *_type, p unsafe.Pointer) bool {
+	if x.tab == nil {
+		return false
+	}
+	xt := *(**_type)(x.tab)
+	if !eqtype(xt, t) {
+		return false
+	}
+	eq := t.equalfn
+	if eq == nil {
+		panic(errorString("comparing uncomparable type " + *t.string))
+	}
+	if isDirectIface(t) {
+		return x.data == p
+	}
+	return eq(x.data, p, t.size)
+}
+
+func ifaceefaceeq(x iface, y eface) bool {
+	if x.tab == nil && y._type == nil {
+		return true
+	}
+	if x.tab == nil || y._type == nil {
+		return false
+	}
+	xt := *(**_type)(x.tab)
+	if !eqtype(xt, y._type) {
+		return false
+	}
+	eq := xt.equalfn
+	if eq == nil {
+		panic(errorString("comparing uncomparable type " + *xt.string))
+	}
+	if isDirectIface(xt) {
+		return x.data == y.data
+	}
+	return eq(x.data, y.data, xt.size)
+}
+
+func efacevaleq(x eface, t *_type, p unsafe.Pointer) bool {
+	if x._type == nil {
+		return false
+	}
+	if !eqtype(x._type, t) {
+		return false
+	}
+	eq := t.equalfn
+	if eq == nil {
+		panic(errorString("comparing uncomparable type " + *t.string))
+	}
+	if isDirectIface(t) {
+		return x.data == p
+	}
+	return eq(x.data, p, t.size)
+}
+
+func eqstring(x, y string) bool {
+	a := stringStructOf(&x)
+	b := stringStructOf(&y)
+	if a.len != b.len {
+		return false
+	}
+	return memcmp(unsafe.Pointer(a.str), unsafe.Pointer(b.str), uintptr(a.len)) == 0
+}
+
+func cmpstring(x, y string) int {
+	a := stringStructOf(&x)
+	b := stringStructOf(&y)
+	l := a.len
+	if l > b.len {
+		l = b.len
+	}
+	i := memcmp(unsafe.Pointer(a.str), unsafe.Pointer(b.str), uintptr(l))
+	if i != 0 {
+		return int(i)
+	}
+	if a.len < b.len {
+		return -1
+	} else if a.len > b.len {
+		return 1
+	}
+	return 0
+}
+
+// Force the creation of function descriptors for equality and hash
+// functions.  These will be referenced directly by the compiler.
+var _ = interhash
+var _ = interequal
+var _ = nilinterhash
+var _ = nilinterequal