4 files changed, 157 insertions, 0 deletions
diff --git a/libgo/go/runtime/internal/sys/intrinsics.go b/libgo/go/runtime/internal/sys/intrinsics.go
new file mode 100644
index 00000000000..f33209a8878
--- /dev/null
+++ b/libgo/go/runtime/internal/sys/intrinsics.go
@@ -0,0 +1,77 @@
+// Copyright 2016 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 sys
+
+//extern __builtin_ctz
+func builtinCtz32(uint32) int32
+
+//extern __builtin_ctzll
+func builtinCtz64(uint64) int32
+
+//go:nosplit
+
+// Ctz64 counts trailing (low-order) zeroes,
+// and if all are zero, then 64.
+func Ctz64(x uint64) uint64 {
+	if x == 0 {
+		return 64
+	}
+	return uint64(builtinCtz64(x))
+}
+
+//go:nosplit
+
+// Ctz32 counts trailing (low-order) zeroes,
+// and if all are zero, then 32.
+func Ctz32(x uint32) uint32 {
+	if x == 0 {
+		return 32
+	}
+	return uint32(builtinCtz32(x))
+}
+
+//go:nosplit
+
+// Ctz16 counts trailing (low-order) zeroes,
+// and if all are zero, then 16.
+func Ctz16(x uint16) uint16 {
+	if x == 0 {
+		return 16
+	}
+	return uint16(builtinCtz32(uint32(x)))
+}
+
+//go:nosplit
+
+// Ctz8 counts trailing (low-order) zeroes,
+// and if all are zero, then 8.
+func Ctz8(x uint8) uint8 {
+	if x == 0 {
+		return 8
+	}
+	return uint8(builtinCtz32(uint32(x)))
+}
+
+//extern __builtin_bswap64
+func bswap64(uint64) uint64
+
+//go:nosplit
+
+// Bswap64 returns its input with byte order reversed
+// 0x0102030405060708 -> 0x0807060504030201
+func Bswap64(x uint64) uint64 {
+	return bswap64(x)
+}
+
+//extern __builtin_bswap32
+func bswap32(uint32) uint32
+
+//go:nosplit
+
+// Bswap32 returns its input with byte order reversed
+// 0x01020304 -> 0x04030201
+func Bswap32(x uint32) uint32 {
+	return bswap32(x)
+}
diff --git a/libgo/go/runtime/internal/sys/intrinsics_test.go b/libgo/go/runtime/internal/sys/intrinsics_test.go
new file mode 100644
index 00000000000..097631bc1e5
--- /dev/null
+++ b/libgo/go/runtime/internal/sys/intrinsics_test.go
@@ -0,0 +1,54 @@
+package sys_test
+
+import (
+	"runtime/internal/sys"
+	"testing"
+)
+
+func TestCtz64(t *testing.T) {
+	for i := uint(0); i <= 64; i++ {
+		x := uint64(5) << i
+		if got := sys.Ctz64(x); got != uint64(i) {
+			t.Errorf("Ctz64(%d)=%d, want %d", x, got, i)
+		}
+	}
+}
+func TestCtz32(t *testing.T) {
+	for i := uint(0); i <= 32; i++ {
+		x := uint32(5) << i
+		if got := sys.Ctz32(x); got != uint32(i) {
+			t.Errorf("Ctz32(%d)=%d, want %d", x, got, i)
+		}
+	}
+}
+func TestCtz16(t *testing.T) {
+	for i := uint(0); i <= 16; i++ {
+		x := uint16(5) << i
+		if got := sys.Ctz16(x); got != uint16(i) {
+			t.Errorf("Ctz16(%d)=%d, want %d", x, got, i)
+		}
+	}
+}
+func TestCtz8(t *testing.T) {
+	for i := uint(0); i <= 8; i++ {
+		x := uint8(5) << i
+		if got := sys.Ctz8(x); got != uint8(i) {
+			t.Errorf("Ctz8(%d)=%d, want %d", x, got, i)
+		}
+	}
+}
+
+func TestBswap64(t *testing.T) {
+	x := uint64(0x1122334455667788)
+	y := sys.Bswap64(x)
+	if y != 0x8877665544332211 {
+		t.Errorf("Bswap(%x)=%x, want 0x8877665544332211", x, y)
+	}
+}
+func TestBswap32(t *testing.T) {
+	x := uint32(0x11223344)
+	y := sys.Bswap32(x)
+	if y != 0x44332211 {
+		t.Errorf("Bswap(%x)=%x, want 0x44332211", x, y)
+	}
+}
diff --git a/libgo/go/runtime/internal/sys/stubs.go b/libgo/go/runtime/internal/sys/stubs.go
new file mode 100644
index 00000000000..0a94502f32d
--- /dev/null
+++ b/libgo/go/runtime/internal/sys/stubs.go
@@ -0,0 +1,11 @@
+// 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 sys
+
+// Declarations for runtime services implemented in C or assembly.
+
+const PtrSize = 4 << (^uintptr(0) >> 63)           // unsafe.Sizeof(uintptr(0)) but an ideal const
+const RegSize = 4 << (^Uintreg(0) >> 63)           // unsafe.Sizeof(uintreg(0)) but an ideal const
+const SpAlign = 1*(1-GoarchArm64) + 16*GoarchArm64 // SP alignment: 1 normally, 16 for ARM64
diff --git a/libgo/go/runtime/internal/sys/sys.go b/libgo/go/runtime/internal/sys/sys.go
new file mode 100644
index 00000000000..586a763717d
--- /dev/null
+++ b/libgo/go/runtime/internal/sys/sys.go
@@ -0,0 +1,15 @@
+// Copyright 2015 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 sys contains system- and configuration- and architecture-specific
+// constants used by the runtime.
+package sys
+
+// The next line makes 'go generate' write the zgen_*.go files with
+// per-OS and per-arch information, including constants
+// named goos_$GOOS and goarch_$GOARCH for every
+// known GOOS and GOARCH. The constant is 1 on the
+// current system, 0 otherwise; multiplying by them is
+// useful for defining GOOS- or GOARCH-specific constants.
+//go:generate go run gengoos.go