From 740043f516f716fe359ffd3bd76f1a30a9aa5eec Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <iant@golang.org>
Date: Sun, 23 Jun 2024 15:21:28 -0700
Subject: [PATCH 1/3] net/netip: unexport fields of addrDetail

For #68113

Change-Id: I19c7d8eff8e3a7a1b6c8e28cb867edeca6be237d
Reviewed-on: https://go-review.googlesource.com/c/go/+/593737
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
---
 src/net/netip/export_test.go |  4 ++++
 src/net/netip/netip.go       | 10 +++++-----
 src/net/netip/netip_test.go  |  8 ++++----
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/net/netip/export_test.go b/src/net/netip/export_test.go
index 4febcad893..b2fae1aa47 100644
--- a/src/net/netip/export_test.go
+++ b/src/net/netip/export_test.go
@@ -16,6 +16,10 @@ type Uint128 = uint128
 
 type AddrDetail = addrDetail
 
+func MakeAddrDetail(isV6 bool, zoneV6 string) AddrDetail {
+	return AddrDetail{isV6: isV6, zoneV6: zoneV6}
+}
+
 func Mk128(hi, lo uint64) Uint128 {
 	return uint128{hi, lo}
 }
diff --git a/src/net/netip/netip.go b/src/net/netip/netip.go
index 57063eeb71..a1e93cb29b 100644
--- a/src/net/netip/netip.go
+++ b/src/net/netip/netip.go
@@ -59,8 +59,8 @@ type Addr struct {
 
 // addrDetail represents the details of an Addr, like address family and IPv6 zone.
 type addrDetail struct {
-	IsV6   bool   // IPv4 is false, IPv6 is true.
-	ZoneV6 string // != "" only if IsV6 is true.
+	isV6   bool   // IPv4 is false, IPv6 is true.
+	zoneV6 string // != "" only if IsV6 is true.
 }
 
 // z0, z4, and z6noz are sentinel Addr.z values.
@@ -68,7 +68,7 @@ type addrDetail struct {
 var (
 	z0    unique.Handle[addrDetail]
 	z4    = unique.Make(addrDetail{})
-	z6noz = unique.Make(addrDetail{IsV6: true})
+	z6noz = unique.Make(addrDetail{isV6: true})
 )
 
 // IPv6LinkLocalAllNodes returns the IPv6 link-local all nodes multicast
@@ -410,7 +410,7 @@ func (ip Addr) Zone() string {
 	if ip.z == z0 {
 		return ""
 	}
-	return ip.z.Value().ZoneV6
+	return ip.z.Value().zoneV6
 }
 
 // Compare returns an integer comparing two IPs.
@@ -495,7 +495,7 @@ func (ip Addr) WithZone(zone string) Addr {
 		ip.z = z6noz
 		return ip
 	}
-	ip.z = unique.Make(addrDetail{IsV6: true, ZoneV6: zone})
+	ip.z = unique.Make(addrDetail{isV6: true, zoneV6: zone})
 	return ip
 }
 
diff --git a/src/net/netip/netip_test.go b/src/net/netip/netip_test.go
index ad0e754208..94c70f2290 100644
--- a/src/net/netip/netip_test.go
+++ b/src/net/netip/netip_test.go
@@ -112,18 +112,18 @@ func TestParseAddr(t *testing.T) {
 		// IPv6 with a zone specifier.
 		{
 			in: "fd7a:115c:a1e0:ab12:4843:cd96:626b:430b%eth0",
-			ip: MkAddr(Mk128(0xfd7a115ca1e0ab12, 0x4843cd96626b430b), unique.Make(AddrDetail{IsV6: true, ZoneV6: "eth0"})),
+			ip: MkAddr(Mk128(0xfd7a115ca1e0ab12, 0x4843cd96626b430b), unique.Make(MakeAddrDetail(true, "eth0"))),
 		},
 		// IPv6 with dotted decimal and zone specifier.
 		{
 			in:  "1:2::ffff:192.168.140.255%eth1",
-			ip:  MkAddr(Mk128(0x0001000200000000, 0x0000ffffc0a88cff), unique.Make(AddrDetail{IsV6: true, ZoneV6: "eth1"})),
+			ip:  MkAddr(Mk128(0x0001000200000000, 0x0000ffffc0a88cff), unique.Make(MakeAddrDetail(true, "eth1"))),
 			str: "1:2::ffff:c0a8:8cff%eth1",
 		},
 		// 4-in-6 with zone
 		{
 			in:  "::ffff:192.168.140.255%eth1",
-			ip:  MkAddr(Mk128(0, 0x0000ffffc0a88cff), unique.Make(AddrDetail{IsV6: true, ZoneV6: "eth1"})),
+			ip:  MkAddr(Mk128(0, 0x0000ffffc0a88cff), unique.Make(MakeAddrDetail(true, "eth1"))),
 			str: "::ffff:192.168.140.255%eth1",
 		},
 		// IPv6 with capital letters.
@@ -1723,7 +1723,7 @@ var parseBenchInputs = []struct {
 }
 
 func BenchmarkParseAddr(b *testing.B) {
-	sinkInternValue = unique.Make(AddrDetail{IsV6: true, ZoneV6: "eth1"}) // Pin to not benchmark the intern package
+	sinkInternValue = unique.Make(MakeAddrDetail(true, "eth1")) // Pin to not benchmark the intern package
 	for _, test := range parseBenchInputs {
 		b.Run(test.name, func(b *testing.B) {
 			b.ReportAllocs()

From 085cf0fcdc4faa2f473839f8cc1860ec5bcf97a3 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@golang.org>
Date: Mon, 24 Jun 2024 07:57:45 -0700
Subject: [PATCH 2/3] net/netip: add test that Compare and reflect.DeepEqual
 match

Updates #68113

Change-Id: I1107686ef364f77f48f55534ea8ec68d1785e1e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/594375
Auto-Submit: Brad Fitzpatrick <bradfitz@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
---
 src/net/netip/netip_test.go | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/net/netip/netip_test.go b/src/net/netip/netip_test.go
index 94c70f2290..e1a0a83f64 100644
--- a/src/net/netip/netip_test.go
+++ b/src/net/netip/netip_test.go
@@ -893,6 +893,15 @@ func TestAddrLessCompare(t *testing.T) {
 		{mustIP("::1%a"), mustIP("::1%b"), true},
 		{mustIP("::1%a"), mustIP("::1%a"), false},
 		{mustIP("::1%b"), mustIP("::1%a"), false},
+
+		// For Issue 68113, verify that an IPv4 address and a
+		// v4-mapped-IPv6 address differing only in their zone
+		// pointer are unequal via all three of
+		// ==/Compare/reflect.DeepEqual. In Go 1.22 and
+		// earlier, these were accidentally equal via
+		// DeepEqual due to their zone pointers (z) differing
+		// but pointing to identical structures.
+		{mustIP("::ffff:11.1.1.12"), mustIP("11.1.1.12"), false},
 	}
 	for _, tt := range tests {
 		got := tt.a.Less(tt.b)
@@ -920,6 +929,12 @@ func TestAddrLessCompare(t *testing.T) {
 				t.Errorf("Less(%q, %q) was correctly %v, but so was Less(%q, %q)", tt.a, tt.b, got, tt.b, tt.a)
 			}
 		}
+
+		// Also check reflect.DeepEqual. See issue 68113.
+		deepEq := reflect.DeepEqual(tt.a, tt.b)
+		if (cmp == 0) != deepEq {
+			t.Errorf("%q and %q differ in == (%v) vs reflect.DeepEqual (%v)", tt.a, tt.b, cmp == 0, deepEq)
+		}
 	}
 
 	// And just sort.

From 0def9d5c02166b50a011b4cc8d4c1d891a04f89d Mon Sep 17 00:00:00 2001
From: Sebastian Nickolls <sebastian.nickolls@arm.com>
Date: Thu, 25 Apr 2024 17:19:20 +0100
Subject: [PATCH 3/3] cmd/internal/obj/arm64: Enable arm64 assembler tests for
 cross-compiler builds

Some of the tests for the arm64 assembler are not running for
cross-compiled arm64 builds with GOARCH=arm64. This patch allows the
tests to run for all architectures and moves the test that can only run on
arm64 into its own conditionally compiled file.

Updates #44734

Change-Id: I045870d47cdc1280bfacc1ef275f34504278ed89
Reviewed-on: https://go-review.googlesource.com/c/go/+/587315
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Sebastian Nickolls <sebastian.nickolls@arm.com>
---
 src/cmd/internal/obj/arm64/asm_arm64_test.go | 297 +------------------
 src/cmd/internal/obj/arm64/asm_test.go       | 258 ++++++++++++++++
 2 files changed, 259 insertions(+), 296 deletions(-)
 create mode 100644 src/cmd/internal/obj/arm64/asm_test.go

diff --git a/src/cmd/internal/obj/arm64/asm_arm64_test.go b/src/cmd/internal/obj/arm64/asm_arm64_test.go
index 068039496a..83d137a084 100644
--- a/src/cmd/internal/obj/arm64/asm_arm64_test.go
+++ b/src/cmd/internal/obj/arm64/asm_arm64_test.go
@@ -4,302 +4,7 @@
 
 package arm64
 
-import (
-	"bytes"
-	"fmt"
-	"internal/testenv"
-	"os"
-	"path/filepath"
-	"regexp"
-	"testing"
-)
-
-func TestSplitImm24uScaled(t *testing.T) {
-	tests := []struct {
-		v       int32
-		shift   int
-		wantErr bool
-		wantHi  int32
-		wantLo  int32
-	}{
-		{
-			v:      0,
-			shift:  0,
-			wantHi: 0,
-			wantLo: 0,
-		},
-		{
-			v:      0x1001,
-			shift:  0,
-			wantHi: 0x1000,
-			wantLo: 0x1,
-		},
-		{
-			v:      0xffffff,
-			shift:  0,
-			wantHi: 0xfff000,
-			wantLo: 0xfff,
-		},
-		{
-			v:       0xffffff,
-			shift:   1,
-			wantErr: true,
-		},
-		{
-			v:      0xfe,
-			shift:  1,
-			wantHi: 0x0,
-			wantLo: 0x7f,
-		},
-		{
-			v:      0x10fe,
-			shift:  1,
-			wantHi: 0x0,
-			wantLo: 0x87f,
-		},
-		{
-			v:      0x2002,
-			shift:  1,
-			wantHi: 0x2000,
-			wantLo: 0x1,
-		},
-		{
-			v:      0xfffffe,
-			shift:  1,
-			wantHi: 0xffe000,
-			wantLo: 0xfff,
-		},
-		{
-			v:      0x1000ffe,
-			shift:  1,
-			wantHi: 0xfff000,
-			wantLo: 0xfff,
-		},
-		{
-			v:       0x1001000,
-			shift:   1,
-			wantErr: true,
-		},
-		{
-			v:       0xfffffe,
-			shift:   2,
-			wantErr: true,
-		},
-		{
-			v:      0x4004,
-			shift:  2,
-			wantHi: 0x4000,
-			wantLo: 0x1,
-		},
-		{
-			v:      0xfffffc,
-			shift:  2,
-			wantHi: 0xffc000,
-			wantLo: 0xfff,
-		},
-		{
-			v:      0x1002ffc,
-			shift:  2,
-			wantHi: 0xfff000,
-			wantLo: 0xfff,
-		},
-		{
-			v:       0x1003000,
-			shift:   2,
-			wantErr: true,
-		},
-		{
-			v:       0xfffffe,
-			shift:   3,
-			wantErr: true,
-		},
-		{
-			v:      0x8008,
-			shift:  3,
-			wantHi: 0x8000,
-			wantLo: 0x1,
-		},
-		{
-			v:      0xfffff8,
-			shift:  3,
-			wantHi: 0xff8000,
-			wantLo: 0xfff,
-		},
-		{
-			v:      0x1006ff8,
-			shift:  3,
-			wantHi: 0xfff000,
-			wantLo: 0xfff,
-		},
-		{
-			v:       0x1007000,
-			shift:   3,
-			wantErr: true,
-		},
-	}
-	for _, test := range tests {
-		hi, lo, err := splitImm24uScaled(test.v, test.shift)
-		switch {
-		case err == nil && test.wantErr:
-			t.Errorf("splitImm24uScaled(%v, %v) succeeded, want error", test.v, test.shift)
-		case err != nil && !test.wantErr:
-			t.Errorf("splitImm24uScaled(%v, %v) failed: %v", test.v, test.shift, err)
-		case !test.wantErr:
-			if got, want := hi, test.wantHi; got != want {
-				t.Errorf("splitImm24uScaled(%x, %x) - got hi %x, want %x", test.v, test.shift, got, want)
-			}
-			if got, want := lo, test.wantLo; got != want {
-				t.Errorf("splitImm24uScaled(%x, %x) - got lo %x, want %x", test.v, test.shift, got, want)
-			}
-		}
-	}
-	for shift := 0; shift <= 3; shift++ {
-		for v := int32(0); v < 0xfff000+0xfff<<shift; v = v + 1<<shift {
-			hi, lo, err := splitImm24uScaled(v, shift)
-			if err != nil {
-				t.Fatalf("splitImm24uScaled(%x, %x) failed: %v", v, shift, err)
-			}
-			if hi+lo<<shift != v {
-				t.Fatalf("splitImm24uScaled(%x, %x) = (%x, %x) is incorrect", v, shift, hi, lo)
-			}
-		}
-	}
-}
-
-// TestLarge generates a very large file to verify that large
-// program builds successfully, in particular, too-far
-// conditional branches are fixed, and also verify that the
-// instruction's pc can be correctly aligned even when branches
-// need to be fixed.
-func TestLarge(t *testing.T) {
-	if testing.Short() {
-		t.Skip("Skip in short mode")
-	}
-	testenv.MustHaveGoBuild(t)
-
-	dir, err := os.MkdirTemp("", "testlarge")
-	if err != nil {
-		t.Fatalf("could not create directory: %v", err)
-	}
-	defer os.RemoveAll(dir)
-
-	// generate a very large function
-	buf := bytes.NewBuffer(make([]byte, 0, 7000000))
-	gen(buf)
-
-	tmpfile := filepath.Join(dir, "x.s")
-	err = os.WriteFile(tmpfile, buf.Bytes(), 0644)
-	if err != nil {
-		t.Fatalf("can't write output: %v\n", err)
-	}
-
-	pattern := `0x0080\s00128\s\(.*\)\tMOVD\t\$3,\sR3`
-
-	// assemble generated file
-	cmd := testenv.Command(t, testenv.GoToolPath(t), "tool", "asm", "-S", "-o", filepath.Join(dir, "test.o"), tmpfile)
-	cmd.Env = append(os.Environ(), "GOOS=linux")
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		t.Errorf("Assemble failed: %v, output: %s", err, out)
-	}
-	matched, err := regexp.MatchString(pattern, string(out))
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !matched {
-		t.Errorf("The alignment is not correct: %t, output:%s\n", matched, out)
-	}
-
-	// build generated file
-	cmd = testenv.Command(t, testenv.GoToolPath(t), "tool", "asm", "-o", filepath.Join(dir, "x.o"), tmpfile)
-	cmd.Env = append(os.Environ(), "GOOS=linux")
-	out, err = cmd.CombinedOutput()
-	if err != nil {
-		t.Errorf("Build failed: %v, output: %s", err, out)
-	}
-}
-
-// gen generates a very large program, with a very far conditional branch.
-func gen(buf *bytes.Buffer) {
-	fmt.Fprintln(buf, "TEXT f(SB),0,$0-0")
-	fmt.Fprintln(buf, "TBZ $5, R0, label")
-	fmt.Fprintln(buf, "CBZ R0, label")
-	fmt.Fprintln(buf, "BEQ label")
-	fmt.Fprintln(buf, "PCALIGN $128")
-	fmt.Fprintln(buf, "MOVD $3, R3")
-	for i := 0; i < 1<<19; i++ {
-		fmt.Fprintln(buf, "MOVD R0, R1")
-	}
-	fmt.Fprintln(buf, "label:")
-	fmt.Fprintln(buf, "RET")
-}
-
-// Issue 20348.
-func TestNoRet(t *testing.T) {
-	dir, err := os.MkdirTemp("", "testnoret")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(dir)
-	tmpfile := filepath.Join(dir, "x.s")
-	if err := os.WriteFile(tmpfile, []byte("TEXT ·stub(SB),$0-0\nNOP\n"), 0644); err != nil {
-		t.Fatal(err)
-	}
-	cmd := testenv.Command(t, testenv.GoToolPath(t), "tool", "asm", "-o", filepath.Join(dir, "x.o"), tmpfile)
-	cmd.Env = append(os.Environ(), "GOOS=linux")
-	if out, err := cmd.CombinedOutput(); err != nil {
-		t.Errorf("%v\n%s", err, out)
-	}
-}
-
-// TestPCALIGN verifies the correctness of the PCALIGN by checking if the
-// code can be aligned to the alignment value.
-func TestPCALIGN(t *testing.T) {
-	testenv.MustHaveGoBuild(t)
-	dir, err := os.MkdirTemp("", "testpcalign")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(dir)
-	tmpfile := filepath.Join(dir, "test.s")
-	tmpout := filepath.Join(dir, "test.o")
-
-	code1 := []byte("TEXT ·foo(SB),$0-0\nMOVD $0, R0\nPCALIGN $8\nMOVD $1, R1\nRET\n")
-	code2 := []byte("TEXT ·foo(SB),$0-0\nMOVD $0, R0\nPCALIGN $16\nMOVD $2, R2\nRET\n")
-	// If the output contains this pattern, the pc-offsite of "MOVD $1, R1" is 8 bytes aligned.
-	out1 := `0x0008\s00008\s\(.*\)\tMOVD\t\$1,\sR1`
-	// If the output contains this pattern, the pc-offsite of "MOVD $2, R2" is 16 bytes aligned.
-	out2 := `0x0010\s00016\s\(.*\)\tMOVD\t\$2,\sR2`
-	var testCases = []struct {
-		name string
-		code []byte
-		out  string
-	}{
-		{"8-byte alignment", code1, out1},
-		{"16-byte alignment", code2, out2},
-	}
-
-	for _, test := range testCases {
-		if err := os.WriteFile(tmpfile, test.code, 0644); err != nil {
-			t.Fatal(err)
-		}
-		cmd := testenv.Command(t, testenv.GoToolPath(t), "tool", "asm", "-S", "-o", tmpout, tmpfile)
-		cmd.Env = append(os.Environ(), "GOOS=linux")
-		out, err := cmd.CombinedOutput()
-		if err != nil {
-			t.Errorf("The %s build failed: %v, output: %s", test.name, err, out)
-			continue
-		}
-
-		matched, err := regexp.MatchString(test.out, string(out))
-		if err != nil {
-			t.Fatal(err)
-		}
-		if !matched {
-			t.Errorf("The %s testing failed!\ninput: %s\noutput: %s\n", test.name, test.code, out)
-		}
-	}
-}
+import "testing"
 
 func testvmovs() (r1, r2 uint64)
 func testvmovd() (r1, r2 uint64)
diff --git a/src/cmd/internal/obj/arm64/asm_test.go b/src/cmd/internal/obj/arm64/asm_test.go
new file mode 100644
index 0000000000..6347bafc7e
--- /dev/null
+++ b/src/cmd/internal/obj/arm64/asm_test.go
@@ -0,0 +1,258 @@
+// 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 arm64
+
+import (
+	"bytes"
+	"fmt"
+	"internal/testenv"
+	"os"
+	"path/filepath"
+	"regexp"
+	"testing"
+)
+
+func runAssembler(t *testing.T, srcdata string) []byte {
+	dir := t.TempDir()
+	defer os.RemoveAll(dir)
+	srcfile := filepath.Join(dir, "testdata.s")
+	outfile := filepath.Join(dir, "testdata.o")
+	os.WriteFile(srcfile, []byte(srcdata), 0644)
+	cmd := testenv.Command(t, testenv.GoToolPath(t), "tool", "asm", "-S", "-o", outfile, srcfile)
+	cmd.Env = append(os.Environ(), "GOOS=linux", "GOARCH=arm64")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Errorf("The build failed: %v, output:\n%s", err, out)
+	}
+	return out
+}
+
+func TestSplitImm24uScaled(t *testing.T) {
+	tests := []struct {
+		v       int32
+		shift   int
+		wantErr bool
+		wantHi  int32
+		wantLo  int32
+	}{
+		{
+			v:      0,
+			shift:  0,
+			wantHi: 0,
+			wantLo: 0,
+		},
+		{
+			v:      0x1001,
+			shift:  0,
+			wantHi: 0x1000,
+			wantLo: 0x1,
+		},
+		{
+			v:      0xffffff,
+			shift:  0,
+			wantHi: 0xfff000,
+			wantLo: 0xfff,
+		},
+		{
+			v:       0xffffff,
+			shift:   1,
+			wantErr: true,
+		},
+		{
+			v:      0xfe,
+			shift:  1,
+			wantHi: 0x0,
+			wantLo: 0x7f,
+		},
+		{
+			v:      0x10fe,
+			shift:  1,
+			wantHi: 0x0,
+			wantLo: 0x87f,
+		},
+		{
+			v:      0x2002,
+			shift:  1,
+			wantHi: 0x2000,
+			wantLo: 0x1,
+		},
+		{
+			v:      0xfffffe,
+			shift:  1,
+			wantHi: 0xffe000,
+			wantLo: 0xfff,
+		},
+		{
+			v:      0x1000ffe,
+			shift:  1,
+			wantHi: 0xfff000,
+			wantLo: 0xfff,
+		},
+		{
+			v:       0x1001000,
+			shift:   1,
+			wantErr: true,
+		},
+		{
+			v:       0xfffffe,
+			shift:   2,
+			wantErr: true,
+		},
+		{
+			v:      0x4004,
+			shift:  2,
+			wantHi: 0x4000,
+			wantLo: 0x1,
+		},
+		{
+			v:      0xfffffc,
+			shift:  2,
+			wantHi: 0xffc000,
+			wantLo: 0xfff,
+		},
+		{
+			v:      0x1002ffc,
+			shift:  2,
+			wantHi: 0xfff000,
+			wantLo: 0xfff,
+		},
+		{
+			v:       0x1003000,
+			shift:   2,
+			wantErr: true,
+		},
+		{
+			v:       0xfffffe,
+			shift:   3,
+			wantErr: true,
+		},
+		{
+			v:      0x8008,
+			shift:  3,
+			wantHi: 0x8000,
+			wantLo: 0x1,
+		},
+		{
+			v:      0xfffff8,
+			shift:  3,
+			wantHi: 0xff8000,
+			wantLo: 0xfff,
+		},
+		{
+			v:      0x1006ff8,
+			shift:  3,
+			wantHi: 0xfff000,
+			wantLo: 0xfff,
+		},
+		{
+			v:       0x1007000,
+			shift:   3,
+			wantErr: true,
+		},
+	}
+	for _, test := range tests {
+		hi, lo, err := splitImm24uScaled(test.v, test.shift)
+		switch {
+		case err == nil && test.wantErr:
+			t.Errorf("splitImm24uScaled(%v, %v) succeeded, want error", test.v, test.shift)
+		case err != nil && !test.wantErr:
+			t.Errorf("splitImm24uScaled(%v, %v) failed: %v", test.v, test.shift, err)
+		case !test.wantErr:
+			if got, want := hi, test.wantHi; got != want {
+				t.Errorf("splitImm24uScaled(%x, %x) - got hi %x, want %x", test.v, test.shift, got, want)
+			}
+			if got, want := lo, test.wantLo; got != want {
+				t.Errorf("splitImm24uScaled(%x, %x) - got lo %x, want %x", test.v, test.shift, got, want)
+			}
+		}
+	}
+	for shift := 0; shift <= 3; shift++ {
+		for v := int32(0); v < 0xfff000+0xfff<<shift; v = v + 1<<shift {
+			hi, lo, err := splitImm24uScaled(v, shift)
+			if err != nil {
+				t.Fatalf("splitImm24uScaled(%x, %x) failed: %v", v, shift, err)
+			}
+			if hi+lo<<shift != v {
+				t.Fatalf("splitImm24uScaled(%x, %x) = (%x, %x) is incorrect", v, shift, hi, lo)
+			}
+		}
+	}
+}
+
+// TestLarge generates a very large file to verify that large
+// program builds successfully, in particular, too-far
+// conditional branches are fixed, and also verify that the
+// instruction's pc can be correctly aligned even when branches
+// need to be fixed.
+func TestLarge(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skip in short mode")
+	}
+	testenv.MustHaveGoBuild(t)
+
+	// generate a very large function
+	buf := bytes.NewBuffer(make([]byte, 0, 7000000))
+	fmt.Fprintln(buf, "TEXT f(SB),0,$0-0")
+	fmt.Fprintln(buf, "TBZ $5, R0, label")
+	fmt.Fprintln(buf, "CBZ R0, label")
+	fmt.Fprintln(buf, "BEQ label")
+	fmt.Fprintln(buf, "PCALIGN $128")
+	fmt.Fprintln(buf, "MOVD $3, R3")
+	for i := 0; i < 1<<19; i++ {
+		fmt.Fprintln(buf, "MOVD R0, R1")
+	}
+	fmt.Fprintln(buf, "label:")
+	fmt.Fprintln(buf, "RET")
+
+	// assemble generated file
+	out := runAssembler(t, buf.String())
+
+	pattern := `0x0080\s00128\s\(.*\)\tMOVD\t\$3,\sR3`
+	matched, err := regexp.MatchString(pattern, string(out))
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !matched {
+		t.Errorf("The alignment is not correct: %t\n", matched)
+	}
+}
+
+// Issue 20348.
+func TestNoRet(t *testing.T) {
+	runAssembler(t, "TEXT ·stub(SB),$0-0\nNOP\n")
+}
+
+// TestPCALIGN verifies the correctness of the PCALIGN by checking if the
+// code can be aligned to the alignment value.
+func TestPCALIGN(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+
+	code1 := "TEXT ·foo(SB),$0-0\nMOVD $0, R0\nPCALIGN $8\nMOVD $1, R1\nRET\n"
+	code2 := "TEXT ·foo(SB),$0-0\nMOVD $0, R0\nPCALIGN $16\nMOVD $2, R2\nRET\n"
+	// If the output contains this pattern, the pc-offset of "MOVD $1, R1" is 8 bytes aligned.
+	out1 := `0x0008\s00008\s\(.*\)\tMOVD\t\$1,\sR1`
+	// If the output contains this pattern, the pc-offset of "MOVD $2, R2" is 16 bytes aligned.
+	out2 := `0x0010\s00016\s\(.*\)\tMOVD\t\$2,\sR2`
+	var testCases = []struct {
+		name string
+		code string
+		out  string
+	}{
+		{"8-byte alignment", code1, out1},
+		{"16-byte alignment", code2, out2},
+	}
+
+	for _, test := range testCases {
+		out := runAssembler(t, test.code)
+		matched, err := regexp.MatchString(test.out, string(out))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !matched {
+			t.Errorf("The %s testing failed!\ninput: %s\noutput: %s\n", test.name, test.code, out)
+		}
+	}
+}