1 // Copyright 2016 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package arm64 6 7 import ( 8 "bytes" 9 "fmt" 10 "internal/testenv" 11 "io/ioutil" 12 "os" 13 "os/exec" 14 "path/filepath" 15 "testing" 16 ) 17 18 // TestLarge generates a very large file to verify that large 19 // program builds successfully, in particular, too-far 20 // conditional branches are fixed. 21 func TestLarge(t *testing.T) { 22 if testing.Short() { 23 t.Skip("Skip in short mode") 24 } 25 testenv.MustHaveGoBuild(t) 26 27 dir, err := ioutil.TempDir("", "testlarge") 28 if err != nil { 29 t.Fatalf("could not create directory: %v", err) 30 } 31 defer os.RemoveAll(dir) 32 33 // generate a very large function 34 buf := bytes.NewBuffer(make([]byte, 0, 7000000)) 35 gen(buf) 36 37 tmpfile := filepath.Join(dir, "x.s") 38 err = ioutil.WriteFile(tmpfile, buf.Bytes(), 0644) 39 if err != nil { 40 t.Fatalf("can't write output: %v\n", err) 41 } 42 43 // build generated file 44 cmd := exec.Command(testenv.GoToolPath(t), "tool", "asm", "-o", filepath.Join(dir, "x.o"), tmpfile) 45 cmd.Env = []string{"GOARCH=arm64", "GOOS=linux"} 46 out, err := cmd.CombinedOutput() 47 if err != nil { 48 t.Errorf("Build failed: %v, output: %s", err, out) 49 } 50 } 51 52 // gen generates a very large program, with a very far conditional branch. 53 func gen(buf *bytes.Buffer) { 54 fmt.Fprintln(buf, "TEXT f(SB),0,$0-0") 55 fmt.Fprintln(buf, "CBZ R0, label") 56 fmt.Fprintln(buf, "BEQ label") 57 for i := 0; i < 1<<19; i++ { 58 fmt.Fprintln(buf, "MOVD R0, R1") 59 } 60 fmt.Fprintln(buf, "label:") 61 fmt.Fprintln(buf, "RET") 62 } 63
