github.com/gocuntian/go@v0.0.0-20160610041250-fee02d270bf8/src/cmd/compile/internal/gc/testdata/ctl_ssa.go (about)

     1  // run
     2  
     3  // Copyright 2015 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // Test control flow
     8  
     9  package main
    10  
    11  // nor_ssa calculates NOR(a, b).
    12  // It is implemented in a way that generates
    13  // phi control values.
    14  func nor_ssa(a, b bool) bool {
    15  	var c bool
    16  	if a {
    17  		c = true
    18  	}
    19  	if b {
    20  		c = true
    21  	}
    22  	if c {
    23  		return false
    24  	}
    25  	return true
    26  }
    27  
    28  func testPhiControl() {
    29  	tests := [...][3]bool{ // a, b, want
    30  		{false, false, true},
    31  		{true, false, false},
    32  		{false, true, false},
    33  		{true, true, false},
    34  	}
    35  	for _, test := range tests {
    36  		a, b := test[0], test[1]
    37  		got := nor_ssa(a, b)
    38  		want := test[2]
    39  		if want != got {
    40  			print("nor(", a, ", ", b, ")=", want, " got ", got, "\n")
    41  			failed = true
    42  		}
    43  	}
    44  }
    45  
    46  func emptyRange_ssa(b []byte) bool {
    47  	for _, x := range b {
    48  		_ = x
    49  	}
    50  	return true
    51  }
    52  
    53  func testEmptyRange() {
    54  	if !emptyRange_ssa([]byte{}) {
    55  		println("emptyRange_ssa([]byte{})=false, want true")
    56  		failed = true
    57  	}
    58  }
    59  
    60  func switch_ssa(a int) int {
    61  	ret := 0
    62  	switch a {
    63  	case 5:
    64  		ret += 5
    65  	case 4:
    66  		ret += 4
    67  	case 3:
    68  		ret += 3
    69  	case 2:
    70  		ret += 2
    71  	case 1:
    72  		ret += 1
    73  	}
    74  	return ret
    75  
    76  }
    77  
    78  func fallthrough_ssa(a int) int {
    79  	ret := 0
    80  	switch a {
    81  	case 5:
    82  		ret++
    83  		fallthrough
    84  	case 4:
    85  		ret++
    86  		fallthrough
    87  	case 3:
    88  		ret++
    89  		fallthrough
    90  	case 2:
    91  		ret++
    92  		fallthrough
    93  	case 1:
    94  		ret++
    95  	}
    96  	return ret
    97  
    98  }
    99  
   100  func testFallthrough() {
   101  	for i := 0; i < 6; i++ {
   102  		if got := fallthrough_ssa(i); got != i {
   103  			println("fallthrough_ssa(i) =", got, "wanted", i)
   104  			failed = true
   105  		}
   106  	}
   107  }
   108  
   109  func testSwitch() {
   110  	for i := 0; i < 6; i++ {
   111  		if got := switch_ssa(i); got != i {
   112  			println("switch_ssa(i) =", got, "wanted", i)
   113  			failed = true
   114  		}
   115  	}
   116  }
   117  
   118  type junk struct {
   119  	step int
   120  }
   121  
   122  // flagOverwrite_ssa is intended to reproduce an issue seen where a XOR
   123  // was scheduled between a compare and branch, clearing flags.
   124  //go:noinline
   125  func flagOverwrite_ssa(s *junk, c int) int {
   126  	if '0' <= c && c <= '9' {
   127  		s.step = 0
   128  		return 1
   129  	}
   130  	if c == 'e' || c == 'E' {
   131  		s.step = 0
   132  		return 2
   133  	}
   134  	s.step = 0
   135  	return 3
   136  }
   137  
   138  func testFlagOverwrite() {
   139  	j := junk{}
   140  	if got := flagOverwrite_ssa(&j, ' '); got != 3 {
   141  		println("flagOverwrite_ssa =", got, "wanted 3")
   142  		failed = true
   143  	}
   144  }
   145  
   146  var failed = false
   147  
   148  func main() {
   149  	testPhiControl()
   150  	testEmptyRange()
   151  
   152  	testSwitch()
   153  	testFallthrough()
   154  
   155  	testFlagOverwrite()
   156  
   157  	if failed {
   158  		panic("failed")
   159  	}
   160  }