Source file src/cmd/compile/internal/ssa/rewrite_test.go

     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 ssa
     6  
     7  import (
     8  	"cmd/compile/internal/rttype"
     9  	"reflect"
    10  	"testing"
    11  	"unsafe"
    12  )
    13  
    14  // We generate memmove for copy(x[1:], x[:]), however we may change it to OpMove,
    15  // because size is known. Check that OpMove is alias-safe, or we did call memmove.
    16  func TestMove(t *testing.T) {
    17  	x := [...]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40}
    18  	copy(x[1:], x[:])
    19  	for i := 1; i < len(x); i++ {
    20  		if int(x[i]) != i {
    21  			t.Errorf("Memmove got converted to OpMove in alias-unsafe way. Got %d instead of %d in position %d", int(x[i]), i, i+1)
    22  		}
    23  	}
    24  }
    25  
    26  func TestMoveSmall(t *testing.T) {
    27  	x := [...]byte{1, 2, 3, 4, 5, 6, 7}
    28  	copy(x[1:], x[:])
    29  	for i := 1; i < len(x); i++ {
    30  		if int(x[i]) != i {
    31  			t.Errorf("Memmove got converted to OpMove in alias-unsafe way. Got %d instead of %d in position %d", int(x[i]), i, i+1)
    32  		}
    33  	}
    34  }
    35  
    36  func TestSubFlags(t *testing.T) {
    37  	if !subFlags32(0, 1).lt() {
    38  		t.Errorf("subFlags32(0,1).lt() returned false")
    39  	}
    40  	if !subFlags32(0, 1).ult() {
    41  		t.Errorf("subFlags32(0,1).ult() returned false")
    42  	}
    43  }
    44  
    45  func TestIsPPC64WordRotateMask(t *testing.T) {
    46  	tests := []struct {
    47  		input    int64
    48  		expected bool
    49  	}{
    50  		{0x00000001, true},
    51  		{0x80000001, true},
    52  		{0x80010001, false},
    53  		{0xFFFFFFFA, false},
    54  		{0xF0F0F0F0, false},
    55  		{0xFFFFFFFD, true},
    56  		{0x80000000, true},
    57  		{0x00000000, false},
    58  		{0xFFFFFFFF, true},
    59  		{0x0000FFFF, true},
    60  		{0xFF0000FF, true},
    61  		{0x00FFFF00, true},
    62  	}
    63  
    64  	for _, v := range tests {
    65  		if v.expected != isPPC64WordRotateMask(v.input) {
    66  			t.Errorf("isPPC64WordRotateMask(0x%x) failed", v.input)
    67  		}
    68  	}
    69  }
    70  
    71  func TestEncodeDecodePPC64WordRotateMask(t *testing.T) {
    72  	tests := []struct {
    73  		rotate int64
    74  		mask   uint64
    75  		nbits,
    76  		mb,
    77  		me,
    78  		encoded int64
    79  	}{
    80  		{1, 0x00000001, 32, 31, 31, 0x20011f20},
    81  		{2, 0x80000001, 32, 31, 0, 0x20021f01},
    82  		{3, 0xFFFFFFFD, 32, 31, 29, 0x20031f1e},
    83  		{4, 0x80000000, 32, 0, 0, 0x20040001},
    84  		{5, 0xFFFFFFFF, 32, 0, 31, 0x20050020},
    85  		{6, 0x0000FFFF, 32, 16, 31, 0x20061020},
    86  		{7, 0xFF0000FF, 32, 24, 7, 0x20071808},
    87  		{8, 0x00FFFF00, 32, 8, 23, 0x20080818},
    88  
    89  		{9, 0x0000000000FFFF00, 64, 40, 55, 0x40092838},
    90  		{10, 0xFFFF000000000000, 64, 0, 15, 0x400A0010},
    91  		{10, 0xFFFF000000000001, 64, 63, 15, 0x400A3f10},
    92  	}
    93  
    94  	for i, v := range tests {
    95  		result := encodePPC64RotateMask(v.rotate, int64(v.mask), v.nbits)
    96  		if result != v.encoded {
    97  			t.Errorf("encodePPC64RotateMask(%d,0x%x,%d) = 0x%x, expected 0x%x", v.rotate, v.mask, v.nbits, result, v.encoded)
    98  		}
    99  		rotate, mb, me, mask := DecodePPC64RotateMask(result)
   100  		if rotate != v.rotate || mb != v.mb || me != v.me || mask != v.mask {
   101  			t.Errorf("DecodePPC64Failure(Test %d) got (%d, %d, %d, %x) expected (%d, %d, %d, %x)", i, rotate, mb, me, mask, v.rotate, v.mb, v.me, v.mask)
   102  		}
   103  	}
   104  }
   105  
   106  func TestMergePPC64ClrlsldiSrw(t *testing.T) {
   107  	tests := []struct {
   108  		clrlsldi int32
   109  		srw      int64
   110  		valid    bool
   111  		rotate   int64
   112  		mask     uint64
   113  	}{
   114  		// ((x>>4)&0xFF)<<4
   115  		{newPPC64ShiftAuxInt(4, 56, 63, 64), 4, true, 0, 0xFF0},
   116  		// ((x>>4)&0xFFFF)<<4
   117  		{newPPC64ShiftAuxInt(4, 48, 63, 64), 4, true, 0, 0xFFFF0},
   118  		// ((x>>4)&0xFFFF)<<17
   119  		{newPPC64ShiftAuxInt(17, 48, 63, 64), 4, false, 0, 0},
   120  		// ((x>>4)&0xFFFF)<<16
   121  		{newPPC64ShiftAuxInt(16, 48, 63, 64), 4, true, 12, 0xFFFF0000},
   122  		// ((x>>32)&0xFFFF)<<17
   123  		{newPPC64ShiftAuxInt(17, 48, 63, 64), 32, false, 0, 0},
   124  	}
   125  	for i, v := range tests {
   126  		result := mergePPC64ClrlsldiSrw(int64(v.clrlsldi), v.srw)
   127  		if v.valid && result == 0 {
   128  			t.Errorf("mergePPC64ClrlsldiSrw(Test %d) did not merge", i)
   129  		} else if !v.valid && result != 0 {
   130  			t.Errorf("mergePPC64ClrlsldiSrw(Test %d) should return 0", i)
   131  		} else if r, _, _, m := DecodePPC64RotateMask(result); v.rotate != r || v.mask != m {
   132  			t.Errorf("mergePPC64ClrlsldiSrw(Test %d) got (%d,0x%x) expected (%d,0x%x)", i, r, m, v.rotate, v.mask)
   133  		}
   134  	}
   135  }
   136  
   137  func TestMergePPC64ClrlsldiRlwinm(t *testing.T) {
   138  	tests := []struct {
   139  		clrlsldi int32
   140  		rlwinm   int64
   141  		valid    bool
   142  		rotate   int64
   143  		mask     uint64
   144  	}{
   145  		// ((x<<4)&0xFF00)<<4
   146  		{newPPC64ShiftAuxInt(4, 56, 63, 64), encodePPC64RotateMask(4, 0xFF00, 32), false, 0, 0},
   147  		// ((x>>4)&0xFF)<<4
   148  		{newPPC64ShiftAuxInt(4, 56, 63, 64), encodePPC64RotateMask(28, 0x0FFFFFFF, 32), true, 0, 0xFF0},
   149  		// ((x>>4)&0xFFFF)<<4
   150  		{newPPC64ShiftAuxInt(4, 48, 63, 64), encodePPC64RotateMask(28, 0xFFFF, 32), true, 0, 0xFFFF0},
   151  		// ((x>>4)&0xFFFF)<<17
   152  		{newPPC64ShiftAuxInt(17, 48, 63, 64), encodePPC64RotateMask(28, 0xFFFF, 32), false, 0, 0},
   153  		// ((x>>4)&0xFFFF)<<16
   154  		{newPPC64ShiftAuxInt(16, 48, 63, 64), encodePPC64RotateMask(28, 0xFFFF, 32), true, 12, 0xFFFF0000},
   155  		// ((x>>4)&0xF000FFFF)<<16
   156  		{newPPC64ShiftAuxInt(16, 48, 63, 64), encodePPC64RotateMask(28, 0xF000FFFF, 32), true, 12, 0xFFFF0000},
   157  	}
   158  	for i, v := range tests {
   159  		result := mergePPC64ClrlsldiRlwinm(v.clrlsldi, v.rlwinm)
   160  		if v.valid && result == 0 {
   161  			t.Errorf("mergePPC64ClrlsldiRlwinm(Test %d) did not merge", i)
   162  		} else if !v.valid && result != 0 {
   163  			t.Errorf("mergePPC64ClrlsldiRlwinm(Test %d) should return 0", i)
   164  		} else if r, _, _, m := DecodePPC64RotateMask(result); v.rotate != r || v.mask != m {
   165  			t.Errorf("mergePPC64ClrlsldiRlwinm(Test %d) got (%d,0x%x) expected (%d,0x%x)", i, r, m, v.rotate, v.mask)
   166  		}
   167  	}
   168  }
   169  
   170  func TestMergePPC64SldiSrw(t *testing.T) {
   171  	tests := []struct {
   172  		sld    int64
   173  		srw    int64
   174  		valid  bool
   175  		rotate int64
   176  		mask   uint64
   177  	}{
   178  		{4, 4, true, 0, 0xFFFFFFF0},
   179  		{4, 8, true, 28, 0x0FFFFFF0},
   180  		{0, 0, true, 0, 0xFFFFFFFF},
   181  		{8, 4, false, 0, 0},
   182  		{0, 32, false, 0, 0},
   183  		{0, 31, true, 1, 0x1},
   184  		{31, 31, true, 0, 0x80000000},
   185  		{32, 32, false, 0, 0},
   186  	}
   187  	for i, v := range tests {
   188  		result := mergePPC64SldiSrw(v.sld, v.srw)
   189  		if v.valid && result == 0 {
   190  			t.Errorf("mergePPC64SldiSrw(Test %d) did not merge", i)
   191  		} else if !v.valid && result != 0 {
   192  			t.Errorf("mergePPC64SldiSrw(Test %d) should return 0", i)
   193  		} else if r, _, _, m := DecodePPC64RotateMask(result); v.rotate != r || v.mask != m {
   194  			t.Errorf("mergePPC64SldiSrw(Test %d) got (%d,0x%x) expected (%d,0x%x)", i, r, m, v.rotate, v.mask)
   195  		}
   196  	}
   197  }
   198  
   199  func TestMergePPC64AndSrwi(t *testing.T) {
   200  	tests := []struct {
   201  		and    int64
   202  		srw    int64
   203  		valid  bool
   204  		rotate int64
   205  		mask   uint64
   206  	}{
   207  		{0x000000FF, 8, true, 24, 0xFF},
   208  		{0xF00000FF, 8, true, 24, 0xFF},
   209  		{0x0F0000FF, 4, false, 0, 0},
   210  		{0x00000000, 4, false, 0, 0},
   211  		{0xF0000000, 4, false, 0, 0},
   212  		{0xF0000000, 32, false, 0, 0},
   213  		{0xFFFFFFFF, 0, true, 0, 0xFFFFFFFF},
   214  	}
   215  	for i, v := range tests {
   216  		result := mergePPC64AndSrwi(v.and, v.srw)
   217  		if v.valid && result == 0 {
   218  			t.Errorf("mergePPC64AndSrwi(Test %d) did not merge", i)
   219  		} else if !v.valid && result != 0 {
   220  			t.Errorf("mergePPC64AndSrwi(Test %d) should return 0", i)
   221  		} else if r, _, _, m := DecodePPC64RotateMask(result); v.rotate != r || v.mask != m {
   222  			t.Errorf("mergePPC64AndSrwi(Test %d) got (%d,0x%x) expected (%d,0x%x)", i, r, m, v.rotate, v.mask)
   223  		}
   224  	}
   225  }
   226  
   227  func TestDisjointTypes(t *testing.T) {
   228  	tests := []struct {
   229  		v1, v2   any // two pointers to some types
   230  		expected bool
   231  	}{
   232  		{new(int8), new(int8), false},
   233  		{new(int8), new(float32), false},
   234  		{new(int8), new(*int8), true},
   235  		{new(*int8), new(*float32), false},
   236  		{new(*int8), new(chan<- int8), false},
   237  		{new(**int8), new(*int8), false},
   238  		{new(***int8), new(**int8), false},
   239  		{new(int8), new(chan<- int8), true},
   240  		{new(int), unsafe.Pointer(nil), false},
   241  		{new(byte), new(string), false},
   242  		{new(int), new(string), false},
   243  		{new(*int8), new(struct{ a, b int }), true},
   244  		{new(*int8), new(struct {
   245  			a *int
   246  			b int
   247  		}), false},
   248  		{new(*int8), new(struct {
   249  			a int
   250  			b *int
   251  		}), false}, // with more precise analysis it should be true
   252  		{new(*byte), new(string), false},
   253  		{new(int), new(struct {
   254  			a int
   255  			b *int
   256  		}), false},
   257  		{new(float64), new(complex128), false},
   258  		{new(*byte), new([]byte), false},
   259  		{new(int), new([]byte), false},
   260  		{new(int), new([2]*byte), false}, // with more recise analysis it should be true
   261  		{new([2]int), new(*byte), true},
   262  	}
   263  	for _, tst := range tests {
   264  		t1 := rttype.FromReflect(reflect.TypeOf(tst.v1))
   265  		t2 := rttype.FromReflect(reflect.TypeOf(tst.v2))
   266  		result := disjointTypes(t1, t2)
   267  		if result != tst.expected {
   268  			t.Errorf("disjointTypes(%s, %s) got %t expected %t", t1.String(), t2.String(), result, tst.expected)
   269  		}
   270  	}
   271  }
   272  
   273  //go:noinline
   274  func foo(p1 *int64, p2 *float64) int64 {
   275  	*p1 = 10
   276  	*p2 = 0 // disjointTypes shouldn't consider this and preceding stores as non-aliasing
   277  	return *p1
   278  }
   279  
   280  func TestDisjointTypesRun(t *testing.T) {
   281  	f := float64(0)
   282  	i := (*int64)(unsafe.Pointer(&f))
   283  	r := foo(i, &f)
   284  	if r != 0 {
   285  		t.Errorf("disjointTypes gives an incorrect answer that leads to an incorrect optimization.")
   286  	}
   287  }
   288  

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