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 "testing" 8 9 // TestNlzNto tests nlz/nto of the same number which is used in some of 10 // the rewrite rules. 11 func TestNlzNto(t *testing.T) { 12 // construct the bit pattern 000...111, nlz(x) + nto(0) = 64 13 var x int64 14 for i := int64(0); i < 64; i++ { 15 if got := nto(x); got != i { 16 t.Errorf("expected nto(0x%X) = %d, got %d", x, i, got) 17 } 18 if got := nlz(x); got != 64-i { 19 t.Errorf("expected nlz(0x%X) = %d, got %d", x, 64-i, got) 20 } 21 x = (x << 1) | 1 22 } 23 24 x = 0 25 // construct the bit pattern 000...111, with bit 33 set as well. 26 for i := int64(0); i < 64; i++ { 27 tx := x | (1 << 32) 28 // nto should be the number of bits we've shifted on, with an extra bit 29 // at iter 32 30 ntoExp := i 31 if ntoExp == 32 { 32 ntoExp = 33 33 } 34 if got := nto(tx); got != ntoExp { 35 t.Errorf("expected nto(0x%X) = %d, got %d", tx, ntoExp, got) 36 } 37 38 // sinec bit 33 is set, nlz can be no greater than 31 39 nlzExp := 64 - i 40 if nlzExp > 31 { 41 nlzExp = 31 42 } 43 if got := nlz(tx); got != nlzExp { 44 t.Errorf("expected nlz(0x%X) = %d, got %d", tx, nlzExp, got) 45 } 46 x = (x << 1) | 1 47 } 48 49 } 50 51 func TestNlz(t *testing.T) { 52 var nlzTests = []struct { 53 v int64 54 exp int64 55 }{{0x00, 64}, 56 {0x01, 63}, 57 {0x0F, 60}, 58 {0xFF, 56}, 59 {0xffffFFFF, 32}, 60 {-0x01, 0}} 61 62 for _, tc := range nlzTests { 63 if got := nlz(tc.v); got != tc.exp { 64 t.Errorf("expected nlz(0x%X) = %d, got %d", tc.v, tc.exp, got) 65 } 66 } 67 } 68 69 func TestNto(t *testing.T) { 70 var ntoTests = []struct { 71 v int64 72 exp int64 73 }{{0x00, 0}, 74 {0x01, 1}, 75 {0x0F, 4}, 76 {0xFF, 8}, 77 {0xffffFFFF, 32}, 78 {-0x01, 64}} 79 80 for _, tc := range ntoTests { 81 if got := nto(tc.v); got != tc.exp { 82 t.Errorf("expected nto(0x%X) = %d, got %d", tc.v, tc.exp, got) 83 } 84 } 85 } 86 87 func TestLog2(t *testing.T) { 88 var log2Tests = []struct { 89 v int64 90 exp int64 91 }{{0, -1}, // nlz expects log2(0) == -1 92 {1, 0}, 93 {2, 1}, 94 {4, 2}, 95 {7, 2}, 96 {8, 3}, 97 {9, 3}, 98 {1024, 10}} 99 100 for _, tc := range log2Tests { 101 if got := log2(tc.v); got != tc.exp { 102 t.Errorf("expected log2(%d) = %d, got %d", tc.v, tc.exp, got) 103 } 104 } 105 } 106 107 // We generate memmove for copy(x[1:], x[:]), however we may change it to OpMove, 108 // because size is known. Check that OpMove is alias-safe, or we did call memmove. 109 func TestMove(t *testing.T) { 110 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} 111 copy(x[1:], x[:]) 112 for i := 1; i < len(x); i++ { 113 if int(x[i]) != i { 114 t.Errorf("Memmove got converted to OpMove in alias-unsafe way. Got %d insted of %d in position %d", int(x[i]), i, i+1) 115 } 116 } 117 } 118 119 func TestMoveSmall(t *testing.T) { 120 x := [...]byte{1, 2, 3, 4, 5, 6, 7} 121 copy(x[1:], x[:]) 122 for i := 1; i < len(x); i++ { 123 if int(x[i]) != i { 124 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) 125 } 126 } 127 } 128
