1 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2 ; Test that the strlen library call simplifier works correctly. 3 ; 4 ; RUN: opt < %s -instcombine -S | FileCheck %s 5 6 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" 7 8 @hello = constant [6 x i8] c"hello\00" 9 @longer = constant [7 x i8] c"longer\00" 10 @null = constant [1 x i8] zeroinitializer 11 @null_hello = constant [7 x i8] c"\00hello\00" 12 @nullstring = constant i8 0 13 @a = common global [32 x i8] zeroinitializer, align 1 14 @null_hello_mid = constant [13 x i8] c"hello wor\00ld\00" 15 16 declare i32 @strlen(i8*) 17 18 ; Check strlen(string constant) -> integer constant. 19 20 define i32 @test_simplify1() { 21 ; CHECK-LABEL: @test_simplify1( 22 ; CHECK-NEXT: ret i32 5 23 ; 24 %hello_p = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 25 %hello_l = call i32 @strlen(i8* %hello_p) 26 ret i32 %hello_l 27 } 28 29 define i32 @test_simplify2() { 30 ; CHECK-LABEL: @test_simplify2( 31 ; CHECK-NEXT: ret i32 0 32 ; 33 %null_p = getelementptr [1 x i8], [1 x i8]* @null, i32 0, i32 0 34 %null_l = call i32 @strlen(i8* %null_p) 35 ret i32 %null_l 36 } 37 38 define i32 @test_simplify3() { 39 ; CHECK-LABEL: @test_simplify3( 40 ; CHECK-NEXT: ret i32 0 41 ; 42 %null_hello_p = getelementptr [7 x i8], [7 x i8]* @null_hello, i32 0, i32 0 43 %null_hello_l = call i32 @strlen(i8* %null_hello_p) 44 ret i32 %null_hello_l 45 } 46 47 define i32 @test_simplify4() { 48 ; CHECK-LABEL: @test_simplify4( 49 ; CHECK-NEXT: ret i32 0 50 ; 51 %len = tail call i32 @strlen(i8* @nullstring) nounwind 52 ret i32 %len 53 } 54 55 ; Check strlen(x) == 0 --> *x == 0. 56 57 define i1 @test_simplify5() { 58 ; CHECK-LABEL: @test_simplify5( 59 ; CHECK-NEXT: ret i1 false 60 ; 61 %hello_p = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 62 %hello_l = call i32 @strlen(i8* %hello_p) 63 %eq_hello = icmp eq i32 %hello_l, 0 64 ret i1 %eq_hello 65 } 66 67 define i1 @test_simplify6(i8* %str_p) { 68 ; CHECK-LABEL: @test_simplify6( 69 ; CHECK-NEXT: [[STRLENFIRST:%.*]] = load i8, i8* [[STR_P:%.*]], align 1 70 ; CHECK-NEXT: [[EQ_NULL:%.*]] = icmp eq i8 [[STRLENFIRST]], 0 71 ; CHECK-NEXT: ret i1 [[EQ_NULL]] 72 ; 73 %str_l = call i32 @strlen(i8* %str_p) 74 %eq_null = icmp eq i32 %str_l, 0 75 ret i1 %eq_null 76 } 77 78 ; Check strlen(x) != 0 --> *x != 0. 79 80 define i1 @test_simplify7() { 81 ; CHECK-LABEL: @test_simplify7( 82 ; CHECK-NEXT: ret i1 true 83 ; 84 %hello_p = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 85 %hello_l = call i32 @strlen(i8* %hello_p) 86 %ne_hello = icmp ne i32 %hello_l, 0 87 ret i1 %ne_hello 88 } 89 90 define i1 @test_simplify8(i8* %str_p) { 91 ; CHECK-LABEL: @test_simplify8( 92 ; CHECK-NEXT: [[STRLENFIRST:%.*]] = load i8, i8* [[STR_P:%.*]], align 1 93 ; CHECK-NEXT: [[NE_NULL:%.*]] = icmp ne i8 [[STRLENFIRST]], 0 94 ; CHECK-NEXT: ret i1 [[NE_NULL]] 95 ; 96 %str_l = call i32 @strlen(i8* %str_p) 97 %ne_null = icmp ne i32 %str_l, 0 98 ret i1 %ne_null 99 } 100 101 define i32 @test_simplify9(i1 %x) { 102 ; CHECK-LABEL: @test_simplify9( 103 ; CHECK-NEXT: [[TMP1:%.*]] = select i1 %x, i32 5, i32 6 104 ; CHECK-NEXT: ret i32 [[TMP1]] 105 ; 106 %hello = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 107 %longer = getelementptr [7 x i8], [7 x i8]* @longer, i32 0, i32 0 108 %s = select i1 %x, i8* %hello, i8* %longer 109 %l = call i32 @strlen(i8* %s) 110 ret i32 %l 111 } 112 113 ; Check the case that should be simplified to a sub instruction. 114 ; strlen(@hello + x) --> 5 - x 115 116 define i32 @test_simplify10(i32 %x) { 117 ; CHECK-LABEL: @test_simplify10( 118 ; CHECK-NEXT: [[TMP1:%.*]] = sub i32 5, %x 119 ; CHECK-NEXT: ret i32 [[TMP1]] 120 ; 121 %hello_p = getelementptr inbounds [6 x i8], [6 x i8]* @hello, i32 0, i32 %x 122 %hello_l = call i32 @strlen(i8* %hello_p) 123 ret i32 %hello_l 124 } 125 126 ; strlen(@null_hello_mid + (x & 7)) --> 9 - (x & 7) 127 128 define i32 @test_simplify11(i32 %x) { 129 ; CHECK-LABEL: @test_simplify11( 130 ; CHECK-NEXT: [[AND:%.*]] = and i32 %x, 7 131 ; CHECK-NEXT: [[TMP1:%.*]] = sub nsw i32 9, [[AND]] 132 ; CHECK-NEXT: ret i32 [[TMP1]] 133 ; 134 %and = and i32 %x, 7 135 %hello_p = getelementptr inbounds [13 x i8], [13 x i8]* @null_hello_mid, i32 0, i32 %and 136 %hello_l = call i32 @strlen(i8* %hello_p) 137 ret i32 %hello_l 138 } 139 140 ; Check cases that shouldn't be simplified. 141 142 define i32 @test_no_simplify1() { 143 ; CHECK-LABEL: @test_no_simplify1( 144 ; CHECK-NEXT: [[A_L:%.*]] = call i32 @strlen(i8* getelementptr inbounds ([32 x i8], [32 x i8]* @a, i32 0, i32 0)) 145 ; CHECK-NEXT: ret i32 [[A_L]] 146 ; 147 %a_p = getelementptr [32 x i8], [32 x i8]* @a, i32 0, i32 0 148 %a_l = call i32 @strlen(i8* %a_p) 149 ret i32 %a_l 150 } 151 152 ; strlen(@null_hello + x) should not be simplified to a sub instruction. 153 154 define i32 @test_no_simplify2(i32 %x) { 155 ; CHECK-LABEL: @test_no_simplify2( 156 ; CHECK-NEXT: [[HELLO_P:%.*]] = getelementptr inbounds [7 x i8], [7 x i8]* @null_hello, i32 0, i32 %x 157 ; CHECK-NEXT: [[HELLO_L:%.*]] = call i32 @strlen(i8* nonnull [[HELLO_P]]) 158 ; CHECK-NEXT: ret i32 [[HELLO_L]] 159 ; 160 %hello_p = getelementptr inbounds [7 x i8], [7 x i8]* @null_hello, i32 0, i32 %x 161 %hello_l = call i32 @strlen(i8* %hello_p) 162 ret i32 %hello_l 163 } 164 165 define i32 @test_no_simplify2_no_null_opt(i32 %x) #0 { 166 ; CHECK-LABEL: @test_no_simplify2_no_null_opt( 167 ; CHECK-NEXT: [[HELLO_P:%.*]] = getelementptr inbounds [7 x i8], [7 x i8]* @null_hello, i32 0, i32 %x 168 ; CHECK-NEXT: [[HELLO_L:%.*]] = call i32 @strlen(i8* [[HELLO_P]]) 169 ; CHECK-NEXT: ret i32 [[HELLO_L]] 170 ; 171 %hello_p = getelementptr inbounds [7 x i8], [7 x i8]* @null_hello, i32 0, i32 %x 172 %hello_l = call i32 @strlen(i8* %hello_p) 173 ret i32 %hello_l 174 } 175 176 ; strlen(@null_hello_mid + (x & 15)) should not be simplified to a sub instruction. 177 178 define i32 @test_no_simplify3(i32 %x) { 179 ; CHECK-LABEL: @test_no_simplify3( 180 ; CHECK-NEXT: [[AND:%.*]] = and i32 %x, 15 181 ; CHECK-NEXT: [[HELLO_P:%.*]] = getelementptr inbounds [13 x i8], [13 x i8]* @null_hello_mid, i32 0, i32 [[AND]] 182 ; CHECK-NEXT: [[HELLO_L:%.*]] = call i32 @strlen(i8* nonnull [[HELLO_P]]) 183 ; CHECK-NEXT: ret i32 [[HELLO_L]] 184 ; 185 %and = and i32 %x, 15 186 %hello_p = getelementptr inbounds [13 x i8], [13 x i8]* @null_hello_mid, i32 0, i32 %and 187 %hello_l = call i32 @strlen(i8* %hello_p) 188 ret i32 %hello_l 189 } 190 191 define i32 @test_no_simplify3_on_null_opt(i32 %x) #0 { 192 ; CHECK-LABEL: @test_no_simplify3_on_null_opt( 193 ; CHECK-NEXT: [[AND:%.*]] = and i32 %x, 15 194 ; CHECK-NEXT: [[HELLO_P:%.*]] = getelementptr inbounds [13 x i8], [13 x i8]* @null_hello_mid, i32 0, i32 [[AND]] 195 ; CHECK-NEXT: [[HELLO_L:%.*]] = call i32 @strlen(i8* [[HELLO_P]]) 196 ; CHECK-NEXT: ret i32 [[HELLO_L]] 197 ; 198 %and = and i32 %x, 15 199 %hello_p = getelementptr inbounds [13 x i8], [13 x i8]* @null_hello_mid, i32 0, i32 %and 200 %hello_l = call i32 @strlen(i8* %hello_p) 201 ret i32 %hello_l 202 } 203 204 attributes #0 = { "null-pointer-is-valid"="true" } 205
