1 ; Test that the strlen library call simplifier works correctly. 2 ; 3 ; RUN: opt < %s -instcombine -S | FileCheck %s 4 5 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" 6 7 @hello = constant [6 x i8] c"hello\00" 8 @longer = constant [7 x i8] c"longer\00" 9 @null = constant [1 x i8] zeroinitializer 10 @null_hello = constant [7 x i8] c"\00hello\00" 11 @nullstring = constant i8 0 12 @a = common global [32 x i8] zeroinitializer, align 1 13 14 declare i32 @strlen(i8*) 15 16 ; Check strlen(string constant) -> integer constant. 17 18 define i32 @test_simplify1() { 19 ; CHECK-LABEL: @test_simplify1( 20 %hello_p = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 21 %hello_l = call i32 @strlen(i8* %hello_p) 22 ret i32 %hello_l 23 ; CHECK-NEXT: ret i32 5 24 } 25 26 define i32 @test_simplify2() { 27 ; CHECK-LABEL: @test_simplify2( 28 %null_p = getelementptr [1 x i8], [1 x i8]* @null, i32 0, i32 0 29 %null_l = call i32 @strlen(i8* %null_p) 30 ret i32 %null_l 31 ; CHECK-NEXT: ret i32 0 32 } 33 34 define i32 @test_simplify3() { 35 ; CHECK-LABEL: @test_simplify3( 36 %null_hello_p = getelementptr [7 x i8], [7 x i8]* @null_hello, i32 0, i32 0 37 %null_hello_l = call i32 @strlen(i8* %null_hello_p) 38 ret i32 %null_hello_l 39 ; CHECK-NEXT: ret i32 0 40 } 41 42 define i32 @test_simplify4() { 43 ; CHECK-LABEL: @test_simplify4( 44 %len = tail call i32 @strlen(i8* @nullstring) nounwind 45 ret i32 %len 46 ; CHECK-NEXT: ret i32 0 47 } 48 49 ; Check strlen(x) == 0 --> *x == 0. 50 51 define i1 @test_simplify5() { 52 ; CHECK-LABEL: @test_simplify5( 53 %hello_p = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 54 %hello_l = call i32 @strlen(i8* %hello_p) 55 %eq_hello = icmp eq i32 %hello_l, 0 56 ret i1 %eq_hello 57 ; CHECK-NEXT: ret i1 false 58 } 59 60 define i1 @test_simplify6() { 61 ; CHECK-LABEL: @test_simplify6( 62 %null_p = getelementptr [1 x i8], [1 x i8]* @null, i32 0, i32 0 63 %null_l = call i32 @strlen(i8* %null_p) 64 %eq_null = icmp eq i32 %null_l, 0 65 ret i1 %eq_null 66 ; CHECK-NEXT: ret i1 true 67 } 68 69 ; Check strlen(x) != 0 --> *x != 0. 70 71 define i1 @test_simplify7() { 72 ; CHECK-LABEL: @test_simplify7( 73 %hello_p = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 74 %hello_l = call i32 @strlen(i8* %hello_p) 75 %ne_hello = icmp ne i32 %hello_l, 0 76 ret i1 %ne_hello 77 ; CHECK-NEXT: ret i1 true 78 } 79 80 define i1 @test_simplify8() { 81 ; CHECK-LABEL: @test_simplify8( 82 %null_p = getelementptr [1 x i8], [1 x i8]* @null, i32 0, i32 0 83 %null_l = call i32 @strlen(i8* %null_p) 84 %ne_null = icmp ne i32 %null_l, 0 85 ret i1 %ne_null 86 ; CHECK-NEXT: ret i1 false 87 } 88 89 define i32 @test_simplify9(i1 %x) { 90 ; CHECK-LABEL: @test_simplify9 91 %hello = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0 92 %longer = getelementptr [7 x i8], [7 x i8]* @longer, i32 0, i32 0 93 %s = select i1 %x, i8* %hello, i8* %longer 94 %l = call i32 @strlen(i8* %s) 95 ; CHECK-NEXT: select i1 %x, i32 5, i32 6 96 ret i32 %l 97 ; CHECK-NEXT: ret 98 } 99 100 ; Check cases that shouldn't be simplified. 101 102 define i32 @test_no_simplify1() { 103 ; CHECK-LABEL: @test_no_simplify1( 104 %a_p = getelementptr [32 x i8], [32 x i8]* @a, i32 0, i32 0 105 %a_l = call i32 @strlen(i8* %a_p) 106 ; CHECK-NEXT: %a_l = call i32 @strlen 107 ret i32 %a_l 108 ; CHECK-NEXT: ret i32 %a_l 109 } 110
