1 ; Test that the strncpy 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 @null = constant [1 x i8] zeroinitializer 9 @null_hello = constant [7 x i8] c"\00hello\00" 10 @a = common global [32 x i8] zeroinitializer, align 1 11 @b = common global [32 x i8] zeroinitializer, align 1 12 13 declare i8* @strncpy(i8*, i8*, i32) 14 declare i32 @puts(i8*) 15 16 ; Check a bunch of strncpy invocations together. 17 18 define i32 @test_simplify1() { 19 ; CHECK-LABEL: @test_simplify1( 20 ; CHECK-NOT: call i8* @strncpy 21 ; CHECK: call i32 @puts 22 %target = alloca [1024 x i8] 23 %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0 24 store i8 0, i8* %arg1 25 26 %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0 27 %rslt1 = call i8* @strncpy(i8* %arg1, i8* %arg2, i32 6) 28 29 %arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0 30 %rslt2 = call i8* @strncpy(i8* %rslt1, i8* %arg3, i32 42) 31 32 %arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0 33 %rslt3 = call i8* @strncpy(i8* %rslt2, i8* %arg4, i32 42) 34 35 call i32 @puts( i8* %rslt3 ) 36 ret i32 0 37 } 38 39 ; Check strncpy(x, "", y) -> memset(x, '\0', y, 1). 40 41 define void @test_simplify2() { 42 ; CHECK-LABEL: @test_simplify2( 43 %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 44 %src = getelementptr [1 x i8]* @null, i32 0, i32 0 45 46 call i8* @strncpy(i8* %dst, i8* %src, i32 32) 47 ; CHECK: call void @llvm.memset.p0i8.i32 48 ret void 49 } 50 51 ; Check strncpy(x, y, 0) -> x. 52 53 define i8* @test_simplify3() { 54 ; CHECK-LABEL: @test_simplify3( 55 %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 56 %src = getelementptr [6 x i8]* @hello, i32 0, i32 0 57 58 %ret = call i8* @strncpy(i8* %dst, i8* %src, i32 0) 59 ret i8* %ret 60 ; CHECK: ret i8* getelementptr inbounds ([32 x i8]* @a, i32 0, i32 0) 61 } 62 63 ; Check strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]. 64 65 define void @test_simplify4() { 66 ; CHECK-LABEL: @test_simplify4( 67 %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 68 %src = getelementptr [6 x i8]* @hello, i32 0, i32 0 69 70 call i8* @strncpy(i8* %dst, i8* %src, i32 6) 71 ; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32 72 ret void 73 } 74 75 ; Check cases that shouldn't be simplified. 76 77 define void @test_no_simplify1() { 78 ; CHECK-LABEL: @test_no_simplify1( 79 %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 80 %src = getelementptr [32 x i8]* @b, i32 0, i32 0 81 82 call i8* @strncpy(i8* %dst, i8* %src, i32 32) 83 ; CHECK: call i8* @strncpy 84 ret void 85 } 86 87 define void @test_no_simplify2() { 88 ; CHECK-LABEL: @test_no_simplify2( 89 %dst = getelementptr [32 x i8]* @a, i32 0, i32 0 90 %src = getelementptr [6 x i8]* @hello, i32 0, i32 0 91 92 call i8* @strncpy(i8* %dst, i8* %src, i32 8) 93 ; CHECK: call i8* @strncpy 94 ret void 95 } 96
