llvm-project/llvm/test/Transforms/SimplifyLibCalls/StrNCpy.ll

; Test that the StrNCpyOptimizer works correctly
; RUN: opt < %s -simplify-libcalls -S | \
; RUN:   not grep {call.*strncpy}

; This transformation requires the pointer size, as it assumes that size_t is
; the size of a pointer.
target datalayout = "-p:64:64:64"

@hello = constant [6 x i8] c"hello\00"		; <[6 x i8]*> [#uses=1]
@null = constant [1 x i8] zeroinitializer		; <[1 x i8]*> [#uses=1]
@null_hello = constant [7 x i8] c"\00hello\00"		; <[7 x i8]*> [#uses=1]

declare i8* @strncpy(i8*, i8*, i32)

declare i32 @puts(i8*)

define i32 @main() {
	%target = alloca [1024 x i8]		; <[1024 x i8]*> [#uses=1]
	%arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0		; <i8*> [#uses=2]
	store i8 0, i8* %arg1
	%arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0		; <i8*> [#uses=1]
	%rslt1 = call i8* @strncpy( i8* %arg1, i8* %arg2, i32 6 )		; <i8*> [#uses=1]
	%arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0		; <i8*> [#uses=1]
	%rslt2 = call i8* @strncpy( i8* %rslt1, i8* %arg3, i32 42 )		; <i8*> [#uses=1]
	%arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0		; <i8*> [#uses=1]
	%rslt3 = call i8* @strncpy( i8* %rslt2, i8* %arg4, i32 42 )		; <i8*> [#uses=1]
	call i32 @puts( i8* %rslt3 )		; <i32>:1 [#uses=0]
	ret i32 0
}