#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int /*<<< orphan*/ printf(char *, char *);
int /*<<< orphan*/ strcpy(char *, char *);
int /*<<< orphan*/ strncat(char *, char *, int);
int main() {
  char src[50], dest[50];
  strcpy(src, "This is source");
  strcpy(dest, "This is destination");
  strncat(dest, src, 15);
  printf("Final destination string : |%s|", dest);
  return (0);
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x80,%rsp
movl   $0x0,-0x4(%rbp)
lea    -0x40(%rbp),%rdi
lea    0xeb3(%rip),%rsi
call   1030 <strcpy@plt>
lea    -0x80(%rbp),%rdi
lea    0xeb2(%rip),%rsi
call   1030 <strcpy@plt>
lea    -0x80(%rbp),%rdi
lea    -0x40(%rbp),%rsi
mov    $0xf,%edx
call   1050 <strncat@plt>
lea    -0x80(%rbp),%rsi
lea    0xea4(%rip),%rdi
call   1040 <printf@plt>
xor    %eax,%eax
add    $0x80,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r14
push   %rbx
sub    $0x78,%rsp
lea    0xec2(%rip),%rsi
lea    0x40(%rsp),%r14
mov    %r14,%rdi
call   1030 <strcpy@plt>
lea    0xebd(%rip),%rsi
mov    %rsp,%rbx
mov    %rbx,%rdi
call   1030 <strcpy@plt>
mov    %rbx,%rdi
mov    %r14,%rsi
mov    $0xf,%edx
call   1050 <strncat@plt>
lea    0xeaf(%rip),%rdi
mov    %rbx,%rsi
call   1040 <printf@plt>
xor    %eax,%eax
add    $0x78,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
@.str = [15 x i8] c"This is source\00"
@.str.1 = [20 x i8] c"This is destination\00"
@.str.2 = [32 x i8] c"Final destination string : |%s|\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca [50 x i8]
%3 = alloca [50 x i8]
store i32 0, i32* %1
%4 = getelementptr inbounds [50 x i8], [50 x i8]* %2, i64 0, i64 0
%5 = call i32 @strcpy(i8* %4, i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0))
%6 = getelementptr inbounds [50 x i8], [50 x i8]* %3, i64 0, i64 0
%7 = call i32 @strcpy(i8* %6, i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.1, i64 0, i64 0))
%8 = getelementptr inbounds [50 x i8], [50 x i8]* %3, i64 0, i64 0
%9 = getelementptr inbounds [50 x i8], [50 x i8]* %2, i64 0, i64 0
%10 = call i32 @strncat(i8* %8, i8* %9, i32 15)
%11 = getelementptr inbounds [50 x i8], [50 x i8]* %3, i64 0, i64 0
%12 = call i32 @printf(i8* getelementptr inbounds ([32 x i8], [32 x i8]* @.str.2, i64 0, i64 0), i8* %11)
ret i32 0
}

LLVM IR (-O2):
@.str = [15 x i8] c"This is source\00"
@.str.1 = [20 x i8] c"This is destination\00"
@.str.2 = [32 x i8] c"Final destination string : |%s|\00"
define i32 @main() {
%1 = alloca [50 x i8]
%2 = alloca [50 x i8]
%3 = getelementptr inbounds [50 x i8], [50 x i8]* %1, i64 0, i64 0
%4 = getelementptr inbounds [50 x i8], [50 x i8]* %2, i64 0, i64 0
%5 = call i32 @strcpy(i8* %3, i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0))
%6 = call i32 @strcpy(i8* %4, i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.1, i64 0, i64 0))
%7 = call i32 @strncat(i8* %4, i8* %3, i32 15)
%8 = call i32 @printf(i8* getelementptr inbounds ([32 x i8], [32 x i8]* @.str.2, i64 0, i64 0), i8* %4)
ret i32 0
}