#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 */
scalar_t__ malloc(int);
int /*<<< orphan*/ memcpy(char *, char const *, int);
int strlen(char const *);
char *strdup2(const char *s1, const char *s2) {
  int l1 = strlen(s1);
  int l2 = strlen(s2) + 1;
  char *str = (char *)malloc(l1 + l2);
  memcpy(str, s1, l1);
  memcpy(str + l1, s2, l2);
  return str;
}


x86 assembly (clang, -O0):
<strdup2>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,-0x14(%rbp)
mov    -0x10(%rbp),%rdi
call   1030 <strlen@plt>
add    $0x1,%eax
mov    %eax,-0x18(%rbp)
mov    -0x14(%rbp),%edi
add    -0x18(%rbp),%edi
call   1050 <malloc@plt>
mov    %rax,-0x20(%rbp)
mov    -0x20(%rbp),%rdi
mov    -0x8(%rbp),%rsi
mov    -0x14(%rbp),%edx
call   1040 <memcpy@plt>
mov    -0x20(%rbp),%rdi
movslq -0x14(%rbp),%rax
add    %rax,%rdi
mov    -0x10(%rbp),%rsi
mov    -0x18(%rbp),%edx
call   1040 <memcpy@plt>
mov    -0x20(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<strdup2>:
push   %rbp
push   %r15
push   %r14
push   %r12
push   %rbx
mov    %rsi,%r14
mov    %rdi,%r15
call   1030 <strlen@plt>
mov    %eax,%ebx
mov    %r14,%rdi
call   1030 <strlen@plt>
lea    0x1(%rax),%r12d
lea    (%rax,%rbx,1),%edi
add    $0x1,%edi
call   1050 <malloc@plt>
mov    %rax,%rbp
mov    %rax,%rdi
mov    %r15,%rsi
mov    %ebx,%edx
call   1040 <memcpy@plt>
movslq %ebx,%rdi
add    %rbp,%rdi
mov    %r14,%rsi
mov    %r12d,%edx
call   1040 <memcpy@plt>
mov    %rbp,%rax
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
define i8* @strdup2(i8* %0, i8* %1) {
%3 = alloca i8*
%4 = alloca i8*
%5 = alloca i32
%6 = alloca i32
%7 = alloca i8*
store i8* %0, i8** %3
store i8* %1, i8** %4
%8 = load i8*, i8** %3
%9 = call i32 @strlen(i8* %8)
store i32 %9, i32* %5
%10 = load i8*, i8** %4
%11 = call i32 @strlen(i8* %10)
%12 = add nsw i32 %11, 1
store i32 %12, i32* %6
%13 = load i32, i32* %5
%14 = load i32, i32* %6
%15 = add nsw i32 %13, %14
%16 = call i64 @malloc(i32 %15)
%17 = inttoptr i64 %16 to i8*
store i8* %17, i8** %7
%18 = load i8*, i8** %7
%19 = load i8*, i8** %3
%20 = load i32, i32* %5
%21 = call i32 @memcpy(i8* %18, i8* %19, i32 %20)
%22 = load i8*, i8** %7
%23 = load i32, i32* %5
%24 = sext i32 %23 to i64
%25 = getelementptr inbounds i8, i8* %22, i64 %24
%26 = load i8*, i8** %4
%27 = load i32, i32* %6
%28 = call i32 @memcpy(i8* %25, i8* %26, i32 %27)
%29 = load i8*, i8** %7
ret i8* %29
}

LLVM IR (-O2):
define i8* @strdup2(i8* %0, i8* %1) {
%3 = tail call i32 @strlen(i8* %0)
%4 = tail call i32 @strlen(i8* %1)
%5 = add nsw i32 %4, 1
%6 = add nsw i32 %5, %3
%7 = tail call i64 @malloc(i32 %6)
%8 = inttoptr i64 %7 to i8*
%9 = tail call i32 @memcpy(i8* %8, i8* %0, i32 %3)
%10 = sext i32 %3 to i64
%11 = getelementptr inbounds i8, i8* %8, i64 %10
%12 = tail call i32 @memcpy(i8* %11, i8* %1, i32 %5)
ret i8* %8
}