#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*/ abort();
scalar_t__ calloc(scalar_t__, int);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ strcpy(char *, char const *);
scalar_t__ strlen(char const *);
char *str_dup(const char *str) {
  char *str_new;
  if (!str)
    return (0);
  {
    if (!((str_new) = (char *)calloc((strlen(str) + 1), sizeof(char)))) {
      perror("malloc failure");
      abort();
    }
  };
  strcpy(str_new, str);
  return str_new;
}


x86 assembly (clang, -O0):
<str_dup>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x10(%rbp)
cmpq   $0x0,-0x10(%rbp)
jne    1174 <str_dup+0x24>
movq   $0x0,-0x8(%rbp)
jmp    11c4 <str_dup+0x74>
mov    -0x10(%rbp),%rdi
call   1050 <strlen@plt>
mov    %rax,%rdi
add    $0x1,%rdi
mov    $0x1,%esi
call   1060 <calloc@plt>
mov    %rax,-0x18(%rbp)
cmp    $0x0,%rax
jne    11af <str_dup+0x5f>
lea    0xe5d(%rip),%rdi
call   1070 <perror@plt>
mov    $0x0,%al
call   1030 <abort@plt>
mov    -0x18(%rbp),%rdi
mov    -0x10(%rbp),%rsi
call   1040 <strcpy@plt>
mov    -0x18(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<str_dup>:
push   %r14
push   %rbx
push   %rax
test   %rdi,%rdi
je     1184 <str_dup+0x34>
mov    %rdi,%r14
call   1050 <strlen@plt>
lea    0x1(%rax),%rdi
mov    $0x1,%esi
call   1060 <calloc@plt>
test   %rax,%rax
je     1191 <str_dup+0x41>
mov    %rax,%rbx
mov    %rax,%rdi
mov    %r14,%rsi
call   1040 <strcpy@plt>
jmp    1186 <str_dup+0x36>
xor    %ebx,%ebx
mov    %rbx,%rax
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret
lea    0xe68(%rip),%rdi
call   1070 <perror@plt>
xor    %eax,%eax
call   1030 <abort@plt>

LLVM IR (-O0):
@.str = [15 x i8] c"malloc failure\00"
define i8* @str_dup(i8* %0) {
%2 = alloca i8*
%3 = alloca i8*
%4 = alloca i8*
store i8* %0, i8** %3
%5 = load i8*, i8** %3
%6 = icmp ne i8* %5, null
br i1 %6, label %8, label %7
7: ; preds = %1
store i8* null, i8** %2
br label %23
8: ; preds = %1
%9 = load i8*, i8** %3
%10 = call i64 @strlen(i8* %9)
%11 = add nsw i64 %10, 1
%12 = call i64 @calloc(i64 %11, i32 1)
%13 = inttoptr i64 %12 to i8*
store i8* %13, i8** %4
%14 = icmp ne i8* %13, null
br i1 %14, label %18, label %15
15: ; preds = %8
%16 = call i32 @perror(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0))
%17 = call i32 (...) @abort()
unreachable
18: ; preds = %8
%19 = load i8*, i8** %4
%20 = load i8*, i8** %3
%21 = call i32 @strcpy(i8* %19, i8* %20)
%22 = load i8*, i8** %4
store i8* %22, i8** %2
br label %23
23: ; preds = %18, %7
%24 = load i8*, i8** %2
ret i8* %24
}

LLVM IR (-O2):
@.str = [15 x i8] c"malloc failure\00"
define i8* @str_dup(i8* %0) {
%2 = icmp eq i8* %0, null
br i1 %2, label %14, label %3
3: ; preds = %1
%4 = tail call i64 @strlen(i8* %0)
%5 = add nsw i64 %4, 1
%6 = tail call i64 @calloc(i64 %5, i32 1)
%7 = inttoptr i64 %6 to i8*
%8 = icmp eq i64 %6, 0
br i1 %8, label %9, label %12
9: ; preds = %3
%10 = tail call i32 @perror(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0))
%11 = tail call i32 (...) @abort()
unreachable
12: ; preds = %3
%13 = tail call i32 @strcpy(i8* %7, i8* %0)
br label %14
14: ; preds = %1, %12
%15 = phi i8* [ %7, %12 ], [ null, %1 ]
ret i8* %15
}