#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 */
size_t MIN(size_t, size_t);
scalar_t__ malloc(size_t);
int /*<<< orphan*/ memcpy(char *, char const *, size_t);
size_t strlen(char const *);
char *strndup(const char *s, size_t n) {
  char *s2;
  size_t len;
  len = strlen(s);
  len = MIN(len, n);
  s2 = (char *)malloc(len + 1);
  if (s2 == NULL) {
    return NULL;
  }
  memcpy(s2, s, len);
  s2[len] = '\0';
  return s2;
}


x86 assembly (clang, -O0):
<strndup>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x10(%rbp)
mov    %rsi,-0x18(%rbp)
mov    -0x10(%rbp),%rdi
call   1040 <strlen@plt>
mov    %rax,-0x28(%rbp)
mov    -0x28(%rbp),%rdi
mov    -0x18(%rbp),%rsi
call   1030 <MIN@plt>
mov    %rax,-0x28(%rbp)
mov    -0x28(%rbp),%rdi
add    $0x1,%rdi
call   1060 <malloc@plt>
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jne    1197 <strndup+0x57>
movq   $0x0,-0x8(%rbp)
jmp    11bc <strndup+0x7c>
mov    -0x20(%rbp),%rdi
mov    -0x10(%rbp),%rsi
mov    -0x28(%rbp),%rdx
call   1050 <memcpy@plt>
mov    -0x20(%rbp),%rax
mov    -0x28(%rbp),%rcx
movb   $0x0,(%rax,%rcx,1)
mov    -0x20(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<strndup>:
push   %r15
push   %r14
push   %rbx
mov    %rsi,%rbx
mov    %rdi,%r14
call   1040 <strlen@plt>
mov    %rax,%rdi
mov    %rbx,%rsi
call   1030 <MIN@plt>
mov    %rax,%r15
lea    0x1(%rax),%rdi
call   1060 <malloc@plt>
test   %rax,%rax
je     1184 <strndup+0x44>
mov    %rax,%rbx
mov    %rax,%rdi
mov    %r14,%rsi
mov    %r15,%rdx
call   1050 <memcpy@plt>
movb   $0x0,(%rbx,%r15,1)
jmp    1186 <strndup+0x46>
xor    %ebx,%ebx
mov    %rbx,%rax
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
define i8* @strndup(i8* %0, i64 %1) {
%3 = alloca i8*
%4 = alloca i8*
%5 = alloca i64
%6 = alloca i8*
%7 = alloca i64
store i8* %0, i8** %4
store i64 %1, i64* %5
%8 = load i8*, i8** %4
%9 = call i64 @strlen(i8* %8)
store i64 %9, i64* %7
%10 = load i64, i64* %7
%11 = load i64, i64* %5
%12 = call i64 @MIN(i64 %10, i64 %11)
store i64 %12, i64* %7
%13 = load i64, i64* %7
%14 = add i64 %13, 1
%15 = call i64 @malloc(i64 %14)
%16 = inttoptr i64 %15 to i8*
store i8* %16, i8** %6
%17 = load i8*, i8** %6
%18 = icmp eq i8* %17, null
br i1 %18, label %19, label %20
19: ; preds = %2
store i8* null, i8** %3
br label %29
20: ; preds = %2
%21 = load i8*, i8** %6
%22 = load i8*, i8** %4
%23 = load i64, i64* %7
%24 = call i32 @memcpy(i8* %21, i8* %22, i64 %23)
%25 = load i8*, i8** %6
%26 = load i64, i64* %7
%27 = getelementptr inbounds i8, i8* %25, i64 %26
store i8 0, i8* %27
%28 = load i8*, i8** %6
store i8* %28, i8** %3
br label %29
29: ; preds = %20, %19
%30 = load i8*, i8** %3
ret i8* %30
}

LLVM IR (-O2):
define i8* @strndup(i8* %0, i64 %1) {
%3 = tail call i64 @strlen(i8* dereferenceable(1) %0)
%4 = tail call i64 @MIN(i64 %3, i64 %1)
%5 = add i64 %4, 1
%6 = tail call i64 @malloc(i64 %5)
%7 = inttoptr i64 %6 to i8*
%8 = icmp eq i64 %6, 0
br i1 %8, label %12, label %9
9: ; preds = %2
%10 = tail call i32 @memcpy(i8* %7, i8* %0, i64 %4)
%11 = getelementptr inbounds i8, i8* %7, i64 %4
store i8 0, i8* %11
br label %12
12: ; preds = %2, %9
%13 = phi i8* [ %7, %9 ], [ null, %2 ]
ret i8* %13
}