#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*/ memcpy(char *, char const *, size_t);
size_t strlen(char const *);
char *xmalloc_inc(size_t, int);
char *xstrndup(const char *s, size_t len) {
  char *new;
  size_t n = strlen(s);
  if (n > len)
    n = len;
  new = xmalloc_inc(n, 1);
  if (new == NULL)
    return NULL;
  memcpy(new, s, n);
  new[n] = '\0';
  return new;
}


x86 assembly (clang, -O0):
<xstrndup>:
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),%rax
cmp    -0x18(%rbp),%rax
jbe    1163 <xstrndup+0x33>
mov    -0x18(%rbp),%rax
mov    %rax,-0x28(%rbp)
mov    -0x28(%rbp),%rdi
mov    $0x1,%esi
call   1030 <xmalloc_inc@plt>
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jne    118d <xstrndup+0x5d>
movq   $0x0,-0x8(%rbp)
jmp    11b2 <xstrndup+0x82>
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):
<xstrndup>:
push   %r15
push   %r14
push   %rbx
mov    %rsi,%r15
mov    %rdi,%r14
call   1040 <strlen@plt>
mov    %rax,%rbx
cmp    %r15,%rax
cmova  %r15,%rbx
mov    %rbx,%rdi
mov    $0x1,%esi
call   1030 <xmalloc_inc@plt>
mov    %rax,%r15
test   %rax,%rax
je     1172 <xstrndup+0x42>
mov    %r15,%rdi
mov    %r14,%rsi
mov    %rbx,%rdx
call   1050 <memcpy@plt>
movb   $0x0,(%r15,%rbx,1)
mov    %r15,%rax
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
define i8* @xstrndup(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 = icmp ugt i64 %10, %11
br i1 %12, label %13, label %15
13: ; preds = %2
%14 = load i64, i64* %5
store i64 %14, i64* %7
br label %15
15: ; preds = %13, %2
%16 = load i64, i64* %7
%17 = call i8* @xmalloc_inc(i64 %16, i32 1)
store i8* %17, i8** %6
%18 = load i8*, i8** %6
%19 = icmp eq i8* %18, null
br i1 %19, label %20, label %21
20: ; preds = %15
store i8* null, i8** %3
br label %30
21: ; preds = %15
%22 = load i8*, i8** %6
%23 = load i8*, i8** %4
%24 = load i64, i64* %7
%25 = call i32 @memcpy(i8* %22, i8* %23, i64 %24)
%26 = load i8*, i8** %6
%27 = load i64, i64* %7
%28 = getelementptr inbounds i8, i8* %26, i64 %27
store i8 0, i8* %28
%29 = load i8*, i8** %6
store i8* %29, i8** %3
br label %30
30: ; preds = %21, %20
%31 = load i8*, i8** %3
ret i8* %31
}

LLVM IR (-O2):
define i8* @xstrndup(i8* %0, i64 %1) {
%3 = tail call i64 @strlen(i8* dereferenceable(1) %0)
%4 = icmp ugt i64 %3, %1
%5 = select i1 %4, i64 %1, i64 %3
%6 = tail call i8* @xmalloc_inc(i64 %5, i32 1)
%7 = icmp eq i8* %6, null
br i1 %7, label %11, label %8
8: ; preds = %2
%9 = tail call i32 @memcpy(i8* %6, i8* %0, i64 %5)
%10 = getelementptr inbounds i8, i8* %6, i64 %5
store i8 0, i8* %10
br label %11
11: ; preds = %2, %8
ret i8* %6
}