#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 rand();
int /*<<< orphan*/ srand(int /*<<< orphan*/);
int /*<<< orphan*/ time(int /*<<< orphan*/ *);
int random_gen(char *buffer, int length) {
  int index;
  int temp;
  srand(time(NULL));
  for (index = 0; index < length - 1; index += 1) {
    temp = rand() % 26 + 97;
    buffer[index] = temp;
  }
  buffer[length - 1] = '\0';
  return 0;
}


x86 assembly (clang, -O0):
<random_gen>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
xor    %eax,%eax
mov    %eax,%edi
call   1040 <time@plt>
mov    %eax,%edi
call   1030 <srand@plt>
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
mov    -0xc(%rbp),%ecx
sub    $0x1,%ecx
cmp    %ecx,%eax
jge    119a <random_gen+0x6a>
mov    $0x0,%al
call   1050 <rand@plt>
mov    $0x1a,%ecx
cltd
idiv   %ecx
add    $0x61,%edx
mov    %edx,-0x14(%rbp)
mov    -0x14(%rbp),%eax
mov    %al,%dl
mov    -0x8(%rbp),%rax
movslq -0x10(%rbp),%rcx
mov    %dl,(%rax,%rcx,1)
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    1156 <random_gen+0x26>
mov    -0x8(%rbp),%rax
mov    -0xc(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movb   $0x0,(%rax,%rcx,1)
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<random_gen>:
push   %rbp
push   %r15
push   %r14
push   %r12
push   %rbx
mov    %esi,%r14d
mov    %rdi,%r12
xor    %edi,%edi
call   1040 <time@plt>
mov    %eax,%edi
call   1030 <srand@plt>
lea    -0x1(%r14),%r15d
cmp    $0x2,%r14d
jl     1196 <random_gen+0x66>
mov    %r15d,%ebp
xor    %ebx,%ebx
nopl   0x0(%rax,%rax,1)
xor    %eax,%eax
call   1050 <rand@plt>
cltq
imul   $0x4ec4ec4f,%rax,%rcx
mov    %rcx,%rdx
shr    $0x3f,%rdx
sar    $0x23,%rcx
add    %edx,%ecx
lea    (%rcx,%rcx,4),%edx
lea    (%rdx,%rdx,4),%edx
add    %ecx,%edx
sub    %edx,%eax
add    $0x61,%al
mov    %al,(%r12,%rbx,1)
add    $0x1,%rbx
cmp    %rbx,%rbp
jne    1160 <random_gen+0x30>
movslq %r15d,%rax
movb   $0x0,(%r12,%rax,1)
xor    %eax,%eax
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
define i32 @random_gen(i8* %0, i32 %1) {
%3 = alloca i8*
%4 = alloca i32
%5 = alloca i32
%6 = alloca i32
store i8* %0, i8** %3
store i32 %1, i32* %4
%7 = call i32 @time(i32* null)
%8 = call i32 @srand(i32 %7)
store i32 0, i32* %5
br label %9
9: ; preds = %24, %2
%10 = load i32, i32* %5
%11 = load i32, i32* %4
%12 = sub nsw i32 %11, 1
%13 = icmp slt i32 %10, %12
br i1 %13, label %14, label %27
14: ; preds = %9
%15 = call i32 (...) @rand()
%16 = srem i32 %15, 26
%17 = add nsw i32 %16, 97
store i32 %17, i32* %6
%18 = load i32, i32* %6
%19 = trunc i32 %18 to i8
%20 = load i8*, i8** %3
%21 = load i32, i32* %5
%22 = sext i32 %21 to i64
%23 = getelementptr inbounds i8, i8* %20, i64 %22
store i8 %19, i8* %23
br label %24
24: ; preds = %14
%25 = load i32, i32* %5
%26 = add nsw i32 %25, 1
store i32 %26, i32* %5
br label %9
27: ; preds = %9
%28 = load i8*, i8** %3
%29 = load i32, i32* %4
%30 = sub nsw i32 %29, 1
%31 = sext i32 %30 to i64
%32 = getelementptr inbounds i8, i8* %28, i64 %31
store i8 0, i8* %32
ret i32 0
}

LLVM IR (-O2):
define i32 @random_gen(i8* nocapture writeonly %0, i32 %1) {
%3 = tail call i32 @time(i32* null)
%4 = tail call i32 @srand(i32 %3)
%5 = add i32 %1, -1
%6 = icmp sgt i32 %1, 1
br i1 %6, label %7, label %18
7: ; preds = %2
%8 = zext i32 %5 to i64
br label %9
9: ; preds = %7, %9
%10 = phi i64 [ 0, %7 ], [ %16, %9 ]
%11 = tail call i32 (...) @rand()
%12 = srem i32 %11, 26
%13 = trunc i32 %12 to i8
%14 = add nsw i8 %13, 97
%15 = getelementptr inbounds i8, i8* %0, i64 %10
store i8 %14, i8* %15
%16 = add nuw nsw i64 %10, 1
%17 = icmp eq i64 %16, %8
br i1 %17, label %18, label %9
18: ; preds = %9, %2
%19 = sext i32 %5 to i64
%20 = getelementptr inbounds i8, i8* %0, i64 %19
store i8 0, i8* %20
ret i32 0
}