#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 strlen(char *);
void decrypt(char arr[], int key) {
  int i;
  for (i = 0; i < strlen(arr); i++) {
    arr[i] = arr[i] - key % 26;
  }
}


x86 assembly (clang, -O0):
<decrypt>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
mov    %eax,-0x14(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x14(%rbp),%eax
cmp    %ecx,%eax
jge    117c <decrypt+0x6c>
mov    -0x8(%rbp),%rax
movslq -0x10(%rbp),%rcx
movsbl (%rax,%rcx,1),%eax
mov    %eax,-0x18(%rbp)
mov    -0xc(%rbp),%eax
mov    $0x1a,%ecx
cltd
idiv   %ecx
mov    -0x18(%rbp),%eax
sub    %edx,%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    1126 <decrypt+0x16>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<decrypt>:
push   %rbp
push   %r14
push   %rbx
mov    %esi,%ebp
mov    %rdi,%rbx
call   1030 <strlen@plt>
test   %eax,%eax
jle    1167 <decrypt+0x57>
movslq %ebp,%r14
imul   $0x4ec4ec4f,%r14,%rax
mov    %rax,%rcx
shr    $0x3f,%rcx
shr    $0x23,%rax
add    %ecx,%eax
lea    (%rax,%rax,4),%ecx
lea    (%rcx,%rcx,4),%ecx
add    %eax,%ecx
sub    %ecx,%r14d
xor    %ebp,%ebp
cs nopw 0x0(%rax,%rax,1)
sub    %r14b,(%rbx,%rbp,1)
add    $0x1,%rbp
mov    %rbx,%rdi
call   1030 <strlen@plt>
cltq
cmp    %rax,%rbp
jl     1150 <decrypt+0x40>
pop    %rbx
pop    %r14
pop    %rbp
ret

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

LLVM IR (-O2):
define void @decrypt(i8* %0, i32 %1) {
%3 = tail call i32 @strlen(i8* %0)
%4 = icmp sgt i32 %3, 0
br i1 %4, label %5, label %17
5: ; preds = %2
%6 = srem i32 %1, 26
%7 = trunc i32 %6 to i8
br label %8
8: ; preds = %5, %8
%9 = phi i64 [ 0, %5 ], [ %13, %8 ]
%10 = getelementptr inbounds i8, i8* %0, i64 %9
%11 = load i8, i8* %10
%12 = sub i8 %11, %7
store i8 %12, i8* %10
%13 = add nuw nsw i64 %9, 1
%14 = tail call i32 @strlen(i8* %0)
%15 = sext i32 %14 to i64
%16 = icmp slt i64 %13, %15
br i1 %16, label %8, label %17
17: ; preds = %8, %2
ret void
}