#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 *);
int compare_char(char *str1, char *str2) {
  for (int i = 0; i < strlen(str1); i++) {
    if (str1[i] != str2[i])
      return 0;
  }
  return 1;
}


x86 assembly (clang, -O0):
<compare_char>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x10(%rbp)
mov    %rsi,-0x18(%rbp)
movl   $0x0,-0x1c(%rbp)
mov    -0x1c(%rbp),%eax
mov    %eax,-0x20(%rbp)
mov    -0x10(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x20(%rbp),%eax
cmp    %ecx,%eax
jge    1182 <compare_char+0x72>
mov    -0x10(%rbp),%rax
movslq -0x1c(%rbp),%rcx
movsbl (%rax,%rcx,1),%eax
mov    -0x18(%rbp),%rcx
movslq -0x1c(%rbp),%rdx
movsbl (%rcx,%rdx,1),%ecx
cmp    %ecx,%eax
je     116f <compare_char+0x5f>
movl   $0x0,-0x4(%rbp)
jmp    1189 <compare_char+0x79>
jmp    1174 <compare_char+0x64>
mov    -0x1c(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x1c(%rbp)
jmp    1127 <compare_char+0x17>
movl   $0x1,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<compare_char>:
push   %rbp
push   %r15
push   %r14
push   %rbx
push   %rax
mov    %rsi,%r15
mov    %rdi,%rbp
call   1030 <strlen@plt>
mov    $0x1,%r14d
test   %eax,%eax
jle    1153 <compare_char+0x43>
xor    %ebx,%ebx
xchg   %ax,%ax
movzbl 0x0(%rbp,%rbx,1),%eax
cmp    (%r15,%rbx,1),%al
jne    1150 <compare_char+0x40>
add    $0x1,%rbx
mov    %rbp,%rdi
call   1030 <strlen@plt>
cltq
cmp    %rax,%rbx
jl     1130 <compare_char+0x20>
jmp    1153 <compare_char+0x43>
xor    %r14d,%r14d
mov    %r14d,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
define i32 @compare_char(i8* %0, i8* %1) {
%3 = alloca i32
%4 = alloca i8*
%5 = alloca i8*
%6 = alloca i32
store i8* %0, i8** %4
store i8* %1, i8** %5
store i32 0, i32* %6
br label %7
7: ; preds = %28, %2
%8 = load i32, i32* %6
%9 = load i8*, i8** %4
%10 = call i32 @strlen(i8* %9)
%11 = icmp slt i32 %8, %10
br i1 %11, label %12, label %31
12: ; preds = %7
%13 = load i8*, i8** %4
%14 = load i32, i32* %6
%15 = sext i32 %14 to i64
%16 = getelementptr inbounds i8, i8* %13, i64 %15
%17 = load i8, i8* %16
%18 = sext i8 %17 to i32
%19 = load i8*, i8** %5
%20 = load i32, i32* %6
%21 = sext i32 %20 to i64
%22 = getelementptr inbounds i8, i8* %19, i64 %21
%23 = load i8, i8* %22
%24 = sext i8 %23 to i32
%25 = icmp ne i32 %18, %24
br i1 %25, label %26, label %27
26: ; preds = %12
store i32 0, i32* %3
br label %32
27: ; preds = %12
br label %28
28: ; preds = %27
%29 = load i32, i32* %6
%30 = add nsw i32 %29, 1
store i32 %30, i32* %6
br label %7
31: ; preds = %7
store i32 1, i32* %3
br label %32
32: ; preds = %31, %26
%33 = load i32, i32* %3
ret i32 %33
}

LLVM IR (-O2):
define i32 @compare_char(i8* %0, i8* nocapture %1) {
%3 = tail call i32 @strlen(i8* %0)
%4 = icmp sgt i32 %3, 0
br i1 %4, label %9, label %17
5: ; preds = %9
%6 = tail call i32 @strlen(i8* %0)
%7 = sext i32 %6 to i64
%8 = icmp slt i64 %16, %7
br i1 %8, label %9, label %17
9: ; preds = %2, %5
%10 = phi i64 [ %16, %5 ], [ 0, %2 ]
%11 = getelementptr inbounds i8, i8* %0, i64 %10
%12 = load i8, i8* %11
%13 = getelementptr inbounds i8, i8* %1, i64 %10
%14 = load i8, i8* %13
%15 = icmp eq i8 %12, %14
%16 = add nuw nsw i64 %10, 1
br i1 %15, label %5, label %17
17: ; preds = %5, %9, %2
%18 = phi i32 [ 1, %2 ], [ 0, %9 ], [ 1, %5 ]
ret i32 %18
}