int main() {
  _Bool b;
  b = isalpha(65);
  if (b != 1)
    return 1;
  if (1 / atoi("1") != 1)
    return 14;
  b = isalpha(52);
  if (b != 0)
    return 2;
  char c1 = 50, c2 = 5;
  if (div(c1, c2) != 10)
    return 3;
  char str1[6], str2[6];
  strcpy(str1, "hello");
  strcpy(str2, "hello");
  if (strcmp(str1, str2))
    return 4;
  void *vp;
  if (strcmp((vp = str1), str2))
    return 13;
  str2[3] = 102;
  if (strcmp(str1, str2) != 6)
    return 5;
  strcpy(str2, "hey");
  char *out = strncpy(str1, str2, 3);
  if (strcmp(str1, "heylo"))
    return 6;
  int (*f2)(int) = isalpha;
  if (f2(5))
    return 12;
  signal(0, isalpha);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
movl   $0x0,-0x4(%rbp)
mov    $0x41,%edi
call   1090 <isalpha@plt>
cmp    $0x0,%eax
setne  %al
and    $0x1,%al
mov    %al,-0x5(%rbp)
mov    -0x5(%rbp),%al
and    $0x1,%al
movzbl %al,%eax
cmp    $0x1,%eax
je     11a1 <main+0x41>
movl   $0x1,-0x4(%rbp)
jmp    1344 <main+0x1e4>
lea    0xe58(%rip),%rdi
mov    $0x0,%al
call   1080 <atoi@plt>
mov    %eax,%ecx
mov    $0x1,%eax
cltd
idiv   %ecx
cmp    $0x1,%eax
je     11ce <main+0x6e>
movl   $0xe,-0x4(%rbp)
jmp    1344 <main+0x1e4>
mov    $0x34,%edi
call   1090 <isalpha@plt>
cmp    $0x0,%eax
setne  %al
and    $0x1,%al
mov    %al,-0x5(%rbp)
mov    -0x5(%rbp),%al
and    $0x1,%al
movzbl %al,%eax
cmp    $0x0,%eax
je     1200 <main+0xa0>
movl   $0x2,-0x4(%rbp)
jmp    1344 <main+0x1e4>
movb   $0x32,-0x6(%rbp)
movb   $0x5,-0x7(%rbp)
movsbl -0x6(%rbp),%edi
movsbl -0x7(%rbp),%esi
mov    $0x0,%al
call   1070 <div@plt>
cmp    $0xa,%eax
je     122c <main+0xcc>
movl   $0x3,-0x4(%rbp)
jmp    1344 <main+0x1e4>
lea    -0xd(%rbp),%rdi
lea    0xdcb(%rip),%rsi
call   1040 <strcpy@plt>
lea    -0x13(%rbp),%rdi
lea    0xdbb(%rip),%rsi
call   1040 <strcpy@plt>
lea    -0xd(%rbp),%rdi
lea    -0x13(%rbp),%rsi
call   1050 <strcmp@plt>
cmp    $0x0,%eax
je     126e <main+0x10e>
movl   $0x4,-0x4(%rbp)
jmp    1344 <main+0x1e4>
lea    -0xd(%rbp),%rdi
mov    %rdi,-0x20(%rbp)
lea    -0x13(%rbp),%rsi
call   1050 <strcmp@plt>
cmp    $0x0,%eax
je     1294 <main+0x134>
movl   $0xd,-0x4(%rbp)
jmp    1344 <main+0x1e4>
movb   $0x66,-0x10(%rbp)
lea    -0xd(%rbp),%rdi
lea    -0x13(%rbp),%rsi
call   1050 <strcmp@plt>
cmp    $0x6,%eax
je     12ba <main+0x15a>
movl   $0x5,-0x4(%rbp)
jmp    1344 <main+0x1e4>
lea    -0x13(%rbp),%rdi
lea    0xd43(%rip),%rsi
call   1040 <strcpy@plt>
lea    -0xd(%rbp),%rdi
lea    -0x13(%rbp),%rsi
mov    $0x3,%edx
call   1030 <strncpy@plt>
mov    %rax,-0x28(%rbp)
lea    -0xd(%rbp),%rdi
lea    0xd21(%rip),%rsi
call   1050 <strcmp@plt>
cmp    $0x0,%eax
je     1305 <main+0x1a5>
movl   $0x6,-0x4(%rbp)
jmp    1344 <main+0x1e4>
mov    0x2cdc(%rip),%rax
mov    %rax,-0x30(%rbp)
mov    $0x5,%edi
call   *-0x30(%rbp)
cmp    $0x0,%eax
je     132d <main+0x1cd>
movl   $0xc,-0x4(%rbp)
jmp    1344 <main+0x1e4>
xor    %edi,%edi
mov    0x2cb2(%rip),%rsi
mov    $0x0,%al
call   1060 <signal@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
sub    $0x10,%rsp
mov    $0x41,%edi
call   1080 <isalpha@plt>
test   %eax,%eax
je     1262 <main+0x112>
lea    0xe92(%rip),%rdi
xor    %eax,%eax
call   1070 <atoi@plt>
mov    $0xe,%ebx
cmp    $0x1,%eax
jne    1267 <main+0x117>
mov    $0x34,%edi
call   1080 <isalpha@plt>
mov    $0x2,%ebx
test   %eax,%eax
jne    1267 <main+0x117>
mov    $0x32,%edi
mov    $0x5,%esi
xor    %eax,%eax
call   1060 <div@plt>
mov    $0x3,%ebx
cmp    $0xa,%eax
jne    1267 <main+0x117>
movl   $0x6c6c6568,0x8(%rsp)
6c
movw   $0x6f,0xc(%rsp)
movl   $0x6c6c6568,(%rsp)
movw   $0x6f,0x4(%rsp)
lea    0x8(%rsp),%rdi
mov    %rsp,%rsi
call   1040 <strcmp@plt>
mov    $0x4,%ebx
test   %eax,%eax
jne    1267 <main+0x117>
movb   $0x66,0x3(%rsp)
lea    0x8(%rsp),%rdi
mov    %rsp,%rsi
call   1040 <strcmp@plt>
mov    $0x5,%ebx
cmp    $0x6,%eax
jne    1267 <main+0x117>
movl   $0x796568,(%rsp)
lea    0x8(%rsp),%rdi
mov    %rsp,%rsi
mov    $0x3,%edx
call   1030 <strncpy@plt>
mov    $0x6c796568,%eax
xor    0x8(%rsp),%eax
movzwl 0xc(%rsp),%ecx
xor    $0x6f,%ecx
or     %eax,%ecx
mov    $0x6,%ebx
jne    1267 <main+0x117>
mov    $0x5,%edi
call   1080 <isalpha@plt>
mov    $0xc,%ebx
test   %eax,%eax
jne    1267 <main+0x117>
mov    0x2d93(%rip),%rsi
xor    %ebx,%ebx
xor    %edi,%edi
xor    %eax,%eax
call   1050 <signal@plt>
jmp    1267 <main+0x117>
mov    $0x1,%ebx
mov    %ebx,%eax
add    $0x10,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [2 x i8] c"1\00"
@.str.1 = [6 x i8] c"hello\00"
@.str.2 = [4 x i8] c"hey\00"
@.str.3 = [6 x i8] c"heylo\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i8
%3 = alloca i8
%4 = alloca i8
%5 = alloca [6 x i8]
%6 = alloca [6 x i8]
%7 = alloca i8*
%8 = alloca i8*
%9 = alloca i32 (i32)*
store i32 0, i32* %1
%10 = call i32 @isalpha(i32 65)
%11 = icmp ne i32 %10, 0
%12 = zext i1 %11 to i8
store i8 %12, i8* %2
%13 = load i8, i8* %2
%14 = trunc i8 %13 to i1
%15 = zext i1 %14 to i32
%16 = icmp ne i32 %15, 1
br i1 %16, label %17, label %18
17: ; preds = %0
store i32 1, i32* %1
br label %80
18: ; preds = %0
%19 = call i32 (i8*, ...) bitcast (i32 (...)* @atoi to i32 (i8*, ...)*)(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
%20 = sdiv i32 1, %19
%21 = icmp ne i32 %20, 1
br i1 %21, label %22, label %23
22: ; preds = %18
store i32 14, i32* %1
br label %80
23: ; preds = %18
%24 = call i32 @isalpha(i32 52)
%25 = icmp ne i32 %24, 0
%26 = zext i1 %25 to i8
store i8 %26, i8* %2
%27 = load i8, i8* %2
%28 = trunc i8 %27 to i1
%29 = zext i1 %28 to i32
%30 = icmp ne i32 %29, 0
br i1 %30, label %31, label %32
31: ; preds = %23
store i32 2, i32* %1
br label %80
32: ; preds = %23
store i8 50, i8* %3
store i8 5, i8* %4
%33 = load i8, i8* %3
%34 = sext i8 %33 to i32
%35 = load i8, i8* %4
%36 = sext i8 %35 to i32
%37 = call i32 (i32, i32, ...) bitcast (i32 (...)* @div to i32 (i32, i32, ...)*)(i32 %34, i32 %36)
%38 = icmp ne i32 %37, 10
br i1 %38, label %39, label %40
39: ; preds = %32
store i32 3, i32* %1
br label %80
40: ; preds = %32
%41 = getelementptr inbounds [6 x i8], [6 x i8]* %5, i64 0, i64 0
%42 = call i8* @strcpy(i8* %41, i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0))
%43 = getelementptr inbounds [6 x i8], [6 x i8]* %6, i64 0, i64 0
%44 = call i8* @strcpy(i8* %43, i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0))
%45 = getelementptr inbounds [6 x i8], [6 x i8]* %5, i64 0, i64 0
%46 = getelementptr inbounds [6 x i8], [6 x i8]* %6, i64 0, i64 0
%47 = call i32 @strcmp(i8* %45, i8* %46)
%48 = icmp ne i32 %47, 0
br i1 %48, label %49, label %50
49: ; preds = %40
store i32 4, i32* %1
br label %80
50: ; preds = %40
%51 = getelementptr inbounds [6 x i8], [6 x i8]* %5, i64 0, i64 0
store i8* %51, i8** %7
%52 = getelementptr inbounds [6 x i8], [6 x i8]* %6, i64 0, i64 0
%53 = call i32 @strcmp(i8* %51, i8* %52)
%54 = icmp ne i32 %53, 0
br i1 %54, label %55, label %56
55: ; preds = %50
store i32 13, i32* %1
br label %80
56: ; preds = %50
%57 = getelementptr inbounds [6 x i8], [6 x i8]* %6, i64 0, i64 3
store i8 102, i8* %57
%58 = getelementptr inbounds [6 x i8], [6 x i8]* %5, i64 0, i64 0
%59 = getelementptr inbounds [6 x i8], [6 x i8]* %6, i64 0, i64 0
%60 = call i32 @strcmp(i8* %58, i8* %59)
%61 = icmp ne i32 %60, 6
br i1 %61, label %62, label %63
62: ; preds = %56
store i32 5, i32* %1
br label %80
63: ; preds = %56
%64 = getelementptr inbounds [6 x i8], [6 x i8]* %6, i64 0, i64 0
%65 = call i8* @strcpy(i8* %64, i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0))
%66 = getelementptr inbounds [6 x i8], [6 x i8]* %5, i64 0, i64 0
%67 = getelementptr inbounds [6 x i8], [6 x i8]* %6, i64 0, i64 0
%68 = call i8* @strncpy(i8* %66, i8* %67, i64 3)
store i8* %68, i8** %8
%69 = getelementptr inbounds [6 x i8], [6 x i8]* %5, i64 0, i64 0
%70 = call i32 @strcmp(i8* %69, i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.3, i64 0, i64 0))
%71 = icmp ne i32 %70, 0
br i1 %71, label %72, label %73
72: ; preds = %63
store i32 6, i32* %1
br label %80
73: ; preds = %63
store i32 (i32)* @isalpha, i32 (i32)** %9
%74 = load i32 (i32)*, i32 (i32)** %9
%75 = call i32 %74(i32 5)
%76 = icmp ne i32 %75, 0
br i1 %76, label %77, label %78
77: ; preds = %73
store i32 12, i32* %1
br label %80
78: ; preds = %73
%79 = call i32 (i32, i32 (i32)*, ...) bitcast (i32 (...)* @signal to i32 (i32, i32 (i32)*, ...)*)(i32 0, i32 (i32)* @isalpha)
store i32 0, i32* %1
br label %80
80: ; preds = %78, %77, %72, %62, %55, %49, %39, %31, %22, %17
%81 = load i32, i32* %1
ret i32 %81
}

LLVM IR (-O2):
@.str = [2 x i8] c"1\00"
@.str.1 = [6 x i8] c"hello\00"
@.str.3 = [6 x i8] c"heylo\00"
define i32 @main() {
%1 = alloca [6 x i8]
%2 = alloca [6 x i8]
%3 = tail call i32 @isalpha(i32 65)
%4 = icmp eq i32 %3, 0
br i1 %4, label %35, label %5
5: ; preds = %0
%6 = tail call i32 (i8*, ...) bitcast (i32 (...)* @atoi to i32 (i8*, ...)*)(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
%7 = icmp eq i32 %6, 1
br i1 %7, label %8, label %35
8: ; preds = %5
%9 = tail call i32 @isalpha(i32 52)
%10 = icmp eq i32 %9, 0
br i1 %10, label %11, label %35
11: ; preds = %8
%12 = tail call i32 (i32, i32, ...) bitcast (i32 (...)* @div to i32 (i32, i32, ...)*)(i32 50, i32 5)
%13 = icmp eq i32 %12, 10
br i1 %13, label %14, label %35
14: ; preds = %11
%15 = getelementptr inbounds [6 x i8], [6 x i8]* %1, i64 0, i64 0
%16 = getelementptr inbounds [6 x i8], [6 x i8]* %2, i64 0, i64 0
%17 = call i32 @strcmp(i8* %15, i8* %16)
%18 = icmp eq i32 %17, 0
br i1 %18, label %19, label %33
19: ; preds = %14
%20 = getelementptr inbounds [6 x i8], [6 x i8]* %2, i64 0, i64 3
store i8 102, i8* %20
%21 = call i32 @strcmp(i8* %15, i8* %16)
%22 = icmp eq i32 %21, 6
br i1 %22, label %23, label %33
23: ; preds = %19
%24 = bitcast [6 x i8]* %2 to i32*
store i32 7955816, i32* %24
%25 = call i8* @strncpy(i8* %15, i8* %16, i64 3)
%26 = call i32 @bcmp(i8* dereferenceable(6) %15, i8* dereferenceable(6) getelementptr inbounds ([6 x i8], [6 x i8]* @.str.3, i64 0, i64 0), i64 6)
%27 = icmp eq i32 %26, 0
br i1 %27, label %28, label %33
28: ; preds = %23
%29 = call i32 @isalpha(i32 5)
%30 = icmp eq i32 %29, 0
br i1 %30, label %31, label %33
31: ; preds = %28
%32 = call i32 (i32, i32 (i32)*, ...) bitcast (i32 (...)* @signal to i32 (i32, i32 (i32)*, ...)*)(i32 0, i32 (i32)* @isalpha)
br label %33
33: ; preds = %19, %31, %28, %23, %14
%34 = phi i32 [ 4, %14 ], [ 5, %19 ], [ 6, %23 ], [ 0, %31 ], [ 12, %28 ]
br label %35
35: ; preds = %33, %11, %8, %5, %0
%36 = phi i32 [ 1, %0 ], [ 14, %5 ], [ 2, %8 ], [ %34, %33 ], [ 3, %11 ]
ret i32 %36
}