#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 atoi(char *);
int /*<<< orphan*/ printf(char *, ...);
int main(int argc, char **argv) {
  int rval = 0;
  if (argc != 2) {
    printf("usage: %s return_status_number(0~255)\n", argv[0]);
    printf("Then observe return status in $?\n");
    printf("ex: $ %s 121; echo $?\n", argv[0]);
    return 2;
  }
  rval = atoi(argv[1]);
  rval = rval % 255;
  return rval;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movl   $0x0,-0x14(%rbp)
cmpl   $0x2,-0x8(%rbp)
je     118b <main+0x6b>
mov    -0x10(%rbp),%rax
mov    (%rax),%rsi
lea    0xeab(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xec4(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x10(%rbp),%rax
mov    (%rax),%rsi
lea    0xed1(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x2,-0x4(%rbp)
jmp    11af <main+0x8f>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1040 <atoi@plt>
mov    %eax,-0x14(%rbp)
mov    -0x14(%rbp),%eax
mov    $0xff,%ecx
cltd
idiv   %ecx
mov    %edx,-0x14(%rbp)
mov    -0x14(%rbp),%eax
mov    %eax,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
mov    %rsi,%rbx
cmp    $0x2,%edi
jne    1167 <main+0x37>
mov    0x8(%rbx),%rdi
call   1050 <atoi@plt>
movslq %eax,%rcx
imul   $0xffffffff80808081,%rcx,%rax
shr    $0x20,%rax
add    %ecx,%eax
mov    %eax,%edx
shr    $0x1f,%edx
sar    $0x7,%eax
add    %edx,%eax
mov    %eax,%edx
shl    $0x8,%edx
sub    %edx,%eax
add    %ecx,%eax
pop    %rbx
ret
mov    (%rbx),%rsi
lea    0xe8f(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xebf(%rip),%rdi
call   1030 <puts@plt>
mov    (%rbx),%rsi
lea    0xe99(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    $0x2,%eax
pop    %rbx
ret

LLVM IR (-O0):
@.str = [39 x i8] c"usage: %s return_status_number(0~255)\0A\00"
@.str.1 = [34 x i8] c"Then observe return status in $?\0A\00"
@.str.2 = [23 x i8] c"ex: $ %s 121; echo $?\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i32
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
store i32 0, i32* %6
%7 = load i32, i32* %4
%8 = icmp ne i32 %7, 2
br i1 %8, label %9, label %19
9: ; preds = %2
%10 = load i8**, i8*** %5
%11 = getelementptr inbounds i8*, i8** %10, i64 0
%12 = load i8*, i8** %11
%13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([39 x i8], [39 x i8]* @.str, i64 0, i64 0), i8* %12)
%14 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([34 x i8], [34 x i8]* @.str.1, i64 0, i64 0))
%15 = load i8**, i8*** %5
%16 = getelementptr inbounds i8*, i8** %15, i64 0
%17 = load i8*, i8** %16
%18 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.2, i64 0, i64 0), i8* %17)
store i32 2, i32* %3
br label %27
19: ; preds = %2
%20 = load i8**, i8*** %5
%21 = getelementptr inbounds i8*, i8** %20, i64 1
%22 = load i8*, i8** %21
%23 = call i32 @atoi(i8* %22)
store i32 %23, i32* %6
%24 = load i32, i32* %6
%25 = srem i32 %24, 255
store i32 %25, i32* %6
%26 = load i32, i32* %6
store i32 %26, i32* %3
br label %27
27: ; preds = %19, %9
%28 = load i32, i32* %3
ret i32 %28
}

LLVM IR (-O2):
@.str = [39 x i8] c"usage: %s return_status_number(0~255)\0A\00"
@.str.2 = [23 x i8] c"ex: $ %s 121; echo $?\0A\00"
@str = [33 x i8] c"Then observe return status in $?\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp eq i32 %0, 2
br i1 %3, label %10, label %4
4: ; preds = %2
%5 = load i8*, i8** %1
%6 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([39 x i8], [39 x i8]* @.str, i64 0, i64 0), i8* %5)
%7 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([33 x i8], [33 x i8]* @str, i64 0, i64 0))
%8 = load i8*, i8** %1
%9 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([23 x i8], [23 x i8]* @.str.2, i64 0, i64 0), i8* %8)
br label %15
10: ; preds = %2
%11 = getelementptr inbounds i8*, i8** %1, i64 1
%12 = load i8*, i8** %11
%13 = tail call i32 @atoi(i8* %12)
%14 = srem i32 %13, 255
br label %15
15: ; preds = %10, %4
%16 = phi i32 [ 2, %4 ], [ %14, %10 ]
ret i32 %16
}