#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 /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ scanf(char *, char *, char *);
int main(int argc, char const *argv[]) {
  char first_name[20];
  char last_name[20];
  printf("Enter first and last name: ");
  scanf("%19s %19s", first_name, last_name);
  printf("First: %s Last:%s\n", first_name, last_name);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x50,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
lea    0xec3(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    -0x30(%rbp),%rsi
lea    -0x50(%rbp),%rdx
lea    0xec9(%rip),%rdi
call   1040 <scanf@plt>
lea    -0x30(%rbp),%rsi
lea    -0x50(%rbp),%rdx
lea    0xebf(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x50,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r14
push   %rbx
sub    $0x38,%rsp
lea    0xed2(%rip),%rdi
xor    %eax,%eax
call   1030 <printf@plt>
lea    0xee0(%rip),%rdi
lea    0x20(%rsp),%rbx
mov    %rsp,%r14
mov    %rbx,%rsi
mov    %r14,%rdx
call   1040 <scanf@plt>
lea    0xed0(%rip),%rdi
mov    %rbx,%rsi
mov    %r14,%rdx
xor    %eax,%eax
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x38,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
@.str = [28 x i8] c"Enter first and last name: \00"
@.str.1 = [10 x i8] c"%19s %19s\00"
@.str.2 = [19 x i8] c"First: %s Last:%s\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca [20 x i8]
%7 = alloca [20 x i8]
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%8 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str, i64 0, i64 0))
%9 = getelementptr inbounds [20 x i8], [20 x i8]* %6, i64 0, i64 0
%10 = getelementptr inbounds [20 x i8], [20 x i8]* %7, i64 0, i64 0
%11 = call i32 @scanf(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i8* %9, i8* %10)
%12 = getelementptr inbounds [20 x i8], [20 x i8]* %6, i64 0, i64 0
%13 = getelementptr inbounds [20 x i8], [20 x i8]* %7, i64 0, i64 0
%14 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.2, i64 0, i64 0), i8* %12, i8* %13)
ret i32 0
}

LLVM IR (-O2):
@.str = [28 x i8] c"Enter first and last name: \00"
@.str.1 = [10 x i8] c"%19s %19s\00"
@.str.2 = [19 x i8] c"First: %s Last:%s\0A\00"
define i32 @main(i32 %0, i8** nocapture readnone %1) {
%3 = alloca [20 x i8]
%4 = alloca [20 x i8]
%5 = getelementptr inbounds [20 x i8], [20 x i8]* %3, i64 0, i64 0
%6 = getelementptr inbounds [20 x i8], [20 x i8]* %4, i64 0, i64 0
%7 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([28 x i8], [28 x i8]* @.str, i64 0, i64 0))
%8 = call i32 @scanf(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i8* %5, i8* %6)
%9 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([19 x i8], [19 x i8]* @.str.2, i64 0, i64 0), i8* %5, i8* %6)
ret i32 0
}