#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 *);
int main(void) {
  char fname[40];
  char lname[40];
  printf("What's your first name?\n");
  scanf("%s", fname);
  printf("What's your last name?\n");
  scanf("%s", lname);
  printf("Your name in format last, first:\n");
  printf("%s, %s\n", lname, fname);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x60,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeca(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    -0x30(%rbp),%rsi
lea    0xed1(%rip),%rdi
call   1040 <scanf@plt>
lea    0xec8(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    -0x60(%rbp),%rsi
lea    0xeb3(%rip),%rdi
call   1040 <scanf@plt>
lea    0xec2(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    -0x60(%rbp),%rsi
lea    -0x30(%rbp),%rdx
lea    0xece(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x60,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %rbx
sub    $0x60,%rsp
lea    0xecb(%rip),%rdi
call   1030 <puts@plt>
lea    0xeb4(%rip),%rbx
lea    0x30(%rsp),%r14
mov    %rbx,%rdi
mov    %r14,%rsi
call   1050 <scanf@plt>
lea    0xec0(%rip),%rdi
call   1030 <puts@plt>
mov    %rsp,%r15
mov    %rbx,%rdi
mov    %r15,%rsi
call   1050 <scanf@plt>
lea    0xebd(%rip),%rdi
call   1030 <puts@plt>
lea    0xe7a(%rip),%rdi
mov    %r15,%rsi
mov    %r14,%rdx
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
add    $0x60,%rsp
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [25 x i8] c"What's your first name?\0A\00"
@.str.1 = [3 x i8] c"%s\00"
@.str.2 = [24 x i8] c"What's your last name?\0A\00"
@.str.3 = [34 x i8] c"Your name in format last, first:\0A\00"
@.str.4 = [8 x i8] c"%s, %s\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca [40 x i8]
%3 = alloca [40 x i8]
store i32 0, i32* %1
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([25 x i8], [25 x i8]* @.str, i64 0, i64 0))
%5 = getelementptr inbounds [40 x i8], [40 x i8]* %2, i64 0, i64 0
%6 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %5)
%7 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.2, i64 0, i64 0))
%8 = getelementptr inbounds [40 x i8], [40 x i8]* %3, i64 0, i64 0
%9 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %8)
%10 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([34 x i8], [34 x i8]* @.str.3, i64 0, i64 0))
%11 = getelementptr inbounds [40 x i8], [40 x i8]* %3, i64 0, i64 0
%12 = getelementptr inbounds [40 x i8], [40 x i8]* %2, i64 0, i64 0
%13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.4, i64 0, i64 0), i8* %11, i8* %12)
ret i32 0
}

LLVM IR (-O2):
@.str.1 = [3 x i8] c"%s\00"
@.str.4 = [8 x i8] c"%s, %s\0A\00"
@str = [24 x i8] c"What's your first name?\00"
@str.5 = [23 x i8] c"What's your last name?\00"
@str.6 = [33 x i8] c"Your name in format last, first:\00"
define i32 @main() {
%1 = alloca [40 x i8]
%2 = alloca [40 x i8]
%3 = getelementptr inbounds [40 x i8], [40 x i8]* %1, i64 0, i64 0
%4 = getelementptr inbounds [40 x i8], [40 x i8]* %2, i64 0, i64 0
%5 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([24 x i8], [24 x i8]* @str, i64 0, i64 0))
%6 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %3)
%7 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([23 x i8], [23 x i8]* @str.5, i64 0, i64 0))
%8 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %4)
%9 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([33 x i8], [33 x i8]* @str.6, i64 0, i64 0))
%10 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([8 x i8], [8 x i8]* @.str.4, i64 0, i64 0), i8* %4, i8* %3)
ret i32 0
}