#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 *, float *);
main() {
  float fah;
  float cels;
  printf("Please insert temperature in degrees fahrenheit:\n");
  scanf("%f", &fah);
  cels = (fah - 32.0) * (5.0 / 9.0);
  printf("In celsius that's: %.1f'C\n", cels);
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
lea    0xee1(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xf05(%rip),%rdi
lea    -0x4(%rbp),%rsi
call   1040 <scanf@plt>
movss  -0x4(%rbp),%xmm0
cvtss2sd %xmm0,%xmm0
movsd  0xeb1(%rip),%xmm1
subsd  %xmm1,%xmm0
movsd  0xe9d(%rip),%xmm1
mulsd  %xmm1,%xmm0
cvtsd2ss %xmm0,%xmm0
movss  %xmm0,-0x8(%rbp)
movss  -0x8(%rbp),%xmm0
cvtss2sd %xmm0,%xmm0
lea    0xec5(%rip),%rdi
mov    $0x1,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xef6(%rip),%rdi
call   1030 <puts@plt>
lea    0xecc(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1050 <scanf@plt>
movss  0x4(%rsp),%xmm0
cvtss2sd %xmm0,%xmm0
addsd  0xea0(%rip),%xmm0
mulsd  0xea0(%rip),%xmm0
cvtsd2ss %xmm0,%xmm0
cvtss2sd %xmm0,%xmm0
lea    0xe9c(%rip),%rdi
mov    $0x1,%al
call   1040 <printf@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [50 x i8] c"Please insert temperature in degrees fahrenheit:\0A\00"
@.str.1 = [3 x i8] c"%f\00"
@.str.2 = [27 x i8] c"In celsius that's: %.1f'C\0A\00"
define i32 @main() {
%1 = alloca float
%2 = alloca float
%3 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([50 x i8], [50 x i8]* @.str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), float* %1)
%5 = load float, float* %1
%6 = fpext float %5 to double
%7 = fsub double %6, 3.200000e+01
%8 = fmul double %7, 0x3FE1C71C71C71C72
%9 = fptrunc double %8 to float
store float %9, float* %2
%10 = load float, float* %2
%11 = fpext float %10 to double
%12 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([27 x i8], [27 x i8]* @.str.2, i64 0, i64 0), double %11)
ret i32 0
}

LLVM IR (-O2):
@.str.1 = [3 x i8] c"%f\00"
@.str.2 = [27 x i8] c"In celsius that's: %.1f'C\0A\00"
@str = [49 x i8] c"Please insert temperature in degrees fahrenheit:\00"
define i32 @main() {
%1 = alloca float
%2 = bitcast float* %1 to i8*
%3 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([49 x i8], [49 x i8]* @str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), float* %1)
%5 = load float, float* %1
%6 = fpext float %5 to double
%7 = fadd double %6, -3.200000e+01
%8 = fmul double %7, 0x3FE1C71C71C71C72
%9 = fptrunc double %8 to float
%10 = fpext float %9 to double
%11 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([27 x i8], [27 x i8]* @.str.2, i64 0, i64 0), double %10)
ret i32 0
}