#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*/ stack_var_adrs_min_update();
void fft_real_n2(double din_re[], int d, double out_re[], double out_im[]) {
  const double x0 = din_re[0 * d];
  const double x1 = din_re[1 * d];
  out_re[0] = x0 + x1;
  out_im[0] = 0.0;
  out_re[1] = x0 - x1;
  out_im[1] = 0.0;
  stack_var_adrs_min_update();
}


x86 assembly (clang, -O0):
<fft_real_n2>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
mov    %rdx,-0x18(%rbp)
mov    %rcx,-0x20(%rbp)
mov    -0x8(%rbp),%rax
imul   $0x0,-0xc(%rbp),%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x28(%rbp)
mov    -0x8(%rbp),%rax
mov    -0xc(%rbp),%ecx
shl    $0x0,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  -0x28(%rbp),%xmm0
addsd  -0x30(%rbp),%xmm0
mov    -0x18(%rbp),%rax
movsd  %xmm0,(%rax)
mov    -0x20(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,(%rax)
movsd  -0x28(%rbp),%xmm0
subsd  -0x30(%rbp),%xmm0
mov    -0x18(%rbp),%rax
movsd  %xmm0,0x8(%rax)
mov    -0x20(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x8(%rax)
mov    $0x0,%al
call   1030 <stack_var_adrs_min_update@plt>
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<fft_real_n2>:
movsd  (%rdi),%xmm0
movslq %esi,%rax
movsd  (%rdi,%rax,8),%xmm1
movapd %xmm0,%xmm2
addsd  %xmm1,%xmm2
movsd  %xmm2,(%rdx)
movq   $0x0,(%rcx)
subsd  %xmm1,%xmm0
movsd  %xmm0,0x8(%rdx)
movq   $0x0,0x8(%rcx)
xor    %eax,%eax
jmp    1030 <stack_var_adrs_min_update@plt>

LLVM IR (-O0):
define void @fft_real_n2(double* %0, i32 %1, double* %2, double* %3) {
%5 = alloca double*
%6 = alloca i32
%7 = alloca double*
%8 = alloca double*
%9 = alloca double
%10 = alloca double
store double* %0, double** %5
store i32 %1, i32* %6
store double* %2, double** %7
store double* %3, double** %8
%11 = load double*, double** %5
%12 = load i32, i32* %6
%13 = mul nsw i32 0, %12
%14 = sext i32 %13 to i64
%15 = getelementptr inbounds double, double* %11, i64 %14
%16 = load double, double* %15
store double %16, double* %9
%17 = load double*, double** %5
%18 = load i32, i32* %6
%19 = mul nsw i32 1, %18
%20 = sext i32 %19 to i64
%21 = getelementptr inbounds double, double* %17, i64 %20
%22 = load double, double* %21
store double %22, double* %10
%23 = load double, double* %9
%24 = load double, double* %10
%25 = fadd double %23, %24
%26 = load double*, double** %7
%27 = getelementptr inbounds double, double* %26, i64 0
store double %25, double* %27
%28 = load double*, double** %8
%29 = getelementptr inbounds double, double* %28, i64 0
store double 0.000000e+00, double* %29
%30 = load double, double* %9
%31 = load double, double* %10
%32 = fsub double %30, %31
%33 = load double*, double** %7
%34 = getelementptr inbounds double, double* %33, i64 1
store double %32, double* %34
%35 = load double*, double** %8
%36 = getelementptr inbounds double, double* %35, i64 1
store double 0.000000e+00, double* %36
%37 = call i32 (...) @stack_var_adrs_min_update()
ret void
}

LLVM IR (-O2):
define void @fft_real_n2(double* nocapture %0, i32 %1, double* nocapture writeonly %2, double* nocapture writeonly %3) {
%5 = load double, double* %0
%6 = sext i32 %1 to i64
%7 = getelementptr inbounds double, double* %0, i64 %6
%8 = load double, double* %7
%9 = fadd double %5, %8
store double %9, double* %2
store double 0.000000e+00, double* %3
%10 = fsub double %5, %8
%11 = getelementptr inbounds double, double* %2, i64 1
store double %10, double* %11
%12 = getelementptr inbounds double, double* %3, i64 1
store double 0.000000e+00, double* %12
%13 = tail call i32 (...) @stack_var_adrs_min_update()
ret void
}