void rfft8pt(float *ioptr) {
  float w0r = 1.0 / 1.414213562373095048801688724209698078569;
  float w1r = 0.9238795325112867561281831893967882868224;
  float w1i = 0.3826834323650897717284599840303988667613;
  float f0r, f0i, f1r, f1i, f2r, f2i, f3r, f3i;
  float f4r, f4i, f5r, f5i, f6r, f6i, f7r, f7i;
  float t0r, t0i, t1r, t1i;
  const float Two = 2.0;
  const float scale = 0.5;
  f0r = ioptr[0];
  f0i = ioptr[1];
  f1r = ioptr[8];
  f1i = ioptr[9];
  f2r = ioptr[4];
  f2i = ioptr[5];
  f3r = ioptr[12];
  f3i = ioptr[13];
  f4r = ioptr[2];
  f4i = ioptr[3];
  f5r = ioptr[10];
  f5i = ioptr[11];
  f6r = ioptr[6];
  f6i = ioptr[7];
  f7r = ioptr[14];
  f7i = ioptr[15];
  t0r = f0r + f1r;
  t0i = f0i + f1i;
  f1r = f0r - f1r;
  f1i = f0i - f1i;
  t1r = f2r - f3r;
  t1i = f2i - f3i;
  f2r = f2r + f3r;
  f2i = f2i + f3i;
  f0r = t0r + f2r;
  f0i = t0i + f2i;
  f2r = t0r - f2r;
  f2i = t0i - f2i;
  f3r = f1r - t1i;
  f3i = f1i + t1r;
  f1r = f1r + t1i;
  f1i = f1i - t1r;
  t0r = f4r + f5r;
  t0i = f4i + f5i;
  f5r = f4r - f5r;
  f5i = f4i - f5i;
  t1r = f6r - f7r;
  t1i = f6i - f7i;
  f6r = f6r + f7r;
  f6i = f6i + f7i;
  f4r = t0r + f6r;
  f4i = t0i + f6i;
  f6r = t0r - f6r;
  f6i = t0i - f6i;
  f7r = f5r - t1i;
  f7i = f5i + t1r;
  f5r = f5r + t1i;
  f5i = f5i - t1r;
  t0r = f0r - f4r;
  t0i = f4i - f0i;
  f0r = f0r + f4r;
  f0i = f0i + f4i;
  t1r = f2r - f6i;
  t1i = f2i + f6r;
  f2r = f2r + f6i;
  f2i = f2i - f6r;
  f4r = f1r - f5r * w0r - f5i * w0r;
  f4i = f1i + f5r * w0r - f5i * w0r;
  f1r = f1r * Two - f4r;
  f1i = f1i * Two - f4i;
  f6r = f3r + f7r * w0r - f7i * w0r;
  f6i = f3i + f7r * w0r + f7i * w0r;
  f3r = f3r * Two - f6r;
  f3i = f3i * Two - f6i;
  f5r = f0r + f0i;
  f5i = f0r - f0i;
  f0r = f2r + t1r;
  f0i = f2i - t1i;
  f7r = f2i + t1i;
  f7i = t1r - f2r;
  f2r = f0r + w0r * f7r + w0r * f7i;
  f2i = f0i - w0r * f7r + w0r * f7i;
  t1r = Two * f0r - f2r;
  t1i = f2i - Two * f0i;
  f0r = f1r + f6r;
  f0i = f1i - f6i;
  f7r = f1i + f6i;
  f7i = f6r - f1r;
  f1r = f0r + w1r * f7r + w1i * f7i;
  f1i = f0i - w1i * f7r + w1r * f7i;
  f6r = Two * f0r - f1r;
  f6i = f1i - Two * f0i;
  f0r = f3r + f4r;
  f0i = f3i - f4i;
  f7r = f3i + f4i;
  f7i = f4r - f3r;
  f3r = f0r + w1i * f7r + w1r * f7i;
  f3i = f0i - w1r * f7r + w1i * f7i;
  f4r = Two * f0r - f3r;
  f4i = f3i - Two * f0i;
  ioptr[8] = t0r;
  ioptr[9] = t0i;
  ioptr[0] = f5r;
  ioptr[1] = f5i;
  ioptr[4] = scale * f2r;
  ioptr[5] = scale * f2i;
  ioptr[12] = scale * t1r;
  ioptr[13] = scale * t1i;
  ioptr[2] = scale * f1r;
  ioptr[3] = scale * f1i;
  ioptr[6] = scale * f3r;
  ioptr[7] = scale * f3i;
  ioptr[10] = scale * f4r;
  ioptr[11] = scale * f4i;
  ioptr[14] = scale * f6r;
  ioptr[15] = scale * f6i;
}


x86 assembly (clang, -O0):
<rfft8pt>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
movss  0xf00(%rip),%xmm0
movss  %xmm0,-0xc(%rbp)
movss  0xeef(%rip),%xmm0
movss  %xmm0,-0x10(%rbp)
movss  0xede(%rip),%xmm0
movss  %xmm0,-0x14(%rbp)
movss  0xecd(%rip),%xmm0
movss  %xmm0,-0x68(%rbp)
movss  0xebc(%rip),%xmm0
movss  %xmm0,-0x6c(%rbp)
mov    -0x8(%rbp),%rax
movss  (%rax),%xmm0
movss  %xmm0,-0x18(%rbp)
mov    -0x8(%rbp),%rax
movss  0x4(%rax),%xmm0
movss  %xmm0,-0x1c(%rbp)
mov    -0x8(%rbp),%rax
movss  0x20(%rax),%xmm0
movss  %xmm0,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movss  0x24(%rax),%xmm0
movss  %xmm0,-0x24(%rbp)
mov    -0x8(%rbp),%rax
movss  0x10(%rax),%xmm0
movss  %xmm0,-0x28(%rbp)
mov    -0x8(%rbp),%rax
movss  0x14(%rax),%xmm0
movss  %xmm0,-0x2c(%rbp)
mov    -0x8(%rbp),%rax
movss  0x30(%rax),%xmm0
movss  %xmm0,-0x30(%rbp)
mov    -0x8(%rbp),%rax
movss  0x34(%rax),%xmm0
movss  %xmm0,-0x34(%rbp)
mov    -0x8(%rbp),%rax
movss  0x8(%rax),%xmm0
movss  %xmm0,-0x38(%rbp)
mov    -0x8(%rbp),%rax
movss  0xc(%rax),%xmm0
movss  %xmm0,-0x3c(%rbp)
mov    -0x8(%rbp),%rax
movss  0x28(%rax),%xmm0
movss  %xmm0,-0x40(%rbp)
mov    -0x8(%rbp),%rax
movss  0x2c(%rax),%xmm0
movss  %xmm0,-0x44(%rbp)
mov    -0x8(%rbp),%rax
movss  0x18(%rax),%xmm0
movss  %xmm0,-0x48(%rbp)
mov    -0x8(%rbp),%rax
movss  0x1c(%rax),%xmm0
movss  %xmm0,-0x4c(%rbp)
mov    -0x8(%rbp),%rax
movss  0x38(%rax),%xmm0
movss  %xmm0,-0x50(%rbp)
mov    -0x8(%rbp),%rax
movss  0x3c(%rax),%xmm0
movss  %xmm0,-0x54(%rbp)
movss  -0x18(%rbp),%xmm0
addss  -0x20(%rbp),%xmm0
movss  %xmm0,-0x58(%rbp)
movss  -0x1c(%rbp),%xmm0
addss  -0x24(%rbp),%xmm0
movss  %xmm0,-0x5c(%rbp)
movss  -0x18(%rbp),%xmm0
subss  -0x20(%rbp),%xmm0
movss  %xmm0,-0x20(%rbp)
movss  -0x1c(%rbp),%xmm0
subss  -0x24(%rbp),%xmm0
movss  %xmm0,-0x24(%rbp)
movss  -0x28(%rbp),%xmm0
subss  -0x30(%rbp),%xmm0
movss  %xmm0,-0x60(%rbp)
movss  -0x2c(%rbp),%xmm0
subss  -0x34(%rbp),%xmm0
movss  %xmm0,-0x64(%rbp)
movss  -0x28(%rbp),%xmm0
addss  -0x30(%rbp),%xmm0
movss  %xmm0,-0x28(%rbp)
movss  -0x2c(%rbp),%xmm0
addss  -0x34(%rbp),%xmm0
movss  %xmm0,-0x2c(%rbp)
movss  -0x58(%rbp),%xmm0
addss  -0x28(%rbp),%xmm0
movss  %xmm0,-0x18(%rbp)
movss  -0x5c(%rbp),%xmm0
addss  -0x2c(%rbp),%xmm0
movss  %xmm0,-0x1c(%rbp)
movss  -0x58(%rbp),%xmm0
subss  -0x28(%rbp),%xmm0
movss  %xmm0,-0x28(%rbp)
movss  -0x5c(%rbp),%xmm0
subss  -0x2c(%rbp),%xmm0
movss  %xmm0,-0x2c(%rbp)
movss  -0x20(%rbp),%xmm0
subss  -0x64(%rbp),%xmm0
movss  %xmm0,-0x30(%rbp)
movss  -0x24(%rbp),%xmm0
addss  -0x60(%rbp),%xmm0
movss  %xmm0,-0x34(%rbp)
movss  -0x20(%rbp),%xmm0
addss  -0x64(%rbp),%xmm0
movss  %xmm0,-0x20(%rbp)
movss  -0x24(%rbp),%xmm0
subss  -0x60(%rbp),%xmm0
movss  %xmm0,-0x24(%rbp)
movss  -0x38(%rbp),%xmm0
addss  -0x40(%rbp),%xmm0
movss  %xmm0,-0x58(%rbp)
movss  -0x3c(%rbp),%xmm0
addss  -0x44(%rbp),%xmm0
movss  %xmm0,-0x5c(%rbp)
movss  -0x38(%rbp),%xmm0
subss  -0x40(%rbp),%xmm0
movss  %xmm0,-0x40(%rbp)
movss  -0x3c(%rbp),%xmm0
subss  -0x44(%rbp),%xmm0
movss  %xmm0,-0x44(%rbp)
movss  -0x48(%rbp),%xmm0
subss  -0x50(%rbp),%xmm0
movss  %xmm0,-0x60(%rbp)
movss  -0x4c(%rbp),%xmm0
subss  -0x54(%rbp),%xmm0
movss  %xmm0,-0x64(%rbp)
movss  -0x48(%rbp),%xmm0
addss  -0x50(%rbp),%xmm0
movss  %xmm0,-0x48(%rbp)
movss  -0x4c(%rbp),%xmm0
addss  -0x54(%rbp),%xmm0
movss  %xmm0,-0x4c(%rbp)
movss  -0x58(%rbp),%xmm0
addss  -0x48(%rbp),%xmm0
movss  %xmm0,-0x38(%rbp)
movss  -0x5c(%rbp),%xmm0
addss  -0x4c(%rbp),%xmm0
movss  %xmm0,-0x3c(%rbp)
movss  -0x58(%rbp),%xmm0
subss  -0x48(%rbp),%xmm0
movss  %xmm0,-0x48(%rbp)
movss  -0x5c(%rbp),%xmm0
subss  -0x4c(%rbp),%xmm0
movss  %xmm0,-0x4c(%rbp)
movss  -0x40(%rbp),%xmm0
subss  -0x64(%rbp),%xmm0
movss  %xmm0,-0x50(%rbp)
movss  -0x44(%rbp),%xmm0
addss  -0x60(%rbp),%xmm0
movss  %xmm0,-0x54(%rbp)
movss  -0x40(%rbp),%xmm0
addss  -0x64(%rbp),%xmm0
movss  %xmm0,-0x40(%rbp)
movss  -0x44(%rbp),%xmm0
subss  -0x60(%rbp),%xmm0
movss  %xmm0,-0x44(%rbp)
movss  -0x18(%rbp),%xmm0
subss  -0x38(%rbp),%xmm0
movss  %xmm0,-0x58(%rbp)
movss  -0x3c(%rbp),%xmm0
subss  -0x1c(%rbp),%xmm0
movss  %xmm0,-0x5c(%rbp)
movss  -0x18(%rbp),%xmm0
addss  -0x38(%rbp),%xmm0
movss  %xmm0,-0x18(%rbp)
movss  -0x1c(%rbp),%xmm0
addss  -0x3c(%rbp),%xmm0
movss  %xmm0,-0x1c(%rbp)
movss  -0x28(%rbp),%xmm0
subss  -0x4c(%rbp),%xmm0
movss  %xmm0,-0x60(%rbp)
movss  -0x2c(%rbp),%xmm0
addss  -0x48(%rbp),%xmm0
movss  %xmm0,-0x64(%rbp)
movss  -0x28(%rbp),%xmm0
addss  -0x4c(%rbp),%xmm0
movss  %xmm0,-0x28(%rbp)
movss  -0x2c(%rbp),%xmm0
subss  -0x48(%rbp),%xmm0
movss  %xmm0,-0x2c(%rbp)
movss  -0x20(%rbp),%xmm0
movss  -0x40(%rbp),%xmm1
movss  -0xc(%rbp),%xmm2
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x44(%rbp),%xmm0
movss  -0xc(%rbp),%xmm2
movd   %xmm0,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm0
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x38(%rbp)
movss  -0x24(%rbp),%xmm0
movss  -0x40(%rbp),%xmm1
movss  -0xc(%rbp),%xmm2
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x44(%rbp),%xmm0
movss  -0xc(%rbp),%xmm2
movd   %xmm0,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm0
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x3c(%rbp)
movss  -0x20(%rbp),%xmm0
movss  -0x38(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
addss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x20(%rbp)
movss  -0x24(%rbp),%xmm0
movss  -0x3c(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
addss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x24(%rbp)
movss  -0x30(%rbp),%xmm0
movss  -0x50(%rbp),%xmm1
movss  -0xc(%rbp),%xmm2
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x54(%rbp),%xmm0
movss  -0xc(%rbp),%xmm2
movd   %xmm0,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm0
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x48(%rbp)
movss  -0x34(%rbp),%xmm0
movss  -0x50(%rbp),%xmm1
movss  -0xc(%rbp),%xmm2
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x54(%rbp),%xmm0
movss  -0xc(%rbp),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x4c(%rbp)
movss  -0x30(%rbp),%xmm0
movss  -0x48(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
addss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x30(%rbp)
movss  -0x34(%rbp),%xmm0
movss  -0x4c(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
addss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x34(%rbp)
movss  -0x18(%rbp),%xmm0
addss  -0x1c(%rbp),%xmm0
movss  %xmm0,-0x40(%rbp)
movss  -0x18(%rbp),%xmm0
subss  -0x1c(%rbp),%xmm0
movss  %xmm0,-0x44(%rbp)
movss  -0x28(%rbp),%xmm0
addss  -0x60(%rbp),%xmm0
movss  %xmm0,-0x18(%rbp)
movss  -0x2c(%rbp),%xmm0
subss  -0x64(%rbp),%xmm0
movss  %xmm0,-0x1c(%rbp)
movss  -0x2c(%rbp),%xmm0
addss  -0x64(%rbp),%xmm0
movss  %xmm0,-0x50(%rbp)
movss  -0x60(%rbp),%xmm0
subss  -0x28(%rbp),%xmm0
movss  %xmm0,-0x54(%rbp)
movss  -0x18(%rbp),%xmm0
movss  -0xc(%rbp),%xmm1
movss  -0x50(%rbp),%xmm2
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0xc(%rbp),%xmm0
movss  -0x54(%rbp),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x28(%rbp)
movss  -0x1c(%rbp),%xmm0
movss  -0xc(%rbp),%xmm1
movss  -0x50(%rbp),%xmm2
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0xc(%rbp),%xmm0
movss  -0x54(%rbp),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x2c(%rbp)
movss  -0x18(%rbp),%xmm0
movss  -0x28(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
addss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x60(%rbp)
movss  -0x2c(%rbp),%xmm0
movss  -0x1c(%rbp),%xmm1
addss  %xmm1,%xmm1
subss  %xmm1,%xmm0
movss  %xmm0,-0x64(%rbp)
movss  -0x20(%rbp),%xmm0
addss  -0x48(%rbp),%xmm0
movss  %xmm0,-0x18(%rbp)
movss  -0x24(%rbp),%xmm0
subss  -0x4c(%rbp),%xmm0
movss  %xmm0,-0x1c(%rbp)
movss  -0x24(%rbp),%xmm0
addss  -0x4c(%rbp),%xmm0
movss  %xmm0,-0x50(%rbp)
movss  -0x48(%rbp),%xmm0
subss  -0x20(%rbp),%xmm0
movss  %xmm0,-0x54(%rbp)
movss  -0x18(%rbp),%xmm0
movss  -0x10(%rbp),%xmm1
movss  -0x50(%rbp),%xmm2
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x14(%rbp),%xmm0
movss  -0x54(%rbp),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x20(%rbp)
movss  -0x1c(%rbp),%xmm0
movss  -0x14(%rbp),%xmm1
movss  -0x50(%rbp),%xmm2
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x10(%rbp),%xmm0
movss  -0x54(%rbp),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x24(%rbp)
movss  -0x18(%rbp),%xmm0
movss  -0x20(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
addss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x48(%rbp)
movss  -0x24(%rbp),%xmm0
movss  -0x1c(%rbp),%xmm1
addss  %xmm1,%xmm1
subss  %xmm1,%xmm0
movss  %xmm0,-0x4c(%rbp)
movss  -0x30(%rbp),%xmm0
addss  -0x38(%rbp),%xmm0
movss  %xmm0,-0x18(%rbp)
movss  -0x34(%rbp),%xmm0
subss  -0x3c(%rbp),%xmm0
movss  %xmm0,-0x1c(%rbp)
movss  -0x34(%rbp),%xmm0
addss  -0x3c(%rbp),%xmm0
movss  %xmm0,-0x50(%rbp)
movss  -0x38(%rbp),%xmm0
subss  -0x30(%rbp),%xmm0
movss  %xmm0,-0x54(%rbp)
movss  -0x18(%rbp),%xmm0
movss  -0x14(%rbp),%xmm1
movss  -0x50(%rbp),%xmm2
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x10(%rbp),%xmm0
movss  -0x54(%rbp),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x30(%rbp)
movss  -0x1c(%rbp),%xmm0
movss  -0x10(%rbp),%xmm1
movss  -0x50(%rbp),%xmm2
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
movss  -0x14(%rbp),%xmm0
movss  -0x54(%rbp),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x34(%rbp)
movss  -0x18(%rbp),%xmm0
movss  -0x30(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
addss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x38(%rbp)
movss  -0x34(%rbp),%xmm0
movss  -0x1c(%rbp),%xmm1
addss  %xmm1,%xmm1
subss  %xmm1,%xmm0
movss  %xmm0,-0x3c(%rbp)
movss  -0x58(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x20(%rax)
movss  -0x5c(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x24(%rax)
movss  -0x40(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,(%rax)
movss  -0x44(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x4(%rax)
movss  0x707(%rip),%xmm0
mulss  -0x28(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x10(%rax)
movss  0x6f1(%rip),%xmm0
mulss  -0x2c(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x14(%rax)
movss  0x6db(%rip),%xmm0
mulss  -0x60(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x30(%rax)
movss  0x6c5(%rip),%xmm0
mulss  -0x64(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x34(%rax)
movss  0x6af(%rip),%xmm0
mulss  -0x20(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x8(%rax)
movss  0x699(%rip),%xmm0
mulss  -0x24(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0xc(%rax)
movss  0x683(%rip),%xmm0
mulss  -0x30(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x18(%rax)
movss  0x66d(%rip),%xmm0
mulss  -0x34(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x1c(%rax)
movss  0x657(%rip),%xmm0
mulss  -0x38(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x28(%rax)
movss  0x641(%rip),%xmm0
mulss  -0x3c(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x2c(%rax)
movss  0x62b(%rip),%xmm0
mulss  -0x48(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x38(%rax)
movss  0x615(%rip),%xmm0
mulss  -0x4c(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x3c(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<rfft8pt>:
movsd  0x20(%rdi),%xmm1
movsd  0x30(%rdi),%xmm6
movsd  0x28(%rdi),%xmm5
movaps %xmm5,-0x28(%rsp)
movsd  (%rdi),%xmm2
movsd  0x8(%rdi),%xmm3
movsd  0x10(%rdi),%xmm7
movsd  0x18(%rdi),%xmm13
movsd  0x38(%rdi),%xmm11
movaps %xmm2,%xmm0
addps  %xmm1,%xmm0
subps  %xmm1,%xmm2
movaps %xmm7,%xmm4
subps  %xmm6,%xmm4
movaps %xmm4,%xmm8
shufps $0x55,%xmm4,%xmm8
movaps %xmm2,%xmm14
subss  %xmm8,%xmm14
addss  %xmm2,%xmm8
shufps $0x55,%xmm2,%xmm2
addps  %xmm6,%xmm7
movaps %xmm0,%xmm1
addps  %xmm7,%xmm1
movaps %xmm3,%xmm6
addps  %xmm5,%xmm6
movaps %xmm13,%xmm9
addps  %xmm11,%xmm13
movaps %xmm6,%xmm12
addps  %xmm13,%xmm12
movaps %xmm12,%xmm10
movaps %xmm1,%xmm5
subss  %xmm12,%xmm5
movaps %xmm5,-0x18(%rsp)
addss  %xmm1,%xmm12
shufps $0x55,%xmm1,%xmm1
subps  %xmm7,%xmm0
movaps %xmm2,%xmm15
addss  %xmm4,%xmm15
subss  %xmm4,%xmm2
subps  -0x28(%rsp),%xmm3
subps  %xmm11,%xmm9
movaps %xmm9,%xmm5
shufps $0x55,%xmm9,%xmm5
movaps %xmm3,%xmm4
subss  %xmm5,%xmm4
addss  %xmm3,%xmm5
movaps %xmm3,%xmm7
shufps $0x55,%xmm3,%xmm7
shufps $0x55,%xmm10,%xmm10
subps  %xmm13,%xmm6
shufps $0xe1,%xmm6,%xmm6
movaps %xmm7,%xmm13
addss  %xmm9,%xmm13
subss  %xmm9,%xmm7
movaps %xmm10,%xmm3
subss  %xmm1,%xmm3
movaps %xmm3,-0x28(%rsp)
addss  %xmm1,%xmm10
movaps %xmm0,%xmm11
subps  %xmm6,%xmm11
addps  %xmm0,%xmm6
movss  0xdfb(%rip),%xmm0
mulss  %xmm0,%xmm5
movaps %xmm8,%xmm1
subss  %xmm5,%xmm1
mulss  %xmm0,%xmm4
mulss  %xmm0,%xmm13
movaps %xmm4,%xmm3
addss  %xmm15,%xmm3
addss  %xmm13,%xmm3
movaps 0xdf1(%rip),%xmm9
movaps %xmm3,%xmm0
xorps  %xmm9,%xmm0
unpcklps %xmm0,%xmm1
xorps  %xmm9,%xmm7
addss  %xmm14,%xmm4
unpcklps %xmm7,%xmm14
unpcklps %xmm15,%xmm7
mulps  0xddf(%rip),%xmm7
addps  %xmm1,%xmm7
addss  %xmm2,%xmm5
subss  %xmm13,%xmm4
movaps %xmm4,%xmm0
xorps  %xmm9,%xmm0
unpcklps %xmm5,%xmm0
movaps %xmm11,%xmm13
shufps $0x1,%xmm6,%xmm13
addss  %xmm8,%xmm8
subss  %xmm7,%xmm8
mulps  0xdbe(%rip),%xmm14
addps  %xmm0,%xmm14
movaps %xmm7,%xmm5
addps  %xmm14,%xmm5
subps  %xmm14,%xmm7
shufps $0x55,%xmm14,%xmm14
addss  %xmm2,%xmm2
subss  %xmm14,%xmm2
movaps %xmm12,%xmm14
addss  %xmm10,%xmm14
subss  %xmm10,%xmm12
movaps %xmm4,%xmm0
unpcklps %xmm2,%xmm0
shufps $0x24,%xmm13,%xmm0
movaps %xmm8,%xmm1
shufps $0x50,%xmm6,%xmm2
shufps $0x0,%xmm6,%xmm8
shufps $0x1,%xmm11,%xmm6
unpcklps %xmm3,%xmm1
shufps $0x24,%xmm6,%xmm1
movaps %xmm0,%xmm10
addps  %xmm1,%xmm10
subps  %xmm1,%xmm0
movaps %xmm10,%xmm1
shufps $0xd8,%xmm0,%xmm1
shufps $0xd8,%xmm1,%xmm1
shufps $0x50,%xmm11,%xmm3
addps  %xmm3,%xmm2
shufps $0x0,%xmm11,%xmm4
subps  %xmm8,%xmm4
mulps  0xd50(%rip),%xmm2
addps  %xmm1,%xmm2
mulps  0xd56(%rip),%xmm4
addps  %xmm2,%xmm4
movaps %xmm4,%xmm2
shufps $0x55,%xmm4,%xmm2
movaps %xmm0,%xmm1
shufps $0x55,%xmm0,%xmm1
addss  %xmm1,%xmm1
subss  %xmm1,%xmm2
movaps %xmm7,%xmm1
shufps $0x1,%xmm5,%xmm1
movaps %xmm5,%xmm3
shufps $0x55,%xmm5,%xmm3
movss  0xcca(%rip),%xmm8
movaps %xmm3,%xmm6
mulss  %xmm8,%xmm6
addss  %xmm5,%xmm6
movss  0xcba(%rip),%xmm5
mulss  %xmm7,%xmm5
addss  %xmm6,%xmm5
movaps %xmm7,%xmm6
shufps $0x55,%xmm7,%xmm6
mulss  0xca7(%rip),%xmm3
addss  %xmm6,%xmm3
mulss  %xmm8,%xmm7
addss  %xmm3,%xmm7
shufps $0x23,%xmm10,%xmm0
shufps $0x22,%xmm0,%xmm1
movaps 0xc9e(%rip),%xmm0
xorps  %xmm4,%xmm0
movaps %xmm4,%xmm3
shufps $0x23,%xmm0,%xmm3
xorps  %xmm5,%xmm9
unpcklps %xmm7,%xmm9
shufps $0x24,%xmm3,%xmm9
mulps  0xcd0(%rip),%xmm1
addps  %xmm9,%xmm1
movaps -0x18(%rsp),%xmm0
movss  %xmm0,0x20(%rdi)
movaps -0x28(%rsp),%xmm0
movss  %xmm0,0x24(%rdi)
movss  %xmm14,(%rdi)
addss  %xmm10,%xmm10
subss  %xmm4,%xmm10
movss  %xmm12,0x4(%rdi)
movaps 0xcac(%rip),%xmm0
mulps  %xmm0,%xmm4
movups %xmm4,0x8(%rdi)
movss  0xc2d(%rip),%xmm3
mulss  %xmm3,%xmm5
movss  %xmm5,0x18(%rdi)
mulss  %xmm3,%xmm7
movss  %xmm7,0x1c(%rdi)
mulps  %xmm0,%xmm1
movups %xmm1,0x28(%rdi)
mulss  %xmm3,%xmm10
movss  %xmm10,0x38(%rdi)
mulss  %xmm3,%xmm2
movss  %xmm2,0x3c(%rdi)
ret

LLVM IR (-O0):
define void @rfft8pt(float* %0) {
%2 = alloca float*
%3 = alloca float
%4 = alloca float
%5 = alloca float
%6 = alloca float
%7 = alloca float
%8 = alloca float
%9 = alloca float
%10 = alloca float
%11 = alloca float
%12 = alloca float
%13 = alloca float
%14 = alloca float
%15 = alloca float
%16 = alloca float
%17 = alloca float
%18 = alloca float
%19 = alloca float
%20 = alloca float
%21 = alloca float
%22 = alloca float
%23 = alloca float
%24 = alloca float
%25 = alloca float
%26 = alloca float
%27 = alloca float
store float* %0, float** %2
store float 0x3FE6A09E60000000, float* %3
store float 0x3FED906BC0000000, float* %4
store float 0x3FD87DE2A0000000, float* %5
store float 2.000000e+00, float* %26
store float 5.000000e-01, float* %27
%28 = load float*, float** %2
%29 = getelementptr inbounds float, float* %28, i64 0
%30 = load float, float* %29
store float %30, float* %6
%31 = load float*, float** %2
%32 = getelementptr inbounds float, float* %31, i64 1
%33 = load float, float* %32
store float %33, float* %7
%34 = load float*, float** %2
%35 = getelementptr inbounds float, float* %34, i64 8
%36 = load float, float* %35
store float %36, float* %8
%37 = load float*, float** %2
%38 = getelementptr inbounds float, float* %37, i64 9
%39 = load float, float* %38
store float %39, float* %9
%40 = load float*, float** %2
%41 = getelementptr inbounds float, float* %40, i64 4
%42 = load float, float* %41
store float %42, float* %10
%43 = load float*, float** %2
%44 = getelementptr inbounds float, float* %43, i64 5
%45 = load float, float* %44
store float %45, float* %11
%46 = load float*, float** %2
%47 = getelementptr inbounds float, float* %46, i64 12
%48 = load float, float* %47
store float %48, float* %12
%49 = load float*, float** %2
%50 = getelementptr inbounds float, float* %49, i64 13
%51 = load float, float* %50
store float %51, float* %13
%52 = load float*, float** %2
%53 = getelementptr inbounds float, float* %52, i64 2
%54 = load float, float* %53
store float %54, float* %14
%55 = load float*, float** %2
%56 = getelementptr inbounds float, float* %55, i64 3
%57 = load float, float* %56
store float %57, float* %15
%58 = load float*, float** %2
%59 = getelementptr inbounds float, float* %58, i64 10
%60 = load float, float* %59
store float %60, float* %16
%61 = load float*, float** %2
%62 = getelementptr inbounds float, float* %61, i64 11
%63 = load float, float* %62
store float %63, float* %17
%64 = load float*, float** %2
%65 = getelementptr inbounds float, float* %64, i64 6
%66 = load float, float* %65
store float %66, float* %18
%67 = load float*, float** %2
%68 = getelementptr inbounds float, float* %67, i64 7
%69 = load float, float* %68
store float %69, float* %19
%70 = load float*, float** %2
%71 = getelementptr inbounds float, float* %70, i64 14
%72 = load float, float* %71
store float %72, float* %20
%73 = load float*, float** %2
%74 = getelementptr inbounds float, float* %73, i64 15
%75 = load float, float* %74
store float %75, float* %21
%76 = load float, float* %6
%77 = load float, float* %8
%78 = fadd float %76, %77
store float %78, float* %22
%79 = load float, float* %7
%80 = load float, float* %9
%81 = fadd float %79, %80
store float %81, float* %23
%82 = load float, float* %6
%83 = load float, float* %8
%84 = fsub float %82, %83
store float %84, float* %8
%85 = load float, float* %7
%86 = load float, float* %9
%87 = fsub float %85, %86
store float %87, float* %9
%88 = load float, float* %10
%89 = load float, float* %12
%90 = fsub float %88, %89
store float %90, float* %24
%91 = load float, float* %11
%92 = load float, float* %13
%93 = fsub float %91, %92
store float %93, float* %25
%94 = load float, float* %10
%95 = load float, float* %12
%96 = fadd float %94, %95
store float %96, float* %10
%97 = load float, float* %11
%98 = load float, float* %13
%99 = fadd float %97, %98
store float %99, float* %11
%100 = load float, float* %22
%101 = load float, float* %10
%102 = fadd float %100, %101
store float %102, float* %6
%103 = load float, float* %23
%104 = load float, float* %11
%105 = fadd float %103, %104
store float %105, float* %7
%106 = load float, float* %22
%107 = load float, float* %10
%108 = fsub float %106, %107
store float %108, float* %10
%109 = load float, float* %23
%110 = load float, float* %11
%111 = fsub float %109, %110
store float %111, float* %11
%112 = load float, float* %8
%113 = load float, float* %25
%114 = fsub float %112, %113
store float %114, float* %12
%115 = load float, float* %9
%116 = load float, float* %24
%117 = fadd float %115, %116
store float %117, float* %13
%118 = load float, float* %8
%119 = load float, float* %25
%120 = fadd float %118, %119
store float %120, float* %8
%121 = load float, float* %9
%122 = load float, float* %24
%123 = fsub float %121, %122
store float %123, float* %9
%124 = load float, float* %14
%125 = load float, float* %16
%126 = fadd float %124, %125
store float %126, float* %22
%127 = load float, float* %15
%128 = load float, float* %17
%129 = fadd float %127, %128
store float %129, float* %23
%130 = load float, float* %14
%131 = load float, float* %16
%132 = fsub float %130, %131
store float %132, float* %16
%133 = load float, float* %15
%134 = load float, float* %17
%135 = fsub float %133, %134
store float %135, float* %17
%136 = load float, float* %18
%137 = load float, float* %20
%138 = fsub float %136, %137
store float %138, float* %24
%139 = load float, float* %19
%140 = load float, float* %21
%141 = fsub float %139, %140
store float %141, float* %25
%142 = load float, float* %18
%143 = load float, float* %20
%144 = fadd float %142, %143
store float %144, float* %18
%145 = load float, float* %19
%146 = load float, float* %21
%147 = fadd float %145, %146
store float %147, float* %19
%148 = load float, float* %22
%149 = load float, float* %18
%150 = fadd float %148, %149
store float %150, float* %14
%151 = load float, float* %23
%152 = load float, float* %19
%153 = fadd float %151, %152
store float %153, float* %15
%154 = load float, float* %22
%155 = load float, float* %18
%156 = fsub float %154, %155
store float %156, float* %18
%157 = load float, float* %23
%158 = load float, float* %19
%159 = fsub float %157, %158
store float %159, float* %19
%160 = load float, float* %16
%161 = load float, float* %25
%162 = fsub float %160, %161
store float %162, float* %20
%163 = load float, float* %17
%164 = load float, float* %24
%165 = fadd float %163, %164
store float %165, float* %21
%166 = load float, float* %16
%167 = load float, float* %25
%168 = fadd float %166, %167
store float %168, float* %16
%169 = load float, float* %17
%170 = load float, float* %24
%171 = fsub float %169, %170
store float %171, float* %17
%172 = load float, float* %6
%173 = load float, float* %14
%174 = fsub float %172, %173
store float %174, float* %22
%175 = load float, float* %15
%176 = load float, float* %7
%177 = fsub float %175, %176
store float %177, float* %23
%178 = load float, float* %6
%179 = load float, float* %14
%180 = fadd float %178, %179
store float %180, float* %6
%181 = load float, float* %7
%182 = load float, float* %15
%183 = fadd float %181, %182
store float %183, float* %7
%184 = load float, float* %10
%185 = load float, float* %19
%186 = fsub float %184, %185
store float %186, float* %24
%187 = load float, float* %11
%188 = load float, float* %18
%189 = fadd float %187, %188
store float %189, float* %25
%190 = load float, float* %10
%191 = load float, float* %19
%192 = fadd float %190, %191
store float %192, float* %10
%193 = load float, float* %11
%194 = load float, float* %18
%195 = fsub float %193, %194
store float %195, float* %11
%196 = load float, float* %8
%197 = load float, float* %16
%198 = load float, float* %3
%199 = fneg float %197
%200 = call float @llvm.fmuladd.f32(float %199, float %198, float %196)
%201 = load float, float* %17
%202 = load float, float* %3
%203 = fneg float %201
%204 = call float @llvm.fmuladd.f32(float %203, float %202, float %200)
store float %204, float* %14
%205 = load float, float* %9
%206 = load float, float* %16
%207 = load float, float* %3
%208 = call float @llvm.fmuladd.f32(float %206, float %207, float %205)
%209 = load float, float* %17
%210 = load float, float* %3
%211 = fneg float %209
%212 = call float @llvm.fmuladd.f32(float %211, float %210, float %208)
store float %212, float* %15
%213 = load float, float* %8
%214 = load float, float* %14
%215 = fneg float %214
%216 = call float @llvm.fmuladd.f32(float %213, float 2.000000e+00, float %215)
store float %216, float* %8
%217 = load float, float* %9
%218 = load float, float* %15
%219 = fneg float %218
%220 = call float @llvm.fmuladd.f32(float %217, float 2.000000e+00, float %219)
store float %220, float* %9
%221 = load float, float* %12
%222 = load float, float* %20
%223 = load float, float* %3
%224 = call float @llvm.fmuladd.f32(float %222, float %223, float %221)
%225 = load float, float* %21
%226 = load float, float* %3
%227 = fneg float %225
%228 = call float @llvm.fmuladd.f32(float %227, float %226, float %224)
store float %228, float* %18
%229 = load float, float* %13
%230 = load float, float* %20
%231 = load float, float* %3
%232 = call float @llvm.fmuladd.f32(float %230, float %231, float %229)
%233 = load float, float* %21
%234 = load float, float* %3
%235 = call float @llvm.fmuladd.f32(float %233, float %234, float %232)
store float %235, float* %19
%236 = load float, float* %12
%237 = load float, float* %18
%238 = fneg float %237
%239 = call float @llvm.fmuladd.f32(float %236, float 2.000000e+00, float %238)
store float %239, float* %12
%240 = load float, float* %13
%241 = load float, float* %19
%242 = fneg float %241
%243 = call float @llvm.fmuladd.f32(float %240, float 2.000000e+00, float %242)
store float %243, float* %13
%244 = load float, float* %6
%245 = load float, float* %7
%246 = fadd float %244, %245
store float %246, float* %16
%247 = load float, float* %6
%248 = load float, float* %7
%249 = fsub float %247, %248
store float %249, float* %17
%250 = load float, float* %10
%251 = load float, float* %24
%252 = fadd float %250, %251
store float %252, float* %6
%253 = load float, float* %11
%254 = load float, float* %25
%255 = fsub float %253, %254
store float %255, float* %7
%256 = load float, float* %11
%257 = load float, float* %25
%258 = fadd float %256, %257
store float %258, float* %20
%259 = load float, float* %24
%260 = load float, float* %10
%261 = fsub float %259, %260
store float %261, float* %21
%262 = load float, float* %6
%263 = load float, float* %3
%264 = load float, float* %20
%265 = call float @llvm.fmuladd.f32(float %263, float %264, float %262)
%266 = load float, float* %3
%267 = load float, float* %21
%268 = call float @llvm.fmuladd.f32(float %266, float %267, float %265)
store float %268, float* %10
%269 = load float, float* %7
%270 = load float, float* %3
%271 = load float, float* %20
%272 = fneg float %270
%273 = call float @llvm.fmuladd.f32(float %272, float %271, float %269)
%274 = load float, float* %3
%275 = load float, float* %21
%276 = call float @llvm.fmuladd.f32(float %274, float %275, float %273)
store float %276, float* %11
%277 = load float, float* %6
%278 = load float, float* %10
%279 = fneg float %278
%280 = call float @llvm.fmuladd.f32(float 2.000000e+00, float %277, float %279)
store float %280, float* %24
%281 = load float, float* %11
%282 = load float, float* %7
%283 = call float @llvm.fmuladd.f32(float -2.000000e+00, float %282, float %281)
store float %283, float* %25
%284 = load float, float* %8
%285 = load float, float* %18
%286 = fadd float %284, %285
store float %286, float* %6
%287 = load float, float* %9
%288 = load float, float* %19
%289 = fsub float %287, %288
store float %289, float* %7
%290 = load float, float* %9
%291 = load float, float* %19
%292 = fadd float %290, %291
store float %292, float* %20
%293 = load float, float* %18
%294 = load float, float* %8
%295 = fsub float %293, %294
store float %295, float* %21
%296 = load float, float* %6
%297 = load float, float* %4
%298 = load float, float* %20
%299 = call float @llvm.fmuladd.f32(float %297, float %298, float %296)
%300 = load float, float* %5
%301 = load float, float* %21
%302 = call float @llvm.fmuladd.f32(float %300, float %301, float %299)
store float %302, float* %8
%303 = load float, float* %7
%304 = load float, float* %5
%305 = load float, float* %20
%306 = fneg float %304
%307 = call float @llvm.fmuladd.f32(float %306, float %305, float %303)
%308 = load float, float* %4
%309 = load float, float* %21
%310 = call float @llvm.fmuladd.f32(float %308, float %309, float %307)
store float %310, float* %9
%311 = load float, float* %6
%312 = load float, float* %8
%313 = fneg float %312
%314 = call float @llvm.fmuladd.f32(float 2.000000e+00, float %311, float %313)
store float %314, float* %18
%315 = load float, float* %9
%316 = load float, float* %7
%317 = call float @llvm.fmuladd.f32(float -2.000000e+00, float %316, float %315)
store float %317, float* %19
%318 = load float, float* %12
%319 = load float, float* %14
%320 = fadd float %318, %319
store float %320, float* %6
%321 = load float, float* %13
%322 = load float, float* %15
%323 = fsub float %321, %322
store float %323, float* %7
%324 = load float, float* %13
%325 = load float, float* %15
%326 = fadd float %324, %325
store float %326, float* %20
%327 = load float, float* %14
%328 = load float, float* %12
%329 = fsub float %327, %328
store float %329, float* %21
%330 = load float, float* %6
%331 = load float, float* %5
%332 = load float, float* %20
%333 = call float @llvm.fmuladd.f32(float %331, float %332, float %330)
%334 = load float, float* %4
%335 = load float, float* %21
%336 = call float @llvm.fmuladd.f32(float %334, float %335, float %333)
store float %336, float* %12
%337 = load float, float* %7
%338 = load float, float* %4
%339 = load float, float* %20
%340 = fneg float %338
%341 = call float @llvm.fmuladd.f32(float %340, float %339, float %337)
%342 = load float, float* %5
%343 = load float, float* %21
%344 = call float @llvm.fmuladd.f32(float %342, float %343, float %341)
store float %344, float* %13
%345 = load float, float* %6
%346 = load float, float* %12
%347 = fneg float %346
%348 = call float @llvm.fmuladd.f32(float 2.000000e+00, float %345, float %347)
store float %348, float* %14
%349 = load float, float* %13
%350 = load float, float* %7
%351 = call float @llvm.fmuladd.f32(float -2.000000e+00, float %350, float %349)
store float %351, float* %15
%352 = load float, float* %22
%353 = load float*, float** %2
%354 = getelementptr inbounds float, float* %353, i64 8
store float %352, float* %354
%355 = load float, float* %23
%356 = load float*, float** %2
%357 = getelementptr inbounds float, float* %356, i64 9
store float %355, float* %357
%358 = load float, float* %16
%359 = load float*, float** %2
%360 = getelementptr inbounds float, float* %359, i64 0
store float %358, float* %360
%361 = load float, float* %17
%362 = load float*, float** %2
%363 = getelementptr inbounds float, float* %362, i64 1
store float %361, float* %363
%364 = load float, float* %10
%365 = fmul float 5.000000e-01, %364
%366 = load float*, float** %2
%367 = getelementptr inbounds float, float* %366, i64 4
store float %365, float* %367
%368 = load float, float* %11
%369 = fmul float 5.000000e-01, %368
%370 = load float*, float** %2
%371 = getelementptr inbounds float, float* %370, i64 5
store float %369, float* %371
%372 = load float, float* %24
%373 = fmul float 5.000000e-01, %372
%374 = load float*, float** %2
%375 = getelementptr inbounds float, float* %374, i64 12
store float %373, float* %375
%376 = load float, float* %25
%377 = fmul float 5.000000e-01, %376
%378 = load float*, float** %2
%379 = getelementptr inbounds float, float* %378, i64 13
store float %377, float* %379
%380 = load float, float* %8
%381 = fmul float 5.000000e-01, %380
%382 = load float*, float** %2
%383 = getelementptr inbounds float, float* %382, i64 2
store float %381, float* %383
%384 = load float, float* %9
%385 = fmul float 5.000000e-01, %384
%386 = load float*, float** %2
%387 = getelementptr inbounds float, float* %386, i64 3
store float %385, float* %387
%388 = load float, float* %12
%389 = fmul float 5.000000e-01, %388
%390 = load float*, float** %2
%391 = getelementptr inbounds float, float* %390, i64 6
store float %389, float* %391
%392 = load float, float* %13
%393 = fmul float 5.000000e-01, %392
%394 = load float*, float** %2
%395 = getelementptr inbounds float, float* %394, i64 7
store float %393, float* %395
%396 = load float, float* %14
%397 = fmul float 5.000000e-01, %396
%398 = load float*, float** %2
%399 = getelementptr inbounds float, float* %398, i64 10
store float %397, float* %399
%400 = load float, float* %15
%401 = fmul float 5.000000e-01, %400
%402 = load float*, float** %2
%403 = getelementptr inbounds float, float* %402, i64 11
store float %401, float* %403
%404 = load float, float* %18
%405 = fmul float 5.000000e-01, %404
%406 = load float*, float** %2
%407 = getelementptr inbounds float, float* %406, i64 14
store float %405, float* %407
%408 = load float, float* %19
%409 = fmul float 5.000000e-01, %408
%410 = load float*, float** %2
%411 = getelementptr inbounds float, float* %410, i64 15
store float %409, float* %411
ret void
}

LLVM IR (-O2):
define void @rfft8pt(float* nocapture %0) {
%2 = getelementptr inbounds float, float* %0, i64 1
%3 = bitcast float* %0 to <2 x float>*
%4 = load <2 x float>, <2 x float>* %3
%5 = getelementptr inbounds float, float* %0, i64 8
%6 = getelementptr inbounds float, float* %0, i64 9
%7 = bitcast float* %5 to <2 x float>*
%8 = load <2 x float>, <2 x float>* %7
%9 = getelementptr inbounds float, float* %0, i64 4
%10 = bitcast float* %9 to <2 x float>*
%11 = load <2 x float>, <2 x float>* %10
%12 = getelementptr inbounds float, float* %0, i64 12
%13 = bitcast float* %12 to <2 x float>*
%14 = load <2 x float>, <2 x float>* %13
%15 = getelementptr inbounds float, float* %0, i64 2
%16 = bitcast float* %15 to <2 x float>*
%17 = load <2 x float>, <2 x float>* %16
%18 = getelementptr inbounds float, float* %0, i64 10
%19 = bitcast float* %18 to <2 x float>*
%20 = load <2 x float>, <2 x float>* %19
%21 = getelementptr inbounds float, float* %0, i64 6
%22 = getelementptr inbounds float, float* %0, i64 7
%23 = bitcast float* %21 to <2 x float>*
%24 = load <2 x float>, <2 x float>* %23
%25 = getelementptr inbounds float, float* %0, i64 14
%26 = getelementptr inbounds float, float* %0, i64 15
%27 = bitcast float* %25 to <2 x float>*
%28 = load <2 x float>, <2 x float>* %27
%29 = fadd <2 x float> %4, %8
%30 = fsub <2 x float> %4, %8
%31 = extractelement <2 x float> %30, i64 0
%32 = fsub <2 x float> %4, %8
%33 = extractelement <2 x float> %32, i64 1
%34 = fsub <2 x float> %11, %14
%35 = extractelement <2 x float> %34, i64 0
%36 = fsub <2 x float> %11, %14
%37 = extractelement <2 x float> %36, i64 1
%38 = fadd <2 x float> %11, %14
%39 = fadd <2 x float> %29, %38
%40 = fadd <2 x float> %29, %38
%41 = extractelement <2 x float> %40, i64 1
%42 = fsub <2 x float> %29, %38
%43 = fsub float %31, %37
%44 = fadd float %33, %35
%45 = fadd float %31, %37
%46 = fsub float %33, %35
%47 = fadd <2 x float> %17, %20
%48 = fsub <2 x float> %17, %20
%49 = extractelement <2 x float> %48, i64 0
%50 = fsub <2 x float> %17, %20
%51 = extractelement <2 x float> %50, i64 1
%52 = fsub <2 x float> %24, %28
%53 = extractelement <2 x float> %52, i64 0
%54 = fsub <2 x float> %24, %28
%55 = extractelement <2 x float> %54, i64 1
%56 = fadd <2 x float> %24, %28
%57 = fadd <2 x float> %47, %56
%58 = fadd <2 x float> %47, %56
%59 = extractelement <2 x float> %58, i64 1
%60 = fsub <2 x float> %47, %56
%61 = shufflevector <2 x float> %60, <2 x float> poison, <2 x i32> <i32 1, i32 0>
%62 = fsub float %49, %55
%63 = fadd float %51, %53
%64 = fadd float %49, %55
%65 = fsub float %51, %53
%66 = fsub <2 x float> %39, %57
%67 = extractelement <2 x float> %66, i64 0
%68 = fsub float %59, %41
%69 = fadd <2 x float> %39, %57
%70 = extractelement <2 x float> %69, i64 0
%71 = fadd float %41, %59
%72 = fsub <2 x float> %42, %61
%73 = fadd <2 x float> %42, %61
%74 = shufflevector <2 x float> %72, <2 x float> %73, <2 x i32> <i32 0, i32 3>
%75 = shufflevector <2 x float> %73, <2 x float> %72, <2 x i32> <i32 0, i32 3>
%76 = fneg float %64
%77 = tail call float @llvm.fmuladd.f32(float %76, float 0x3FE6A09E60000000, float %45)
%78 = fneg float %65
%79 = tail call float @llvm.fmuladd.f32(float %64, float 0x3FE6A09E60000000, float %46)
%80 = tail call float @llvm.fmuladd.f32(float %62, float 0x3FE6A09E60000000, float %44)
%81 = tail call float @llvm.fmuladd.f32(float %63, float 0x3FE6A09E60000000, float %80)
%82 = fneg float %81
%83 = insertelement <2 x float> poison, float %78, i64 0
%84 = insertelement <2 x float> %83, float %44, i64 1
%85 = insertelement <2 x float> poison, float %77, i64 0
%86 = insertelement <2 x float> %85, float %82, i64 1
%87 = call <2 x float> @llvm.fmuladd.v2f32(<2 x float> %84, <2 x float> <float 0x3FE6A09E60000000, float 2.000000e+00>, <2 x float> %86)
%88 = extractelement <2 x float> %87, i64 0
%89 = fneg float %88
%90 = tail call float @llvm.fmuladd.f32(float %45, float 2.000000e+00, float %89)
%91 = tail call float @llvm.fmuladd.f32(float %62, float 0x3FE6A09E60000000, float %43)
%92 = fneg float %63
%93 = tail call float @llvm.fmuladd.f32(float %92, float 0x3FE6A09E60000000, float %91)
%94 = fneg float %93
%95 = insertelement <2 x float> poison, float %43, i64 0
%96 = insertelement <2 x float> %95, float %78, i64 1
%97 = insertelement <2 x float> poison, float %94, i64 0
%98 = insertelement <2 x float> %97, float %79, i64 1
%99 = call <2 x float> @llvm.fmuladd.v2f32(<2 x float> %96, <2 x float> <float 2.000000e+00, float 0x3FE6A09E60000000>, <2 x float> %98)
%100 = extractelement <2 x float> %99, i64 1
%101 = fneg float %100
%102 = tail call float @llvm.fmuladd.f32(float %46, float 2.000000e+00, float %101)
%103 = fadd float %70, %71
%104 = fsub float %70, %71
%105 = insertelement <4 x float> poison, float %93, i64 0
%106 = insertelement <4 x float> %105, float %102, i64 1
%107 = shufflevector <2 x float> %75, <2 x float> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
%108 = shufflevector <4 x float> %106, <4 x float> %107, <4 x i32> <i32 0, i32 1, i32 4, i32 5>
%109 = insertelement <4 x float> poison, float %90, i64 0
%110 = insertelement <4 x float> %109, float %81, i64 1
%111 = shufflevector <2 x float> %74, <2 x float> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
%112 = shufflevector <4 x float> %110, <4 x float> %111, <4 x i32> <i32 0, i32 1, i32 4, i32 5>
%113 = fadd <4 x float> %108, %112
%114 = fsub <4 x float> %108, %112
%115 = shufflevector <4 x float> %113, <4 x float> %114, <4 x i32> <i32 0, i32 5, i32 2, i32 7>
%116 = insertelement <2 x float> %72, float %81, i64 0
%117 = insertelement <2 x float> %73, float %102, i64 0
%118 = fadd <2 x float> %116, %117
%119 = shufflevector <2 x float> %118, <2 x float> poison, <4 x i32> <i32 0, i32 0, i32 1, i32 1>
%120 = insertelement <2 x float> poison, float %93, i64 0
%121 = shufflevector <2 x float> %120, <2 x float> %72, <2 x i32> <i32 0, i32 2>
%122 = insertelement <2 x float> poison, float %90, i64 0
%123 = shufflevector <2 x float> %122, <2 x float> %73, <2 x i32> <i32 0, i32 2>
%124 = fsub <2 x float> %121, %123
%125 = shufflevector <2 x float> %124, <2 x float> poison, <4 x i32> <i32 0, i32 0, i32 1, i32 1>
%126 = call <4 x float> @llvm.fmuladd.v4f32(<4 x float> %119, <4 x float> <float 0x3FED906BC0000000, float 0xBFD87DE2A0000000, float 0x3FE6A09E60000000, float 0xBFE6A09E60000000>, <4 x float> %115)
%127 = call <4 x float> @llvm.fmuladd.v4f32(<4 x float> %125, <4 x float> <float 0x3FD87DE2A0000000, float 0x3FED906BC0000000, float 0x3FE6A09E60000000, float 0x3FE6A09E60000000>, <4 x float> %126)
%128 = extractelement <4 x float> %127, i64 2
%129 = fneg float %128
%130 = extractelement <4 x float> %127, i64 0
%131 = fneg float %130
%132 = extractelement <4 x float> %113, i64 0
%133 = tail call float @llvm.fmuladd.f32(float %132, float 2.000000e+00, float %131)
%134 = extractelement <4 x float> %127, i64 1
%135 = extractelement <4 x float> %114, i64 1
%136 = tail call float @llvm.fmuladd.f32(float %135, float -2.000000e+00, float %134)
%137 = fadd <2 x float> %87, %99
%138 = fsub <2 x float> %87, %99
%139 = shufflevector <2 x float> %137, <2 x float> %138, <2 x i32> <i32 0, i32 3>
%140 = fadd <2 x float> %99, %87
%141 = extractelement <2 x float> %140, i64 1
%142 = fsub <2 x float> %87, %99
%143 = extractelement <2 x float> %142, i64 0
%144 = extractelement <2 x float> %137, i64 0
%145 = tail call float @llvm.fmuladd.f32(float %141, float 0x3FD87DE2A0000000, float %144)
%146 = tail call float @llvm.fmuladd.f32(float %143, float 0x3FED906BC0000000, float %145)
%147 = extractelement <2 x float> %138, i64 1
%148 = tail call float @llvm.fmuladd.f32(float %141, float 0xBFED906BC0000000, float %147)
%149 = tail call float @llvm.fmuladd.f32(float %143, float 0x3FD87DE2A0000000, float %148)
%150 = fneg float %146
%151 = shufflevector <2 x float> %139, <2 x float> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
%152 = shufflevector <4 x float> %151, <4 x float> %113, <4 x i32> <i32 0, i32 1, i32 6, i32 undef>
%153 = shufflevector <4 x float> %152, <4 x float> %114, <4 x i32> <i32 0, i32 1, i32 2, i32 7>
%154 = insertelement <4 x float> poison, float %150, i64 0
%155 = insertelement <4 x float> %154, float %149, i64 1
%156 = insertelement <4 x float> %155, float %129, i64 2
%157 = shufflevector <4 x float> %156, <4 x float> %127, <4 x i32> <i32 0, i32 1, i32 2, i32 7>
%158 = call <4 x float> @llvm.fmuladd.v4f32(<4 x float> %153, <4 x float> <float 2.000000e+00, float -2.000000e+00, float 2.000000e+00, float -2.000000e+00>, <4 x float> %157)
store float %67, float* %5
store float %68, float* %6
store float %103, float* %0
store float %104, float* %2
%159 = fmul <4 x float> %127, <float 5.000000e-01, float 5.000000e-01, float 5.000000e-01, float 5.000000e-01>
%160 = bitcast float* %15 to <4 x float>*
store <4 x float> %159, <4 x float>* %160
%161 = fmul float %146, 5.000000e-01
store float %161, float* %21
%162 = fmul float %149, 5.000000e-01
store float %162, float* %22
%163 = fmul <4 x float> %158, <float 5.000000e-01, float 5.000000e-01, float 5.000000e-01, float 5.000000e-01>
%164 = bitcast float* %18 to <4 x float>*
store <4 x float> %163, <4 x float>* %164
%165 = fmul float %133, 5.000000e-01
store float %165, float* %25
%166 = fmul float %136, 5.000000e-01
store float %166, float* %26
ret void
}