#include "../../cryptonight.hpp"
#include "cn_gpu.hpp"

#pragma GCC target("sse2")

inline void prep_dv(__m128i* idx, __m128i& v, __m128& n)
{
	v = _mm_load_si128(idx);
	n = _mm_cvtepi32_ps(v);
}

inline __m128 fma_break(__m128 x)
{
	// Break the dependency chain by setitng the exp to ?????01
	x = _mm_and_ps(_mm_castsi128_ps(_mm_set1_epi32(0xFEFFFFFF)), x);
	return _mm_or_ps(_mm_castsi128_ps(_mm_set1_epi32(0x00800000)), x);
}

// 14
inline void sub_round(__m128 n0, __m128 n1, __m128 n2, __m128 n3, __m128 rnd_c, __m128& n, __m128& d, __m128& c)
{
	n1 = _mm_add_ps(n1, c);
	__m128 nn = _mm_mul_ps(n0, c);
	nn = _mm_mul_ps(n1, _mm_mul_ps(nn, nn));
	nn = fma_break(nn);
	n = _mm_add_ps(n, nn);

	n3 = _mm_sub_ps(n3, c);
	__m128 dd = _mm_mul_ps(n2, c);
	dd = _mm_mul_ps(n3, _mm_mul_ps(dd, dd));
	dd = fma_break(dd);
	d = _mm_add_ps(d, dd);

	//Constant feedback
	c = _mm_add_ps(c, rnd_c);
	c = _mm_add_ps(c, _mm_set1_ps(0.734375f));
	__m128 r = _mm_add_ps(nn, dd);
	r = _mm_and_ps(_mm_castsi128_ps(_mm_set1_epi32(0x807FFFFF)), r);
	r = _mm_or_ps(_mm_castsi128_ps(_mm_set1_epi32(0x40000000)), r);
	c = _mm_add_ps(c, r);
}

// 14*8 + 2 = 112
inline void round_compute(__m128 n0, __m128 n1, __m128 n2, __m128 n3, __m128 rnd_c, __m128& c, __m128& r)
{
	__m128 n = _mm_setzero_ps(), d = _mm_setzero_ps();

	sub_round(n0, n1, n2, n3, rnd_c, n, d, c);
	sub_round(n1, n2, n3, n0, rnd_c, n, d, c);
	sub_round(n2, n3, n0, n1, rnd_c, n, d, c);
	sub_round(n3, n0, n1, n2, rnd_c, n, d, c);
	sub_round(n3, n2, n1, n0, rnd_c, n, d, c);
	sub_round(n2, n1, n0, n3, rnd_c, n, d, c);
	sub_round(n1, n0, n3, n2, rnd_c, n, d, c);
	sub_round(n0, n3, n2, n1, rnd_c, n, d, c);

	// Make sure abs(d) > 2.0 - this prevents division by zero and accidental overflows by division by < 1.0
	d = _mm_and_ps(_mm_castsi128_ps(_mm_set1_epi32(0xFF7FFFFF)), d);
	d = _mm_or_ps(_mm_castsi128_ps(_mm_set1_epi32(0x40000000)), d);
	r = _mm_add_ps(r, _mm_div_ps(n, d));
}

// 112×4 = 448
template <bool add>
inline __m128i single_comupte(__m128 n0, __m128 n1, __m128 n2, __m128 n3, float cnt, __m128 rnd_c, __m128& sum)
{
	__m128 c = _mm_set1_ps(cnt);
	__m128 r = _mm_setzero_ps();

	round_compute(n0, n1, n2, n3, rnd_c, c, r);
	round_compute(n0, n1, n2, n3, rnd_c, c, r);
	round_compute(n0, n1, n2, n3, rnd_c, c, r);
	round_compute(n0, n1, n2, n3, rnd_c, c, r);

	// do a quick fmod by setting exp to 2
	r = _mm_and_ps(_mm_castsi128_ps(_mm_set1_epi32(0x807FFFFF)), r);
	r = _mm_or_ps(_mm_castsi128_ps(_mm_set1_epi32(0x40000000)), r);

	if(add)
		sum = _mm_add_ps(sum, r);
	else
		sum = r;

	r = _mm_mul_ps(r, _mm_set1_ps(536870880.0f)); // 35
	return _mm_cvttps_epi32(r);
}

template <size_t rot>
inline void single_comupte_wrap(__m128 n0, __m128 n1, __m128 n2, __m128 n3, float cnt, __m128 rnd_c, __m128& sum, __m128i& out)
{
	__m128i r = single_comupte<rot % 2 != 0>(n0, n1, n2, n3, cnt, rnd_c, sum);
	if(rot != 0)
		r = _mm_or_si128(_mm_slli_si128(r, 16 - rot), _mm_srli_si128(r, rot));
	out = _mm_xor_si128(out, r);
}

inline __m128i* scratchpad_ptr(uint8_t* lpad, uint32_t idx, size_t n, const uint32_t mask) { return reinterpret_cast<__m128i*>(lpad + (idx & mask) + n * 16); }

void cn_gpu_inner_ssse3(const uint8_t* spad, uint8_t* lpad, const xmrstak_algo& algo)
{
	const uint32_t ITER = algo.Iter();
	const uint32_t mask = algo.Mask();

	uint32_t s = reinterpret_cast<const uint32_t*>(spad)[0] >> 8;
	__m128i* idx0 = scratchpad_ptr(lpad, s, 0, mask);
	__m128i* idx1 = scratchpad_ptr(lpad, s, 1, mask);
	__m128i* idx2 = scratchpad_ptr(lpad, s, 2, mask);
	__m128i* idx3 = scratchpad_ptr(lpad, s, 3, mask);
	__m128 sum0 = _mm_setzero_ps();

	for(size_t i = 0; i < ITER; i++)
	{
		__m128 n0, n1, n2, n3;
		__m128i v0, v1, v2, v3;
		__m128 suma, sumb, sum1, sum2, sum3;

		prep_dv(idx0, v0, n0);
		prep_dv(idx1, v1, n1);
		prep_dv(idx2, v2, n2);
		prep_dv(idx3, v3, n3);
		__m128 rc = sum0;

		__m128i out, out2;
		out = _mm_setzero_si128();
		single_comupte_wrap<0>(n0, n1, n2, n3, 1.3437500f, rc, suma, out);
		single_comupte_wrap<1>(n0, n2, n3, n1, 1.2812500f, rc, suma, out);
		single_comupte_wrap<2>(n0, n3, n1, n2, 1.3593750f, rc, sumb, out);
		single_comupte_wrap<3>(n0, n3, n2, n1, 1.3671875f, rc, sumb, out);
		sum0 = _mm_add_ps(suma, sumb);
		_mm_store_si128(idx0, _mm_xor_si128(v0, out));
		out2 = out;

		out = _mm_setzero_si128();
		single_comupte_wrap<0>(n1, n0, n2, n3, 1.4296875f, rc, suma, out);
		single_comupte_wrap<1>(n1, n2, n3, n0, 1.3984375f, rc, suma, out);
		single_comupte_wrap<2>(n1, n3, n0, n2, 1.3828125f, rc, sumb, out);
		single_comupte_wrap<3>(n1, n3, n2, n0, 1.3046875f, rc, sumb, out);
		sum1 = _mm_add_ps(suma, sumb);
		_mm_store_si128(idx1, _mm_xor_si128(v1, out));
		out2 = _mm_xor_si128(out2, out);

		out = _mm_setzero_si128();
		single_comupte_wrap<0>(n2, n1, n0, n3, 1.4140625f, rc, suma, out);
		single_comupte_wrap<1>(n2, n0, n3, n1, 1.2734375f, rc, suma, out);
		single_comupte_wrap<2>(n2, n3, n1, n0, 1.2578125f, rc, sumb, out);
		single_comupte_wrap<3>(n2, n3, n0, n1, 1.2890625f, rc, sumb, out);
		sum2 = _mm_add_ps(suma, sumb);
		_mm_store_si128(idx2, _mm_xor_si128(v2, out));
		out2 = _mm_xor_si128(out2, out);

		out = _mm_setzero_si128();
		single_comupte_wrap<0>(n3, n1, n2, n0, 1.3203125f, rc, suma, out);
		single_comupte_wrap<1>(n3, n2, n0, n1, 1.3515625f, rc, suma, out);
		single_comupte_wrap<2>(n3, n0, n1, n2, 1.3359375f, rc, sumb, out);
		single_comupte_wrap<3>(n3, n0, n2, n1, 1.4609375f, rc, sumb, out);
		sum3 = _mm_add_ps(suma, sumb);
		_mm_store_si128(idx3, _mm_xor_si128(v3, out));
		out2 = _mm_xor_si128(out2, out);
		sum0 = _mm_add_ps(sum0, sum1);
		sum2 = _mm_add_ps(sum2, sum3);
		sum0 = _mm_add_ps(sum0, sum2);

		sum0 = _mm_and_ps(_mm_castsi128_ps(_mm_set1_epi32(0x7fffffff)), sum0); // take abs(va) by masking the float sign bit
		// vs range 0 - 64
		n0 = _mm_mul_ps(sum0, _mm_set1_ps(16777216.0f));
		v0 = _mm_cvttps_epi32(n0);
		v0 = _mm_xor_si128(v0, out2);
		v1 = _mm_shuffle_epi32(v0, _MM_SHUFFLE(0, 1, 2, 3));
		v0 = _mm_xor_si128(v0, v1);
		v1 = _mm_shuffle_epi32(v0, _MM_SHUFFLE(0, 1, 0, 1));
		v0 = _mm_xor_si128(v0, v1);

		// vs is now between 0 and 1
		sum0 = _mm_div_ps(sum0, _mm_set1_ps(64.0f));
		uint32_t n = _mm_cvtsi128_si32(v0);
		idx0 = scratchpad_ptr(lpad, n, 0, mask);
		idx1 = scratchpad_ptr(lpad, n, 1, mask);
		idx2 = scratchpad_ptr(lpad, n, 2, mask);
		idx3 = scratchpad_ptr(lpad, n, 3, mask);
	}
}
