__attribute__((target ("avx")))
never_inline
void memsetd_l2(dword *t, dword data, size_t len)
{
	__m128i val4 = _mm_set1_epi32(data);
	__m256i val8 = _mm256_set1_epi32(data);
	auto Set4 = [&](size_t at) { _mm_storeu_si128((__m128i *)(t + at), val4); };
	#define Set8(at) _mm256_storeu_si256((__m256i *)(t + at), val8);
	Set4(len - 4); // fill tail
	if(len >= 32) {
		if(len >= 1024*1024) { // for really huge data, bypass the cache
			huge_memsetd(t, data, len);
			return;
		}
		Set8(0); // align up on 16 bytes boundary
		const dword *e = t + len;
		t = (dword *)(((uintptr_t)t | 31) + 1);
		len = e - t;
		e -= 32;
		while(t <= e) {
			Set8(0); Set8(8); Set8(16); Set8(24);
			t += 32;
		}
	}
	if(len & 16) {
		Set8(0); Set8(8);
		t += 16;
	}
	if(len & 8) {
		Set8(0);
		t += 8;
	}
	if(len & 4)
		Set4(0);
}

inline
void FillX(void *p, dword data, size_t len)
{
	dword *t = (dword *)p;
	if(len < 4) {
		if(len & 2) {
			t[0] = t[1] = t[len - 1] = data;
			return;
		}
		if(len & 1)
			t[0] = data;
		return;
	}

	if(len >= 16) {
		memsetd_l2(t, data, len);
		return;
	}

	__m128i val4 = _mm_set1_epi32(data);
	auto Set4 = [&](size_t at) { _mm_storeu_si128((__m128i *)(t + at), val4); };
	Set4(len - 4); // fill tail
	if(len & 8) {
		Set4(0); Set4(4);
		t += 8;
	}
	if(len & 4)
		Set4(0);
}