Add array to int function implementation.

This commit is contained in:
King_DuckZ 2018-07-25 00:10:33 +01:00
parent cbeb12afdd
commit b935e7e72e
2 changed files with 174 additions and 5 deletions

View file

@ -28,9 +28,29 @@
#if !defined(INT_CONV_WITHOUT_HELPERS)
# include <string_view>
#endif
#include <emmintrin.h>
#if defined(__SSE4_1__)
# include <smmintrin.h>
#endif
namespace dhandy {
namespace implem {
namespace {
[[gnu::always_inline]]
inline __m128i muly(const __m128i &a, const __m128i &b) {
#if defined(__SSE4_1__) // modern CPU - use SSE 4.1
return _mm_mullo_epi32(a, b);
#else // old CPU - use SSE 2
__m128i tmp1 = _mm_mul_epu32(a,b); /* mul 2,0*/
__m128i tmp2 = _mm_mul_epu32( _mm_srli_si128(a,4), _mm_srli_si128(b,4)); /* mul 3,1 */
return _mm_unpacklo_epi32(_mm_shuffle_epi32(tmp1, _MM_SHUFFLE (0,0,2,0)), _mm_shuffle_epi32(tmp2, _MM_SHUFFLE (0,0,2,0))); /* shuffle results to [63..0] and pack */
#endif
}
} //unnamed namespace
template <typename T, typename C, unsigned int Base, typename Tr>
T to_integer_sse (const C* s, std::size_t l);
template <typename I, std::size_t Base>
constexpr std::size_t max_digit_count = static_cast<std::size_t>(
sprout::ceil(
@ -89,7 +109,7 @@ namespace dhandy {
in = static_cast<I>(Num::cast(in) / static_cast<I>(Base));
} while (in);
if (was_negative)
arr.push_front(Tr::minus());
arr.push_front(Tr::Minus);
return arr;
}
};
@ -133,21 +153,129 @@ namespace dhandy {
arr.push_front(Tr::to_digit(static_cast<int>(lookup[Num::abs(in) * 2 + 0] - '0')));
}
if (was_negative)
arr.push_front(Tr::minus());
arr.push_front(Tr::Minus);
return arr;
}
};
template <typename I, unsigned int Base, typename Tr>
struct AryConversion {
template <typename C>
static I from_ary (C* beg, C* end) {
I retval = 0;
I factor = 1;
std::size_t i = end - beg;
const bool was_negative = (i and *beg == Tr::Minus);
if (i and (*beg == Tr::Minus or *beg == Tr::Plus)) {
i--;
beg++;
}
while (i--) {
retval += Tr::from_digit(beg[i]) * factor;
factor *= Base;
}
return retval;
}
};
template <typename I, typename Tr, typename=typename std::enable_if<Tr::BehavesLikeASCII and std::is_integral<I>::value and not std::is_same<I, bool>::value and sizeof(I) <= sizeof(uint32_t)>::type>
using SelectIForSSEToInt = I;
template <typename I, unsigned int Base, typename Tr>
struct AryConversion<SelectIForSSEToInt<I, Tr>, Base, Tr> {
template <typename C> static I from_ary (C* beg, C* end) { return to_integer_sse<I, C, Base, Tr>(beg, end - beg); }
};
template <unsigned int Base, typename Tr>
struct AryConversion<bool, Base, Tr> {
template <typename C> static bool from_ary (C* beg, C* end) {
if (end == beg)
return false;
return (Tr::from_digit(*beg) ? true : false);
}
};
template <typename T>
[[gnu::always_inline,gnu::pure]]
inline T negated_ifn (T n, bool negate) {
//return static_cast<int32_t>(((static_cast<unsigned int>(n) - (mask bitand 1)) xor mask) bitor ((mask bitand 1) << 31));
return (negate ? -n : n);
}
template <typename T, typename C, unsigned int Base, typename Tr>
[[gnu::pure]]
T to_integer_sse (const C* s, std::size_t l) {
static const constexpr int base1 = static_cast<int>(Base);
static const constexpr int base2 = base1 * base1;
static const constexpr int base3 = base1 * base1 * base1;
static const constexpr int base4 = base2 * base2;
__builtin_prefetch(s, 0);
const bool was_negative = (l and *s == Tr::Minus);
if (l and (*s == Tr::Minus or *s == Tr::Plus)) {
l--;
s++;
}
switch (l) {
case 0:
return 0;
case 1:
return negated_ifn(Tr::from_digit(*s), was_negative);
case 2:
return negated_ifn(Tr::from_digit(s[0]) * base1 + Tr::from_digit(s[1]), was_negative);
case 3:
return negated_ifn(Tr::from_digit(s[0]) * base2 + Tr::from_digit(s[1]) * base1 + Tr::from_digit(s[2]), was_negative);
default:
{
__m128i factor = _mm_set_epi32(base3, base2, base1, 1);
__m128i res = _mm_set1_epi32(0);
const __m128i char_0 = _mm_set1_epi32(Tr::FirstDigit);
const __m128i char_a = _mm_set1_epi32(Tr::FirstLetter);
std::size_t idx = 0;
const std::size_t cap = l bitand -4;
do {
const __m128i digits = _mm_set_epi32(s[cap - idx - 3 - 1], s[cap - idx - 2 - 1], s[cap - idx - 1 - 1], s[cap - idx - 0 - 1]);
const __m128i mask = _mm_cmplt_epi32(digits, char_a);
const __m128i addend = _mm_add_epi32(_mm_andnot_si128(mask, _mm_sub_epi32(char_a, _mm_set1_epi32(10))), _mm_and_si128(mask, char_0));
res = _mm_add_epi32(res, muly(_mm_sub_epi32(digits, addend), factor));
factor = muly(factor, _mm_set1_epi32(base4));
idx += 4;
} while (l - idx > 3);
{
res = _mm_add_epi32(res, _mm_srli_si128(res, 8));
res = _mm_add_epi32(res, _mm_srli_si128(res, 4));
const std::array<int, 4> scale {1, base1, base2, base3};
return negated_ifn(to_integer_sse<T, C, Base, Tr>(s + idx, l - idx) + _mm_cvtsi128_si32(res) * scale[l - idx], was_negative);
}
}
}
}
} //namespace implem
template <typename C, C FirstLetter='a'>
template <typename C, C FDigit='0', C FLetter='a', C CPlus='+', C CMinus='-'>
struct ASCIITranslator {
static const constexpr bool BehavesLikeASCII = true;
static const constexpr C FirstDigit = FDigit;
static const constexpr C FirstLetter = FLetter;
static const constexpr C Plus = CPlus;
static const constexpr C Minus = CMinus;
static constexpr C to_digit (unsigned int num) {
return (num <= 9 ?
static_cast<C>(num + '0') :
static_cast<C>(num + FirstDigit) :
static_cast<C>(num + FirstLetter - 10)
);
}
static constexpr C minus() { return '-'; }
static constexpr int from_digit (C dig) {
return (dig < FirstLetter ?
dig - FirstDigit :
dig - FirstLetter + 10
);
}
};
template <typename C>
using ASCIITranslatorUpcase = ASCIITranslator<C, 'A'>;
@ -157,6 +285,11 @@ namespace dhandy {
return implem::IntConversion<std::decay_t<I>, Base, Tr>::to_ary(in);
}
template <typename R, typename C, unsigned int Base=10, typename Tr=ASCIITranslator<C>>
inline R ary_to_int (C* beg, C* end) {
return implem::AryConversion<R, Base, Tr>::from_ary(beg, end);
}
#if !defined(INT_CONV_WITHOUT_HELPERS)
template <typename T, std::size_t S>
std::basic_string_view<T> to_string_view (const ReversedSizedArray<T, S>& ary) {

View file

@ -25,6 +25,14 @@ template <typename T> using int_info_10 = dhandy::implem::int_info<T, 10>;
template <typename T> using int_info_16 = dhandy::implem::int_info<T, 16>;
template <typename T> using int_info_2 = dhandy::implem::int_info<T, 2>;
namespace {
template <typename T, unsigned int Base>
void AryConversionTestHelper (const std::string_view& s, T expected) {
using AryConversion = dhandy::implem::AryConversion<T, Base, dhandy::ASCIITranslator<char>>;
CHECK(AryConversion::from_ary(s.data(), s.data() + s.size()) == expected);
}
} //unnamed namespace
TEST_CASE ("Check int to char array conversions", "[s2i][int_conv]") {
using dhandy::int_to_ary;
using dhandy::bt::string;
@ -101,3 +109,31 @@ TEST_CASE ("Check int to char array conversions", "[s2i][int_conv]") {
CHECK(to_string_view(int_to_ary<__int128_t, 16>(num * 0x10000 + 0xffff)) == "ffffffffffffffffffff");
#endif
}
TEST_CASE ("Check char array to int conversions", "[i2s][int_conv]") {
AryConversionTestHelper<uint32_t, 10>("0", 0);
AryConversionTestHelper<int32_t, 10>("0", 0);
AryConversionTestHelper<int16_t, 10>("0", 0);
AryConversionTestHelper<int16_t, 16>("ff", 0xff);
AryConversionTestHelper<uint8_t, 16>("ff", 0xff);
AryConversionTestHelper<uint32_t, 36>("rs", 1000);
AryConversionTestHelper<uint16_t, 8>("20", 16);
AryConversionTestHelper<int32_t, 10>("1", 1);
AryConversionTestHelper<int32_t, 10>("10", 10);
AryConversionTestHelper<int32_t, 10>("100", 100);
AryConversionTestHelper<int32_t, 10>("999", 999);
AryConversionTestHelper<int32_t, 10>("1000", 1000);
AryConversionTestHelper<int32_t, 10>("1001", 1001);
AryConversionTestHelper<int32_t, 10>("12345", 12345);
AryConversionTestHelper<int32_t, 10>("123456", 123456);
AryConversionTestHelper<int32_t, 10>("1234567", 1234567);
AryConversionTestHelper<int32_t, 10>("12345678", 12345678);
AryConversionTestHelper<int32_t, 10>("123456789", 123456789);
AryConversionTestHelper<int32_t, 10>("2147483647", 2147483647);
AryConversionTestHelper<uint64_t, 16>("ffffffffffffffff", 0xffffffffffffffff);
AryConversionTestHelper<int64_t, 16>("ffffffffffffffff", 0xffffffffffffffff);
AryConversionTestHelper<int64_t, 16>("7fffffffffffffff", 0x7fffffffffffffff);
AryConversionTestHelper<int32_t, 16>("7fffffff", 0x7fffffff);
AryConversionTestHelper<bool, 10>("1", true);
AryConversionTestHelper<bool, 10>("0", false);
}