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be3c532bf4
- Make __fto64 function more readable - Call worker function directly for __rt_sdiv/udiv - Adapt __rt_sdiv64/udiv64 asm shims accordingly - Add header files to CMake source list CORE-17607 CORE-17614 CORE-17703 CORE-17604 Addendum tof2bc1f0e,e448094eand54406bf4.
104 lines
2.2 KiB
C
104 lines
2.2 KiB
C
/*
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* PROJECT: ReactOS CRT library
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* LICENSE: MIT (https://spdx.org/licenses/MIT)
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* PURPOSE: Float to integer conversion (__dtoi64/dtou64/stoi64/stou64)
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* COPYRIGHT: Copyright 2021 Roman Masanin <36927roma@gmail.com>
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*/
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#ifdef _USE_64_BITS_
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typedef double FLOAT_TYPE;
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typedef unsigned long long FINT_TYPE;
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#define FRACTION_LEN 52
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#define EXPONENT_LEN 11
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#else
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typedef float FLOAT_TYPE;
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typedef unsigned int FINT_TYPE;
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#define FRACTION_LEN 23
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#define EXPONENT_LEN 8
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#endif
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typedef
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#ifndef _USE_SIGNED_
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unsigned
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#endif
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long long FTO64_RESULT;
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typedef union _FTO64_UNION
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{
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FLOAT_TYPE value;
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FINT_TYPE raw;
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} FTO64_UNION;
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#define SIGN_MASK (((FINT_TYPE)1) << (FRACTION_LEN + EXPONENT_LEN))
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#define FRACTION_ONE (((FINT_TYPE)1) << FRACTION_LEN)
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#define FRACTION_MASK ((FRACTION_ONE) - 1)
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#define EXPONENT_MASK ((1 << EXPONENT_LEN) - 1)
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#define EXPONENT_ZERO ((1 << (EXPONENT_LEN - 1)) - 1)
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#ifdef _USE_SIGNED_
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#define EXPONENT_MAX 62
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#define INTNAN 0x8000000000000000ULL
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#else
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#define EXPONENT_MAX 63
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#define INTNAN 0xFFFFFFFFFFFFFFFFULL
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#endif
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#define EXPONENT_INFINITY EXPONENT_MASK
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#define NEGATE(x) (~(x) + 1)
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FTO64_RESULT
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__fto64(FLOAT_TYPE fvalue)
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{
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FTO64_UNION u = { .value = fvalue };
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FINT_TYPE value = u.raw;
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int exponent;
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FTO64_RESULT fraction;
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exponent = (int)(value >> FRACTION_LEN);
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exponent &= EXPONENT_MASK;
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/* infinity and other NaNs */
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if (exponent == EXPONENT_INFINITY)
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return INTNAN;
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/* subnormals and signed zeros */
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if (exponent == 0)
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return 0;
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exponent -= EXPONENT_ZERO;
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/* number is less then one */
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if (exponent < 0)
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return 0;
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/* number is too big */
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if (exponent > EXPONENT_MAX)
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return INTNAN;
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#ifndef _USE_SIGNED_
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if (value & SIGN_MASK)
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return INTNAN;
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#endif
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fraction = value & FRACTION_MASK;
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fraction |= FRACTION_ONE;
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exponent -= FRACTION_LEN;
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if (exponent != 0)
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{
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if (exponent < 0)
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fraction = fraction >> NEGATE(exponent);
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else
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fraction = fraction << exponent;
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}
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#ifdef _USE_SIGNED_
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if (value & SIGN_MASK)
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fraction = NEGATE(fraction);
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#endif
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return fraction;
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}
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