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Diffstat (limited to 'third_party/rust/glslopt/glsl-optimizer/src/util/softfloat.c')
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1 files changed, 1475 insertions, 0 deletions
diff --git a/third_party/rust/glslopt/glsl-optimizer/src/util/softfloat.c b/third_party/rust/glslopt/glsl-optimizer/src/util/softfloat.c new file mode 100644 index 0000000000..591128efd4 --- /dev/null +++ b/third_party/rust/glslopt/glsl-optimizer/src/util/softfloat.c @@ -0,0 +1,1475 @@ +/* + * License for Berkeley SoftFloat Release 3e + * + * John R. Hauser + * 2018 January 20 + * + * The following applies to the whole of SoftFloat Release 3e as well as to + * each source file individually. + * + * Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 The Regents of the + * University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions, and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions, and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * + * The functions listed in this file are modified versions of the ones + * from the Berkeley SoftFloat 3e Library. + * + * Their implementation correctness has been checked with the Berkeley + * TestFloat Release 3e tool for x86_64. + */ + +#include "rounding.h" +#include "bitscan.h" +#include "softfloat.h" + +#if defined(BIG_ENDIAN) +#define word_incr -1 +#define index_word(total, n) ((total) - 1 - (n)) +#define index_word_hi(total) 0 +#define index_word_lo(total) ((total) - 1) +#define index_multiword_hi(total, n) 0 +#define index_multiword_lo(total, n) ((total) - (n)) +#define index_multiword_hi_but(total, n) 0 +#define index_multiword_lo_but(total, n) (n) +#else +#define word_incr 1 +#define index_word(total, n) (n) +#define index_word_hi(total) ((total) - 1) +#define index_word_lo(total) 0 +#define index_multiword_hi(total, n) ((total) - (n)) +#define index_multiword_lo(total, n) 0 +#define index_multiword_hi_but(total, n) (n) +#define index_multiword_lo_but(total, n) 0 +#endif + +typedef union { double f; int64_t i; uint64_t u; } di_type; +typedef union { float f; int32_t i; uint32_t u; } fi_type; + +const uint8_t count_leading_zeros8[256] = { + 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, + 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 +}; + +/** + * \brief Shifts 'a' right by the number of bits given in 'dist', which must be in + * the range 1 to 63. If any nonzero bits are shifted off, they are "jammed" + * into the least-significant bit of the shifted value by setting the + * least-significant bit to 1. This shifted-and-jammed value is returned. + * + * From softfloat_shortShiftRightJam64() + */ +static inline +uint64_t _mesa_short_shift_right_jam64(uint64_t a, uint8_t dist) +{ + return a >> dist | ((a & (((uint64_t) 1 << dist) - 1)) != 0); +} + +/** + * \brief Shifts 'a' right by the number of bits given in 'dist', which must not + * be zero. If any nonzero bits are shifted off, they are "jammed" into the + * least-significant bit of the shifted value by setting the least-significant + * bit to 1. This shifted-and-jammed value is returned. + * The value of 'dist' can be arbitrarily large. In particular, if 'dist' is + * greater than 64, the result will be either 0 or 1, depending on whether 'a' + * is zero or nonzero. + * + * From softfloat_shiftRightJam64() + */ +static inline +uint64_t _mesa_shift_right_jam64(uint64_t a, uint32_t dist) +{ + return + (dist < 63) ? a >> dist | ((uint64_t) (a << (-dist & 63)) != 0) : (a != 0); +} + +/** + * \brief Shifts 'a' right by the number of bits given in 'dist', which must not be + * zero. If any nonzero bits are shifted off, they are "jammed" into the + * least-significant bit of the shifted value by setting the least-significant + * bit to 1. This shifted-and-jammed value is returned. + * The value of 'dist' can be arbitrarily large. In particular, if 'dist' is + * greater than 32, the result will be either 0 or 1, depending on whether 'a' + * is zero or nonzero. + * + * From softfloat_shiftRightJam32() + */ +static inline +uint32_t _mesa_shift_right_jam32(uint32_t a, uint16_t dist) +{ + return + (dist < 31) ? a >> dist | ((uint32_t) (a << (-dist & 31)) != 0) : (a != 0); +} + +/** + * \brief Extracted from softfloat_roundPackToF64() + */ +static inline +double _mesa_roundtozero_f64(int64_t s, int64_t e, int64_t m) +{ + di_type result; + + if ((uint64_t) e >= 0x7fd) { + if (e < 0) { + m = _mesa_shift_right_jam64(m, -e); + e = 0; + } else if ((e > 0x7fd) || (0x8000000000000000 <= m)) { + e = 0x7ff; + m = 0; + result.u = (s << 63) + (e << 52) + m; + result.u -= 1; + return result.f; + } + } + + m >>= 10; + if (m == 0) + e = 0; + + result.u = (s << 63) + (e << 52) + m; + return result.f; +} + +/** + * \brief Extracted from softfloat_roundPackToF32() + */ +static inline +float _mesa_round_f32(int32_t s, int32_t e, int32_t m, bool rtz) +{ + fi_type result; + uint8_t round_increment = rtz ? 0 : 0x40; + + if ((uint32_t) e >= 0xfd) { + if (e < 0) { + m = _mesa_shift_right_jam32(m, -e); + e = 0; + } else if ((e > 0xfd) || (0x80000000 <= m + round_increment)) { + e = 0xff; + m = 0; + result.u = (s << 31) + (e << 23) + m; + result.u -= !round_increment; + return result.f; + } + } + + uint8_t round_bits; + round_bits = m & 0x7f; + m = ((uint32_t) m + round_increment) >> 7; + m &= ~(uint32_t) (! (round_bits ^ 0x40) & !rtz); + if (m == 0) + e = 0; + + result.u = (s << 31) + (e << 23) + m; + return result.f; +} + +/** + * \brief Extracted from softfloat_roundPackToF16() + */ +static inline +uint16_t _mesa_roundtozero_f16(int16_t s, int16_t e, int16_t m) +{ + if ((uint16_t) e >= 0x1d) { + if (e < 0) { + m = _mesa_shift_right_jam32(m, -e); + e = 0; + } else if ((e > 0x1d) || (0x8000 <= m)) { + e = 0x1f; + m = 0; + return (s << 15) + (e << 10) + m - 1; + } + } + + m >>= 4; + if (m == 0) + e = 0; + + return (s << 15) + (e << 10) + m; +} + +/** + * \brief Shifts the N-bit unsigned integer pointed to by 'a' left by the number of + * bits given in 'dist', where N = 'size_words' * 32. The value of 'dist' + * must be in the range 1 to 31. Any nonzero bits shifted off are lost. The + * shifted N-bit result is stored at the location pointed to by 'm_out'. Each + * of 'a' and 'm_out' points to a 'size_words'-long array of 32-bit elements + * that concatenate in the platform's normal endian order to form an N-bit + * integer. + * + * From softfloat_shortShiftLeftM() + */ +static inline void +_mesa_short_shift_left_m(uint8_t size_words, const uint32_t *a, uint8_t dist, uint32_t *m_out) +{ + uint8_t neg_dist; + unsigned index, last_index; + uint32_t part_word, a_word; + + neg_dist = -dist; + index = index_word_hi(size_words); + last_index = index_word_lo(size_words); + part_word = a[index] << dist; + while (index != last_index) { + a_word = a[index - word_incr]; + m_out[index] = part_word | a_word >> (neg_dist & 31); + index -= word_incr; + part_word = a_word << dist; + } + m_out[index] = part_word; +} + +/** + * \brief Shifts the N-bit unsigned integer pointed to by 'a' left by the number of + * bits given in 'dist', where N = 'size_words' * 32. The value of 'dist' + * must not be zero. Any nonzero bits shifted off are lost. The shifted + * N-bit result is stored at the location pointed to by 'm_out'. Each of 'a' + * and 'm_out' points to a 'size_words'-long array of 32-bit elements that + * concatenate in the platform's normal endian order to form an N-bit + * integer. The value of 'dist' can be arbitrarily large. In particular, if + * 'dist' is greater than N, the stored result will be 0. + * + * From softfloat_shiftLeftM() + */ +static inline void +_mesa_shift_left_m(uint8_t size_words, const uint32_t *a, uint32_t dist, uint32_t *m_out) +{ + uint32_t word_dist; + uint8_t inner_dist; + uint8_t i; + + word_dist = dist >> 5; + if (word_dist < size_words) { + a += index_multiword_lo_but(size_words, word_dist); + inner_dist = dist & 31; + if (inner_dist) { + _mesa_short_shift_left_m(size_words - word_dist, a, inner_dist, + m_out + index_multiword_hi_but(size_words, word_dist)); + if (!word_dist) + return; + } else { + uint32_t *dest = m_out + index_word_hi(size_words); + a += index_word_hi(size_words - word_dist); + for (i = size_words - word_dist; i; --i) { + *dest = *a; + a -= word_incr; + dest -= word_incr; + } + } + m_out += index_multiword_lo(size_words, word_dist); + } else { + word_dist = size_words; + } + do { + *m_out++ = 0; + --word_dist; + } while (word_dist); +} + +/** + * \brief Shifts the N-bit unsigned integer pointed to by 'a' right by the number of + * bits given in 'dist', where N = 'size_words' * 32. The value of 'dist' + * must be in the range 1 to 31. Any nonzero bits shifted off are lost. The + * shifted N-bit result is stored at the location pointed to by 'm_out'. Each + * of 'a' and 'm_out' points to a 'size_words'-long array of 32-bit elements + * that concatenate in the platform's normal endian order to form an N-bit + * integer. + * + * From softfloat_shortShiftRightM() + */ +static inline void +_mesa_short_shift_right_m(uint8_t size_words, const uint32_t *a, uint8_t dist, uint32_t *m_out) +{ + uint8_t neg_dist; + unsigned index, last_index; + uint32_t part_word, a_word; + + neg_dist = -dist; + index = index_word_lo(size_words); + last_index = index_word_hi(size_words); + part_word = a[index] >> dist; + while (index != last_index) { + a_word = a[index + word_incr]; + m_out[index] = a_word << (neg_dist & 31) | part_word; + index += word_incr; + part_word = a_word >> dist; + } + m_out[index] = part_word; +} + +/** + * \brief Shifts the N-bit unsigned integer pointed to by 'a' right by the number of + * bits given in 'dist', where N = 'size_words' * 32. The value of 'dist' + * must be in the range 1 to 31. If any nonzero bits are shifted off, they + * are "jammed" into the least-significant bit of the shifted value by setting + * the least-significant bit to 1. This shifted-and-jammed N-bit result is + * stored at the location pointed to by 'm_out'. Each of 'a' and 'm_out' + * points to a 'size_words'-long array of 32-bit elements that concatenate in + * the platform's normal endian order to form an N-bit integer. + * + * + * From softfloat_shortShiftRightJamM() + */ +static inline void +_mesa_short_shift_right_jam_m(uint8_t size_words, const uint32_t *a, uint8_t dist, uint32_t *m_out) +{ + uint8_t neg_dist; + unsigned index, last_index; + uint64_t part_word, a_word; + + neg_dist = -dist; + index = index_word_lo(size_words); + last_index = index_word_hi(size_words); + a_word = a[index]; + part_word = a_word >> dist; + if (part_word << dist != a_word ) + part_word |= 1; + while (index != last_index) { + a_word = a[index + word_incr]; + m_out[index] = a_word << (neg_dist & 31) | part_word; + index += word_incr; + part_word = a_word >> dist; + } + m_out[index] = part_word; +} + +/** + * \brief Shifts the N-bit unsigned integer pointed to by 'a' right by the number of + * bits given in 'dist', where N = 'size_words' * 32. The value of 'dist' + * must not be zero. If any nonzero bits are shifted off, they are "jammed" + * into the least-significant bit of the shifted value by setting the + * least-significant bit to 1. This shifted-and-jammed N-bit result is stored + * at the location pointed to by 'm_out'. Each of 'a' and 'm_out' points to a + * 'size_words'-long array of 32-bit elements that concatenate in the + * platform's normal endian order to form an N-bit integer. The value of + * 'dist' can be arbitrarily large. In particular, if 'dist' is greater than + * N, the stored result will be either 0 or 1, depending on whether the + * original N bits are all zeros. + * + * From softfloat_shiftRightJamM() + */ +static inline void +_mesa_shift_right_jam_m(uint8_t size_words, const uint32_t *a, uint32_t dist, uint32_t *m_out) +{ + uint32_t word_jam, word_dist, *tmp; + uint8_t i, inner_dist; + + word_jam = 0; + word_dist = dist >> 5; + if (word_dist) { + if (size_words < word_dist) + word_dist = size_words; + tmp = (uint32_t *) (a + index_multiword_lo(size_words, word_dist)); + i = word_dist; + do { + word_jam = *tmp++; + if (word_jam) + break; + --i; + } while (i); + tmp = m_out; + } + if (word_dist < size_words) { + a += index_multiword_hi_but(size_words, word_dist); + inner_dist = dist & 31; + if (inner_dist) { + _mesa_short_shift_right_jam_m(size_words - word_dist, a, inner_dist, + m_out + index_multiword_lo_but(size_words, word_dist)); + if (!word_dist) { + if (word_jam) + m_out[index_word_lo(size_words)] |= 1; + return; + } + } else { + a += index_word_lo(size_words - word_dist); + tmp = m_out + index_word_lo(size_words); + for (i = size_words - word_dist; i; --i) { + *tmp = *a; + a += word_incr; + tmp += word_incr; + } + } + tmp = m_out + index_multiword_hi(size_words, word_dist); + } + do { + *tmp++ = 0; + --word_dist; + } while (word_dist); + if (word_jam) + m_out[index_word_lo(size_words)] |= 1; +} + +/** + * \brief Calculate a + b but rounding to zero. + * + * Notice that this mainly differs from the original Berkeley SoftFloat 3e + * implementation in that we don't really treat NaNs, Zeroes nor the + * signalling flags. Any NaN is good for us and the sign of the Zero is not + * important. + * + * From f64_add() + */ +double +_mesa_double_add_rtz(double a, double b) +{ + const di_type a_di = {a}; + uint64_t a_flt_m = a_di.u & 0x0fffffffffffff; + uint64_t a_flt_e = (a_di.u >> 52) & 0x7ff; + uint64_t a_flt_s = (a_di.u >> 63) & 0x1; + const di_type b_di = {b}; + uint64_t b_flt_m = b_di.u & 0x0fffffffffffff; + uint64_t b_flt_e = (b_di.u >> 52) & 0x7ff; + uint64_t b_flt_s = (b_di.u >> 63) & 0x1; + int64_t s, e, m = 0; + + s = a_flt_s; + + const int64_t exp_diff = a_flt_e - b_flt_e; + + /* Handle special cases */ + + if (a_flt_s != b_flt_s) { + return _mesa_double_sub_rtz(a, -b); + } else if ((a_flt_e == 0) && (a_flt_m == 0)) { + /* 'a' is zero, return 'b' */ + return b; + } else if ((b_flt_e == 0) && (b_flt_m == 0)) { + /* 'b' is zero, return 'a' */ + return a; + } else if (a_flt_e == 0x7ff && a_flt_m != 0) { + /* 'a' is a NaN, return NaN */ + return a; + } else if (b_flt_e == 0x7ff && b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } else if (a_flt_e == 0x7ff && a_flt_m == 0) { + /* Inf + x = Inf */ + return a; + } else if (b_flt_e == 0x7ff && b_flt_m == 0) { + /* x + Inf = Inf */ + return b; + } else if (exp_diff == 0 && a_flt_e == 0) { + di_type result_di; + result_di.u = a_di.u + b_flt_m; + return result_di.f; + } else if (exp_diff == 0) { + e = a_flt_e; + m = 0x0020000000000000 + a_flt_m + b_flt_m; + m <<= 9; + } else if (exp_diff < 0) { + a_flt_m <<= 9; + b_flt_m <<= 9; + e = b_flt_e; + + if (a_flt_e != 0) + a_flt_m += 0x2000000000000000; + else + a_flt_m <<= 1; + + a_flt_m = _mesa_shift_right_jam64(a_flt_m, -exp_diff); + m = 0x2000000000000000 + a_flt_m + b_flt_m; + if (m < 0x4000000000000000) { + --e; + m <<= 1; + } + } else { + a_flt_m <<= 9; + b_flt_m <<= 9; + e = a_flt_e; + + if (b_flt_e != 0) + b_flt_m += 0x2000000000000000; + else + b_flt_m <<= 1; + + b_flt_m = _mesa_shift_right_jam64(b_flt_m, exp_diff); + m = 0x2000000000000000 + a_flt_m + b_flt_m; + if (m < 0x4000000000000000) { + --e; + m <<= 1; + } + } + + return _mesa_roundtozero_f64(s, e, m); +} + +/** + * \brief Returns the number of leading 0 bits before the most-significant 1 bit of + * 'a'. If 'a' is zero, 64 is returned. + */ +static inline unsigned +_mesa_count_leading_zeros64(uint64_t a) +{ + return 64 - util_last_bit64(a); +} + +/** + * \brief Returns the number of leading 0 bits before the most-significant 1 bit of + * 'a'. If 'a' is zero, 32 is returned. + */ +static inline unsigned +_mesa_count_leading_zeros32(uint32_t a) +{ + return 32 - util_last_bit(a); +} + +static inline double +_mesa_norm_round_pack_f64(int64_t s, int64_t e, int64_t m) +{ + int8_t shift_dist; + + shift_dist = _mesa_count_leading_zeros64(m) - 1; + e -= shift_dist; + if ((10 <= shift_dist) && ((unsigned) e < 0x7fd)) { + di_type result; + result.u = (s << 63) + ((m ? e : 0) << 52) + (m << (shift_dist - 10)); + return result.f; + } else { + return _mesa_roundtozero_f64(s, e, m << shift_dist); + } +} + +/** + * \brief Replaces the N-bit unsigned integer pointed to by 'm_out' by the + * 2s-complement of itself, where N = 'size_words' * 32. Argument 'm_out' + * points to a 'size_words'-long array of 32-bit elements that concatenate in + * the platform's normal endian order to form an N-bit integer. + * + * From softfloat_negXM() + */ +static inline void +_mesa_neg_x_m(uint8_t size_words, uint32_t *m_out) +{ + unsigned index, last_index; + uint8_t carry; + uint32_t word; + + index = index_word_lo(size_words); + last_index = index_word_hi(size_words); + carry = 1; + for (;;) { + word = ~m_out[index] + carry; + m_out[index] = word; + if (index == last_index) + break; + index += word_incr; + if (word) + carry = 0; + } +} + +/** + * \brief Adds the two N-bit integers pointed to by 'a' and 'b', where N = + * 'size_words' * 32. The addition is modulo 2^N, so any carry out is + * lost. The N-bit sum is stored at the location pointed to by 'm_out'. Each + * of 'a', 'b', and 'm_out' points to a 'size_words'-long array of 32-bit + * elements that concatenate in the platform's normal endian order to form an + * N-bit integer. + * + * From softfloat_addM() + */ +static inline void +_mesa_add_m(uint8_t size_words, const uint32_t *a, const uint32_t *b, uint32_t *m_out) +{ + unsigned index, last_index; + uint8_t carry; + uint32_t a_word, word; + + index = index_word_lo(size_words); + last_index = index_word_hi(size_words); + carry = 0; + for (;;) { + a_word = a[index]; + word = a_word + b[index] + carry; + m_out[index] = word; + if (index == last_index) + break; + if (word != a_word) + carry = (word < a_word); + index += word_incr; + } +} + +/** + * \brief Subtracts the two N-bit integers pointed to by 'a' and 'b', where N = + * 'size_words' * 32. The subtraction is modulo 2^N, so any borrow out (carry + * out) is lost. The N-bit difference is stored at the location pointed to by + * 'm_out'. Each of 'a', 'b', and 'm_out' points to a 'size_words'-long array + * of 32-bit elements that concatenate in the platform's normal endian order + * to form an N-bit integer. + * + * From softfloat_subM() + */ +static inline void +_mesa_sub_m(uint8_t size_words, const uint32_t *a, const uint32_t *b, uint32_t *m_out) +{ + unsigned index, last_index; + uint8_t borrow; + uint32_t a_word, b_word; + + index = index_word_lo(size_words); + last_index = index_word_hi(size_words); + borrow = 0; + for (;;) { + a_word = a[index]; + b_word = b[index]; + m_out[index] = a_word - b_word - borrow; + if (index == last_index) + break; + borrow = borrow ? (a_word <= b_word) : (a_word < b_word); + index += word_incr; + } +} + +/* Calculate a - b but rounding to zero. + * + * Notice that this mainly differs from the original Berkeley SoftFloat 3e + * implementation in that we don't really treat NaNs, Zeroes nor the + * signalling flags. Any NaN is good for us and the sign of the Zero is not + * important. + * + * From f64_sub() + */ +double +_mesa_double_sub_rtz(double a, double b) +{ + const di_type a_di = {a}; + uint64_t a_flt_m = a_di.u & 0x0fffffffffffff; + uint64_t a_flt_e = (a_di.u >> 52) & 0x7ff; + uint64_t a_flt_s = (a_di.u >> 63) & 0x1; + const di_type b_di = {b}; + uint64_t b_flt_m = b_di.u & 0x0fffffffffffff; + uint64_t b_flt_e = (b_di.u >> 52) & 0x7ff; + uint64_t b_flt_s = (b_di.u >> 63) & 0x1; + int64_t s, e, m = 0; + int64_t m_diff = 0; + unsigned shift_dist = 0; + + s = a_flt_s; + + const int64_t exp_diff = a_flt_e - b_flt_e; + + /* Handle special cases */ + + if (a_flt_s != b_flt_s) { + return _mesa_double_add_rtz(a, -b); + } else if ((a_flt_e == 0) && (a_flt_m == 0)) { + /* 'a' is zero, return '-b' */ + return -b; + } else if ((b_flt_e == 0) && (b_flt_m == 0)) { + /* 'b' is zero, return 'a' */ + return a; + } else if (a_flt_e == 0x7ff && a_flt_m != 0) { + /* 'a' is a NaN, return NaN */ + return a; + } else if (b_flt_e == 0x7ff && b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } else if (a_flt_e == 0x7ff && a_flt_m == 0) { + if (b_flt_e == 0x7ff && b_flt_m == 0) { + /* Inf - Inf = NaN */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0x1; + return result.f; + } + /* Inf - x = Inf */ + return a; + } else if (b_flt_e == 0x7ff && b_flt_m == 0) { + /* x - Inf = -Inf */ + return -b; + } else if (exp_diff == 0) { + m_diff = a_flt_m - b_flt_m; + + if (m_diff == 0) + return 0; + if (a_flt_e) + --a_flt_e; + if (m_diff < 0) { + s = !s; + m_diff = -m_diff; + } + + shift_dist = _mesa_count_leading_zeros64(m_diff) - 11; + e = a_flt_e - shift_dist; + if (e < 0) { + shift_dist = a_flt_e; + e = 0; + } + + di_type result; + result.u = (s << 63) + (e << 52) + (m_diff << shift_dist); + return result.f; + } else if (exp_diff < 0) { + a_flt_m <<= 10; + b_flt_m <<= 10; + s = !s; + + a_flt_m += (a_flt_e) ? 0x4000000000000000 : a_flt_m; + a_flt_m = _mesa_shift_right_jam64(a_flt_m, -exp_diff); + b_flt_m |= 0x4000000000000000; + e = b_flt_e; + m = b_flt_m - a_flt_m; + } else { + a_flt_m <<= 10; + b_flt_m <<= 10; + + b_flt_m += (b_flt_e) ? 0x4000000000000000 : b_flt_m; + b_flt_m = _mesa_shift_right_jam64(b_flt_m, exp_diff); + a_flt_m |= 0x4000000000000000; + e = a_flt_e; + m = a_flt_m - b_flt_m; + } + + return _mesa_norm_round_pack_f64(s, e - 1, m); +} + +static inline void +_mesa_norm_subnormal_mantissa_f64(uint64_t m, uint64_t *exp, uint64_t *m_out) +{ + int shift_dist; + + shift_dist = _mesa_count_leading_zeros64(m) - 11; + *exp = 1 - shift_dist; + *m_out = m << shift_dist; +} + +static inline void +_mesa_norm_subnormal_mantissa_f32(uint32_t m, uint32_t *exp, uint32_t *m_out) +{ + int shift_dist; + + shift_dist = _mesa_count_leading_zeros32(m) - 8; + *exp = 1 - shift_dist; + *m_out = m << shift_dist; +} + +/** + * \brief Multiplies 'a' and 'b' and stores the 128-bit product at the location + * pointed to by 'zPtr'. Argument 'zPtr' points to an array of four 32-bit + * elements that concatenate in the platform's normal endian order to form a + * 128-bit integer. + * + * From softfloat_mul64To128M() + */ +static inline void +_mesa_softfloat_mul_f64_to_f128_m(uint64_t a, uint64_t b, uint32_t *m_out) +{ + uint32_t a32, a0, b32, b0; + uint64_t z0, mid1, z64, mid; + + a32 = a >> 32; + a0 = a; + b32 = b >> 32; + b0 = b; + z0 = (uint64_t) a0 * b0; + mid1 = (uint64_t) a32 * b0; + mid = mid1 + (uint64_t) a0 * b32; + z64 = (uint64_t) a32 * b32; + z64 += (uint64_t) (mid < mid1) << 32 | mid >> 32; + mid <<= 32; + z0 += mid; + m_out[index_word(4, 1)] = z0 >> 32; + m_out[index_word(4, 0)] = z0; + z64 += (z0 < mid); + m_out[index_word(4, 3)] = z64 >> 32; + m_out[index_word(4, 2)] = z64; +} + +/* Calculate a * b but rounding to zero. + * + * Notice that this mainly differs from the original Berkeley SoftFloat 3e + * implementation in that we don't really treat NaNs, Zeroes nor the + * signalling flags. Any NaN is good for us and the sign of the Zero is not + * important. + * + * From f64_mul() + */ +double +_mesa_double_mul_rtz(double a, double b) +{ + const di_type a_di = {a}; + uint64_t a_flt_m = a_di.u & 0x0fffffffffffff; + uint64_t a_flt_e = (a_di.u >> 52) & 0x7ff; + uint64_t a_flt_s = (a_di.u >> 63) & 0x1; + const di_type b_di = {b}; + uint64_t b_flt_m = b_di.u & 0x0fffffffffffff; + uint64_t b_flt_e = (b_di.u >> 52) & 0x7ff; + uint64_t b_flt_s = (b_di.u >> 63) & 0x1; + int64_t s, e, m = 0; + + s = a_flt_s ^ b_flt_s; + + if (a_flt_e == 0x7ff) { + if (a_flt_m != 0) { + /* 'a' is a NaN, return NaN */ + return a; + } else if (b_flt_e == 0x7ff && b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } + + if (!(b_flt_e | b_flt_m)) { + /* Inf * 0 = NaN */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0x1; + return result.f; + } + /* Inf * x = Inf */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0; + return result.f; + } + + if (b_flt_e == 0x7ff) { + if (b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } + if (!(a_flt_e | a_flt_m)) { + /* 0 * Inf = NaN */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0x1; + return result.f; + } + /* x * Inf = Inf */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0; + return result.f; + } + + if (a_flt_e == 0) { + if (a_flt_m == 0) { + /* 'a' is zero. Return zero */ + di_type result; + result.u = (s << 63) + 0; + return result.f; + } + _mesa_norm_subnormal_mantissa_f64(a_flt_m , &a_flt_e, &a_flt_m); + } + if (b_flt_e == 0) { + if (b_flt_m == 0) { + /* 'b' is zero. Return zero */ + di_type result; + result.u = (s << 63) + 0; + return result.f; + } + _mesa_norm_subnormal_mantissa_f64(b_flt_m , &b_flt_e, &b_flt_m); + } + + e = a_flt_e + b_flt_e - 0x3ff; + a_flt_m = (a_flt_m | 0x0010000000000000) << 10; + b_flt_m = (b_flt_m | 0x0010000000000000) << 11; + + uint32_t m_128[4]; + _mesa_softfloat_mul_f64_to_f128_m(a_flt_m, b_flt_m, m_128); + + m = (uint64_t) m_128[index_word(4, 3)] << 32 | m_128[index_word(4, 2)]; + if (m_128[index_word(4, 1)] || m_128[index_word(4, 0)]) + m |= 1; + + if (m < 0x4000000000000000) { + --e; + m <<= 1; + } + + return _mesa_roundtozero_f64(s, e, m); +} + + +/** + * \brief Calculate a * b + c but rounding to zero. + * + * Notice that this mainly differs from the original Berkeley SoftFloat 3e + * implementation in that we don't really treat NaNs, Zeroes nor the + * signalling flags. Any NaN is good for us and the sign of the Zero is not + * important. + * + * From f64_mulAdd() + */ +double +_mesa_double_fma_rtz(double a, double b, double c) +{ + const di_type a_di = {a}; + uint64_t a_flt_m = a_di.u & 0x0fffffffffffff; + uint64_t a_flt_e = (a_di.u >> 52) & 0x7ff; + uint64_t a_flt_s = (a_di.u >> 63) & 0x1; + const di_type b_di = {b}; + uint64_t b_flt_m = b_di.u & 0x0fffffffffffff; + uint64_t b_flt_e = (b_di.u >> 52) & 0x7ff; + uint64_t b_flt_s = (b_di.u >> 63) & 0x1; + const di_type c_di = {c}; + uint64_t c_flt_m = c_di.u & 0x0fffffffffffff; + uint64_t c_flt_e = (c_di.u >> 52) & 0x7ff; + uint64_t c_flt_s = (c_di.u >> 63) & 0x1; + int64_t s, e, m = 0; + + c_flt_s ^= 0; + s = a_flt_s ^ b_flt_s ^ 0; + + if (a_flt_e == 0x7ff) { + if (a_flt_m != 0) { + /* 'a' is a NaN, return NaN */ + return a; + } else if (b_flt_e == 0x7ff && b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } else if (c_flt_e == 0x7ff && c_flt_m != 0) { + /* 'c' is a NaN, return NaN */ + return c; + } + + if (!(b_flt_e | b_flt_m)) { + /* Inf * 0 + y = NaN */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0x1; + return result.f; + } + + if ((c_flt_e == 0x7ff && c_flt_m == 0) && (s != c_flt_s)) { + /* Inf * x - Inf = NaN */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0x1; + return result.f; + } + + /* Inf * x + y = Inf */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0; + return result.f; + } + + if (b_flt_e == 0x7ff) { + if (b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } else if (c_flt_e == 0x7ff && c_flt_m != 0) { + /* 'c' is a NaN, return NaN */ + return c; + } + + if (!(a_flt_e | a_flt_m)) { + /* 0 * Inf + y = NaN */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0x1; + return result.f; + } + + if ((c_flt_e == 0x7ff && c_flt_m == 0) && (s != c_flt_s)) { + /* x * Inf - Inf = NaN */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0x1; + return result.f; + } + + /* x * Inf + y = Inf */ + di_type result; + e = 0x7ff; + result.u = (s << 63) + (e << 52) + 0; + return result.f; + } + + if (c_flt_e == 0x7ff) { + if (c_flt_m != 0) { + /* 'c' is a NaN, return NaN */ + return c; + } + + /* x * y + Inf = Inf */ + return c; + } + + if (a_flt_e == 0) { + if (a_flt_m == 0) { + /* 'a' is zero, return 'c' */ + return c; + } + _mesa_norm_subnormal_mantissa_f64(a_flt_m , &a_flt_e, &a_flt_m); + } + + if (b_flt_e == 0) { + if (b_flt_m == 0) { + /* 'b' is zero, return 'c' */ + return c; + } + _mesa_norm_subnormal_mantissa_f64(b_flt_m , &b_flt_e, &b_flt_m); + } + + e = a_flt_e + b_flt_e - 0x3fe; + a_flt_m = (a_flt_m | 0x0010000000000000) << 10; + b_flt_m = (b_flt_m | 0x0010000000000000) << 11; + + uint32_t m_128[4]; + _mesa_softfloat_mul_f64_to_f128_m(a_flt_m, b_flt_m, m_128); + + m = (uint64_t) m_128[index_word(4, 3)] << 32 | m_128[index_word(4, 2)]; + + int64_t shift_dist = 0; + if (!(m & 0x4000000000000000)) { + --e; + shift_dist = -1; + } + + if (c_flt_e == 0) { + if (c_flt_m == 0) { + /* 'c' is zero, return 'a * b' */ + if (shift_dist) + m <<= 1; + + if (m_128[index_word(4, 1)] || m_128[index_word(4, 0)]) + m |= 1; + return _mesa_roundtozero_f64(s, e - 1, m); + } + _mesa_norm_subnormal_mantissa_f64(c_flt_m , &c_flt_e, &c_flt_m); + } + c_flt_m = (c_flt_m | 0x0010000000000000) << 10; + + uint32_t c_flt_m_128[4]; + int64_t exp_diff = e - c_flt_e; + if (exp_diff < 0) { + e = c_flt_e; + if ((s == c_flt_s) || (exp_diff < -1)) { + shift_dist -= exp_diff; + if (shift_dist) { + m = _mesa_shift_right_jam64(m, shift_dist); + } + } else { + if (!shift_dist) { + _mesa_short_shift_right_m(4, m_128, 1, m_128); + } + } + } else { + if (shift_dist) + _mesa_add_m(4, m_128, m_128, m_128); + if (!exp_diff) { + m = (uint64_t) m_128[index_word(4, 3)] << 32 + | m_128[index_word(4, 2)]; + } else { + c_flt_m_128[index_word(4, 3)] = c_flt_m >> 32; + c_flt_m_128[index_word(4, 2)] = c_flt_m; + c_flt_m_128[index_word(4, 1)] = 0; + c_flt_m_128[index_word(4, 0)] = 0; + _mesa_shift_right_jam_m(4, c_flt_m_128, exp_diff, c_flt_m_128); + } + } + + if (s == c_flt_s) { + if (exp_diff <= 0) { + m += c_flt_m; + } else { + _mesa_add_m(4, m_128, c_flt_m_128, m_128); + m = (uint64_t) m_128[index_word(4, 3)] << 32 + | m_128[index_word(4, 2)]; + } + if (m & 0x8000000000000000) { + e++; + m = _mesa_short_shift_right_jam64(m, 1); + } + } else { + if (exp_diff < 0) { + s = c_flt_s; + if (exp_diff < -1) { + m = c_flt_m - m; + if (m_128[index_word(4, 1)] || m_128[index_word(4, 0)]) { + m = (m - 1) | 1; + } + if (!(m & 0x4000000000000000)) { + --e; + m <<= 1; + } + return _mesa_roundtozero_f64(s, e - 1, m); + } else { + c_flt_m_128[index_word(4, 3)] = c_flt_m >> 32; + c_flt_m_128[index_word(4, 2)] = c_flt_m; + c_flt_m_128[index_word(4, 1)] = 0; + c_flt_m_128[index_word(4, 0)] = 0; + _mesa_sub_m(4, c_flt_m_128, m_128, m_128); + } + } else if (!exp_diff) { + m -= c_flt_m; + if (!m && !m_128[index_word(4, 1)] && !m_128[index_word(4, 0)]) { + /* Return zero */ + di_type result; + result.u = (s << 63) + 0; + return result.f; + } + m_128[index_word(4, 3)] = m >> 32; + m_128[index_word(4, 2)] = m; + if (m & 0x8000000000000000) { + s = !s; + _mesa_neg_x_m(4, m_128); + } + } else { + _mesa_sub_m(4, m_128, c_flt_m_128, m_128); + if (1 < exp_diff) { + m = (uint64_t) m_128[index_word(4, 3)] << 32 + | m_128[index_word(4, 2)]; + if (!(m & 0x4000000000000000)) { + --e; + m <<= 1; + } + if (m_128[index_word(4, 1)] || m_128[index_word(4, 0)]) + m |= 1; + return _mesa_roundtozero_f64(s, e - 1, m); + } + } + + shift_dist = 0; + m = (uint64_t) m_128[index_word(4, 3)] << 32 + | m_128[index_word(4, 2)]; + if (!m) { + shift_dist = 64; + m = (uint64_t) m_128[index_word(4, 1)] << 32 + | m_128[index_word(4, 0)]; + } + shift_dist += _mesa_count_leading_zeros64(m) - 1; + if (shift_dist) { + e -= shift_dist; + _mesa_shift_left_m(4, m_128, shift_dist, m_128); + m = (uint64_t) m_128[index_word(4, 3)] << 32 + | m_128[index_word(4, 2)]; + } + } + + if (m_128[index_word(4, 1)] || m_128[index_word(4, 0)]) + m |= 1; + return _mesa_roundtozero_f64(s, e - 1, m); +} + + +/** + * \brief Calculate a * b + c but rounding to zero. + * + * Notice that this mainly differs from the original Berkeley SoftFloat 3e + * implementation in that we don't really treat NaNs, Zeroes nor the + * signalling flags. Any NaN is good for us and the sign of the Zero is not + * important. + * + * From f32_mulAdd() + */ +float +_mesa_float_fma_rtz(float a, float b, float c) +{ + const fi_type a_fi = {a}; + uint32_t a_flt_m = a_fi.u & 0x07fffff; + uint32_t a_flt_e = (a_fi.u >> 23) & 0xff; + uint32_t a_flt_s = (a_fi.u >> 31) & 0x1; + const fi_type b_fi = {b}; + uint32_t b_flt_m = b_fi.u & 0x07fffff; + uint32_t b_flt_e = (b_fi.u >> 23) & 0xff; + uint32_t b_flt_s = (b_fi.u >> 31) & 0x1; + const fi_type c_fi = {c}; + uint32_t c_flt_m = c_fi.u & 0x07fffff; + uint32_t c_flt_e = (c_fi.u >> 23) & 0xff; + uint32_t c_flt_s = (c_fi.u >> 31) & 0x1; + int32_t s, e, m = 0; + + c_flt_s ^= 0; + s = a_flt_s ^ b_flt_s ^ 0; + + if (a_flt_e == 0xff) { + if (a_flt_m != 0) { + /* 'a' is a NaN, return NaN */ + return a; + } else if (b_flt_e == 0xff && b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } else if (c_flt_e == 0xff && c_flt_m != 0) { + /* 'c' is a NaN, return NaN */ + return c; + } + + if (!(b_flt_e | b_flt_m)) { + /* Inf * 0 + y = NaN */ + fi_type result; + e = 0xff; + result.u = (s << 31) + (e << 23) + 0x1; + return result.f; + } + + if ((c_flt_e == 0xff && c_flt_m == 0) && (s != c_flt_s)) { + /* Inf * x - Inf = NaN */ + fi_type result; + e = 0xff; + result.u = (s << 31) + (e << 23) + 0x1; + return result.f; + } + + /* Inf * x + y = Inf */ + fi_type result; + e = 0xff; + result.u = (s << 31) + (e << 23) + 0; + return result.f; + } + + if (b_flt_e == 0xff) { + if (b_flt_m != 0) { + /* 'b' is a NaN, return NaN */ + return b; + } else if (c_flt_e == 0xff && c_flt_m != 0) { + /* 'c' is a NaN, return NaN */ + return c; + } + + if (!(a_flt_e | a_flt_m)) { + /* 0 * Inf + y = NaN */ + fi_type result; + e = 0xff; + result.u = (s << 31) + (e << 23) + 0x1; + return result.f; + } + + if ((c_flt_e == 0xff && c_flt_m == 0) && (s != c_flt_s)) { + /* x * Inf - Inf = NaN */ + fi_type result; + e = 0xff; + result.u = (s << 31) + (e << 23) + 0x1; + return result.f; + } + + /* x * Inf + y = Inf */ + fi_type result; + e = 0xff; + result.u = (s << 31) + (e << 23) + 0; + return result.f; + } + + if (c_flt_e == 0xff) { + if (c_flt_m != 0) { + /* 'c' is a NaN, return NaN */ + return c; + } + + /* x * y + Inf = Inf */ + return c; + } + + if (a_flt_e == 0) { + if (a_flt_m == 0) { + /* 'a' is zero, return 'c' */ + return c; + } + _mesa_norm_subnormal_mantissa_f32(a_flt_m , &a_flt_e, &a_flt_m); + } + + if (b_flt_e == 0) { + if (b_flt_m == 0) { + /* 'b' is zero, return 'c' */ + return c; + } + _mesa_norm_subnormal_mantissa_f32(b_flt_m , &b_flt_e, &b_flt_m); + } + + e = a_flt_e + b_flt_e - 0x7e; + a_flt_m = (a_flt_m | 0x00800000) << 7; + b_flt_m = (b_flt_m | 0x00800000) << 7; + + uint64_t m_64 = (uint64_t) a_flt_m * b_flt_m; + if (m_64 < 0x2000000000000000) { + --e; + m_64 <<= 1; + } + + if (c_flt_e == 0) { + if (c_flt_m == 0) { + /* 'c' is zero, return 'a * b' */ + m = _mesa_short_shift_right_jam64(m_64, 31); + return _mesa_round_f32(s, e - 1, m, true); + } + _mesa_norm_subnormal_mantissa_f32(c_flt_m , &c_flt_e, &c_flt_m); + } + c_flt_m = (c_flt_m | 0x00800000) << 6; + + int16_t exp_diff = e - c_flt_e; + if (s == c_flt_s) { + if (exp_diff <= 0) { + e = c_flt_e; + m = c_flt_m + _mesa_shift_right_jam64(m_64, 32 - exp_diff); + } else { + m_64 += _mesa_shift_right_jam64((uint64_t) c_flt_m << 32, exp_diff); + m = _mesa_short_shift_right_jam64(m_64, 32); + } + if (m < 0x40000000) { + --e; + m <<= 1; + } + } else { + uint64_t c_flt_m_64 = (uint64_t) c_flt_m << 32; + if (exp_diff < 0) { + s = c_flt_s; + e = c_flt_e; + m_64 = c_flt_m_64 - _mesa_shift_right_jam64(m_64, -exp_diff); + } else if (!exp_diff) { + m_64 -= c_flt_m_64; + if (!m_64) { + /* Return zero */ + fi_type result; + result.u = (s << 31) + 0; + return result.f; + } + if (m_64 & 0x8000000000000000) { + s = !s; + m_64 = -m_64; + } + } else { + m_64 -= _mesa_shift_right_jam64(c_flt_m_64, exp_diff); + } + int8_t shift_dist = _mesa_count_leading_zeros64(m_64) - 1; + e -= shift_dist; + shift_dist -= 32; + if (shift_dist < 0) { + m = _mesa_short_shift_right_jam64(m_64, -shift_dist); + } else { + m = (uint32_t) m_64 << shift_dist; + } + } + + return _mesa_round_f32(s, e, m, true); +} + + +/** + * \brief Converts from 64bits to 32bits float and rounds according to + * instructed. + * + * From f64_to_f32() + */ +float +_mesa_double_to_f32(double val, bool rtz) +{ + const di_type di = {val}; + uint64_t flt_m = di.u & 0x0fffffffffffff; + uint64_t flt_e = (di.u >> 52) & 0x7ff; + uint64_t flt_s = (di.u >> 63) & 0x1; + int32_t s, e, m = 0; + + s = flt_s; + + if (flt_e == 0x7ff) { + if (flt_m != 0) { + /* 'val' is a NaN, return NaN */ + fi_type result; + e = 0xff; + m = 0x1; + result.u = (s << 31) + (e << 23) + m; + return result.f; + } + + /* 'val' is Inf, return Inf */ + fi_type result; + e = 0xff; + result.u = (s << 31) + (e << 23) + m; + return result.f; + } + + if (!(flt_e | flt_m)) { + /* 'val' is zero, return zero */ + fi_type result; + e = 0; + result.u = (s << 31) + (e << 23) + m; + return result.f; + } + + m = _mesa_short_shift_right_jam64(flt_m, 22); + if ( ! (flt_e | m) ) { + /* 'val' is denorm, return zero */ + fi_type result; + e = 0; + result.u = (s << 31) + (e << 23) + m; + return result.f; + } + + return _mesa_round_f32(s, flt_e - 0x381, m | 0x40000000, rtz); +} + + +/** + * \brief Converts from 32bits to 16bits float and rounds the result to zero. + * + * From f32_to_f16() + */ +uint16_t +_mesa_float_to_half_rtz(float val) +{ + const fi_type fi = {val}; + const uint32_t flt_m = fi.u & 0x7fffff; + const uint32_t flt_e = (fi.u >> 23) & 0xff; + const uint32_t flt_s = (fi.u >> 31) & 0x1; + int16_t s, e, m = 0; + + s = flt_s; + + if (flt_e == 0xff) { + if (flt_m != 0) { + /* 'val' is a NaN, return NaN */ + e = 0x1f; + m = 0x1; + return (s << 15) + (e << 10) + m; + } + + /* 'val' is Inf, return Inf */ + e = 0x1f; + return (s << 15) + (e << 10) + m; + } + + if (!(flt_e | flt_m)) { + /* 'val' is zero, return zero */ + e = 0; + return (s << 15) + (e << 10) + m; + } + + m = flt_m >> 9 | ((flt_m & 0x1ff) != 0); + if ( ! (flt_e | m) ) { + /* 'val' is denorm, return zero */ + e = 0; + return (s << 15) + (e << 10) + m; + } + + return _mesa_roundtozero_f16(s, flt_e - 0x71, m | 0x4000); +} |