Adding upstream version 5:7.2.4.upstream/5%7.2.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 373 insertions, 0 deletions

diff --git a/deps/fpconv/fpconv_dtoa.c b/deps/fpconv/fpconv_dtoa.c
new file mode 100644
index 0000000..ad2f2de
--- /dev/null
+++ b/deps/fpconv/fpconv_dtoa.c
@@ -0,0 +1,373 @@
+/* fpconv_dtoa.c -- floating point conversion utilities.
+ *
+ * Fast and accurate double to string conversion based on Florian Loitsch's
+ * Grisu-algorithm[1].
+ *
+ * [1] https://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2013-2019, night-shift <as.smljk at gmail dot com>
+ * Copyright (c) 2009, Florian Loitsch < florian.loitsch at inria dot fr >
+ * All rights reserved.
+ *
+ * Boost Software License - Version 1.0 - August 17th, 2003
+ *
+ * Permission is hereby granted, free of charge, to any person or organization
+ * obtaining a copy of the software and accompanying documentation covered by
+ * this license (the "Software") to use, reproduce, display, distribute,
+ * execute, and transmit the Software, and to prepare derivative works of the
+ * Software, and to permit third-parties to whom the Software is furnished to
+ * do so, all subject to the following:
+ *
+ * The copyright notices in the Software and this entire statement, including
+ * the above license grant, this restriction and the following disclaimer,
+ * must be included in all copies of the Software, in whole or in part, and
+ * all derivative works of the Software, unless such copies or derivative
+ * works are solely in the form of machine-executable object code generated by
+ * a source language processor.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+ * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+ * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "fpconv_dtoa.h"
+
+#include "fpconv_powers.h"
+
+#include <stdbool.h>
+#include <string.h>
+
+#define fracmask 0x000FFFFFFFFFFFFFU
+#define expmask 0x7FF0000000000000U
+#define hiddenbit 0x0010000000000000U
+#define signmask 0x8000000000000000U
+#define expbias (1023 + 52)
+
+#define absv(n) ((n) < 0 ? -(n) : (n))
+#define minv(a, b) ((a) < (b) ? (a) : (b))
+
+static uint64_t tens[] = { 10000000000000000000U,
+                           1000000000000000000U,
+                           100000000000000000U,
+                           10000000000000000U,
+                           1000000000000000U,
+                           100000000000000U,
+                           10000000000000U,
+                           1000000000000U,
+                           100000000000U,
+                           10000000000U,
+                           1000000000U,
+                           100000000U,
+                           10000000U,
+                           1000000U,
+                           100000U,
+                           10000U,
+                           1000U,
+                           100U,
+                           10U,
+                           1U };
+
+static inline uint64_t get_dbits(double d) {
+    union
+    {
+        double dbl;
+        uint64_t i;
+    } dbl_bits = { d };
+
+    return dbl_bits.i;
+}
+
+static Fp build_fp(double d) {
+    uint64_t bits = get_dbits(d);
+
+    Fp fp;
+    fp.frac = bits & fracmask;
+    fp.exp = (bits & expmask) >> 52;
+
+    if (fp.exp) {
+        fp.frac += hiddenbit;
+        fp.exp -= expbias;
+
+    } else {
+        fp.exp = -expbias + 1;
+    }
+
+    return fp;
+}
+
+static void normalize(Fp *fp) {
+    while ((fp->frac & hiddenbit) == 0) {
+        fp->frac <<= 1;
+        fp->exp--;
+    }
+
+    int shift = 64 - 52 - 1;
+    fp->frac <<= shift;
+    fp->exp -= shift;
+}
+
+static void get_normalized_boundaries(Fp *fp, Fp *lower, Fp *upper) {
+    upper->frac = (fp->frac << 1) + 1;
+    upper->exp = fp->exp - 1;
+
+    while ((upper->frac & (hiddenbit << 1)) == 0) {
+        upper->frac <<= 1;
+        upper->exp--;
+    }
+
+    int u_shift = 64 - 52 - 2;
+
+    upper->frac <<= u_shift;
+    upper->exp = upper->exp - u_shift;
+
+    int l_shift = fp->frac == hiddenbit ? 2 : 1;
+
+    lower->frac = (fp->frac << l_shift) - 1;
+    lower->exp = fp->exp - l_shift;
+
+    lower->frac <<= lower->exp - upper->exp;
+    lower->exp = upper->exp;
+}
+
+static Fp multiply(Fp *a, Fp *b) {
+    const uint64_t lomask = 0x00000000FFFFFFFF;
+
+    uint64_t ah_bl = (a->frac >> 32) * (b->frac & lomask);
+    uint64_t al_bh = (a->frac & lomask) * (b->frac >> 32);
+    uint64_t al_bl = (a->frac & lomask) * (b->frac & lomask);
+    uint64_t ah_bh = (a->frac >> 32) * (b->frac >> 32);
+
+    uint64_t tmp = (ah_bl & lomask) + (al_bh & lomask) + (al_bl >> 32);
+    /* round up */
+    tmp += 1U << 31;
+
+    Fp fp = { ah_bh + (ah_bl >> 32) + (al_bh >> 32) + (tmp >> 32), a->exp + b->exp + 64 };
+
+    return fp;
+}
+
+static void round_digit(char *digits,
+                        int ndigits,
+                        uint64_t delta,
+                        uint64_t rem,
+                        uint64_t kappa,
+                        uint64_t frac) {
+    while (rem < frac && delta - rem >= kappa &&
+           (rem + kappa < frac || frac - rem > rem + kappa - frac)) {
+        digits[ndigits - 1]--;
+        rem += kappa;
+    }
+}
+
+static int generate_digits(Fp *fp, Fp *upper, Fp *lower, char *digits, int *K) {
+    uint64_t wfrac = upper->frac - fp->frac;
+    uint64_t delta = upper->frac - lower->frac;
+
+    Fp one;
+    one.frac = 1ULL << -upper->exp;
+    one.exp = upper->exp;
+
+    uint64_t part1 = upper->frac >> -one.exp;
+    uint64_t part2 = upper->frac & (one.frac - 1);
+
+    int idx = 0, kappa = 10;
+    uint64_t *divp;
+    /* 1000000000 */
+    for (divp = tens + 10; kappa > 0; divp++) {
+        uint64_t div = *divp;
+        unsigned digit = part1 / div;
+
+        if (digit || idx) {
+            digits[idx++] = digit + '0';
+        }
+
+        part1 -= digit * div;
+        kappa--;
+
+        uint64_t tmp = (part1 << -one.exp) + part2;
+        if (tmp <= delta) {
+            *K += kappa;
+            round_digit(digits, idx, delta, tmp, div << -one.exp, wfrac);
+
+            return idx;
+        }
+    }
+
+    /* 10 */
+    uint64_t *unit = tens + 18;
+
+    while (true) {
+        part2 *= 10;
+        delta *= 10;
+        kappa--;
+
+        unsigned digit = part2 >> -one.exp;
+        if (digit || idx) {
+            digits[idx++] = digit + '0';
+        }
+
+        part2 &= one.frac - 1;
+        if (part2 < delta) {
+            *K += kappa;
+            round_digit(digits, idx, delta, part2, one.frac, wfrac * *unit);
+
+            return idx;
+        }
+
+        unit--;
+    }
+}
+
+static int grisu2(double d, char *digits, int *K) {
+    Fp w = build_fp(d);
+
+    Fp lower, upper;
+    get_normalized_boundaries(&w, &lower, &upper);
+
+    normalize(&w);
+
+    int k;
+    Fp cp = find_cachedpow10(upper.exp, &k);
+
+    w = multiply(&w, &cp);
+    upper = multiply(&upper, &cp);
+    lower = multiply(&lower, &cp);
+
+    lower.frac++;
+    upper.frac--;
+
+    *K = -k;
+
+    return generate_digits(&w, &upper, &lower, digits, K);
+}
+
+static int emit_digits(char *digits, int ndigits, char *dest, int K, bool neg) {
+    int exp = absv(K + ndigits - 1);
+
+    /* write plain integer */
+    if (K >= 0 && (exp < (ndigits + 7))) {
+        memcpy(dest, digits, ndigits);
+        memset(dest + ndigits, '0', K);
+
+        return ndigits + K;
+    }
+
+    /* write decimal w/o scientific notation */
+    if (K < 0 && (K > -7 || exp < 4)) {
+        int offset = ndigits - absv(K);
+        /* fp < 1.0 -> write leading zero */
+        if (offset <= 0) {
+            offset = -offset;
+            dest[0] = '0';
+            dest[1] = '.';
+            memset(dest + 2, '0', offset);
+            memcpy(dest + offset + 2, digits, ndigits);
+
+            return ndigits + 2 + offset;
+
+            /* fp > 1.0 */
+        } else {
+            memcpy(dest, digits, offset);
+            dest[offset] = '.';
+            memcpy(dest + offset + 1, digits + offset, ndigits - offset);
+
+            return ndigits + 1;
+        }
+    }
+
+    /* write decimal w/ scientific notation */
+    ndigits = minv(ndigits, 18 - neg);
+
+    int idx = 0;
+    dest[idx++] = digits[0];
+
+    if (ndigits > 1) {
+        dest[idx++] = '.';
+        memcpy(dest + idx, digits + 1, ndigits - 1);
+        idx += ndigits - 1;
+    }
+
+    dest[idx++] = 'e';
+
+    char sign = K + ndigits - 1 < 0 ? '-' : '+';
+    dest[idx++] = sign;
+
+    int cent = 0;
+
+    if (exp > 99) {
+        cent = exp / 100;
+        dest[idx++] = cent + '0';
+        exp -= cent * 100;
+    }
+    if (exp > 9) {
+        int dec = exp / 10;
+        dest[idx++] = dec + '0';
+        exp -= dec * 10;
+
+    } else if (cent) {
+        dest[idx++] = '0';
+    }
+
+    dest[idx++] = exp % 10 + '0';
+
+    return idx;
+}
+
+static int filter_special(double fp, char *dest) {
+    if (fp == 0.0) {
+        dest[0] = '0';
+        return 1;
+    }
+
+    uint64_t bits = get_dbits(fp);
+
+    bool nan = (bits & expmask) == expmask;
+
+    if (!nan) {
+        return 0;
+    }
+
+    if (bits & fracmask) {
+        dest[0] = 'n';
+        dest[1] = 'a';
+        dest[2] = 'n';
+
+    } else {
+        dest[0] = 'i';
+        dest[1] = 'n';
+        dest[2] = 'f';
+    }
+
+    return 3;
+}
+
+int fpconv_dtoa(double d, char dest[24]) {
+    char digits[18];
+
+    int str_len = 0;
+    bool neg = false;
+
+    if (get_dbits(d) & signmask) {
+        dest[0] = '-';
+        str_len++;
+        neg = true;
+    }
+
+    int spec = filter_special(d, dest + str_len);
+
+    if (spec) {
+        return str_len + spec;
+    }
+
+    int K = 0;
+    int ndigits = grisu2(d, digits, &K);
+
+    str_len += emit_digits(digits, ndigits, dest + str_len, K, neg);
+
+    return str_len;
+}