Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

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

1 files changed, 828 insertions, 0 deletions

diff --git a/sal/rtl/math.cxx b/sal/rtl/math.cxx
new file mode 100644
index 000000000..0d70e9718
--- /dev/null
+++ b/sal/rtl/math.cxx
@@ -0,0 +1,828 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <rtl/math.h>
+
+#include <o3tl/safeint.hxx>
+#include <osl/diagnose.h>
+#include <rtl/character.hxx>
+#include <rtl/math.hxx>
+
+#include <algorithm>
+#include <cassert>
+#include <cfenv>
+#include <cmath>
+#include <float.h>
+#include <limits>
+#include <limits.h>
+#include <math.h>
+#include <memory>
+#include <stdlib.h>
+
+#include "strtmpl.hxx"
+
+#include <dtoa.h>
+
+constexpr int minExp = -323, maxExp = 308;
+constexpr double n10s[] = {
+    1e-323, 1e-322, 1e-321, 1e-320, 1e-319, 1e-318, 1e-317, 1e-316, 1e-315, 1e-314, 1e-313, 1e-312,
+    1e-311, 1e-310, 1e-309, 1e-308, 1e-307, 1e-306, 1e-305, 1e-304, 1e-303, 1e-302, 1e-301, 1e-300,
+    1e-299, 1e-298, 1e-297, 1e-296, 1e-295, 1e-294, 1e-293, 1e-292, 1e-291, 1e-290, 1e-289, 1e-288,
+    1e-287, 1e-286, 1e-285, 1e-284, 1e-283, 1e-282, 1e-281, 1e-280, 1e-279, 1e-278, 1e-277, 1e-276,
+    1e-275, 1e-274, 1e-273, 1e-272, 1e-271, 1e-270, 1e-269, 1e-268, 1e-267, 1e-266, 1e-265, 1e-264,
+    1e-263, 1e-262, 1e-261, 1e-260, 1e-259, 1e-258, 1e-257, 1e-256, 1e-255, 1e-254, 1e-253, 1e-252,
+    1e-251, 1e-250, 1e-249, 1e-248, 1e-247, 1e-246, 1e-245, 1e-244, 1e-243, 1e-242, 1e-241, 1e-240,
+    1e-239, 1e-238, 1e-237, 1e-236, 1e-235, 1e-234, 1e-233, 1e-232, 1e-231, 1e-230, 1e-229, 1e-228,
+    1e-227, 1e-226, 1e-225, 1e-224, 1e-223, 1e-222, 1e-221, 1e-220, 1e-219, 1e-218, 1e-217, 1e-216,
+    1e-215, 1e-214, 1e-213, 1e-212, 1e-211, 1e-210, 1e-209, 1e-208, 1e-207, 1e-206, 1e-205, 1e-204,
+    1e-203, 1e-202, 1e-201, 1e-200, 1e-199, 1e-198, 1e-197, 1e-196, 1e-195, 1e-194, 1e-193, 1e-192,
+    1e-191, 1e-190, 1e-189, 1e-188, 1e-187, 1e-186, 1e-185, 1e-184, 1e-183, 1e-182, 1e-181, 1e-180,
+    1e-179, 1e-178, 1e-177, 1e-176, 1e-175, 1e-174, 1e-173, 1e-172, 1e-171, 1e-170, 1e-169, 1e-168,
+    1e-167, 1e-166, 1e-165, 1e-164, 1e-163, 1e-162, 1e-161, 1e-160, 1e-159, 1e-158, 1e-157, 1e-156,
+    1e-155, 1e-154, 1e-153, 1e-152, 1e-151, 1e-150, 1e-149, 1e-148, 1e-147, 1e-146, 1e-145, 1e-144,
+    1e-143, 1e-142, 1e-141, 1e-140, 1e-139, 1e-138, 1e-137, 1e-136, 1e-135, 1e-134, 1e-133, 1e-132,
+    1e-131, 1e-130, 1e-129, 1e-128, 1e-127, 1e-126, 1e-125, 1e-124, 1e-123, 1e-122, 1e-121, 1e-120,
+    1e-119, 1e-118, 1e-117, 1e-116, 1e-115, 1e-114, 1e-113, 1e-112, 1e-111, 1e-110, 1e-109, 1e-108,
+    1e-107, 1e-106, 1e-105, 1e-104, 1e-103, 1e-102, 1e-101, 1e-100, 1e-99,  1e-98,  1e-97,  1e-96,
+    1e-95,  1e-94,  1e-93,  1e-92,  1e-91,  1e-90,  1e-89,  1e-88,  1e-87,  1e-86,  1e-85,  1e-84,
+    1e-83,  1e-82,  1e-81,  1e-80,  1e-79,  1e-78,  1e-77,  1e-76,  1e-75,  1e-74,  1e-73,  1e-72,
+    1e-71,  1e-70,  1e-69,  1e-68,  1e-67,  1e-66,  1e-65,  1e-64,  1e-63,  1e-62,  1e-61,  1e-60,
+    1e-59,  1e-58,  1e-57,  1e-56,  1e-55,  1e-54,  1e-53,  1e-52,  1e-51,  1e-50,  1e-49,  1e-48,
+    1e-47,  1e-46,  1e-45,  1e-44,  1e-43,  1e-42,  1e-41,  1e-40,  1e-39,  1e-38,  1e-37,  1e-36,
+    1e-35,  1e-34,  1e-33,  1e-32,  1e-31,  1e-30,  1e-29,  1e-28,  1e-27,  1e-26,  1e-25,  1e-24,
+    1e-23,  1e-22,  1e-21,  1e-20,  1e-19,  1e-18,  1e-17,  1e-16,  1e-15,  1e-14,  1e-13,  1e-12,
+    1e-11,  1e-10,  1e-9,   1e-8,   1e-7,   1e-6,   1e-5,   1e-4,   1e-3,   1e-2,   1e-1,   1e0,
+    1e1,    1e2,    1e3,    1e4,    1e5,    1e6,    1e7,    1e8,    1e9,    1e10,   1e11,   1e12,
+    1e13,   1e14,   1e15,   1e16,   1e17,   1e18,   1e19,   1e20,   1e21,   1e22,   1e23,   1e24,
+    1e25,   1e26,   1e27,   1e28,   1e29,   1e30,   1e31,   1e32,   1e33,   1e34,   1e35,   1e36,
+    1e37,   1e38,   1e39,   1e40,   1e41,   1e42,   1e43,   1e44,   1e45,   1e46,   1e47,   1e48,
+    1e49,   1e50,   1e51,   1e52,   1e53,   1e54,   1e55,   1e56,   1e57,   1e58,   1e59,   1e60,
+    1e61,   1e62,   1e63,   1e64,   1e65,   1e66,   1e67,   1e68,   1e69,   1e70,   1e71,   1e72,
+    1e73,   1e74,   1e75,   1e76,   1e77,   1e78,   1e79,   1e80,   1e81,   1e82,   1e83,   1e84,
+    1e85,   1e86,   1e87,   1e88,   1e89,   1e90,   1e91,   1e92,   1e93,   1e94,   1e95,   1e96,
+    1e97,   1e98,   1e99,   1e100,  1e101,  1e102,  1e103,  1e104,  1e105,  1e106,  1e107,  1e108,
+    1e109,  1e110,  1e111,  1e112,  1e113,  1e114,  1e115,  1e116,  1e117,  1e118,  1e119,  1e120,
+    1e121,  1e122,  1e123,  1e124,  1e125,  1e126,  1e127,  1e128,  1e129,  1e130,  1e131,  1e132,
+    1e133,  1e134,  1e135,  1e136,  1e137,  1e138,  1e139,  1e140,  1e141,  1e142,  1e143,  1e144,
+    1e145,  1e146,  1e147,  1e148,  1e149,  1e150,  1e151,  1e152,  1e153,  1e154,  1e155,  1e156,
+    1e157,  1e158,  1e159,  1e160,  1e161,  1e162,  1e163,  1e164,  1e165,  1e166,  1e167,  1e168,
+    1e169,  1e170,  1e171,  1e172,  1e173,  1e174,  1e175,  1e176,  1e177,  1e178,  1e179,  1e180,
+    1e181,  1e182,  1e183,  1e184,  1e185,  1e186,  1e187,  1e188,  1e189,  1e190,  1e191,  1e192,
+    1e193,  1e194,  1e195,  1e196,  1e197,  1e198,  1e199,  1e200,  1e201,  1e202,  1e203,  1e204,
+    1e205,  1e206,  1e207,  1e208,  1e209,  1e210,  1e211,  1e212,  1e213,  1e214,  1e215,  1e216,
+    1e217,  1e218,  1e219,  1e220,  1e221,  1e222,  1e223,  1e224,  1e225,  1e226,  1e227,  1e228,
+    1e229,  1e230,  1e231,  1e232,  1e233,  1e234,  1e235,  1e236,  1e237,  1e238,  1e239,  1e240,
+    1e241,  1e242,  1e243,  1e244,  1e245,  1e246,  1e247,  1e248,  1e249,  1e250,  1e251,  1e252,
+    1e253,  1e254,  1e255,  1e256,  1e257,  1e258,  1e259,  1e260,  1e261,  1e262,  1e263,  1e264,
+    1e265,  1e266,  1e267,  1e268,  1e269,  1e270,  1e271,  1e272,  1e273,  1e274,  1e275,  1e276,
+    1e277,  1e278,  1e279,  1e280,  1e281,  1e282,  1e283,  1e284,  1e285,  1e286,  1e287,  1e288,
+    1e289,  1e290,  1e291,  1e292,  1e293,  1e294,  1e295,  1e296,  1e297,  1e298,  1e299,  1e300,
+    1e301,  1e302,  1e303,  1e304,  1e305,  1e306,  1e307,  1e308,
+};
+static_assert(SAL_N_ELEMENTS(n10s) == maxExp - minExp + 1);
+
+// return pow(10.0,nExp) optimized for exponents in the interval [-323,308] (i.e., incl. denormals)
+static double getN10Exp(int nExp)
+{
+    if (nExp < minExp || nExp > maxExp)
+        return pow(10.0, static_cast<double>(nExp)); // will return 0 or INF with IEEE 754
+    return n10s[nExp - minExp];
+}
+
+namespace {
+
+/** If value (passed as absolute value) is an integer representable as double,
+    which we handle explicitly at some places.
+ */
+bool isRepresentableInteger(double fAbsValue)
+{
+    assert(fAbsValue >= 0.0);
+    const sal_Int64 kMaxInt = (static_cast< sal_Int64 >(1) << 53) - 1;
+    if (fAbsValue <= static_cast< double >(kMaxInt))
+    {
+        sal_Int64 nInt = static_cast< sal_Int64 >(fAbsValue);
+        // Check the integer range again because double comparison may yield
+        // true within the precision range.
+        // XXX loplugin:fpcomparison complains about floating-point comparison
+        // for static_cast<double>(nInt) == fAbsValue, though we actually want
+        // this here.
+        if (nInt > kMaxInt)
+            return false;
+        double fInt = static_cast< double >(nInt);
+        return !(fInt < fAbsValue) && !(fInt > fAbsValue);
+    }
+    return false;
+}
+
+// Returns 1-based index of least significant bit in a number, or zero if number is zero
+int findFirstSetBit(unsigned n)
+{
+#if defined _WIN32
+    unsigned long pos;
+    unsigned char bNonZero = _BitScanForward(&pos, n);
+    return (bNonZero == 0) ? 0 : pos + 1;
+#else
+    return __builtin_ffs(n);
+#endif
+}
+
+/** Returns number of binary bits for fractional part of the number
+    Expects a proper non-negative double value, not +-INF, not NAN
+ */
+int getBitsInFracPart(double fAbsValue)
+{
+    assert(std::isfinite(fAbsValue) && fAbsValue >= 0.0);
+    if (fAbsValue == 0.0)
+        return 0;
+    auto pValParts = reinterpret_cast< const sal_math_Double * >(&fAbsValue);
+    int nExponent = pValParts->inf_parts.exponent - 1023;
+    if (nExponent >= 52)
+        return 0; // All bits in fraction are in integer part of the number
+    int nLeastSignificant = findFirstSetBit(pValParts->inf_parts.fraction_lo);
+    if (nLeastSignificant == 0)
+    {
+        nLeastSignificant = findFirstSetBit(pValParts->inf_parts.fraction_hi);
+        if (nLeastSignificant == 0)
+            nLeastSignificant = 53; // the implied leading 1 is the least significant
+        else
+            nLeastSignificant += 32;
+    }
+    int nFracSignificant = 53 - nLeastSignificant;
+    int nBitsInFracPart = nFracSignificant - nExponent;
+
+    return std::max(nBitsInFracPart, 0);
+}
+
+}
+
+void SAL_CALL rtl_math_doubleToString(rtl_String ** pResult,
+                                      sal_Int32 * pResultCapacity,
+                                      sal_Int32 nResultOffset, double fValue,
+                                      rtl_math_StringFormat eFormat,
+                                      sal_Int32 nDecPlaces,
+                                      char cDecSeparator,
+                                      sal_Int32 const * pGroups,
+                                      char cGroupSeparator,
+                                      sal_Bool bEraseTrailingDecZeros)
+    SAL_THROW_EXTERN_C()
+{
+    rtl::str::doubleToString(
+        pResult, pResultCapacity, nResultOffset, fValue, eFormat, nDecPlaces,
+        cDecSeparator, pGroups, cGroupSeparator, bEraseTrailingDecZeros);
+}
+
+void SAL_CALL rtl_math_doubleToUString(rtl_uString ** pResult,
+                                       sal_Int32 * pResultCapacity,
+                                       sal_Int32 nResultOffset, double fValue,
+                                       rtl_math_StringFormat eFormat,
+                                       sal_Int32 nDecPlaces,
+                                       sal_Unicode cDecSeparator,
+                                       sal_Int32 const * pGroups,
+                                       sal_Unicode cGroupSeparator,
+                                       sal_Bool bEraseTrailingDecZeros)
+    SAL_THROW_EXTERN_C()
+{
+    rtl::str::doubleToString(
+        pResult, pResultCapacity, nResultOffset, fValue, eFormat, nDecPlaces,
+        cDecSeparator, pGroups, cGroupSeparator, bEraseTrailingDecZeros);
+}
+
+namespace {
+
+template< typename CharT >
+double stringToDouble(CharT const * pBegin, CharT const * pEnd,
+                             CharT cDecSeparator, CharT cGroupSeparator,
+                             rtl_math_ConversionStatus * pStatus,
+                             CharT const ** pParsedEnd)
+{
+    double fVal = 0.0;
+    rtl_math_ConversionStatus eStatus = rtl_math_ConversionStatus_Ok;
+
+    CharT const * p0 = pBegin;
+    while (p0 != pEnd && (*p0 == CharT(' ') || *p0 == CharT('\t')))
+    {
+        ++p0;
+    }
+
+    bool bSign;
+    bool explicitSign = false;
+    if (p0 != pEnd && *p0 == CharT('-'))
+    {
+        bSign = true;
+        explicitSign = true;
+        ++p0;
+    }
+    else
+    {
+        bSign = false;
+        if (p0 != pEnd && *p0 == CharT('+'))
+        {
+            explicitSign = true;
+            ++p0;
+        }
+    }
+
+    CharT const * p = p0;
+    bool bDone = false;
+
+    // #i112652# XMLSchema-2
+    if ((pEnd - p) >= 3)
+    {
+        if (!explicitSign && (CharT('N') == p[0]) && (CharT('a') == p[1])
+            && (CharT('N') == p[2]))
+        {
+            p += 3;
+            fVal = std::numeric_limits<double>::quiet_NaN();
+            bDone = true;
+        }
+        else if ((CharT('I') == p[0]) && (CharT('N') == p[1])
+                 && (CharT('F') == p[2]))
+        {
+            p += 3;
+            fVal = HUGE_VAL;
+            eStatus = rtl_math_ConversionStatus_OutOfRange;
+            bDone = true;
+        }
+    }
+
+    if (!bDone) // do not recognize e.g. NaN1.23
+    {
+        std::unique_ptr<char[]> bufInHeap;
+        std::unique_ptr<const CharT * []> bufInHeapMap;
+        constexpr int bufOnStackSize = 256;
+        char bufOnStack[bufOnStackSize];
+        const CharT* bufOnStackMap[bufOnStackSize];
+        char* buf = bufOnStack;
+        const CharT** bufmap = bufOnStackMap;
+        int bufpos = 0;
+        const size_t bufsize = pEnd - p + (bSign ? 2 : 1);
+        if (bufsize > bufOnStackSize)
+        {
+            bufInHeap = std::make_unique<char[]>(bufsize);
+            bufInHeapMap = std::make_unique<const CharT*[]>(bufsize);
+            buf = bufInHeap.get();
+            bufmap = bufInHeapMap.get();
+        }
+
+        if (bSign)
+        {
+            buf[0] = '-';
+            bufmap[0] = p; // yes, this may be the same pointer as for the next mapping
+            bufpos = 1;
+        }
+        // Put first zero to buffer for strings like "-0"
+        if (p != pEnd && *p == CharT('0'))
+        {
+            buf[bufpos] = '0';
+            bufmap[bufpos] = p;
+            ++bufpos;
+            ++p;
+        }
+        // Leading zeros and group separators between digits may be safely
+        // ignored. p0 < p implies that there was a leading 0 already,
+        // consecutive group separators may not happen as *(p+1) is checked for
+        // digit.
+        while (p != pEnd && (*p == CharT('0') || (*p == cGroupSeparator
+                        && p0 < p && p+1 < pEnd && rtl::isAsciiDigit(*(p+1)))))
+        {
+            ++p;
+        }
+
+        // integer part of mantissa
+        for (; p != pEnd; ++p)
+        {
+            CharT c = *p;
+            if (rtl::isAsciiDigit(c))
+            {
+                buf[bufpos] = static_cast<char>(c);
+                bufmap[bufpos] = p;
+                ++bufpos;
+            }
+            else if (c != cGroupSeparator)
+            {
+                break;
+            }
+            else if (p == p0 || (p+1 == pEnd) || !rtl::isAsciiDigit(*(p+1)))
+            {
+                // A leading or trailing (not followed by a digit) group
+                // separator character is not a group separator.
+                break;
+            }
+        }
+
+        // fraction part of mantissa
+        if (p != pEnd && *p == cDecSeparator)
+        {
+            buf[bufpos] = '.';
+            bufmap[bufpos] = p;
+            ++bufpos;
+            ++p;
+
+            for (; p != pEnd; ++p)
+            {
+                CharT c = *p;
+                if (!rtl::isAsciiDigit(c))
+                {
+                    break;
+                }
+                buf[bufpos] = static_cast<char>(c);
+                bufmap[bufpos] = p;
+                ++bufpos;
+            }
+        }
+
+        // Exponent
+        if (p != p0 && p != pEnd && (*p == CharT('E') || *p == CharT('e')))
+        {
+            buf[bufpos] = 'E';
+            bufmap[bufpos] = p;
+            ++bufpos;
+            ++p;
+            if (p != pEnd && *p == CharT('-'))
+            {
+                buf[bufpos] = '-';
+                bufmap[bufpos] = p;
+                ++bufpos;
+                ++p;
+            }
+            else if (p != pEnd && *p == CharT('+'))
+                ++p;
+
+            for (; p != pEnd; ++p)
+            {
+                CharT c = *p;
+                if (!rtl::isAsciiDigit(c))
+                    break;
+
+                buf[bufpos] = static_cast<char>(c);
+                bufmap[bufpos] = p;
+                ++bufpos;
+            }
+        }
+        else if (p - p0 == 2 && p != pEnd && p[0] == CharT('#')
+                 && p[-1] == cDecSeparator && p[-2] == CharT('1'))
+        {
+            if (pEnd - p >= 4 && p[1] == CharT('I') && p[2] == CharT('N')
+                && p[3] == CharT('F'))
+            {
+                // "1.#INF", "+1.#INF", "-1.#INF"
+                p += 4;
+                fVal = HUGE_VAL;
+                eStatus = rtl_math_ConversionStatus_OutOfRange;
+                // Eat any further digits:
+                while (p != pEnd && rtl::isAsciiDigit(*p))
+                    ++p;
+                bDone = true;
+            }
+            else if (pEnd - p >= 4 && p[1] == CharT('N') && p[2] == CharT('A')
+                && p[3] == CharT('N'))
+            {
+                // "1.#NAN", "+1.#NAN", "-1.#NAN"
+                p += 4;
+                fVal = std::copysign(std::numeric_limits<double>::quiet_NaN(), bSign ? -1.0 : 1.0);
+                bSign = false; // don't negate again
+
+                // Eat any further digits:
+                while (p != pEnd && rtl::isAsciiDigit(*p))
+                {
+                    ++p;
+                }
+                bDone = true;
+            }
+        }
+
+        if (!bDone)
+        {
+            buf[bufpos] = '\0';
+            bufmap[bufpos] = p;
+            char* pCharParseEnd;
+            errno = 0;
+            fVal = strtod_nolocale(buf, &pCharParseEnd);
+            if (errno == ERANGE)
+            {
+                // Check for the dreaded rounded to 15 digits max value
+                // 1.79769313486232e+308 for 1.7976931348623157e+308 we wrote
+                // everywhere, accept with or without plus sign in exponent.
+                const char* b = buf;
+                if (b[0] == '-')
+                    ++b;
+                if (((pCharParseEnd - b == 21) || (pCharParseEnd - b == 20))
+                        && !strncmp( b, "1.79769313486232", 16)
+                        && (b[16] == 'e' || b[16] == 'E')
+                        && (((pCharParseEnd - b == 21) && !strncmp( b+17, "+308", 4))
+                         || ((pCharParseEnd - b == 20) && !strncmp( b+17, "308", 3))))
+                {
+                    fVal = (buf < b) ? -DBL_MAX : DBL_MAX;
+                }
+                else
+                {
+                    eStatus = rtl_math_ConversionStatus_OutOfRange;
+                }
+            }
+            p = bufmap[pCharParseEnd - buf];
+            bSign = false;
+        }
+    }
+
+    // overflow also if more than DBL_MAX_10_EXP digits without decimal
+    // separator, or 0. and more than DBL_MIN_10_EXP digits, ...
+    bool bHuge = fVal == HUGE_VAL; // g++ 3.0.1 requires it this way...
+    if (bHuge)
+        eStatus = rtl_math_ConversionStatus_OutOfRange;
+
+    if (bSign)
+        fVal = -fVal;
+
+    if (pStatus)
+        *pStatus = eStatus;
+
+    if (pParsedEnd)
+        *pParsedEnd = p == p0 ? pBegin : p;
+
+    return fVal;
+}
+
+}
+
+double SAL_CALL rtl_math_stringToDouble(char const * pBegin,
+                                        char const * pEnd,
+                                        char cDecSeparator,
+                                        char cGroupSeparator,
+                                        rtl_math_ConversionStatus * pStatus,
+                                        char const ** pParsedEnd)
+    SAL_THROW_EXTERN_C()
+{
+    return stringToDouble(
+        reinterpret_cast<unsigned char const *>(pBegin),
+        reinterpret_cast<unsigned char const *>(pEnd),
+        static_cast<unsigned char>(cDecSeparator),
+        static_cast<unsigned char>(cGroupSeparator), pStatus,
+        reinterpret_cast<unsigned char const **>(pParsedEnd));
+}
+
+double SAL_CALL rtl_math_uStringToDouble(sal_Unicode const * pBegin,
+                                         sal_Unicode const * pEnd,
+                                         sal_Unicode cDecSeparator,
+                                         sal_Unicode cGroupSeparator,
+                                         rtl_math_ConversionStatus * pStatus,
+                                         sal_Unicode const ** pParsedEnd)
+    SAL_THROW_EXTERN_C()
+{
+    return stringToDouble(pBegin, pEnd, cDecSeparator, cGroupSeparator, pStatus,
+                          pParsedEnd);
+}
+
+double SAL_CALL rtl_math_round(double fValue, int nDecPlaces,
+                               enum rtl_math_RoundingMode eMode)
+    SAL_THROW_EXTERN_C()
+{
+    if (!std::isfinite(fValue))
+        return fValue;
+
+    if (fValue == 0.0)
+        return fValue;
+
+    if (nDecPlaces == 0)
+    {
+        switch (eMode)
+        {
+            case rtl_math_RoundingMode_Corrected:
+                return std::round(fValue);
+            case rtl_math_RoundingMode_HalfEven:
+                if (const int oldMode = std::fegetround(); std::fesetround(FE_TONEAREST) == 0)
+                {
+                    fValue = std::nearbyint(fValue);
+                    std::fesetround(oldMode);
+                    return fValue;
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    const double fOrigValue = fValue;
+
+    // sign adjustment
+    bool bSign = std::signbit( fValue );
+    if (bSign)
+        fValue = -fValue;
+
+    // Rounding to decimals between integer distance precision (gaps) does not
+    // make sense, do not even try to multiply/divide and introduce inaccuracy.
+    // For same reasons, do not attempt to round integers to decimals.
+    if (nDecPlaces >= 0
+            && (fValue >= 0x1p52
+                || isRepresentableInteger(fValue)))
+        return fOrigValue;
+
+    double fFac = 0;
+    if (nDecPlaces != 0)
+    {
+        if (nDecPlaces > 0)
+        {
+            // Determine how many decimals are representable in the precision.
+            // Anything greater 2^52 and 0.0 was already ruled out above.
+            // Theoretically 0.5, 0.25, 0.125, 0.0625, 0.03125, ...
+            const sal_math_Double* pd = reinterpret_cast<const sal_math_Double*>(&fValue);
+            const sal_Int32 nDec = 52 - (pd->parts.exponent - 1023);
+
+            if (nDec <= 0)
+            {
+                assert(!"Shouldn't this had been caught already as large number?");
+                return fOrigValue;
+            }
+
+            if (nDec < nDecPlaces)
+                nDecPlaces = nDec;
+        }
+
+        // Avoid 1e-5 (1.0000000000000001e-05) and such inaccurate fractional
+        // factors that later when dividing back spoil things. For negative
+        // decimals divide first with the inverse, then multiply the rounded
+        // value back.
+        fFac = getN10Exp(abs(nDecPlaces));
+
+        if (fFac == 0.0 || (nDecPlaces < 0 && !std::isfinite(fFac)))
+            // Underflow, rounding to that many integer positions would be 0.
+            return 0.0;
+
+        if (!std::isfinite(fFac))
+            // Overflow with very small values and high number of decimals.
+            return fOrigValue;
+
+        if (nDecPlaces < 0)
+            fValue /= fFac;
+        else
+            fValue *= fFac;
+
+        if (!std::isfinite(fValue))
+            return fOrigValue;
+    }
+
+    // Round only if not already in distance precision gaps of integers, where
+    // for [2^52,2^53) adding 0.5 would even yield the next representable
+    // integer.
+    if (fValue < 0x1p52)
+    {
+        switch ( eMode )
+        {
+            case rtl_math_RoundingMode_Corrected :
+                fValue = rtl::math::approxFloor(fValue + 0.5);
+            break;
+            case rtl_math_RoundingMode_Down:
+                fValue = rtl::math::approxFloor(fValue);
+            break;
+            case rtl_math_RoundingMode_Up:
+                fValue = rtl::math::approxCeil(fValue);
+            break;
+            case rtl_math_RoundingMode_Floor:
+                fValue = bSign ? rtl::math::approxCeil(fValue)
+                    : rtl::math::approxFloor( fValue );
+            break;
+            case rtl_math_RoundingMode_Ceiling:
+                fValue = bSign ? rtl::math::approxFloor(fValue)
+                    : rtl::math::approxCeil(fValue);
+            break;
+            case rtl_math_RoundingMode_HalfDown :
+                {
+                    double f = floor(fValue);
+                    fValue = ((fValue - f) <= 0.5) ? f : ceil(fValue);
+                }
+            break;
+            case rtl_math_RoundingMode_HalfUp:
+                {
+                    double f = floor(fValue);
+                    fValue = ((fValue - f) < 0.5) ? f : ceil(fValue);
+                }
+            break;
+            case rtl_math_RoundingMode_HalfEven:
+#if defined FLT_ROUNDS
+                /*
+                   Use fast version. FLT_ROUNDS may be defined to a function by some compilers!
+
+                   DBL_EPSILON is the smallest fractional number which can be represented,
+                   its reciprocal is therefore the smallest number that cannot have a
+                   fractional part. Once you add this reciprocal to `x', its fractional part
+                   is stripped off. Simply subtracting the reciprocal back out returns `x'
+                   without its fractional component.
+                   Simple, clever, and elegant - thanks to Ross Cottrell, the original author,
+                   who placed it into public domain.
+
+                   volatile: prevent compiler from being too smart
+                */
+                if (FLT_ROUNDS == 1)
+                {
+                    volatile double x = fValue + 1.0 / DBL_EPSILON;
+                    fValue = x - 1.0 / DBL_EPSILON;
+                }
+                else
+#endif // FLT_ROUNDS
+                {
+                    double f = floor(fValue);
+                    if ((fValue - f) != 0.5)
+                    {
+                        fValue = floor( fValue + 0.5 );
+                    }
+                    else
+                    {
+                        double g = f / 2.0;
+                        fValue = (g == floor( g )) ? f : (f + 1.0);
+                    }
+                }
+            break;
+            default:
+                OSL_ASSERT(false);
+            break;
+        }
+    }
+
+    if (nDecPlaces != 0)
+    {
+        if (nDecPlaces < 0)
+            fValue *= fFac;
+        else
+            fValue /= fFac;
+    }
+
+    if (!std::isfinite(fValue))
+        return fOrigValue;
+
+    return bSign ? -fValue : fValue;
+}
+
+double SAL_CALL rtl_math_pow10Exp(double fValue, int nExp) SAL_THROW_EXTERN_C()
+{
+    return fValue * getN10Exp(nExp);
+}
+
+double SAL_CALL rtl_math_approxValue( double fValue ) SAL_THROW_EXTERN_C()
+{
+    const double fBigInt = 0x1p41; // 2^41 -> only 11 bits left for fractional part, fine as decimal
+    if (fValue == 0.0 || fValue == HUGE_VAL || !std::isfinite( fValue) || fValue > fBigInt)
+    {
+        // We don't handle these conditions.  Bail out.
+        return fValue;
+    }
+
+    double fOrigValue = fValue;
+
+    bool bSign = std::signbit(fValue);
+    if (bSign)
+        fValue = -fValue;
+
+    // If the value is either integer representable as double,
+    // or only has small number of bits in fraction part, then we need not do any approximation
+    if (isRepresentableInteger(fValue) || getBitsInFracPart(fValue) <= 11)
+        return fOrigValue;
+
+    int nExp = static_cast< int >(floor(log10(fValue)));
+    nExp = 14 - nExp;
+    double fExpValue = getN10Exp(abs(nExp));
+
+    if (nExp < 0)
+        fValue /= fExpValue;
+    else
+        fValue *= fExpValue;
+
+    // If the original value was near DBL_MIN we got an overflow. Restore and
+    // bail out.
+    if (!std::isfinite(fValue))
+        return fOrigValue;
+
+    fValue = std::round(fValue);
+
+    if (nExp < 0)
+        fValue *= fExpValue;
+    else
+        fValue /= fExpValue;
+
+    // If the original value was near DBL_MAX we got an overflow. Restore and
+    // bail out.
+    if (!std::isfinite(fValue))
+        return fOrigValue;
+
+    return bSign ? -fValue : fValue;
+}
+
+bool SAL_CALL rtl_math_approxEqual(double a, double b) SAL_THROW_EXTERN_C()
+{
+    static const double e48 = 0x1p-48;
+    static const double e44 = 0x1p-44;
+
+    if (a == b)
+        return true;
+
+    if (a == 0.0 || b == 0.0)
+        return false;
+
+    const double d = fabs(a - b);
+    if (!std::isfinite(d))
+        return false;   // Nan or Inf involved
+
+    a = fabs(a);
+    if (d > (a * e44))
+        return false;
+    b = fabs(b);
+    if (d > (b * e44))
+        return false;
+
+    if (isRepresentableInteger(d) && isRepresentableInteger(a) && isRepresentableInteger(b))
+        return false;   // special case for representable integers.
+
+    return (d < a * e48 && d < b * e48);
+}
+
+double SAL_CALL rtl_math_expm1(double fValue) SAL_THROW_EXTERN_C()
+{
+    return expm1(fValue);
+}
+
+double SAL_CALL rtl_math_log1p(double fValue) SAL_THROW_EXTERN_C()
+{
+#ifdef __APPLE__
+    if (fValue == -0.0)
+        return fValue; // macOS 10.8 libc returns 0.0 for -0.0
+#endif
+
+    return log1p(fValue);
+}
+
+double SAL_CALL rtl_math_atanh(double fValue) SAL_THROW_EXTERN_C()
+{
+    return ::atanh(fValue);
+}
+
+/** Parent error function (erf) */
+double SAL_CALL rtl_math_erf(double x) SAL_THROW_EXTERN_C()
+{
+    return erf(x);
+}
+
+/** Parent complementary error function (erfc) */
+double SAL_CALL rtl_math_erfc(double x) SAL_THROW_EXTERN_C()
+{
+    return erfc(x);
+}
+
+/** improved accuracy of asinh for |x| large and for x near zero
+    @see #i97605#
+ */
+double SAL_CALL rtl_math_asinh(double fX) SAL_THROW_EXTERN_C()
+{
+    if ( fX == 0.0 )
+        return 0.0;
+
+    double fSign = 1.0;
+    if ( fX < 0.0 )
+    {
+        fX = - fX;
+        fSign = -1.0;
+    }
+
+    if ( fX < 0.125 )
+        return fSign * rtl_math_log1p( fX + fX*fX / (1.0 + sqrt( 1.0 + fX*fX)));
+
+    if ( fX < 1.25e7 )
+        return fSign * log( fX + sqrt( 1.0 + fX*fX));
+
+    return fSign * log( 2.0*fX);
+}
+
+/** improved accuracy of acosh for x large and for x near 1
+    @see #i97605#
+ */
+double SAL_CALL rtl_math_acosh(double fX) SAL_THROW_EXTERN_C()
+{
+    volatile double fZ = fX - 1.0;
+    if (fX < 1.0)
+        return std::numeric_limits<double>::quiet_NaN();
+    if ( fX == 1.0 )
+        return 0.0;
+
+    if ( fX < 1.1 )
+        return rtl_math_log1p( fZ + sqrt( fZ*fZ + 2.0*fZ));
+
+    if ( fX < 1.25e7 )
+        return log( fX + sqrt( fX*fX - 1.0));
+
+    return log( 2.0*fX);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */