msvcrt: Use the fma()/fmaf() implementation from the bundled musl library.
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4 changed files with 16 additions and 271 deletions
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@ -3310,263 +3310,6 @@ double CDECL floor( double x )
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return u.f;
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}
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/*********************************************************************
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* fma (MSVCRT.@)
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*
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* Copied from musl: src/math/fma.c
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*/
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struct fma_num
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{
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UINT64 m;
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int e;
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int sign;
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};
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static struct fma_num normalize(double x)
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{
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UINT64 ix = *(UINT64*)&x;
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int e = ix >> 52;
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int sign = e & 0x800;
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struct fma_num ret;
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e &= 0x7ff;
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if (!e) {
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x *= 0x1p63;
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ix = *(UINT64*)&x;
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e = ix >> 52 & 0x7ff;
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e = e ? e - 63 : 0x800;
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}
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ix &= (1ull << 52) - 1;
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ix |= 1ull << 52;
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ix <<= 1;
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e -= 0x3ff + 52 + 1;
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ret.m = ix;
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ret.e = e;
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ret.sign = sign;
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return ret;
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}
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static void mul(UINT64 *hi, UINT64 *lo, UINT64 x, UINT64 y)
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{
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UINT64 t1, t2, t3;
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UINT64 xlo = (UINT32)x, xhi = x >> 32;
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UINT64 ylo = (UINT32)y, yhi = y >> 32;
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t1 = xlo * ylo;
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t2 = xlo * yhi + xhi * ylo;
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t3 = xhi * yhi;
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*lo = t1 + (t2 << 32);
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*hi = t3 + (t2 >> 32) + (t1 > *lo);
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}
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double CDECL fma( double x, double y, double z )
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{
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int e, d, sign, samesign, nonzero;
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UINT64 rhi, rlo, zhi, zlo;
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struct fma_num nx, ny, nz;
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double r;
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INT64 i;
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/* normalize so top 10bits and last bit are 0 */
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nx = normalize(x);
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ny = normalize(y);
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nz = normalize(z);
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if (nx.e >= 0x7ff - 0x3ff - 52 - 1 || ny.e >= 0x7ff - 0x3ff - 52 - 1) {
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r = x * y + z;
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if (!isnan(x) && !isnan(y) && !isnan(z) && isnan(r)) *_errno() = EDOM;
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return r;
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}
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if (nz.e >= 0x7ff - 0x3ff - 52 - 1) {
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if (nz.e > 0x7ff - 0x3ff - 52 - 1) {/* z==0 */
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r = x * y + z;
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if (!isnan(x) && !isnan(y) && isnan(r)) *_errno() = EDOM;
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return r;
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}
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return z;
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}
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/* mul: r = x*y */
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mul(&rhi, &rlo, nx.m, ny.m);
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/* either top 20 or 21 bits of rhi and last 2 bits of rlo are 0 */
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/* align exponents */
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e = nx.e + ny.e;
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d = nz.e - e;
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/* shift bits z<<=kz, r>>=kr, so kz+kr == d, set e = e+kr (== ez-kz) */
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if (d > 0) {
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if (d < 64) {
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zlo = nz.m << d;
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zhi = nz.m >> (64 - d);
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} else {
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zlo = 0;
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zhi = nz.m;
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e = nz.e - 64;
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d -= 64;
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if (d < 64 && d) {
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rlo = rhi << (64 - d) | rlo >> d | !!(rlo << (64 - d));
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rhi = rhi >> d;
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} else if (d) {
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rlo = 1;
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rhi = 0;
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}
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}
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} else {
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zhi = 0;
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d = -d;
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if (d == 0) {
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zlo = nz.m;
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} else if (d < 64) {
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zlo = nz.m >> d | !!(nz.m << (64 - d));
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} else {
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zlo = 1;
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}
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}
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/* add */
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sign = nx.sign ^ ny.sign;
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samesign = !(sign ^ nz.sign);
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nonzero = 1;
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if (samesign) {
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/* r += z */
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rlo += zlo;
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rhi += zhi + (rlo < zlo);
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} else {
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/* r -= z */
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UINT64 t = rlo;
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rlo -= zlo;
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rhi = rhi - zhi - (t < rlo);
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if (rhi >> 63) {
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rlo = -rlo;
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rhi = -rhi - !!rlo;
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sign = !sign;
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}
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nonzero = !!rhi;
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}
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/* set rhi to top 63bit of the result (last bit is sticky) */
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if (nonzero) {
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e += 64;
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if (rhi >> 32) {
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BitScanReverse((DWORD*)&d, rhi >> 32);
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d = 31 - d - 1;
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} else {
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BitScanReverse((DWORD*)&d, rhi);
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d = 63 - d - 1;
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}
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/* note: d > 0 */
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rhi = rhi << d | rlo >> (64 - d) | !!(rlo << d);
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} else if (rlo) {
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if (rlo >> 32) {
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BitScanReverse((DWORD*)&d, rlo >> 32);
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d = 31 - d - 1;
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} else {
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BitScanReverse((DWORD*)&d, rlo);
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d = 63 - d - 1;
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}
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if (d < 0)
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rhi = rlo >> 1 | (rlo & 1);
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else
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rhi = rlo << d;
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} else {
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/* exact +-0 */
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return x * y + z;
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}
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e -= d;
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/* convert to double */
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i = rhi; /* i is in [1<<62,(1<<63)-1] */
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if (sign)
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i = -i;
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r = i; /* |r| is in [0x1p62,0x1p63] */
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if (e < -1022 - 62) {
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/* result is subnormal before rounding */
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if (e == -1022 - 63) {
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double c = 0x1p63;
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if (sign)
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c = -c;
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if (r == c) {
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/* min normal after rounding, underflow depends
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on arch behaviour which can be imitated by
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a double to float conversion */
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float fltmin = 0x0.ffffff8p-63 * FLT_MIN * r;
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return DBL_MIN / FLT_MIN * fltmin;
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}
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/* one bit is lost when scaled, add another top bit to
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only round once at conversion if it is inexact */
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if (rhi << 53) {
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double tiny;
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i = rhi >> 1 | (rhi & 1) | 1ull << 62;
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if (sign)
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i = -i;
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r = i;
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r = 2 * r - c; /* remove top bit */
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/* raise underflow portably, such that it
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cannot be optimized away */
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tiny = DBL_MIN / FLT_MIN * r;
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r += (double)(tiny * tiny) * (r - r);
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}
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} else {
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/* only round once when scaled */
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d = 10;
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i = (rhi >> d | !!(rhi << (64 - d))) << d;
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if (sign)
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i = -i;
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r = i;
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}
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}
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return scalbn(r, e);
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}
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/*********************************************************************
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* fmaf (MSVCRT.@)
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*
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* Copied from musl: src/math/fmaf.c
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*/
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float CDECL fmaf( float x, float y, float z )
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{
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union { double f; UINT64 i; } u;
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double xy, err;
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int e, neg;
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xy = (double)x * y;
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u.f = xy + z;
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e = u.i>>52 & 0x7ff;
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/* Common case: The double precision result is fine. */
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if ((u.i & 0x1fffffff) != 0x10000000 || /* not a halfway case */
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e == 0x7ff || /* NaN */
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(u.f - xy == z && u.f - z == xy) || /* exact */
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(_controlfp(0, 0) & _MCW_RC) != _RC_NEAR) /* not round-to-nearest */
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{
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if (!isnan(x) && !isnan(y) && !isnan(z) && isnan(u.f)) *_errno() = EDOM;
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/* underflow may not be raised correctly, example:
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fmaf(0x1p-120f, 0x1p-120f, 0x1p-149f) */
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if (e < 0x3ff-126 && e >= 0x3ff-149 && _statusfp() & _SW_INEXACT)
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fp_barrierf((float)u.f * (float)u.f);
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return u.f;
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}
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/*
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* If result is inexact, and exactly halfway between two float values,
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* we need to adjust the low-order bit in the direction of the error.
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*/
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neg = u.i >> 63;
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if (neg == (z > xy))
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err = xy - u.f + z;
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else
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err = z - u.f + xy;
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if (neg == (err < 0))
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u.i++;
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else
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u.i--;
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return u.f;
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}
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#if defined(__i386__) || defined(__x86_64__)
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static void _setfp_sse( unsigned int *cw, unsigned int cw_mask,
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unsigned int *sw, unsigned int sw_mask )
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@ -1297,8 +1297,6 @@
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@ cdecl fgetws(ptr long ptr)
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@ cdecl floor(double)
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@ cdecl -arch=!i386 floorf(float)
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@ cdecl fma(double double double)
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@ cdecl -arch=!i386 fmaf(float float float)
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@ cdecl fmod(double double)
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@ cdecl -arch=!i386 fmodf(float float)
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@ cdecl fopen(str str)
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@ -58,19 +58,23 @@ static void mul(uint64_t *hi, uint64_t *lo, uint64_t x, uint64_t y)
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double __cdecl fma(double x, double y, double z)
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{
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#pragma STDC FENV_ACCESS ON
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/* normalize so top 10bits and last bit are 0 */
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struct num nx, ny, nz;
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nx = normalize(x);
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ny = normalize(y);
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nz = normalize(z);
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if (nx.e >= ZEROINFNAN || ny.e >= ZEROINFNAN)
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return x*y + z;
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if (nx.e >= ZEROINFNAN || ny.e >= ZEROINFNAN) {
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double r = x * y + z;
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if (!isnan(x) && !isnan(y) && !isnan(z) && isnan(r)) errno = EDOM;
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return r;
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}
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if (nz.e >= ZEROINFNAN) {
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if (nz.e > ZEROINFNAN) /* z==0 */
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return x*y + z;
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if (nz.e > ZEROINFNAN) { /* z==0 */
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double r = x * y + z;
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if (!isnan(x) && !isnan(y) && isnan(r)) errno = EDOM;
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return r;
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}
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return z;
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}
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@ -86,7 +90,7 @@ double __cdecl fma(double x, double y, double z)
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if (d > 0) {
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if (d < 64) {
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zlo = nz.m<<d;
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zhi = nz.m>>64-d;
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zhi = nz.m>>(64-d);
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} else {
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zlo = 0;
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zhi = nz.m;
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@ -94,7 +98,7 @@ double __cdecl fma(double x, double y, double z)
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d -= 64;
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if (d == 0) {
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} else if (d < 64) {
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rlo = rhi<<64-d | rlo>>d | !!(rlo<<64-d);
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rlo = rhi<<(64-d) | rlo>>d | !!(rlo<<(64-d));
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rhi = rhi>>d;
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} else {
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rlo = 1;
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@ -107,7 +111,7 @@ double __cdecl fma(double x, double y, double z)
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if (d == 0) {
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zlo = nz.m;
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} else if (d < 64) {
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zlo = nz.m>>d | !!(nz.m<<64-d);
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zlo = nz.m>>d | !!(nz.m<<(64-d));
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} else {
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zlo = 1;
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}
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@ -139,7 +143,7 @@ double __cdecl fma(double x, double y, double z)
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e += 64;
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d = a_clz_64(rhi)-1;
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/* note: d > 0 */
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rhi = rhi<<d | rlo>>64-d | !!(rlo<<d);
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rhi = rhi<<d | rlo>>(64-d) | !!(rlo<<d);
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} else if (rlo) {
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d = a_clz_64(rlo)-1;
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if (d < 0)
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@ -190,7 +194,7 @@ double __cdecl fma(double x, double y, double z)
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} else {
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/* only round once when scaled */
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d = 10;
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i = ( rhi>>d | !!(rhi<<64-d) ) << d;
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i = ( rhi>>d | !!(rhi<<(64-d)) ) << d;
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if (sign)
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i = -i;
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r = i;
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@ -39,7 +39,6 @@
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*/
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float __cdecl fmaf(float x, float y, float z)
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{
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#pragma STDC FENV_ACCESS ON
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double xy, result;
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union {double f; uint64_t i;} u;
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int e;
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@ -54,6 +53,7 @@ float __cdecl fmaf(float x, float y, float z)
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(result - xy == z && result - z == xy) || /* exact */
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fegetround() != FE_TONEAREST) /* not round-to-nearest */
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{
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if (!isnan(x) && !isnan(y) && !isnan(z) && isnan(u.f)) errno = EDOM;
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/*
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underflow may not be raised correctly, example:
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fmaf(0x1p-120f, 0x1p-120f, 0x1p-149f)
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