/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2011 Nexenta Systems, Inc. All rights reserved. */ /* * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #if defined(ELFOBJ) #pragma weak fma = __fma #endif #include "libm.h" #include "fma.h" #include "fenv_inlines.h" #if defined(__sparc) static const union { unsigned i[2]; double d; } C[] = { { 0x3fe00000u, 0 }, { 0x40000000u, 0 }, { 0x43300000u, 0 }, { 0x41a00000u, 0 }, { 0x3e500000u, 0 }, { 0x3df00000u, 0 }, { 0x3bf00000u, 0 }, { 0x7fe00000u, 0 }, { 0x00100000u, 0 }, { 0x00100001u, 0 } }; #define half C[0].d #define two C[1].d #define two52 C[2].d #define two27 C[3].d #define twom26 C[4].d #define twom32 C[5].d #define twom64 C[6].d #define huge C[7].d #define tiny C[8].d #define tiny2 C[9].d static const unsigned int fsr_rm = 0xc0000000u; /* * fma for SPARC: 64-bit double precision, big-endian */ double __fma(double x, double y, double z) { union { unsigned i[2]; double d; } xx, yy, zz; double xhi, yhi, xlo, ylo, t; unsigned int xy0, xy1, xy2, xy3, z0, z1, z2, z3, fsr, rm, sticky; int hx, hy, hz, ex, ey, ez, exy, sxy, sz, e, ibit; volatile double dummy; /* extract the high order words of the arguments */ xx.d = x; yy.d = y; zz.d = z; hx = xx.i[0] & ~0x80000000; hy = yy.i[0] & ~0x80000000; hz = zz.i[0] & ~0x80000000; /* dispense with inf, nan, and zero cases */ if (hx >= 0x7ff00000 || hy >= 0x7ff00000 || (hx | xx.i[1]) == 0 || (hy | yy.i[1]) == 0) /* x or y is inf, nan, or zero */ return (x * y + z); if (hz >= 0x7ff00000) /* z is inf or nan */ return (x + z); /* avoid spurious under/overflow in x * y */ if ((hz | zz.i[1]) == 0) /* z is zero */ /* * x * y isn't zero but could underflow to zero, * so don't add z, lest we perturb the sign */ return (x * y); /* * now x, y, and z are all finite and nonzero; save the fsr and * set round-to-negative-infinity mode (and clear nonstandard * mode before we try to scale subnormal operands) */ __fenv_getfsr32(&fsr); __fenv_setfsr32(&fsr_rm); /* extract signs and exponents, and normalize subnormals */ sxy = (xx.i[0] ^ yy.i[0]) & 0x80000000; sz = zz.i[0] & 0x80000000; ex = hx >> 20; if (!ex) { xx.d = x * two52; ex = ((xx.i[0] & ~0x80000000) >> 20) - 52; } ey = hy >> 20; if (!ey) { yy.d = y * two52; ey = ((yy.i[0] & ~0x80000000) >> 20) - 52; } ez = hz >> 20; if (!ez) { zz.d = z * two52; ez = ((zz.i[0] & ~0x80000000) >> 20) - 52; } /* multiply x*y to 106 bits */ exy = ex + ey - 0x3ff; xx.i[0] = (xx.i[0] & 0xfffff) | 0x3ff00000; yy.i[0] = (yy.i[0] & 0xfffff) | 0x3ff00000; x = xx.d; y = yy.d; xhi = ((x + twom26) + two27) - two27; yhi = ((y + twom26) + two27) - two27; xlo = x - xhi; ylo = y - yhi; x *= y; y = ((xhi * yhi - x) + xhi * ylo + xlo * yhi) + xlo * ylo; if (x >= two) { x *= half; y *= half; exy++; } /* extract the significands */ xx.d = x; xy0 = (xx.i[0] & 0xfffff) | 0x100000; xy1 = xx.i[1]; yy.d = t = y + twom32; xy2 = yy.i[1]; yy.d = (y - (t - twom32)) + twom64; xy3 = yy.i[1]; z0 = (zz.i[0] & 0xfffff) | 0x100000; z1 = zz.i[1]; z2 = z3 = 0; /* * now x*y is represented by sxy, exy, and xy[0-3], and z is * represented likewise; swap if need be so |xy| <= |z| */ if (exy > ez || (exy == ez && (xy0 > z0 || (xy0 == z0 && (xy1 > z1 || (xy1 == z1 && (xy2 | xy3) != 0)))))) { e = sxy; sxy = sz; sz = e; e = exy; exy = ez; ez = e; e = xy0; xy0 = z0; z0 = e; e = xy1; xy1 = z1; z1 = e; z2 = xy2; xy2 = 0; z3 = xy3; xy3 = 0; } /* shift the significand of xy keeping a sticky bit */ e = ez - exy; if (e > 116) { xy0 = xy1 = xy2 = 0; xy3 = 1; } else if (e >= 96) { sticky = xy3 | xy2 | xy1 | ((xy0 << 1) << (127 - e)); xy3 = xy0 >> (e - 96); if (sticky) xy3 |= 1; xy0 = xy1 = xy2 = 0; } else if (e >= 64) { sticky = xy3 | xy2 | ((xy1 << 1) << (95 - e)); xy3 = (xy1 >> (e - 64)) | ((xy0 << 1) << (95 - e)); if (sticky) xy3 |= 1; xy2 = xy0 >> (e - 64); xy0 = xy1 = 0; } else if (e >= 32) { sticky = xy3 | ((xy2 << 1) << (63 - e)); xy3 = (xy2 >> (e - 32)) | ((xy1 << 1) << (63 - e)); if (sticky) xy3 |= 1; xy2 = (xy1 >> (e - 32)) | ((xy0 << 1) << (63 - e)); xy1 = xy0 >> (e - 32); xy0 = 0; } else if (e) { sticky = (xy3 << 1) << (31 - e); xy3 = (xy3 >> e) | ((xy2 << 1) << (31 - e)); if (sticky) xy3 |= 1; xy2 = (xy2 >> e) | ((xy1 << 1) << (31 - e)); xy1 = (xy1 >> e) | ((xy0 << 1) << (31 - e)); xy0 >>= e; } /* if this is a magnitude subtract, negate the significand of xy */ if (sxy ^ sz) { xy0 = ~xy0; xy1 = ~xy1; xy2 = ~xy2; xy3 = -xy3; if (xy3 == 0) if (++xy2 == 0) if (++xy1 == 0) xy0++; } /* add, propagating carries */ z3 += xy3; e = (z3 < xy3); z2 += xy2; if (e) { z2++; e = (z2 <= xy2); } else e = (z2 < xy2); z1 += xy1; if (e) { z1++; e = (z1 <= xy1); } else e = (z1 < xy1); z0 += xy0; if (e) z0++; /* postnormalize and collect rounding information into z2 */ if (ez < 1) { /* result is tiny; shift right until exponent is within range */ e = 1 - ez; if (e > 56) { z2 = 1; /* result can't be exactly zero */ z0 = z1 = 0; } else if (e >= 32) { sticky = z3 | z2 | ((z1 << 1) << (63 - e)); z2 = (z1 >> (e - 32)) | ((z0 << 1) << (63 - e)); if (sticky) z2 |= 1; z1 = z0 >> (e - 32); z0 = 0; } else { sticky = z3 | (z2 << 1) << (31 - e); z2 = (z2 >> e) | ((z1 << 1) << (31 - e)); if (sticky) z2 |= 1; z1 = (z1 >> e) | ((z0 << 1) << (31 - e)); z0 >>= e; } ez = 1; } else if (z0 >= 0x200000) { /* carry out; shift right by one */ sticky = (z2 & 1) | z3; z2 = (z2 >> 1) | (z1 << 31); if (sticky) z2 |= 1; z1 = (z1 >> 1) | (z0 << 31); z0 >>= 1; ez++; } else { if (z0 < 0x100000 && (z0 | z1 | z2 | z3) != 0) { /* * borrow/cancellation; shift left as much as * exponent allows */ while (!(z0 | (z1 & 0xffe00000)) && ez >= 33) { z0 = z1; z1 = z2; z2 = z3; z3 = 0; ez -= 32; } while (z0 < 0x100000 && ez > 1) { z0 = (z0 << 1) | (z1 >> 31); z1 = (z1 << 1) | (z2 >> 31); z2 = (z2 << 1) | (z3 >> 31); z3 <<= 1; ez--; } } if (z3) z2 |= 1; } /* get the rounding mode and clear current exceptions */ rm = fsr >> 30; fsr &= ~FSR_CEXC; /* strip off the integer bit, if there is one */ ibit = z0 & 0x100000; if (ibit) z0 -= 0x100000; else { ez = 0; if (!(z0 | z1 | z2)) { /* exact zero */ zz.i[0] = rm == FSR_RM ? 0x80000000 : 0; zz.i[1] = 0; __fenv_setfsr32(&fsr); return (zz.d); } } /* * flip the sense of directed roundings if the result is negative; * the logic below applies to a positive result */ if (sz) rm ^= rm >> 1; /* round and raise exceptions */ if (z2) { fsr |= FSR_NXC; /* decide whether to round the fraction up */ if (rm == FSR_RP || (rm == FSR_RN && (z2 > 0x80000000u || (z2 == 0x80000000u && (z1 & 1))))) { /* round up and renormalize if necessary */ if (++z1 == 0) { if (++z0 == 0x100000) { z0 = 0; ez++; } } } } /* check for under/overflow */ if (ez >= 0x7ff) { if (rm == FSR_RN || rm == FSR_RP) { zz.i[0] = sz | 0x7ff00000; zz.i[1] = 0; } else { zz.i[0] = sz | 0x7fefffff; zz.i[1] = 0xffffffff; } fsr |= FSR_OFC | FSR_NXC; } else { zz.i[0] = sz | (ez << 20) | z0; zz.i[1] = z1; /* * !ibit => exact result was tiny before rounding, * z2 nonzero => result delivered is inexact */ if (!ibit) { if (z2) fsr |= FSR_UFC | FSR_NXC; else if (fsr & FSR_UFM) fsr |= FSR_UFC; } } /* restore the fsr and emulate exceptions as needed */ if ((fsr & FSR_CEXC) & (fsr >> 23)) { __fenv_setfsr32(&fsr); if (fsr & FSR_OFC) { dummy = huge; dummy *= huge; } else if (fsr & FSR_UFC) { dummy = tiny; if (fsr & FSR_NXC) dummy *= tiny; else dummy -= tiny2; } else { dummy = huge; dummy += tiny; } } else { fsr |= (fsr & 0x1f) << 5; __fenv_setfsr32(&fsr); } return (zz.d); } #elif defined(__x86) #if defined(__amd64) #define NI 4 #else #define NI 3 #endif /* * fma for x86: 64-bit double precision, little-endian */ double __fma(double x, double y, double z) { union { unsigned i[NI]; long double e; } xx, yy, zz; long double xe, ye, xhi, xlo, yhi, ylo; int ex, ey, ez; unsigned cwsw, oldcwsw, rm; /* convert the operands to double extended */ xx.e = (long double) x; yy.e = (long double) y; zz.e = (long double) z; /* extract the exponents of the arguments */ ex = xx.i[2] & 0x7fff; ey = yy.i[2] & 0x7fff; ez = zz.i[2] & 0x7fff; /* dispense with inf, nan, and zero cases */ if (ex == 0x7fff || ey == 0x7fff || ex == 0 || ey == 0) /* x or y is inf, nan, or zero */ return ((double) (xx.e * yy.e + zz.e)); if (ez >= 0x7fff) /* z is inf or nan */ return ((double) (xx.e + zz.e)); /* avoid spurious inexact in x * y */ /* * save the control and status words, mask all exceptions, and * set rounding to 64-bit precision and to-nearest */ __fenv_getcwsw(&oldcwsw); cwsw = (oldcwsw & 0xf0c0ffff) | 0x033f0000; __fenv_setcwsw(&cwsw); /* multiply x*y to 106 bits */ xe = xx.e; xx.i[0] = 0; xhi = xx.e; /* hi 32 bits */ xlo = xe - xhi; /* lo 21 bits */ ye = yy.e; yy.i[0] = 0; yhi = yy.e; ylo = ye - yhi; xe = xe * ye; ye = ((xhi * yhi - xe) + xhi * ylo + xlo * yhi) + xlo * ylo; /* distill the sum of xe, ye, and z */ xhi = ye + zz.e; yhi = xhi - ye; xlo = (zz.e - yhi) + (ye - (xhi - yhi)); /* now (xhi,xlo) = ye + z */ yhi = xe + xhi; ye = yhi - xe; ylo = (xhi - ye) + (xe - (yhi - ye)); /* now (yhi,ylo) = xe + xhi */ xhi = xlo + ylo; xe = xhi - xlo; xlo = (ylo - xe) + (xlo - (xhi - xe)); /* now (xhi,xlo) = xlo + ylo */ yy.e = yhi + xhi; ylo = (yhi - yy.e) + xhi; /* now (yy.e,ylo) = xhi + yhi */ if (yy.i[1] != 0) { /* yy.e is nonzero */ /* perturb yy.e if its least significant 10 bits are zero */ if (!(yy.i[0] & 0x3ff)) { xx.e = ylo + xlo; if (xx.i[1] != 0) { xx.i[2] = (xx.i[2] & 0x8000) | ((yy.i[2] & 0x7fff) - 63); xx.i[1] = 0x80000000; xx.i[0] = 0; yy.e += xx.e; } } } else { /* set sign of zero result according to rounding direction */ rm = oldcwsw & 0x0c000000; yy.i[2] = ((rm == FCW_RM)? 0x8000 : 0); } /* * restore the control and status words and convert the result * to double */ __fenv_setcwsw(&oldcwsw); return ((double) yy.e); } #else #error Unknown architecture #endif