/* * linux/arch/arm/vfp/vfpdouble.c * * This code is derived in part from John R. Housers softfloat library, which * carries the following notice: * * =========================================================================== * This C source file is part of the SoftFloat IEC/IEEE Floating-point * Arithmetic Package, Release 2. * * Written by John R. Hauser. This work was made possible in part by the * International Computer Science Institute, located at Suite 600, 1947 Center * Street, Berkeley, California 94704. Funding was partially provided by the * National Science Foundation under grant MIP-9311980. The original version * of this code was written as part of a project to build a fixed-point vector * processor in collaboration with the University of California at Berkeley, * overseen by Profs. Nelson Morgan and John Wawrzynek. More information * is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/ * arithmetic/softfloat.html'. * * THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort * has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT * TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO * PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY * AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE. * * Derivative works are acceptable, even for commercial purposes, so long as * (1) they include prominent notice that the work is derivative, and (2) they * include prominent notice akin to these three paragraphs for those parts of * this code that are retained. * =========================================================================== */ #include #include #include #include #include #include "vfpinstr.h" #include "vfp.h" static struct vfp_double vfp_double_default_qnan = { .exponent = 2047, .sign = 0, .significand = VFP_DOUBLE_SIGNIFICAND_QNAN, }; static void vfp_double_dump(const char *str, struct vfp_double *d) { pr_debug("VFP: %s: sign=%d exponent=%d significand=%016llx\n", str, d->sign != 0, d->exponent, d->significand); } static void vfp_double_normalise_denormal(struct vfp_double *vd) { int bits = 31 - fls(vd->significand >> 32); if (bits == 31) bits = 62 - fls(vd->significand); vfp_double_dump("normalise_denormal: in", vd); if (bits) { vd->exponent -= bits - 1; vd->significand <<= bits; } vfp_double_dump("normalise_denormal: out", vd); } u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func) { u64 significand, incr; int exponent, shift, underflow; u32 rmode; vfp_double_dump("pack: in", vd); /* * Infinities and NaNs are a special case. */ if (vd->exponent == 2047 && (vd->significand == 0 || exceptions)) goto pack; /* * Special-case zero. */ if (vd->significand == 0) { vd->exponent = 0; goto pack; } exponent = vd->exponent; significand = vd->significand; shift = 32 - fls(significand >> 32); if (shift == 32) shift = 64 - fls(significand); if (shift) { exponent -= shift; significand <<= shift; } #ifdef DEBUG vd->exponent = exponent; vd->significand = significand; vfp_double_dump("pack: normalised", vd); #endif /* * Tiny number? */ underflow = exponent < 0; if (underflow) { significand = vfp_shiftright64jamming(significand, -exponent); exponent = 0; #ifdef DEBUG vd->exponent = exponent; vd->significand = significand; vfp_double_dump("pack: tiny number", vd); #endif if (!(significand & ((1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1))) underflow = 0; } /* * Select rounding increment. */ incr = 0; rmode = fpscr & FPSCR_RMODE_MASK; if (rmode == FPSCR_ROUND_NEAREST) { incr = 1ULL << VFP_DOUBLE_LOW_BITS; if ((significand & (1ULL << (VFP_DOUBLE_LOW_BITS + 1))) == 0) incr -= 1; } else if (rmode == FPSCR_ROUND_TOZERO) { incr = 0; } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vd->sign != 0)) incr = (1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1; pr_debug("VFP: rounding increment = 0x%08llx\n", incr); /* * Is our rounding going to overflow? */ if ((significand + incr) < significand) { exponent += 1; significand = (significand >> 1) | (significand & 1); incr >>= 1; #ifdef DEBUG vd->exponent = exponent; vd->significand = significand; vfp_double_dump("pack: overflow", vd); #endif } /* * If any of the low bits (which will be shifted out of the * number) are non-zero, the result is inexact. */ if (significand & ((1 << (VFP_DOUBLE_LOW_BITS + 1)) - 1)) exceptions |= FPSCR_IXC; /* * Do our rounding. */ significand += incr; /* * Infinity? */ if (exponent >= 2046) { exceptions |= FPSCR_OFC | FPSCR_IXC; if (incr == 0) { vd->exponent = 2045; vd->significand = 0x7fffffffffffffffULL; } else { vd->exponent = 2047; /* infinity */ vd->significand = 0; } } else { if (significand >> (VFP_DOUBLE_LOW_BITS + 1) == 0) exponent = 0; if (exponent || significand > 0x8000000000000000ULL) underflow = 0; if (underflow) exceptions |= FPSCR_UFC; vd->exponent = exponent; vd->significand = significand >> 1; } pack: vfp_double_dump("pack: final", vd); { s64 d = vfp_double_pack(vd); pr_debug("VFP: %s: d(d%d)=%016llx exceptions=%08x\n", func, dd, d, exceptions); vfp_put_double(dd, d); } return exceptions & ~VFP_NAN_FLAG; } /* * Propagate the NaN, setting exceptions if it is signalling. * 'n' is always a NaN. 'm' may be a number, NaN or infinity. */ static u32 vfp_propagate_nan(struct vfp_double *vdd, struct vfp_double *vdn, struct vfp_double *vdm, u32 fpscr) { struct vfp_double *nan; int tn, tm = 0; tn = vfp_double_type(vdn); if (vdm) tm = vfp_double_type(vdm); if (fpscr & FPSCR_DEFAULT_NAN) /* * Default NaN mode - always returns a quiet NaN */ nan = &vfp_double_default_qnan; else { /* * Contemporary mode - select the first signalling * NAN, or if neither are signalling, the first * quiet NAN. */ if (tn == VFP_SNAN || (tm != VFP_SNAN && tn == VFP_QNAN)) nan = vdn; else nan = vdm; /* * Make the NaN quiet. */ nan->significand |= VFP_DOUBLE_SIGNIFICAND_QNAN; } *vdd = *nan; /* * If one was a signalling NAN, raise invalid operation. */ return tn == VFP_SNAN || tm == VFP_SNAN ? FPSCR_IOC : VFP_NAN_FLAG; } /* * Extended operations */ static u32 vfp_double_fabs(int dd, int unused, int dm, u32 fpscr) { vfp_put_double(dd, vfp_double_packed_abs(vfp_get_double(dm))); return 0; } static u32 vfp_double_fcpy(int dd, int unused, int dm, u32 fpscr) { vfp_put_double(dd, vfp_get_double(dm)); return 0; } static u32 vfp_double_fneg(int dd, int unused, int dm, u32 fpscr) { vfp_put_double(dd, vfp_double_packed_negate(vfp_get_double(dm))); return 0; } static u32 vfp_double_fsqrt(int dd, int unused, int dm, u32 fpscr) { struct vfp_double vdm, vdd; int ret, tm; vfp_double_unpack(&vdm, vfp_get_double(dm)); tm = vfp_double_type(&vdm); if (tm & (VFP_NAN|VFP_INFINITY)) { struct vfp_double *vdp = &vdd; if (tm & VFP_NAN) ret = vfp_propagate_nan(vdp, &vdm, NULL, fpscr); else if (vdm.sign == 0) { sqrt_copy: vdp = &vdm; ret = 0; } else { sqrt_invalid: vdp = &vfp_double_default_qnan; ret = FPSCR_IOC; } vfp_put_double(dd, vfp_double_pack(vdp)); return ret; } /* * sqrt(+/- 0) == +/- 0 */ if (tm & VFP_ZERO) goto sqrt_copy; /* * Normalise a denormalised number */ if (tm & VFP_DENORMAL) vfp_double_normalise_denormal(&vdm); /* * sqrt(<0) = invalid */ if (vdm.sign) goto sqrt_invalid; vfp_double_dump("sqrt", &vdm); /* * Estimate the square root. */ vdd.sign = 0; vdd.exponent = ((vdm.exponent - 1023) >> 1) + 1023; vdd.significand = (u64)vfp_estimate_sqrt_significand(vdm.exponent, vdm.significand >> 32) << 31; vfp_double_dump("sqrt estimate1", &vdd); vdm.significand >>= 1 + (vdm.exponent & 1); vdd.significand += 2 + vfp_estimate_div128to64(vdm.significand, 0, vdd.significand); vfp_double_dump("sqrt estimate2", &vdd); /* * And now adjust. */ if ((vdd.significand & VFP_DOUBLE_LOW_BITS_MASK) <= 5) { if (vdd.significand < 2) { vdd.significand = ~0ULL; } else { u64 termh, terml, remh, reml; vdm.significand <<= 2; mul64to128(&termh, &terml, vdd.significand, vdd.significand); sub128(&remh, &reml, vdm.significand, 0, termh, terml); while ((s64)remh < 0) { vdd.significand -= 1; shift64left(&termh, &terml, vdd.significand); terml |= 1; add128(&remh, &reml, remh, reml, termh, terml); } vdd.significand |= (remh | reml) != 0; } } vdd.significand = vfp_shiftright64jamming(vdd.significand, 1); return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fsqrt"); } /* * Equal := ZC * Less than := N * Greater than := C * Unordered := CV */ static u32 vfp_compare(int dd, int signal_on_qnan, int dm, u32 fpscr) { s64 d, m; u32 ret = 0; m = vfp_get_double(dm); if (vfp_double_packed_exponent(m) == 2047 && vfp_double_packed_mantissa(m)) { ret |= FPSCR_C | FPSCR_V; if (signal_on_qnan || !(vfp_double_packed_mantissa(m) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) /* * Signalling NaN, or signalling on quiet NaN */ ret |= FPSCR_IOC; } d = vfp_get_double(dd); if (vfp_double_packed_exponent(d) == 2047 && vfp_double_packed_mantissa(d)) { ret |= FPSCR_C | FPSCR_V; if (signal_on_qnan || !(vfp_double_packed_mantissa(d) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) /* * Signalling NaN, or signalling on quiet NaN */ ret |= FPSCR_IOC; } if (ret == 0) { if (d == m || vfp_double_packed_abs(d | m) == 0) { /* * equal */ ret |= FPSCR_Z | FPSCR_C; } else if (vfp_double_packed_sign(d ^ m)) { /* * different signs */ if (vfp_double_packed_sign(d)) /* * d is negative, so d < m */ ret |= FPSCR_N; else /* * d is positive, so d > m */ ret |= FPSCR_C; } else if ((vfp_double_packed_sign(d) != 0) ^ (d < m)) { /* * d < m */ ret |= FPSCR_N; } else if ((vfp_double_packed_sign(d) != 0) ^ (d > m)) { /* * d > m */ ret |= FPSCR_C; } } return ret; } static u32 vfp_double_fcmp(int dd, int unused, int dm, u32 fpscr) { return vfp_compare(dd, 0, dm, fpscr); } static u32 vfp_double_fcmpe(int dd, int unused, int dm, u32 fpscr) { return vfp_compare(dd, 1, dm, fpscr); } static u32 vfp_double_fcmpz(int dd, int unused, int dm, u32 fpscr) { return vfp_compare(dd, 0, VFP_REG_ZERO, fpscr); } static u32 vfp_double_fcmpez(int dd, int unused, int dm, u32 fpscr) { return vfp_compare(dd, 1, VFP_REG_ZERO, fpscr); } static u32 vfp_double_fcvts(int sd, int unused, int dm, u32 fpscr) { struct vfp_double vdm; struct vfp_single vsd; int tm; u32 exceptions = 0; vfp_double_unpack(&vdm, vfp_get_double(dm)); tm = vfp_double_type(&vdm); /* * If we have a signalling NaN, signal invalid operation. */ if (tm == VFP_SNAN) exceptions = FPSCR_IOC; if (tm & VFP_DENORMAL) vfp_double_normalise_denormal(&vdm); vsd.sign = vdm.sign; vsd.significand = vfp_hi64to32jamming(vdm.significand); /* * If we have an infinity or a NaN, the exponent must be 255 */ if (tm & (VFP_INFINITY|VFP_NAN)) { vsd.exponent = 255; if (tm & VFP_NAN) vsd.significand |= VFP_SINGLE_SIGNIFICAND_QNAN; goto pack_nan; } else if (tm & VFP_ZERO) vsd.exponent = 0; else vsd.exponent = vdm.exponent - (1023 - 127); return vfp_single_normaliseround(sd, &vsd, fpscr, exceptions, "fcvts"); pack_nan: vfp_put_float(sd, vfp_single_pack(&vsd)); return exceptions; } static u32 vfp_double_fuito(int dd, int unused, int dm, u32 fpscr) { struct vfp_double vdm; u32 m = vfp_get_float(dm); vdm.sign = 0; vdm.exponent = 1023 + 63 - 1; vdm.significand = (u64)m; return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fuito"); } static u32 vfp_double_fsito(int dd, int unused, int dm, u32 fpscr) { struct vfp_double vdm; u32 m = vfp_get_float(dm); vdm.sign = (m & 0x80000000) >> 16; vdm.exponent = 1023 + 63 - 1; vdm.significand = vdm.sign ? -m : m; return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fsito"); } static u32 vfp_double_ftoui(int sd, int unused, int dm, u32 fpscr) { struct vfp_double vdm; u32 d, exceptions = 0; int rmode = fpscr & FPSCR_RMODE_MASK; int tm; vfp_double_unpack(&vdm, vfp_get_double(dm)); /* * Do we have a denormalised number? */ tm = vfp_double_type(&vdm); if (tm & VFP_DENORMAL) exceptions |= FPSCR_IDC; if (tm & VFP_NAN) vdm.sign = 0; if (vdm.exponent >= 1023 + 32) { d = vdm.sign ? 0 : 0xffffffff; exceptions = FPSCR_IOC; } else if (vdm.exponent >= 1023 - 1) { int shift = 1023 + 63 - vdm.exponent; u64 rem, incr = 0; /* * 2^0 <= m < 2^32-2^8 */ d = (vdm.significand << 1) >> shift; rem = vdm.significand << (65 - shift); if (rmode == FPSCR_ROUND_NEAREST) { incr = 0x8000000000000000ULL; if ((d & 1) == 0) incr -= 1; } else if (rmode == FPSCR_ROUND_TOZERO) { incr = 0; } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { incr = ~0ULL; } if ((rem + incr) < rem) { if (d < 0xffffffff) d += 1; else exceptions |= FPSCR_IOC; } if (d && vdm.sign) { d = 0; exceptions |= FPSCR_IOC; } else if (rem) exceptions |= FPSCR_IXC; } else { d = 0; if (vdm.exponent | vdm.significand) { exceptions |= FPSCR_IXC; if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) d = 1; else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) { d = 0; exceptions |= FPSCR_IOC; } } } pr_debug("VFP: ftoui: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions); vfp_put_float(sd, d); return exceptions; } static u32 vfp_double_ftouiz(int sd, int unused, int dm, u32 fpscr) { return vfp_double_ftoui(sd, unused, dm, FPSCR_ROUND_TOZERO); } static u32 vfp_double_ftosi(int sd, int unused, int dm, u32 fpscr) { struct vfp_double vdm; u32 d, exceptions = 0; int rmode = fpscr & FPSCR_RMODE_MASK; int tm; vfp_double_unpack(&vdm, vfp_get_double(dm)); vfp_double_dump("VDM", &vdm); /* * Do we have denormalised number? */ tm = vfp_double_type(&vdm); if (tm & VFP_DENORMAL) exceptions |= FPSCR_IDC; if (tm & VFP_NAN) { d = 0; exceptions |= FPSCR_IOC; } else if (vdm.exponent >= 1023 + 32) { d = 0x7fffffff; if (vdm.sign) d = ~d; exceptions |= FPSCR_IOC; } else if (vdm.exponent >= 1023 - 1) { int shift = 1023 + 63 - vdm.exponent; /* 58 */ u64 rem, incr = 0; d = (vdm.significand << 1) >> shift; rem = vdm.significand << (65 - shift); if (rmode == FPSCR_ROUND_NEAREST) { incr = 0x8000000000000000ULL; if ((d & 1) == 0) incr -= 1; } else if (rmode == FPSCR_ROUND_TOZERO) { incr = 0; } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { incr = ~0ULL; } if ((rem + incr) < rem && d < 0xffffffff) d += 1; if (d > 0x7fffffff + (vdm.sign != 0)) { d = 0x7fffffff + (vdm.sign != 0); exceptions |= FPSCR_IOC; } else if (rem) exceptions |= FPSCR_IXC; if (vdm.sign) d = -d; } else { d = 0; if (vdm.exponent | vdm.significand) { exceptions |= FPSCR_IXC; if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) d = 1; else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) d = -1; } } pr_debug("VFP: ftosi: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions); vfp_put_float(sd, (s32)d); return exceptions; } static u32 vfp_double_ftosiz(int dd, int unused, int dm, u32 fpscr) { return vfp_double_ftosi(dd, unused, dm, FPSCR_ROUND_TOZERO); } static u32 (* const fop_extfns[32])(int dd, int unused, int dm, u32 fpscr) = { [FEXT_TO_IDX(FEXT_FCPY)] = vfp_double_fcpy, [FEXT_TO_IDX(FEXT_FABS)] = vfp_double_fabs, [FEXT_TO_IDX(FEXT_FNEG)] = vfp_double_fneg, [FEXT_TO_IDX(FEXT_FSQRT)] = vfp_double_fsqrt, [FEXT_TO_IDX(FEXT_FCMP)] = vfp_double_fcmp, [FEXT_TO_IDX(FEXT_FCMPE)] = vfp_double_fcmpe, [FEXT_TO_IDX(FEXT_FCMPZ)] = vfp_double_fcmpz, [FEXT_TO_IDX(FEXT_FCMPEZ)] = vfp_double_fcmpez, [FEXT_TO_IDX(FEXT_FCVT)] = vfp_double_fcvts, [FEXT_TO_IDX(FEXT_FUITO)] = vfp_double_fuito, [FEXT_TO_IDX(FEXT_FSITO)] = vfp_double_fsito, [FEXT_TO_IDX(FEXT_FTOUI)] = vfp_double_ftoui, [FEXT_TO_IDX(FEXT_FTOUIZ)] = vfp_double_ftouiz, [FEXT_TO_IDX(FEXT_FTOSI)] = vfp_double_ftosi, [FEXT_TO_IDX(FEXT_FTOSIZ)] = vfp_double_ftosiz, }; static u32 vfp_double_fadd_nonnumber(struct vfp_double *vdd, struct vfp_double *vdn, struct vfp_double *vdm, u32 fpscr) { struct vfp_double *vdp; u32 exceptions = 0; int tn, tm; tn = vfp_double_type(vdn); tm = vfp_double_type(vdm); if (tn & tm & VFP_INFINITY) { /* * Two infinities. Are they different signs? */ if (vdn->sign ^ vdm->sign) { /* * different signs -> invalid */ exceptions = FPSCR_IOC; vdp = &vfp_double_default_qnan; } else { /* * same signs -> valid */ vdp = vdn; } } else if (tn & VFP_INFINITY && tm & VFP_NUMBER) { /* * One infinity and one number -> infinity */ vdp = vdn; } else { /* * 'n' is a NaN of some type */ return vfp_propagate_nan(vdd, vdn, vdm, fpscr); } *vdd = *vdp; return exceptions; } static u32 vfp_double_add(struct vfp_double *vdd, struct vfp_double *vdn, struct vfp_double *vdm, u32 fpscr) { u32 exp_diff; u64 m_sig; if (vdn->significand & (1ULL << 63) || vdm->significand & (1ULL << 63)) { pr_info("VFP: bad FP values in %s\n", __func__); vfp_double_dump("VDN", vdn); vfp_double_dump("VDM", vdm); } /* * Ensure that 'n' is the largest magnitude number. Note that * if 'n' and 'm' have equal exponents, we do not swap them. * This ensures that NaN propagation works correctly. */ if (vdn->exponent < vdm->exponent) { struct vfp_double *t = vdn; vdn = vdm; vdm = t; } /* * Is 'n' an infinity or a NaN? Note that 'm' may be a number, * infinity or a NaN here. */ if (vdn->exponent == 2047) return vfp_double_fadd_nonnumber(vdd, vdn, vdm, fpscr); /* * We have two proper numbers, where 'vdn' is the larger magnitude. * * Copy 'n' to 'd' before doing the arithmetic. */ *vdd = *vdn; /* * Align 'm' with the result. */ exp_diff = vdn->exponent - vdm->exponent; m_sig = vfp_shiftright64jamming(vdm->significand, exp_diff); /* * If the signs are different, we are really subtracting. */ if (vdn->sign ^ vdm->sign) { m_sig = vdn->significand - m_sig; if ((s64)m_sig < 0) { vdd->sign = vfp_sign_negate(vdd->sign); m_sig = -m_sig; } else if (m_sig == 0) { vdd->sign = (fpscr & FPSCR_RMODE_MASK) == FPSCR_ROUND_MINUSINF ? 0x8000 : 0; } } else { m_sig += vdn->significand; } vdd->significand = m_sig; return 0; } static u32 vfp_double_multiply(struct vfp_double *vdd, struct vfp_double *vdn, struct vfp_double *vdm, u32 fpscr) { vfp_double_dump("VDN", vdn); vfp_double_dump("VDM", vdm); /* * Ensure that 'n' is the largest magnitude number. Note that * if 'n' and 'm' have equal exponents, we do not swap them. * This ensures that NaN propagation works correctly. */ if (vdn->exponent < vdm->exponent) { struct vfp_double *t = vdn; vdn = vdm; vdm = t; pr_debug("VFP: swapping M <-> N\n"); } vdd->sign = vdn->sign ^ vdm->sign; /* * If 'n' is an infinity or NaN, handle it. 'm' may be anything. */ if (vdn->exponent == 2047) { if (vdn->significand || (vdm->exponent == 2047 && vdm->significand)) return vfp_propagate_nan(vdd, vdn, vdm, fpscr); if ((vdm->exponent | vdm->significand) == 0) { *vdd = vfp_double_default_qnan; return FPSCR_IOC; } vdd->exponent = vdn->exponent; vdd->significand = 0; return 0; } /* * If 'm' is zero, the result is always zero. In this case, * 'n' may be zero or a number, but it doesn't matter which. */ if ((vdm->exponent | vdm->significand) == 0) { vdd->exponent = 0; vdd->significand = 0; return 0; } /* * We add 2 to the destination exponent for the same reason * as the addition case - though this time we have +1 from * each input operand. */ vdd->exponent = vdn->exponent + vdm->exponent - 1023 + 2; vdd->significand = vfp_hi64multiply64(vdn->significand, vdm->significand); vfp_double_dump("VDD", vdd); return 0; } #define NEG_MULTIPLY (1 << 0) #define NEG_SUBTRACT (1 << 1) static u32 vfp_double_multiply_accumulate(int dd, int dn, int dm, u32 fpscr, u32 negate, char *func) { struct vfp_double vdd, vdp, vdn, vdm; u32 exceptions; vfp_double_unpack(&vdn, vfp_get_double(dn)); if (vdn.exponent == 0 && vdn.significand) vfp_double_normalise_denormal(&vdn); vfp_double_unpack(&vdm, vfp_get_double(dm)); if (vdm.exponent == 0 && vdm.significand) vfp_double_normalise_denormal(&vdm); exceptions = vfp_double_multiply(&vdp, &vdn, &vdm, fpscr); if (negate & NEG_MULTIPLY) vdp.sign = vfp_sign_negate(vdp.sign); vfp_double_unpack(&vdn, vfp_get_double(dd)); if (negate & NEG_SUBTRACT) vdn.sign = vfp_sign_negate(vdn.sign); exceptions |= vfp_double_add(&vdd, &vdn, &vdp, fpscr); return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, func); } /* * Standard operations */ /* * sd = sd + (sn * sm) */ static u32 vfp_double_fmac(int dd, int dn, int dm, u32 fpscr) { return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, 0, "fmac"); } /* * sd = sd - (sn * sm) */ static u32 vfp_double_fnmac(int dd, int dn, int dm, u32 fpscr) { return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_MULTIPLY, "fnmac"); } /* * sd = -sd + (sn * sm) */ static u32 vfp_double_fmsc(int dd, int dn, int dm, u32 fpscr) { return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT, "fmsc"); } /* * sd = -sd - (sn * sm) */ static u32 vfp_double_fnmsc(int dd, int dn, int dm, u32 fpscr) { return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT | NEG_MULTIPLY, "fnmsc"); } /* * sd = sn * sm */ static u32 vfp_double_fmul(int dd, int dn, int dm, u32 fpscr) { struct vfp_double vdd, vdn, vdm; u32 exceptions; vfp_double_unpack(&vdn, vfp_get_double(dn)); if (vdn.exponent == 0 && vdn.significand) vfp_double_normalise_denormal(&vdn); vfp_double_unpack(&vdm, vfp_get_double(dm)); if (vdm.exponent == 0 && vdm.significand) vfp_double_normalise_denormal(&vdm); exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr); return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fmul"); } /* * sd = -(sn * sm) */ static u32 vfp_double_fnmul(int dd, int dn, int dm, u32 fpscr) { struct vfp_double vdd, vdn, vdm; u32 exceptions; vfp_double_unpack(&vdn, vfp_get_double(dn)); if (vdn.exponent == 0 && vdn.significand) vfp_double_normalise_denormal(&vdn); vfp_double_unpack(&vdm, vfp_get_double(dm)); if (vdm.exponent == 0 && vdm.significand) vfp_double_normalise_denormal(&vdm); exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr); vdd.sign = vfp_sign_negate(vdd.sign); return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fnmul"); } /* * sd = sn + sm */ static u32 vfp_double_fadd(int dd, int dn, int dm, u32 fpscr) { struct vfp_double vdd, vdn, vdm; u32 exceptions; vfp_double_unpack(&vdn, vfp_get_double(dn)); if (vdn.exponent == 0 && vdn.significand) vfp_double_normalise_denormal(&vdn); vfp_double_unpack(&vdm, vfp_get_double(dm)); if (vdm.exponent == 0 && vdm.significand) vfp_double_normalise_denormal(&vdm); exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr); return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fadd"); } /* * sd = sn - sm */ static u32 vfp_double_fsub(int dd, int dn, int dm, u32 fpscr) { struct vfp_double vdd, vdn, vdm; u32 exceptions; vfp_double_unpack(&vdn, vfp_get_double(dn)); if (vdn.exponent == 0 && vdn.significand) vfp_double_normalise_denormal(&vdn); vfp_double_unpack(&vdm, vfp_get_double(dm)); if (vdm.exponent == 0 && vdm.significand) vfp_double_normalise_denormal(&vdm); /* * Subtraction is like addition, but with a negated operand. */ vdm.sign = vfp_sign_negate(vdm.sign); exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr); return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fsub"); } /* * sd = sn / sm */ static u32 vfp_double_fdiv(int dd, int dn, int dm, u32 fpscr) { struct vfp_double vdd, vdn, vdm; u32 exceptions = 0; int tm, tn; vfp_double_unpack(&vdn, vfp_get_double(dn)); vfp_double_unpack(&vdm, vfp_get_double(dm)); vdd.sign = vdn.sign ^ vdm.sign; tn = vfp_double_type(&vdn); tm = vfp_double_type(&vdm); /* * Is n a NAN? */ if (tn & VFP_NAN) goto vdn_nan; /* * Is m a NAN? */ if (tm & VFP_NAN) goto vdm_nan; /* * If n and m are infinity, the result is invalid * If n and m are zero, the result is invalid */ if (tm & tn & (VFP_INFINITY|VFP_ZERO)) goto invalid; /* * If n is infinity, the result is infinity */ if (tn & VFP_INFINITY) goto infinity; /* * If m is zero, raise div0 exceptions */ if (tm & VFP_ZERO) goto divzero; /* * If m is infinity, or n is zero, the result is zero */ if (tm & VFP_INFINITY || tn & VFP_ZERO) goto zero; if (tn & VFP_DENORMAL) vfp_double_normalise_denormal(&vdn); if (tm & VFP_DENORMAL) vfp_double_normalise_denormal(&vdm); /* * Ok, we have two numbers, we can perform division. */ vdd.exponent = vdn.exponent - vdm.exponent + 1023 - 1; vdm.significand <<= 1; if (vdm.significand <= (2 * vdn.significand)) { vdn.significand >>= 1; vdd.exponent++; } vdd.significand = vfp_estimate_div128to64(vdn.significand, 0, vdm.significand); if ((vdd.significand & 0x1ff) <= 2) { u64 termh, terml, remh, reml; mul64to128(&termh, &terml, vdm.significand, vdd.significand); sub128(&remh, &reml, vdn.significand, 0, termh, terml); while ((s64)remh < 0) { vdd.significand -= 1; add128(&remh, &reml, remh, reml, 0, vdm.significand); } vdd.significand |= (reml != 0); } return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fdiv"); vdn_nan: exceptions = vfp_propagate_nan(&vdd, &vdn, &vdm, fpscr); pack: vfp_put_double(dd, vfp_double_pack(&vdd)); return exceptions; vdm_nan: exceptions = vfp_propagate_nan(&vdd, &vdm, &vdn, fpscr); goto pack; zero: vdd.exponent = 0; vdd.significand = 0; goto pack; divzero: exceptions = FPSCR_DZC; infinity: vdd.exponent = 2047; vdd.significand = 0; goto pack; invalid: vfp_put_double(dd, vfp_double_pack(&vfp_double_default_qnan)); return FPSCR_IOC; } static u32 (* const fop_fns[16])(int dd, int dn, int dm, u32 fpscr) = { [FOP_TO_IDX(FOP_FMAC)] = vfp_double_fmac, [FOP_TO_IDX(FOP_FNMAC)] = vfp_double_fnmac, [FOP_TO_IDX(FOP_FMSC)] = vfp_double_fmsc, [FOP_TO_IDX(FOP_FNMSC)] = vfp_double_fnmsc, [FOP_TO_IDX(FOP_FMUL)] = vfp_double_fmul, [FOP_TO_IDX(FOP_FNMUL)] = vfp_double_fnmul, [FOP_TO_IDX(FOP_FADD)] = vfp_double_fadd, [FOP_TO_IDX(FOP_FSUB)] = vfp_double_fsub, [FOP_TO_IDX(FOP_FDIV)] = vfp_double_fdiv, }; #define FREG_BANK(x) ((x) & 0x0c) #define FREG_IDX(x) ((x) & 3) u32 vfp_double_cpdo(u32 inst, u32 fpscr) { u32 op = inst & FOP_MASK; u32 exceptions = 0; unsigned int dd = vfp_get_sd(inst); unsigned int dn = vfp_get_sn(inst); unsigned int dm = vfp_get_sm(inst); unsigned int vecitr, veclen, vecstride; u32 (*fop)(int, int, s32, u32); veclen = fpscr & FPSCR_LENGTH_MASK; vecstride = (1 + ((fpscr & FPSCR_STRIDE_MASK) == FPSCR_STRIDE_MASK)) * 2; /* * If destination bank is zero, vector length is always '1'. * ARM DDI0100F C5.1.3, C5.3.2. */ if (FREG_BANK(dd) == 0) veclen = 0; pr_debug("VFP: vecstride=%u veclen=%u\n", vecstride, (veclen >> FPSCR_LENGTH_BIT) + 1); fop = (op == FOP_EXT) ? fop_extfns[dn] : fop_fns[FOP_TO_IDX(op)]; if (!fop) goto invalid; for (vecitr = 0; vecitr <= veclen; vecitr += 1 << FPSCR_LENGTH_BIT) { u32 except; if (op == FOP_EXT) pr_debug("VFP: itr%d (d%u.%u) = op[%u] (d%u.%u)\n", vecitr >> FPSCR_LENGTH_BIT, dd >> 1, dd & 1, dn, dm >> 1, dm & 1); else pr_debug("VFP: itr%d (d%u.%u) = (d%u.%u) op[%u] (d%u.%u)\n", vecitr >> FPSCR_LENGTH_BIT, dd >> 1, dd & 1, dn >> 1, dn & 1, FOP_TO_IDX(op), dm >> 1, dm & 1); except = fop(dd, dn, dm, fpscr); pr_debug("VFP: itr%d: exceptions=%08x\n", vecitr >> FPSCR_LENGTH_BIT, except); exceptions |= except; /* * This ensures that comparisons only operate on scalars; * comparisons always return with one FPSCR status bit set. */ if (except & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V)) break; /* * CHECK: It appears to be undefined whether we stop when * we encounter an exception. We continue. */ dd = FREG_BANK(dd) + ((FREG_IDX(dd) + vecstride) & 6); dn = FREG_BANK(dn) + ((FREG_IDX(dn) + vecstride) & 6); if (FREG_BANK(dm) != 0) dm = FREG_BANK(dm) + ((FREG_IDX(dm) + vecstride) & 6); } return exceptions; invalid: return ~0; }