--- /dev/null
+/*
+ * 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 <linux/kernel.h>
+#include <asm/bitops.h>
+#include <asm/ptrace.h>
+#include <asm/vfp.h>
+
+#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;
+}
+
+/*
+ * 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 : 0x100;
+}
+
+/*
+ * 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, -1, fpscr);
+}
+
+static u32 vfp_double_fcmpez(int dd, int unused, int dm, u32 fpscr)
+{
+ return vfp_compare(dd, 1, -1, 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;
+
+ vfp_double_unpack(&vdm, vfp_get_double(dm));
+ vfp_double_dump("VDM", &vdm);
+
+ /*
+ * Do we have denormalised number?
+ */
+ if (vfp_double_type(&vdm) & VFP_DENORMAL)
+ exceptions |= FPSCR_IDC;
+
+ 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 {
+ 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;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff