1 files changed, 243 insertions, 0 deletions

diff --git a/arch/mips/math-emu/ieee754dp.c b/arch/mips/math-emu/ieee754dp.c
new file mode 100644
index 000000000000..3e214aac4b12
--- /dev/null
+++ b/arch/mips/math-emu/ieee754dp.c
@@ -0,0 +1,243 @@
+/* IEEE754 floating point arithmetic
+ * double precision: common utilities
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ * http://www.algor.co.uk
+ *
+ * ########################################################################
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * ########################################################################
+ */
+
+
+#include "ieee754dp.h"
+
+int ieee754dp_class(ieee754dp x)
+{
+        COMPXDP;
+        EXPLODEXDP;
+        return xc;
+}
+
+int ieee754dp_isnan(ieee754dp x)
+{
+        return ieee754dp_class(x) >= IEEE754_CLASS_SNAN;
+}
+
+int ieee754dp_issnan(ieee754dp x)
+{
+        assert(ieee754dp_isnan(x));
+        return ((DPMANT(x) & DP_MBIT(DP_MBITS-1)) == DP_MBIT(DP_MBITS-1));
+}
+
+
+ieee754dp ieee754dp_xcpt(ieee754dp r, const char *op, ...)
+{
+        struct ieee754xctx ax;
+        if (!TSTX())
+                return r;
+
+        ax.op = op;
+        ax.rt = IEEE754_RT_DP;
+        ax.rv.dp = r;
+        va_start(ax.ap, op);
+        ieee754_xcpt(&ax);
+        return ax.rv.dp;
+}
+
+ieee754dp ieee754dp_nanxcpt(ieee754dp r, const char *op, ...)
+{
+        struct ieee754xctx ax;
+
+        assert(ieee754dp_isnan(r));
+
+        if (!ieee754dp_issnan(r))       /* QNAN does not cause invalid op !! */
+                return r;
+
+        if (!SETANDTESTCX(IEEE754_INVALID_OPERATION)) {
+                /* not enabled convert to a quiet NaN */
+                DPMANT(r) &= (~DP_MBIT(DP_MBITS-1));
+                if (ieee754dp_isnan(r))
+                        return r;
+                else
+                        return ieee754dp_indef();
+        }
+
+        ax.op = op;
+        ax.rt = 0;
+        ax.rv.dp = r;
+        va_start(ax.ap, op);
+        ieee754_xcpt(&ax);
+        return ax.rv.dp;
+}
+
+ieee754dp ieee754dp_bestnan(ieee754dp x, ieee754dp y)
+{
+        assert(ieee754dp_isnan(x));
+        assert(ieee754dp_isnan(y));
+
+        if (DPMANT(x) > DPMANT(y))
+                return x;
+        else
+                return y;
+}
+
+
+static u64 get_rounding(int sn, u64 xm)
+{
+        /* inexact must round of 3 bits
+         */
+        if (xm & (DP_MBIT(3) - 1)) {
+                switch (ieee754_csr.rm) {
+                case IEEE754_RZ:
+                        break;
+                case IEEE754_RN:
+                        xm += 0x3 + ((xm >> 3) & 1);
+                        /* xm += (xm&0x8)?0x4:0x3 */
+                        break;
+                case IEEE754_RU:        /* toward +Infinity */
+                        if (!sn)        /* ?? */
+                                xm += 0x8;
+                        break;
+                case IEEE754_RD:        /* toward -Infinity */
+                        if (sn) /* ?? */
+                                xm += 0x8;
+                        break;
+                }
+        }
+        return xm;
+}
+
+
+/* generate a normal/denormal number with over,under handling
+ * sn is sign
+ * xe is an unbiased exponent
+ * xm is 3bit extended precision value.
+ */
+ieee754dp ieee754dp_format(int sn, int xe, u64 xm)
+{
+        assert(xm);             /* we don't gen exact zeros (probably should) */
+
+        assert((xm >> (DP_MBITS + 1 + 3)) == 0);        /* no execess */
+        assert(xm & (DP_HIDDEN_BIT << 3));
+
+        if (xe < DP_EMIN) {
+                /* strip lower bits */
+                int es = DP_EMIN - xe;
+
+                if (ieee754_csr.nod) {
+                        SETCX(IEEE754_UNDERFLOW);
+                        SETCX(IEEE754_INEXACT);
+
+                        switch(ieee754_csr.rm) {
+                        case IEEE754_RN:
+                                return ieee754dp_zero(sn);
+                        case IEEE754_RZ:
+                                return ieee754dp_zero(sn);
+                        case IEEE754_RU:    /* toward +Infinity */
+                                if(sn == 0)
+                                        return ieee754dp_min(0);
+                                else
+                                        return ieee754dp_zero(1);
+                        case IEEE754_RD:    /* toward -Infinity */
+                                if(sn == 0)
+                                        return ieee754dp_zero(0);
+                                else
+                                        return ieee754dp_min(1);
+                        }
+                }
+
+                if (xe == DP_EMIN - 1
+                                && get_rounding(sn, xm) >> (DP_MBITS + 1 + 3))
+                {
+                        /* Not tiny after rounding */
+                        SETCX(IEEE754_INEXACT);
+                        xm = get_rounding(sn, xm);
+                        xm >>= 1;
+                        /* Clear grs bits */
+                        xm &= ~(DP_MBIT(3) - 1);
+                        xe++;
+                }
+                else {
+                        /* sticky right shift es bits
+                         */
+                        xm = XDPSRS(xm, es);
+                        xe += es;
+                        assert((xm & (DP_HIDDEN_BIT << 3)) == 0);
+                        assert(xe == DP_EMIN);
+                }
+        }
+        if (xm & (DP_MBIT(3) - 1)) {
+                SETCX(IEEE754_INEXACT);
+                if ((xm & (DP_HIDDEN_BIT << 3)) == 0) {
+                        SETCX(IEEE754_UNDERFLOW);
+                }
+
+                /* inexact must round of 3 bits
+                 */
+                xm = get_rounding(sn, xm);
+                /* adjust exponent for rounding add overflowing
+                 */
+                if (xm >> (DP_MBITS + 3 + 1)) {
+                        /* add causes mantissa overflow */
+                        xm >>= 1;
+                        xe++;
+                }
+        }
+        /* strip grs bits */
+        xm >>= 3;
+
+        assert((xm >> (DP_MBITS + 1)) == 0);    /* no execess */
+        assert(xe >= DP_EMIN);
+
+        if (xe > DP_EMAX) {
+                SETCX(IEEE754_OVERFLOW);
+                SETCX(IEEE754_INEXACT);
+                /* -O can be table indexed by (rm,sn) */
+                switch (ieee754_csr.rm) {
+                case IEEE754_RN:
+                        return ieee754dp_inf(sn);
+                case IEEE754_RZ:
+                        return ieee754dp_max(sn);
+                case IEEE754_RU:        /* toward +Infinity */
+                        if (sn == 0)
+                                return ieee754dp_inf(0);
+                        else
+                                return ieee754dp_max(1);
+                case IEEE754_RD:        /* toward -Infinity */
+                        if (sn == 0)
+                                return ieee754dp_max(0);
+                        else
+                                return ieee754dp_inf(1);
+                }
+        }
+        /* gen norm/denorm/zero */
+
+        if ((xm & DP_HIDDEN_BIT) == 0) {
+                /* we underflow (tiny/zero) */
+                assert(xe == DP_EMIN);
+                if (ieee754_csr.mx & IEEE754_UNDERFLOW)
+                        SETCX(IEEE754_UNDERFLOW);
+                return builddp(sn, DP_EMIN - 1 + DP_EBIAS, xm);
+        } else {
+                assert((xm >> (DP_MBITS + 1)) == 0);    /* no execess */
+                assert(xm & DP_HIDDEN_BIT);
+
+                return builddp(sn, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT);
+        }
+}