1 files changed, 223 insertions, 0 deletions

diff --git a/arch/m68k/math-emu/fp_log.c b/arch/m68k/math-emu/fp_log.c
new file mode 100644
index 000000000000..87b4f0158560
--- /dev/null
+++ b/arch/m68k/math-emu/fp_log.c
@@ -0,0 +1,223 @@
+/*
+
+  fp_trig.c: floating-point math routines for the Linux-m68k
+  floating point emulator.
+
+  Copyright (c) 1998-1999 David Huggins-Daines / Roman Zippel.
+
+  I hereby give permission, free of charge, to copy, modify, and
+  redistribute this software, in source or binary form, provided that
+  the above copyright notice and the following disclaimer are included
+  in all such copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS", WITH ABSOLUTELY NO WARRANTY, REAL
+  OR IMPLIED.
+
+*/
+
+#include "fp_emu.h"
+
+static const struct fp_ext fp_one =
+{
+        .exp = 0x3fff,
+};
+
+extern struct fp_ext *fp_fadd(struct fp_ext *dest, const struct fp_ext *src);
+extern struct fp_ext *fp_fdiv(struct fp_ext *dest, const struct fp_ext *src);
+extern struct fp_ext *fp_fmul(struct fp_ext *dest, const struct fp_ext *src);
+
+struct fp_ext *
+fp_fsqrt(struct fp_ext *dest, struct fp_ext *src)
+{
+        struct fp_ext tmp, src2;
+        int i, exp;
+
+        dprint(PINSTR, "fsqrt\n");
+
+        fp_monadic_check(dest, src);
+
+        if (IS_ZERO(dest))
+                return dest;
+
+        if (dest->sign) {
+                fp_set_nan(dest);
+                return dest;
+        }
+        if (IS_INF(dest))
+                return dest;
+
+        /*
+         *               sqrt(m) * 2^(p)        , if e = 2*p
+         * sqrt(m*2^e) =
+         *               sqrt(2*m) * 2^(p)      , if e = 2*p + 1
+         *
+         * So we use the last bit of the exponent to decide wether to
+         * use the m or 2*m.
+         *
+         * Since only the fractional part of the mantissa is stored and
+         * the integer part is assumed to be one, we place a 1 or 2 into
+         * the fixed point representation.
+         */
+        exp = dest->exp;
+        dest->exp = 0x3FFF;
+        if (!(exp & 1))         /* lowest bit of exponent is set */
+                dest->exp++;
+        fp_copy_ext(&src2, dest);
+
+        /*
+         * The taylor row arround a for sqrt(x) is:
+         *      sqrt(x) = sqrt(a) + 1/(2*sqrt(a))*(x-a) + R
+         * With a=1 this gives:
+         *      sqrt(x) = 1 + 1/2*(x-1)
+         *              = 1/2*(1+x)
+         */
+        fp_fadd(dest, &fp_one);
+        dest->exp--;            /* * 1/2 */
+
+        /*
+         * We now apply the newton rule to the function
+         *      f(x) := x^2 - r
+         * which has a null point on x = sqrt(r).
+         *
+         * It gives:
+         *      x' := x - f(x)/f'(x)
+         *          = x - (x^2 -r)/(2*x)
+         *          = x - (x - r/x)/2
+         *          = (2*x - x + r/x)/2
+         *          = (x + r/x)/2
+         */
+        for (i = 0; i < 9; i++) {
+                fp_copy_ext(&tmp, &src2);
+
+                fp_fdiv(&tmp, dest);
+                fp_fadd(dest, &tmp);
+                dest->exp--;
+        }
+
+        dest->exp += (exp - 0x3FFF) / 2;
+
+        return dest;
+}
+
+struct fp_ext *
+fp_fetoxm1(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("fetoxm1\n");
+
+        fp_monadic_check(dest, src);
+
+        if (IS_ZERO(dest))
+                return dest;
+
+        return dest;
+}
+
+struct fp_ext *
+fp_fetox(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("fetox\n");
+
+        fp_monadic_check(dest, src);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_ftwotox(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("ftwotox\n");
+
+        fp_monadic_check(dest, src);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_ftentox(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("ftentox\n");
+
+        fp_monadic_check(dest, src);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_flogn(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("flogn\n");
+
+        fp_monadic_check(dest, src);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_flognp1(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("flognp1\n");
+
+        fp_monadic_check(dest, src);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_flog10(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("flog10\n");
+
+        fp_monadic_check(dest, src);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_flog2(struct fp_ext *dest, struct fp_ext *src)
+{
+        uprint("flog2\n");
+
+        fp_monadic_check(dest, src);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_fgetexp(struct fp_ext *dest, struct fp_ext *src)
+{
+        dprint(PINSTR, "fgetexp\n");
+
+        fp_monadic_check(dest, src);
+
+        if (IS_INF(dest)) {
+                fp_set_nan(dest);
+                return dest;
+        }
+        if (IS_ZERO(dest))
+                return dest;
+
+        fp_conv_long2ext(dest, (int)dest->exp - 0x3FFF);
+
+        fp_normalize_ext(dest);
+
+        return dest;
+}
+
+struct fp_ext *
+fp_fgetman(struct fp_ext *dest, struct fp_ext *src)
+{
+        dprint(PINSTR, "fgetman\n");
+
+        fp_monadic_check(dest, src);
+
+        if (IS_ZERO(dest))
+                return dest;
+
+        if (IS_INF(dest))
+                return dest;
+
+        dest->exp = 0x3FFF;
+
+        return dest;
+}
+