altos: Add 64-bit add/mul/shift for SDCC

[fw/altos] / src / core / ao_int64.c

diff --git a/src/core/ao_int64.c b/src/core/ao_int64.c
new file mode 100644 (file)
index 0000000..1fe717d
--- /dev/null
+++ b/src/core/ao_int64.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright © 2013 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that 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 <ao_int64.h>
+
+void ao_plus64(ao_int64_t *r, ao_int64_t *a, ao_int64_t *b) {
+       uint32_t        t;
+
+       r->low = t = a->low + b->low;
+       r->high = a->high + b->high;
+       if (t < a->low)
+               r->high++;
+}
+
+void ao_rshift64(ao_int64_t *r, ao_int64_t *a, uint8_t d) {
+       if (d < 32) {
+               r->high = (int32_t) a->high >> d;
+               r->low = a->low >> d;
+               if (d)
+                       r->low |= a->high << (32 - d);
+       } else {
+               d &= 0x1f;
+               r->high = 0;
+               r->low = (int32_t) a->high >> d;
+       }
+}
+
+void ao_lshift64(ao_int64_t *r, ao_int64_t *a, uint8_t d) {
+       if (d < 32) {
+               r->high = a->high << d;
+               r->low = a->low << d;
+               if (d)
+                       r->high |= a->low >> (32 - d);
+       } else {
+               d &= 0x1f;
+               r->low = 0;
+               r->high = a->low << d;
+       }
+}
+
+void ao_umul64(ao_int64_t *r, uint32_t a, uint32_t b)
+{
+       uint32_t        r1;
+       uint32_t        r2, r3, r4;
+       ao_int64_t      s,t,u,v;
+       r1 = (uint32_t) (uint16_t) a * (uint16_t) b;
+       r2 = (uint32_t) (uint16_t) (a >> 16) * (uint16_t) b;
+       r3 = (uint32_t) (uint16_t) a * (uint16_t) (b >> 16);
+       r4 = (uint32_t) (uint16_t) (a >> 16) * (uint16_t) (b >> 16);
+
+       s.low = r1;
+       s.high = r4;
+
+       t.high = (uint32_t) r2 >> 16;
+       t.low = r2 << 16;
+       ao_plus64(&u, &s, &t);
+
+       v.high = (int32_t) r3 >> 16;
+       v.low = r3 << 16;
+       ao_plus64(r, &u, &v);
+}
+
+void ao_neg64(ao_int64_t *r, ao_int64_t *a) {
+       r->high = ~a->high;
+       r->low = ~a->low;
+       if (!++r->low)
+               r->high++;
+}
+
+void ao_mul64(ao_int64_t *r, int32_t a, int32_t b) {
+       uint8_t         negative = 0;
+
+       if (a < 0) {
+               a = -a;
+               negative = 1;
+       }
+       if (b < 0) {
+               b = -b;
+               negative = !negative;
+       }
+       ao_umul64(r, a, b);
+       if (negative)
+               ao_neg64(r, r);
+}
+
+void ao_umul64_16(ao_int64_t *r, ao_int64_t *a, uint16_t b) {
+       uint32_t        low = a->low;
+       ao_umul64(r, (uint32_t) low >> 1, (uint32_t) b << 1);
+       if (low & 1) {
+               if ((uint32_t) (r->low += b) < (uint32_t) b)
+                       r->high++;
+       }
+       r->high += a->high * b;
+}
+
+void ao_mul64_16(ao_int64_t *r, ao_int64_t *a, uint16_t b) {
+       if ((int32_t) a->high < 0) {
+               ao_int64_t      t;
+
+               ao_neg64(&t, a);
+               ao_umul64_16(r, &t, b);
+               ao_neg64(r, r);
+       } else
+               ao_umul64_16(r, a, b);
+}