X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=interpreters%2Fnitfol%2Fop_math.c;fp=interpreters%2Fnitfol%2Fop_math.c;h=923bcde0d887a8a092037cdb1a84c94bc9ed371a;hb=c98ccb87aa2581cbcd0458682727274b6e9a8cf7;hp=0000000000000000000000000000000000000000;hpb=a1689380dcfe59c99e70da8c311ace071d113ce5;p=rodin%2Fchimara.git

diff --git a/interpreters/nitfol/op_math.c b/interpreters/nitfol/op_math.c
new file mode 100644
index 0000000..923bcde
--- /dev/null
+++ b/interpreters/nitfol/op_math.c
@@ -0,0 +1,253 @@
+/*  Nitfol - z-machine interpreter using Glk for output.
+    Copyright (C) 1999  Evin Robertson
+
+    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; either version 2 of the License, or
+    (at your option) any later version.
+
+    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, USA.
+
+    The author can be reached at nitfol@deja.com
+*/
+#include "nitfol.h"
+
+
+void op_load(void)
+{
+  mop_store_result(get_var(operand[0]));
+}
+
+void op_store(void)
+{
+  set_var(operand[0], operand[1]);
+}
+
+void op_add(void)
+{
+  mop_store_result(ARITHMASK(operand[0] + operand[1]));
+}
+
+void op_sub(void)
+{
+  mop_store_result(ARITHMASK(operand[0] + neg(operand[1])));
+}
+
+
+void op_and(void)
+{
+  mop_store_result(operand[0] & operand[1]);
+}
+
+void op_or(void)
+{
+  mop_store_result(operand[0] | operand[1]);
+}
+
+void op_not(void)
+{
+  mop_store_result(ARITHMASK(~operand[0]));
+}
+
+
+void op_art_shift(void)
+{
+  if(is_neg(operand[1])) {
+    if(is_neg(operand[0])) {
+      zword i;
+      zword foo = operand[0];
+      /* FIXME: is there a better way? */
+      for(i = 0; i < neg(operand[1]); i++) {
+	foo >>= 1;
+	foo |= ZWORD_TOPBITMASK;
+      }
+      mop_store_result(foo);
+    } else {
+      mop_store_result(operand[0] >> neg(operand[1]));
+    }
+  } else {
+      mop_store_result(ARITHMASK(operand[0] << operand[1]));
+  }
+}
+
+void op_log_shift(void)
+{
+  if(is_neg(operand[1]))
+    mop_store_result(operand[0] >> neg(operand[1]) );
+  else
+    mop_store_result(ARITHMASK(operand[0] << operand[1]));
+}
+
+
+void op_dec(void)
+{
+  zword val = ARITHMASK(get_var(operand[0]) - 1);
+  set_var(operand[0], val);
+}
+
+void op_dec_chk(void)
+{
+  zword val = ARITHMASK(get_var(operand[0]) - 1);
+  set_var(operand[0], val);
+
+  if(is_lessthan(val, operand[1]))
+    mop_take_branch();
+  else
+    mop_skip_branch();
+}
+
+void op_inc(void)
+{
+  zword val = ARITHMASK(get_var(operand[0]) + 1);
+  set_var(operand[0], val);
+}
+
+void op_inc_chk(void)
+{
+  unsigned val = ARITHMASK(get_var(operand[0]) + 1);
+  set_var(operand[0], val);
+
+  if(is_greaterthan(val, operand[1]))
+    mop_take_branch();
+  else
+    mop_skip_branch();
+}
+
+
+zword z_mult(zword a, zword b)
+{
+  int sign = 0;
+
+  if(is_neg(a)) {
+    a = neg(a);
+    sign = 1;
+  }
+  if(is_neg(b)) {
+    b = neg(b);
+    sign ^= 1;
+  }
+
+  if(sign)
+    return ARITHMASK(neg(a * b));
+  else
+    return ARITHMASK(a * b);
+
+}
+
+
+zword z_div(zword a, zword b)
+{
+  int sign = 0;
+  
+  if(b == 0) {
+    n_show_error(E_MATH, "division by zero", a);
+    return ZWORD_MAX;
+  }
+  
+  if(is_neg(a)) {
+    a = neg(a);
+    sign = 1;
+  }
+  if(is_neg(b)) {
+    b = neg(b);
+    sign ^= 1;
+  }
+
+  if(sign)
+    return neg(a / b);
+  else
+    return a / b;
+}
+
+
+zword z_mod(zword a, zword b)
+{
+  int sign = 0;
+
+  if(b == 0) {
+    n_show_error(E_MATH, "modulo by zero", a);
+    return 0;
+  }
+
+  if(is_neg(a)) {
+    a = neg(a);
+    sign = 1;
+  }
+  if(is_neg(b)) {
+    b = neg(b);
+  }
+
+  if(sign)
+    return neg(a % b);
+  else
+    return a % b;
+}
+
+
+void op_div(void)
+{
+  mop_store_result(z_div(operand[0], operand[1]));
+}
+
+
+void op_mod(void)
+{
+  mop_store_result(z_mod(operand[0], operand[1]));
+}
+
+
+void op_mul(void)
+{
+  mop_store_result(z_mult(operand[0], operand[1]));
+}
+
+
+/* FIXME: use our own rng */
+zword z_random(zword num)
+{
+  static BOOL rising = FALSE;
+  static unsigned r = 0;
+  zword result = 0;
+  
+  if(num == 0) {
+    if(faked_random_seed)
+      srand(faked_random_seed);
+    else
+      srand(time(NULL));
+    rising = FALSE;
+  } else if(is_neg(num)) {
+    if(neg(num) < 1000) {
+      r = 0;
+      rising = TRUE;
+    } else {
+      srand(neg(num));
+      rising = FALSE;
+    }
+  } else {
+    if(rising) {
+      r++;
+      if(r > num)
+	r = 1;
+      result = r;
+    } else {
+      result = (1 + (rand() % num));
+    }
+  }
+  return result;
+}
+
+void op_random(void)
+{
+  if(operand[0] == 0)
+    n_show_port(E_MATH, "some interpreters don't like @random 0", operand[0]);
+
+  mop_store_result(z_random(operand[0]));
+}
+