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Diffstat (limited to 'apps/plugins/frotz/math.c')
-rw-r--r-- | apps/plugins/frotz/math.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/apps/plugins/frotz/math.c b/apps/plugins/frotz/math.c new file mode 100644 index 0000000000..5ff5163230 --- /dev/null +++ b/apps/plugins/frotz/math.c | |||
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1 | /* math.c - Arithmetic, compare and logical opcodes | ||
2 | * Copyright (c) 1995-1997 Stefan Jokisch | ||
3 | * | ||
4 | * This file is part of Frotz. | ||
5 | * | ||
6 | * Frotz is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License as published by | ||
8 | * the Free Software Foundation; either version 2 of the License, or | ||
9 | * (at your option) any later version. | ||
10 | * | ||
11 | * Frotz is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public License | ||
17 | * along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA | ||
19 | */ | ||
20 | |||
21 | #include "frotz.h" | ||
22 | |||
23 | /* | ||
24 | * z_add, 16bit addition. | ||
25 | * | ||
26 | * zargs[0] = first value | ||
27 | * zargs[1] = second value | ||
28 | * | ||
29 | */ | ||
30 | |||
31 | void z_add (void) | ||
32 | { | ||
33 | |||
34 | store ((zword) ((short) zargs[0] + (short) zargs[1])); | ||
35 | |||
36 | }/* z_add */ | ||
37 | |||
38 | /* | ||
39 | * z_and, bitwise AND operation. | ||
40 | * | ||
41 | * zargs[0] = first value | ||
42 | * zargs[1] = second value | ||
43 | * | ||
44 | */ | ||
45 | |||
46 | void z_and (void) | ||
47 | { | ||
48 | |||
49 | store ((zword) (zargs[0] & zargs[1])); | ||
50 | |||
51 | }/* z_and */ | ||
52 | |||
53 | /* | ||
54 | * z_art_shift, arithmetic SHIFT operation. | ||
55 | * | ||
56 | * zargs[0] = value | ||
57 | * zargs[1] = #positions to shift left (positive) or right | ||
58 | * | ||
59 | */ | ||
60 | |||
61 | void z_art_shift (void) | ||
62 | { | ||
63 | |||
64 | if ((short) zargs[1] > 0) | ||
65 | store ((zword) ((short) zargs[0] << (short) zargs[1])); | ||
66 | else | ||
67 | store ((zword) ((short) zargs[0] >> - (short) zargs[1])); | ||
68 | |||
69 | }/* z_art_shift */ | ||
70 | |||
71 | /* | ||
72 | * z_div, signed 16bit division. | ||
73 | * | ||
74 | * zargs[0] = first value | ||
75 | * zargs[1] = second value | ||
76 | * | ||
77 | */ | ||
78 | |||
79 | void z_div (void) | ||
80 | { | ||
81 | |||
82 | if (zargs[1] == 0) | ||
83 | runtime_error (ERR_DIV_ZERO); | ||
84 | |||
85 | store ((zword) ((short) zargs[0] / (short) zargs[1])); | ||
86 | |||
87 | }/* z_div */ | ||
88 | |||
89 | /* | ||
90 | * z_je, branch if the first value equals any of the following. | ||
91 | * | ||
92 | * zargs[0] = first value | ||
93 | * zargs[1] = second value (optional) | ||
94 | * ... | ||
95 | * zargs[3] = fourth value (optional) | ||
96 | * | ||
97 | */ | ||
98 | |||
99 | void z_je (void) | ||
100 | { | ||
101 | |||
102 | branch ( | ||
103 | zargc > 1 && (zargs[0] == zargs[1] || ( | ||
104 | zargc > 2 && (zargs[0] == zargs[2] || ( | ||
105 | zargc > 3 && (zargs[0] == zargs[3])))))); | ||
106 | |||
107 | }/* z_je */ | ||
108 | |||
109 | /* | ||
110 | * z_jg, branch if the first value is greater than the second. | ||
111 | * | ||
112 | * zargs[0] = first value | ||
113 | * zargs[1] = second value | ||
114 | * | ||
115 | */ | ||
116 | |||
117 | void z_jg (void) | ||
118 | { | ||
119 | |||
120 | branch ((short) zargs[0] > (short) zargs[1]); | ||
121 | |||
122 | }/* z_jg */ | ||
123 | |||
124 | /* | ||
125 | * z_jl, branch if the first value is less than the second. | ||
126 | * | ||
127 | * zargs[0] = first value | ||
128 | * zargs[1] = second value | ||
129 | * | ||
130 | */ | ||
131 | |||
132 | void z_jl (void) | ||
133 | { | ||
134 | |||
135 | branch ((short) zargs[0] < (short) zargs[1]); | ||
136 | |||
137 | }/* z_jl */ | ||
138 | |||
139 | /* | ||
140 | * z_jz, branch if value is zero. | ||
141 | * | ||
142 | * zargs[0] = value | ||
143 | * | ||
144 | */ | ||
145 | |||
146 | void z_jz (void) | ||
147 | { | ||
148 | |||
149 | branch ((short) zargs[0] == 0); | ||
150 | |||
151 | }/* z_jz */ | ||
152 | |||
153 | /* | ||
154 | * z_log_shift, logical SHIFT operation. | ||
155 | * | ||
156 | * zargs[0] = value | ||
157 | * zargs[1] = #positions to shift left (positive) or right (negative) | ||
158 | * | ||
159 | */ | ||
160 | |||
161 | void z_log_shift (void) | ||
162 | { | ||
163 | |||
164 | if ((short) zargs[1] > 0) | ||
165 | store ((zword) (zargs[0] << (short) zargs[1])); | ||
166 | else | ||
167 | store ((zword) (zargs[0] >> - (short) zargs[1])); | ||
168 | |||
169 | }/* z_log_shift */ | ||
170 | |||
171 | /* | ||
172 | * z_mod, remainder after signed 16bit division. | ||
173 | * | ||
174 | * zargs[0] = first value | ||
175 | * zargs[1] = second value | ||
176 | * | ||
177 | */ | ||
178 | |||
179 | void z_mod (void) | ||
180 | { | ||
181 | |||
182 | if (zargs[1] == 0) | ||
183 | runtime_error (ERR_DIV_ZERO); | ||
184 | |||
185 | store ((zword) ((short) zargs[0] % (short) zargs[1])); | ||
186 | |||
187 | }/* z_mod */ | ||
188 | |||
189 | /* | ||
190 | * z_mul, 16bit multiplication. | ||
191 | * | ||
192 | * zargs[0] = first value | ||
193 | * zargs[1] = second value | ||
194 | * | ||
195 | */ | ||
196 | |||
197 | void z_mul (void) | ||
198 | { | ||
199 | |||
200 | store ((zword) ((short) zargs[0] * (short) zargs[1])); | ||
201 | |||
202 | }/* z_mul */ | ||
203 | |||
204 | /* | ||
205 | * z_not, bitwise NOT operation. | ||
206 | * | ||
207 | * zargs[0] = value | ||
208 | * | ||
209 | */ | ||
210 | |||
211 | void z_not (void) | ||
212 | { | ||
213 | |||
214 | store ((zword) ~zargs[0]); | ||
215 | |||
216 | }/* z_not */ | ||
217 | |||
218 | /* | ||
219 | * z_or, bitwise OR operation. | ||
220 | * | ||
221 | * zargs[0] = first value | ||
222 | * zargs[1] = second value | ||
223 | * | ||
224 | */ | ||
225 | |||
226 | void z_or (void) | ||
227 | { | ||
228 | |||
229 | store ((zword) (zargs[0] | zargs[1])); | ||
230 | |||
231 | }/* z_or */ | ||
232 | |||
233 | /* | ||
234 | * z_sub, 16bit substraction. | ||
235 | * | ||
236 | * zargs[0] = first value | ||
237 | * zargs[1] = second value | ||
238 | * | ||
239 | */ | ||
240 | |||
241 | void z_sub (void) | ||
242 | { | ||
243 | |||
244 | store ((zword) ((short) zargs[0] - (short) zargs[1])); | ||
245 | |||
246 | }/* z_sub */ | ||
247 | |||
248 | /* | ||
249 | * z_test, branch if all the flags of a bit mask are set in a value. | ||
250 | * | ||
251 | * zargs[0] = value to be examined | ||
252 | * zargs[1] = bit mask | ||
253 | * | ||
254 | */ | ||
255 | |||
256 | void z_test (void) | ||
257 | { | ||
258 | |||
259 | branch ((zargs[0] & zargs[1]) == zargs[1]); | ||
260 | |||
261 | }/* z_test */ | ||