-
Notifications
You must be signed in to change notification settings - Fork 521
/
lpm.cc
359 lines (296 loc) · 10.6 KB
/
lpm.cc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
/*
* VHDL code generation for LPM devices.
*
* Copyright (C) 2008-2009 Nick Gasson (nick@nickg.me.uk)
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "vhdl_target.h"
#include "state.hh"
#include <iostream>
#include <cassert>
/*
* Return the base of a part select.
*/
static vhdl_expr *part_select_base(vhdl_scope *scope, ivl_lpm_t lpm)
{
vhdl_expr *off;
ivl_nexus_t base = ivl_lpm_data(lpm, 1);
if (base != NULL)
off = readable_ref(scope, base);
else
off = new vhdl_const_int(ivl_lpm_base(lpm));
// Array indexes must be integers
vhdl_type integer(VHDL_TYPE_INTEGER);
return off->cast(&integer);
}
static vhdl_expr *binop_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm, vhdl_binop_t op)
{
unsigned out_width = ivl_lpm_width(lpm);
vhdl_type *result_type =
vhdl_type::type_for(out_width, ivl_lpm_signed(lpm) != 0);
vhdl_binop_expr *expr = new vhdl_binop_expr(op, result_type);
for (unsigned i = 0; i < ivl_lpm_size(lpm); i++) {
vhdl_expr *e = readable_ref(scope, ivl_lpm_data(lpm, i));
if (NULL == e)
return NULL;
// It's possible that the inputs are a mixture of signed and unsigned
// in which case we must cast them to the output type
e = e->cast(vhdl_type::type_for(e->get_type()->get_width(),
ivl_lpm_signed(lpm) != 0));
// Bit of a hack: the LPM inputs are in the wrong order for concatenation
if (op == VHDL_BINOP_CONCAT)
expr->add_expr_front(e);
else
expr->add_expr(e);
}
if (op == VHDL_BINOP_MULT) {
// Need to resize the output to the desired size,
// as this does not happen automatically in VHDL
vhdl_fcall *resize =
new vhdl_fcall("Resize", vhdl_type::nsigned(out_width));
resize->add_expr(expr);
resize->add_expr(new vhdl_const_int(out_width));
return resize;
}
else
return expr;
}
static vhdl_expr *rel_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm, vhdl_binop_t op)
{
vhdl_binop_expr *expr = new vhdl_binop_expr(op, vhdl_type::boolean());
vhdl_expr *lhs = readable_ref(scope, ivl_lpm_data(lpm, 0));
if (NULL == lhs)
return NULL;
vhdl_expr *rhs = readable_ref(scope, ivl_lpm_data(lpm, 1));
if (NULL == rhs) {
delete lhs;
return NULL;
}
// Ensure LHS and RHS are the same type
if (lhs->get_type() != rhs->get_type())
rhs = rhs->cast(lhs->get_type());
expr->add_expr(lhs);
expr->add_expr(rhs);
return expr;
}
static vhdl_expr *part_select_vp_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
{
vhdl_var_ref *selfrom = readable_ref(scope, ivl_lpm_data(lpm, 0));
if (NULL == selfrom)
return NULL;
vhdl_expr *off = part_select_base(scope, lpm);;
if (NULL == off)
return NULL;
if (selfrom->get_type()->get_width() > 1)
selfrom->set_slice(off, ivl_lpm_width(lpm) - 1);
return selfrom;
}
static vhdl_expr *part_select_pv_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
{
return readable_ref(scope, ivl_lpm_data(lpm, 0));
}
static vhdl_expr *ufunc_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
{
ivl_scope_t f_scope = ivl_lpm_define(lpm);
vhdl_fcall *fcall = new vhdl_fcall(ivl_scope_basename(f_scope), NULL);
for (unsigned i = 0; i < ivl_lpm_size(lpm); i++) {
vhdl_var_ref *ref = readable_ref(scope, ivl_lpm_data(lpm, i));
if (NULL == ref) {
delete fcall;
return NULL;
}
fcall->add_expr(ref);
}
return fcall;
}
static vhdl_expr *reduction_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm,
support_function_t f, bool invert)
{
vhdl_var_ref *ref = readable_ref(scope, ivl_lpm_data(lpm, 0));
if (NULL == ref)
return NULL;
vhdl_expr *result;
if (ref->get_type()->get_name() == VHDL_TYPE_STD_LOGIC)
result = ref;
else {
require_support_function(f);
vhdl_fcall *fcall = new vhdl_fcall(support_function::function_name(f),
vhdl_type::std_logic());
vhdl_type std_logic_vector(VHDL_TYPE_STD_LOGIC_VECTOR);
fcall->add_expr(ref->cast(&std_logic_vector));
result = fcall;
}
if (invert)
return new vhdl_unaryop_expr
(VHDL_UNARYOP_NOT, result, vhdl_type::std_logic());
else
return result;
}
static vhdl_expr *sign_extend_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
{
vhdl_expr *ref = readable_ref(scope, ivl_lpm_data(lpm, 0));
if (ref)
return ref->resize(ivl_lpm_width(lpm));
else
return NULL;
}
static vhdl_expr *array_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
{
ivl_signal_t array = ivl_lpm_array(lpm);
if (!seen_signal_before(array))
return NULL;
const char *renamed = get_renamed_signal(array).c_str();
vhdl_decl *adecl = scope->get_decl(renamed);
assert(adecl);
vhdl_type *atype = new vhdl_type(*adecl->get_type());
vhdl_expr *select = readable_ref(scope, ivl_lpm_select(lpm));
if (NULL == select) {
delete atype;
return NULL;
}
vhdl_var_ref *ref = new vhdl_var_ref(renamed, atype);
vhdl_type integer(VHDL_TYPE_INTEGER);
ref->set_slice(select->cast(&integer));
return ref;
}
static vhdl_expr *shift_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm,
vhdl_binop_t shift_op)
{
vhdl_expr *lhs = readable_ref(scope, ivl_lpm_data(lpm, 0));
vhdl_expr *rhs = readable_ref(scope, ivl_lpm_data(lpm, 1));
if (!lhs || !rhs)
return NULL;
// The RHS must be an integer
vhdl_type integer(VHDL_TYPE_INTEGER);
vhdl_expr *r_cast = rhs->cast(&integer);
vhdl_type *rtype = new vhdl_type(*lhs->get_type());
return new vhdl_binop_expr(lhs, shift_op, r_cast, rtype);
}
static vhdl_expr *repeat_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
{
vhdl_expr *in = readable_ref(scope, ivl_lpm_data(lpm, 0));
return new vhdl_bit_spec_expr(NULL, in);
}
static vhdl_expr *lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
{
switch (ivl_lpm_type(lpm)) {
case IVL_LPM_ADD:
return binop_lpm_to_expr(scope, lpm, VHDL_BINOP_ADD);
case IVL_LPM_SUB:
return binop_lpm_to_expr(scope, lpm, VHDL_BINOP_SUB);
case IVL_LPM_MULT:
return binop_lpm_to_expr(scope, lpm, VHDL_BINOP_MULT);
case IVL_LPM_DIVIDE:
return binop_lpm_to_expr(scope, lpm, VHDL_BINOP_DIV);
case IVL_LPM_MOD:
return binop_lpm_to_expr(scope, lpm, VHDL_BINOP_MOD);
case IVL_LPM_CONCAT:
return binop_lpm_to_expr(scope, lpm, VHDL_BINOP_CONCAT);
case IVL_LPM_CMP_GE:
return rel_lpm_to_expr(scope, lpm, VHDL_BINOP_GEQ);
case IVL_LPM_CMP_GT:
return rel_lpm_to_expr(scope, lpm, VHDL_BINOP_GT);
case IVL_LPM_CMP_NE:
case IVL_LPM_CMP_NEE:
return rel_lpm_to_expr(scope, lpm, VHDL_BINOP_NEQ);
case IVL_LPM_CMP_EQ:
case IVL_LPM_CMP_EEQ:
return rel_lpm_to_expr(scope, lpm, VHDL_BINOP_EQ);
case IVL_LPM_PART_VP:
return part_select_vp_lpm_to_expr(scope, lpm);
case IVL_LPM_PART_PV:
return part_select_pv_lpm_to_expr(scope, lpm);
case IVL_LPM_UFUNC:
return ufunc_lpm_to_expr(scope, lpm);
case IVL_LPM_RE_AND:
return reduction_lpm_to_expr(scope, lpm, SF_REDUCE_AND, false);
case IVL_LPM_RE_NAND:
return reduction_lpm_to_expr(scope, lpm, SF_REDUCE_AND, true);
case IVL_LPM_RE_NOR:
return reduction_lpm_to_expr(scope, lpm, SF_REDUCE_OR, true);
case IVL_LPM_RE_OR:
return reduction_lpm_to_expr(scope, lpm, SF_REDUCE_OR, false);
case IVL_LPM_RE_XOR:
return reduction_lpm_to_expr(scope, lpm, SF_REDUCE_XOR, false);
case IVL_LPM_RE_XNOR:
return reduction_lpm_to_expr(scope, lpm, SF_REDUCE_XNOR, true);
case IVL_LPM_SIGN_EXT:
return sign_extend_lpm_to_expr(scope, lpm);
case IVL_LPM_ARRAY:
return array_lpm_to_expr(scope, lpm);
case IVL_LPM_SHIFTL:
return shift_lpm_to_expr(scope, lpm, VHDL_BINOP_SL);
case IVL_LPM_SHIFTR:
return shift_lpm_to_expr(scope, lpm, VHDL_BINOP_SR);
case IVL_LPM_REPEAT:
return repeat_lpm_to_expr(scope, lpm);
default:
error("Unsupported LPM type: %d", ivl_lpm_type(lpm));
return NULL;
}
}
static int draw_mux_lpm(vhdl_arch *arch, ivl_lpm_t lpm)
{
int nselects = ivl_lpm_selects(lpm);
if (nselects > 1) {
error("Only 1 LPM select bit supported at the moment");
return 1;
}
vhdl_scope *scope = arch->get_scope();
vhdl_expr *s0 = readable_ref(scope, ivl_lpm_data(lpm, 0));
vhdl_expr *s1 = readable_ref(scope, ivl_lpm_data(lpm, 1));
vhdl_expr *sel = readable_ref(scope, ivl_lpm_select(lpm));
vhdl_expr *b1 = new vhdl_const_bit('1');
vhdl_expr *t1 =
new vhdl_binop_expr(sel, VHDL_BINOP_EQ, b1, vhdl_type::boolean());
vhdl_var_ref *out = nexus_to_var_ref(scope, ivl_lpm_q(lpm));
// Make sure s0 and s1 have the same type as the output
s0 = s0->cast(out->get_type());
s1 = s1->cast(out->get_type());
vhdl_cassign_stmt *s = new vhdl_cassign_stmt(out, s0);
s->add_condition(s1, t1);
arch->add_stmt(s);
return 0;
}
int draw_lpm(vhdl_arch *arch, ivl_lpm_t lpm)
{
if (ivl_lpm_type(lpm) == IVL_LPM_MUX)
return draw_mux_lpm(arch, lpm);
vhdl_expr *f = lpm_to_expr(arch->get_scope(), lpm);
if (NULL == f)
return 1;
vhdl_var_ref *out = nexus_to_var_ref(arch->get_scope(), ivl_lpm_q(lpm));
if (ivl_lpm_type(lpm) == IVL_LPM_PART_PV) {
vhdl_expr *off = part_select_base(arch->get_scope(), lpm);
assert(off);
out->set_slice(off, ivl_lpm_width(lpm) - 1);
}
// Converting from Boolean to std_logic is a common case so should be
// replaced by an idiomatic VHDL construct rather than a call to a
// conversion function
bool bool_to_logic =
out->get_type()->get_name() == VHDL_TYPE_STD_LOGIC
&& f->get_type()->get_name() == VHDL_TYPE_BOOLEAN;
if (bool_to_logic) {
vhdl_cassign_stmt* s =
new vhdl_cassign_stmt(out, new vhdl_const_bit('0'));
s->add_condition(new vhdl_const_bit('1'), f);
arch->add_stmt(s);
}
else
arch->add_stmt(new vhdl_cassign_stmt(out, f->cast(out->get_type())));
return 0;
}