2 * yosys -- Yosys Open SYnthesis Suite
4 * Copyright (C) 2012 Clifford Wolf <clifford@clifford.at>
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 #include "kernel/rtlil.h"
21 #include "kernel/register.h"
22 #include "kernel/sigtools.h"
23 #include "kernel/celltypes.h"
24 #include "kernel/cellaigs.h"
25 #include "kernel/log.h"
32 PRIVATE_NAMESPACE_BEGIN
34 pool
<string
> used_names
;
35 dict
<IdString
, string
> namecache
;
38 typedef unsigned FDirection
;
39 static const FDirection FD_NODIRECTION
= 0x0;
40 static const FDirection FD_IN
= 0x1;
41 static const FDirection FD_OUT
= 0x2;
42 static const FDirection FD_INOUT
= 0x3;
43 static const int FIRRTL_MAX_DSH_WIDTH_ERROR
= 20; // For historic reasons, this is actually one greater than the maximum allowed shift width
45 // Shamelessly copied from ilang_backend.cc. Something better is surely possible here.
46 void dump_const(std::ostream
&f
, const RTLIL::Const
&data
, int width
= -1, int offset
= 0, bool autoint
= true)
49 width
= data
.bits
.size() - offset
;
50 if ((data
.flags
& RTLIL::CONST_FLAG_STRING
) == 0 || width
!= (int)data
.bits
.size()) {
51 if (width
== 32 && autoint
) {
53 for (int i
= 0; i
< width
; i
++) {
54 log_assert(offset
+i
< (int)data
.bits
.size());
55 switch (data
.bits
[offset
+i
]) {
56 case RTLIL::S0
: break;
57 case RTLIL::S1
: val
|= 1 << i
; break;
58 default: val
= -1; break;
62 f
<< stringf("%d", val
);
66 f
<< stringf("%d'", width
);
67 for (int i
= offset
+width
-1; i
>= offset
; i
--) {
68 log_assert(i
< (int)data
.bits
.size());
69 switch (data
.bits
[i
]) {
70 case RTLIL::S0
: f
<< stringf("0"); break;
71 case RTLIL::S1
: f
<< stringf("1"); break;
72 case RTLIL::Sx
: f
<< stringf("x"); break;
73 case RTLIL::Sz
: f
<< stringf("z"); break;
74 case RTLIL::Sa
: f
<< stringf("-"); break;
75 case RTLIL::Sm
: f
<< stringf("m"); break;
80 std::string str
= data
.decode_string();
81 for (size_t i
= 0; i
< str
.size(); i
++) {
84 else if (str
[i
] == '\t')
87 f
<< stringf("\\%03o", str
[i
]);
88 else if (str
[i
] == '"')
90 else if (str
[i
] == '\\')
99 std::string
getFileinfo(dict
<RTLIL::IdString
, RTLIL::Const
> attributes
)
101 std::ostringstream fileinfo
;
102 for (auto &it
: attributes
) {
103 if (it
.first
== "\\src") {
105 dump_const(fileinfo
, it
.second
);
109 return fileinfo
.str();
112 // Get a port direction with respect to a specific module.
113 FDirection
getPortFDirection(IdString id
, Module
*module
)
115 Wire
*wire
= module
->wires_
.at(id
);
116 FDirection direction
= FD_NODIRECTION
;
117 if (wire
&& wire
->port_id
)
119 if (wire
->port_input
)
121 if (wire
->port_output
)
132 new_id
= stringf("_%d", autoid_counter
++);
133 if (used_names
.count(new_id
) == 0) break;
136 used_names
.insert(new_id
);
140 const char *make_id(IdString id
)
142 if (namecache
.count(id
) != 0)
143 return namecache
.at(id
).c_str();
145 string new_id
= log_id(id
);
147 for (int i
= 0; i
< GetSize(new_id
); i
++)
149 char &ch
= new_id
[i
];
150 if ('a' <= ch
&& ch
<= 'z') continue;
151 if ('A' <= ch
&& ch
<= 'Z') continue;
152 if ('0' <= ch
&& ch
<= '9' && i
!= 0) continue;
153 if ('_' == ch
) continue;
157 while (used_names
.count(new_id
) != 0)
160 namecache
[id
] = new_id
;
161 used_names
.insert(new_id
);
162 return namecache
.at(id
).c_str();
170 dict
<SigBit
, pair
<string
, int>> reverse_wire_map
;
172 RTLIL::Design
*design
;
175 // Define read/write ports and memories.
176 // We'll collect their definitions and emit the corresponding FIRRTL definitions at the appropriate point in module construction.
177 // For the moment, we don't handle $readmemh or $readmemb.
178 // These will be part of a subsequent PR.
187 read_port(string name
, bool clk_enable
, bool clk_parity
, bool transparent
, RTLIL::SigSpec clk
, RTLIL::SigSpec ena
, RTLIL::SigSpec addr
) : name(name
), clk_enable(clk_enable
), clk_parity(clk_parity
), transparent(transparent
), clk(clk
), ena(ena
), addr(addr
) {
188 // Current (3/13/2019) conventions:
189 // generate a constant 0 for clock and a constant 1 for enable if they are undefined.
190 if (!clk
.is_fully_def())
191 this->clk
= SigSpec(State::S0
);
192 if (!ena
.is_fully_def())
193 this->ena
= SigSpec(State::S1
);
195 string
gen_read(const char * indent
) {
196 string addr_expr
= make_expr(addr
);
197 string ena_expr
= make_expr(ena
);
198 string clk_expr
= make_expr(clk
);
199 string addr_str
= stringf("%s%s.addr <= %s\n", indent
, name
.c_str(), addr_expr
.c_str());
200 string ena_str
= stringf("%s%s.en <= %s\n", indent
, name
.c_str(), ena_expr
.c_str());
201 string clk_str
= stringf("%s%s.clk <= asClock(%s)\n", indent
, name
.c_str(), clk_expr
.c_str());
202 return addr_str
+ ena_str
+ clk_str
;
205 struct write_port
: read_port
{
207 write_port(string name
, bool clk_enable
, bool clk_parity
, bool transparent
, RTLIL::SigSpec clk
, RTLIL::SigSpec ena
, RTLIL::SigSpec addr
, RTLIL::SigSpec mask
) : read_port(name
, clk_enable
, clk_parity
, transparent
, clk
, ena
, addr
), mask(mask
) {
208 if (!clk
.is_fully_def())
209 this->clk
= SigSpec(RTLIL::Const(0));
210 if (!ena
.is_fully_def())
211 this->ena
= SigSpec(RTLIL::Const(0));
212 if (!mask
.is_fully_def())
213 this->ena
= SigSpec(RTLIL::Const(1));
215 string
gen_read(const char * /* indent */) {
216 log_error("gen_read called on write_port: %s\n", name
.c_str());
217 return stringf("gen_read called on write_port: %s\n", name
.c_str());
219 string
gen_write(const char * indent
) {
220 string addr_expr
= make_expr(addr
);
221 string ena_expr
= make_expr(ena
);
222 string clk_expr
= make_expr(clk
);
223 string mask_expr
= make_expr(mask
);
224 string mask_str
= stringf("%s%s.mask <= %s\n", indent
, name
.c_str(), mask_expr
.c_str());
225 string addr_str
= stringf("%s%s.addr <= %s\n", indent
, name
.c_str(), addr_expr
.c_str());
226 string ena_str
= stringf("%s%s.en <= %s\n", indent
, name
.c_str(), ena_expr
.c_str());
227 string clk_str
= stringf("%s%s.clk <= asClock(%s)\n", indent
, name
.c_str(), clk_expr
.c_str());
228 return addr_str
+ ena_str
+ clk_str
+ mask_str
;
231 /* Memories defined within this module. */
233 Cell
*pCell
; // for error reporting
234 string name
; // memory name
235 int abits
; // number of address bits
236 int size
; // size (in units) of the memory
237 int width
; // size (in bits) of each element
240 vector
<read_port
> read_ports
;
241 vector
<write_port
> write_ports
;
242 std::string init_file
;
243 std::string init_file_srcFileSpec
;
245 memory(Cell
*pCell
, string name
, int abits
, int size
, int width
) : pCell(pCell
), name(name
), abits(abits
), size(size
), width(width
), read_latency(0), write_latency(1), init_file(""), init_file_srcFileSpec("") {
246 // Provide defaults for abits or size if one (but not the other) is specified.
247 if (this->abits
== 0 && this->size
!= 0) {
248 this->abits
= ceil_log2(this->size
);
249 } else if (this->abits
!= 0 && this->size
== 0) {
250 this->size
= 1 << this->abits
;
252 // Sanity-check this construction.
253 if (this->name
== "") {
254 log_error("Nameless memory%s\n", this->atLine());
256 if (this->abits
== 0 && this->size
== 0) {
257 log_error("Memory %s has zero address bits and size%s\n", this->name
.c_str(), this->atLine());
259 if (this->width
== 0) {
260 log_error("Memory %s has zero width%s\n", this->name
.c_str(), this->atLine());
263 // We need a default constructor for the dict insert.
264 memory() : pCell(0), read_latency(0), write_latency(1), init_file(""), init_file_srcFileSpec(""){}
266 const char *atLine() {
269 auto p
= pCell
->attributes
.find("\\src");
270 srcLine
= " at " + p
->second
.decode_string();
273 return srcLine
.c_str();
275 void add_memory_read_port(read_port
&rp
) {
276 read_ports
.push_back(rp
);
278 void add_memory_write_port(write_port
&wp
) {
279 write_ports
.push_back(wp
);
281 void add_memory_file(std::string init_file
, std::string init_file_srcFileSpec
) {
282 this->init_file
= init_file
;
283 this->init_file_srcFileSpec
= init_file_srcFileSpec
;
287 dict
<string
, memory
> memories
;
289 void register_memory(memory
&m
)
291 memories
[m
.name
] = m
;
294 void register_reverse_wire_map(string id
, SigSpec sig
)
296 for (int i
= 0; i
< GetSize(sig
); i
++)
297 reverse_wire_map
[sig
[i
]] = make_pair(id
, i
);
300 FirrtlWorker(Module
*module
, std::ostream
&f
, RTLIL::Design
*theDesign
) : module(module
), f(f
), design(theDesign
), indent(" ")
304 static string
make_expr(const SigSpec
&sig
)
308 for (auto chunk
: sig
.chunks())
312 if (chunk
.wire
== nullptr)
314 std::vector
<RTLIL::State
> bits
= chunk
.data
;
315 new_expr
= stringf("UInt<%d>(\"h", GetSize(bits
));
317 while (GetSize(bits
) % 4 != 0)
318 bits
.push_back(State::S0
);
320 for (int i
= GetSize(bits
)-4; i
>= 0; i
-= 4)
323 if (bits
[i
+0] == State::S1
) val
+= 1;
324 if (bits
[i
+1] == State::S1
) val
+= 2;
325 if (bits
[i
+2] == State::S1
) val
+= 4;
326 if (bits
[i
+3] == State::S1
) val
+= 8;
327 new_expr
.push_back(val
< 10 ? '0' + val
: 'a' + val
- 10);
332 else if (chunk
.offset
== 0 && chunk
.width
== chunk
.wire
->width
)
334 new_expr
= make_id(chunk
.wire
->name
);
338 string wire_id
= make_id(chunk
.wire
->name
);
339 new_expr
= stringf("bits(%s, %d, %d)", wire_id
.c_str(), chunk
.offset
+ chunk
.width
- 1, chunk
.offset
);
345 expr
= "cat(" + new_expr
+ ", " + expr
+ ")";
351 std::string
fid(RTLIL::IdString internal_id
)
353 return make_id(internal_id
);
356 std::string
cellname(RTLIL::Cell
*cell
)
358 return fid(cell
->name
).c_str();
361 void process_instance(RTLIL::Cell
*cell
, vector
<string
> &wire_exprs
)
363 std::string cell_type
= fid(cell
->type
);
364 std::string instanceOf
;
365 // If this is a parameterized module, its parent module is encoded in the cell type
366 if (cell
->type
.begins_with("$paramod"))
368 std::string::iterator it
;
369 for (it
= cell_type
.begin(); it
< cell_type
.end(); it
++)
372 case '\\': /* FALL_THROUGH */
373 case '=': /* FALL_THROUGH */
374 case '\'': /* FALL_THROUGH */
375 case '$': instanceOf
.append("_"); break;
376 default: instanceOf
.append(1, *it
); break;
382 instanceOf
= cell_type
;
385 std::string cell_name
= cellname(cell
);
386 std::string cell_name_comment
;
387 if (cell_name
!= fid(cell
->name
))
388 cell_name_comment
= " /* " + fid(cell
->name
) + " */ ";
390 cell_name_comment
= "";
391 // Find the module corresponding to this instance.
392 auto instModule
= design
->module(cell
->type
);
393 // If there is no instance for this, just return.
394 if (instModule
== NULL
)
396 log_warning("No instance for %s.%s\n", cell_type
.c_str(), cell_name
.c_str());
399 auto cellFileinfo
= getFileinfo(cell
->attributes
);
400 wire_exprs
.push_back(stringf("%s" "inst %s%s of %s %s", indent
.c_str(), cell_name
.c_str(), cell_name_comment
.c_str(), instanceOf
.c_str(), cellFileinfo
.c_str()));
402 for (auto it
= cell
->connections().begin(); it
!= cell
->connections().end(); ++it
) {
403 if (it
->second
.size() > 0) {
404 const SigSpec
&secondSig
= it
->second
;
405 const std::string firstName
= cell_name
+ "." + make_id(it
->first
);
406 const std::string secondExpr
= make_expr(secondSig
);
407 // Find the direction for this port.
408 FDirection dir
= getPortFDirection(it
->first
, instModule
);
409 std::string sourceExpr
, sinkExpr
;
410 const SigSpec
*sinkSig
= nullptr;
413 log_warning("Instance port connection %s.%s is INOUT; treating as OUT\n", cell_type
.c_str(), log_signal(it
->second
));
416 sourceExpr
= firstName
;
417 sinkExpr
= secondExpr
;
418 sinkSig
= &secondSig
;
421 log_warning("Instance port connection %s.%s is NODIRECTION; treating as IN\n", cell_type
.c_str(), log_signal(it
->second
));
424 sourceExpr
= secondExpr
;
425 sinkExpr
= firstName
;
428 log_error("Instance port %s.%s unrecognized connection direction 0x%x !\n", cell_type
.c_str(), log_signal(it
->second
), dir
);
431 // Check for subfield assignment.
432 std::string bitsString
= "bits(";
433 if (sinkExpr
.compare(0, bitsString
.length(), bitsString
) == 0) {
434 if (sinkSig
== nullptr)
435 log_error("Unknown subfield %s.%s\n", cell_type
.c_str(), sinkExpr
.c_str());
436 // Don't generate the assignment here.
437 // Add the source and sink to the "reverse_wire_map" and we'll output the assignment
438 // as part of the coalesced subfield assignments for this wire.
439 register_reverse_wire_map(sourceExpr
, *sinkSig
);
441 wire_exprs
.push_back(stringf("\n%s%s <= %s %s", indent
.c_str(), sinkExpr
.c_str(), sourceExpr
.c_str(), cellFileinfo
.c_str()));
445 wire_exprs
.push_back(stringf("\n"));
449 // Given an expression for a shift amount, and a maximum width,
450 // generate the FIRRTL expression for equivalent dynamic shift taking into account FIRRTL shift semantics.
451 std::string
gen_dshl(const string b_expr
, const int b_width
)
453 string result
= b_expr
;
454 if (b_width
>= FIRRTL_MAX_DSH_WIDTH_ERROR
) {
455 int max_shift_width_bits
= FIRRTL_MAX_DSH_WIDTH_ERROR
- 1;
456 string max_shift_string
= stringf("UInt<%d>(%d)", max_shift_width_bits
, (1<<max_shift_width_bits
) - 1);
457 // Deal with the difference in semantics between FIRRTL and verilog
458 result
= stringf("mux(gt(%s, %s), %s, bits(%s, %d, 0))", b_expr
.c_str(), max_shift_string
.c_str(), max_shift_string
.c_str(), b_expr
.c_str(), max_shift_width_bits
- 1);
465 auto moduleFileinfo
= getFileinfo(module
->attributes
);
466 f
<< stringf(" module %s: %s\n", make_id(module
->name
), moduleFileinfo
.c_str());
467 vector
<string
> port_decls
, wire_decls
, cell_exprs
, wire_exprs
;
469 for (auto wire
: module
->wires())
471 const auto wireName
= make_id(wire
->name
);
472 auto wireFileinfo
= getFileinfo(wire
->attributes
);
474 // If a wire has initial data, issue a warning since FIRRTL doesn't currently support it.
475 if (wire
->attributes
.count("\\init")) {
476 log_warning("Initial value (%s) for (%s.%s) not supported\n",
477 wire
->attributes
.at("\\init").as_string().c_str(),
478 log_id(module
), log_id(wire
));
482 if (wire
->port_input
&& wire
->port_output
)
483 log_error("Module port %s.%s is inout!\n", log_id(module
), log_id(wire
));
484 port_decls
.push_back(stringf(" %s %s: UInt<%d> %s\n", wire
->port_input
? "input" : "output",
485 wireName
, wire
->width
, wireFileinfo
.c_str()));
489 wire_decls
.push_back(stringf(" wire %s: UInt<%d> %s\n", wireName
, wire
->width
, wireFileinfo
.c_str()));
493 for (auto cell
: module
->cells())
495 static Const
ndef(0, 0);
497 // Is this cell is a module instance?
498 if (cell
->type
[0] != '$')
500 process_instance(cell
, wire_exprs
);
503 // Not a module instance. Set up cell properties
504 bool extract_y_bits
= false; // Assume no extraction of final bits will be required.
505 int a_width
= cell
->parameters
.at("\\A_WIDTH", ndef
).as_int(); // The width of "A"
506 int b_width
= cell
->parameters
.at("\\B_WIDTH", ndef
).as_int(); // The width of "A"
507 const int y_width
= cell
->parameters
.at("\\Y_WIDTH", ndef
).as_int(); // The width of the result
508 const bool a_signed
= cell
->parameters
.at("\\A_SIGNED", ndef
).as_bool();
509 const bool b_signed
= cell
->parameters
.at("\\B_SIGNED", ndef
).as_bool();
510 bool firrtl_is_signed
= a_signed
; // The result is signed (subsequent code may change this).
511 int firrtl_width
= 0;
513 bool always_uint
= false;
514 string y_id
= make_id(cell
->name
);
515 std::string cellFileinfo
= getFileinfo(cell
->attributes
);
517 if (cell
->type
.in("$not", "$logic_not", "$neg", "$reduce_and", "$reduce_or", "$reduce_xor", "$reduce_bool", "$reduce_xnor"))
519 string a_expr
= make_expr(cell
->getPort("\\A"));
520 wire_decls
.push_back(stringf(" wire %s: UInt<%d> %s\n", y_id
.c_str(), y_width
, cellFileinfo
.c_str()));
523 a_expr
= "asSInt(" + a_expr
+ ")";
526 // Don't use the results of logical operations (a single bit) to control padding
527 if (!(cell
->type
.in("$eq", "$eqx", "$gt", "$ge", "$lt", "$le", "$ne", "$nex", "$reduce_bool", "$logic_not") && y_width
== 1) ) {
528 a_expr
= stringf("pad(%s, %d)", a_expr
.c_str(), y_width
);
531 // Assume the FIRRTL width is a single bit.
533 if (cell
->type
== "$not") primop
= "not";
534 else if (cell
->type
== "$neg") {
536 firrtl_is_signed
= true; // Result of "neg" is signed (an SInt).
537 firrtl_width
= a_width
;
538 } else if (cell
->type
== "$logic_not") {
540 a_expr
= stringf("%s, UInt(0)", a_expr
.c_str());
542 else if (cell
->type
== "$reduce_and") primop
= "andr";
543 else if (cell
->type
== "$reduce_or") primop
= "orr";
544 else if (cell
->type
== "$reduce_xor") primop
= "xorr";
545 else if (cell
->type
== "$reduce_xnor") {
547 a_expr
= stringf("xorr(%s)", a_expr
.c_str());
549 else if (cell
->type
== "$reduce_bool") {
551 // Use the sign of the a_expr and its width as the type (UInt/SInt) and width of the comparand.
552 a_expr
= stringf("%s, %cInt<%d>(0)", a_expr
.c_str(), a_signed
? 'S' : 'U', a_width
);
555 string expr
= stringf("%s(%s)", primop
.c_str(), a_expr
.c_str());
557 if ((firrtl_is_signed
&& !always_uint
))
558 expr
= stringf("asUInt(%s)", expr
.c_str());
560 cell_exprs
.push_back(stringf(" %s <= %s %s\n", y_id
.c_str(), expr
.c_str(), cellFileinfo
.c_str()));
561 register_reverse_wire_map(y_id
, cell
->getPort("\\Y"));
565 if (cell
->type
.in("$add", "$sub", "$mul", "$div", "$mod", "$xor", "$xnor", "$and", "$or", "$eq", "$eqx",
566 "$gt", "$ge", "$lt", "$le", "$ne", "$nex", "$shr", "$sshr", "$sshl", "$shl",
567 "$logic_and", "$logic_or", "$pow"))
569 string a_expr
= make_expr(cell
->getPort("\\A"));
570 string b_expr
= make_expr(cell
->getPort("\\B"));
571 std::string cellFileinfo
= getFileinfo(cell
->attributes
);
572 wire_decls
.push_back(stringf(" wire %s: UInt<%d> %s\n", y_id
.c_str(), y_width
, cellFileinfo
.c_str()));
575 a_expr
= "asSInt(" + a_expr
+ ")";
576 // Expand the "A" operand to the result width
577 if (a_width
< y_width
) {
578 a_expr
= stringf("pad(%s, %d)", a_expr
.c_str(), y_width
);
582 // Shift amount is always unsigned, and needn't be padded to result width,
583 // otherwise, we need to cast the b_expr appropriately
584 if (b_signed
&& !cell
->type
.in("$shr", "$sshr", "$shl", "$sshl", "$pow")) {
585 b_expr
= "asSInt(" + b_expr
+ ")";
586 // Expand the "B" operand to the result width
587 if (b_width
< y_width
) {
588 b_expr
= stringf("pad(%s, %d)", b_expr
.c_str(), y_width
);
593 // For the arithmetic ops, expand operand widths to result widths befor performing the operation.
594 // This corresponds (according to iverilog) to what verilog compilers implement.
595 if (cell
->type
.in("$add", "$sub", "$mul", "$div", "$mod", "$xor", "$xnor", "$and", "$or"))
597 if (a_width
< y_width
) {
598 a_expr
= stringf("pad(%s, %d)", a_expr
.c_str(), y_width
);
601 if (b_width
< y_width
) {
602 b_expr
= stringf("pad(%s, %d)", b_expr
.c_str(), y_width
);
606 // Assume the FIRRTL width is the width of "A"
607 firrtl_width
= a_width
;
608 auto a_sig
= cell
->getPort("\\A");
610 if (cell
->type
== "$add") {
612 firrtl_is_signed
= a_signed
| b_signed
;
613 firrtl_width
= max(a_width
, b_width
);
614 } else if (cell
->type
== "$sub") {
616 firrtl_is_signed
= true;
617 int a_widthInc
= (!a_signed
&& b_signed
) ? 2 : (a_signed
&& !b_signed
) ? 1 : 0;
618 int b_widthInc
= (a_signed
&& !b_signed
) ? 2 : (!a_signed
&& b_signed
) ? 1 : 0;
619 firrtl_width
= max(a_width
+ a_widthInc
, b_width
+ b_widthInc
);
620 } else if (cell
->type
== "$mul") {
622 firrtl_is_signed
= a_signed
| b_signed
;
623 firrtl_width
= a_width
+ b_width
;
624 } else if (cell
->type
== "$div") {
626 firrtl_is_signed
= a_signed
| b_signed
;
627 firrtl_width
= a_width
;
628 } else if (cell
->type
== "$mod") {
630 firrtl_width
= min(a_width
, b_width
);
631 } else if (cell
->type
== "$and") {
634 firrtl_width
= max(a_width
, b_width
);
636 else if (cell
->type
== "$or" ) {
639 firrtl_width
= max(a_width
, b_width
);
641 else if (cell
->type
== "$xor") {
644 firrtl_width
= max(a_width
, b_width
);
646 else if (cell
->type
== "$xnor") {
649 firrtl_width
= max(a_width
, b_width
);
651 else if ((cell
->type
== "$eq") | (cell
->type
== "$eqx")) {
656 else if ((cell
->type
== "$ne") | (cell
->type
== "$nex")) {
661 else if (cell
->type
== "$gt") {
666 else if (cell
->type
== "$ge") {
671 else if (cell
->type
== "$lt") {
676 else if (cell
->type
== "$le") {
681 else if ((cell
->type
== "$shl") | (cell
->type
== "$sshl")) {
682 // FIRRTL will widen the result (y) by the amount of the shift.
683 // We'll need to offset this by extracting the un-widened portion as Verilog would do.
684 extract_y_bits
= true;
685 // Is the shift amount constant?
686 auto b_sig
= cell
->getPort("\\B");
687 if (b_sig
.is_fully_const()) {
689 int shift_amount
= b_sig
.as_int();
690 b_expr
= std::to_string(shift_amount
);
691 firrtl_width
= a_width
+ shift_amount
;
694 // Convert from FIRRTL left shift semantics.
695 b_expr
= gen_dshl(b_expr
, b_width
);
696 firrtl_width
= a_width
+ (1 << b_width
) - 1;
699 else if ((cell
->type
== "$shr") | (cell
->type
== "$sshr")) {
700 // We don't need to extract a specific range of bits.
701 extract_y_bits
= false;
702 // Is the shift amount constant?
703 auto b_sig
= cell
->getPort("\\B");
704 if (b_sig
.is_fully_const()) {
706 int shift_amount
= b_sig
.as_int();
707 b_expr
= std::to_string(shift_amount
);
708 firrtl_width
= max(1, a_width
- shift_amount
);
711 firrtl_width
= a_width
;
713 // We'll need to do some special fixups if the source (and thus result) is signed.
714 if (firrtl_is_signed
) {
715 // If this is a "logical" shift right, pretend the source is unsigned.
716 if (cell
->type
== "$shr") {
717 a_expr
= "asUInt(" + a_expr
+ ")";
721 else if ((cell
->type
== "$logic_and")) {
723 a_expr
= "neq(" + a_expr
+ ", UInt(0))";
724 b_expr
= "neq(" + b_expr
+ ", UInt(0))";
728 else if ((cell
->type
== "$logic_or")) {
730 a_expr
= "neq(" + a_expr
+ ", UInt(0))";
731 b_expr
= "neq(" + b_expr
+ ", UInt(0))";
735 else if ((cell
->type
== "$pow")) {
736 if (a_sig
.is_fully_const() && a_sig
.as_int() == 2) {
737 // We'll convert this to a shift. To simplify things, change the a_expr to "1"
738 // so we can use b_expr directly as a shift amount.
739 // Only support 2 ** N (i.e., shift left)
740 // FIRRTL will widen the result (y) by the amount of the shift.
741 // We'll need to offset this by extracting the un-widened portion as Verilog would do.
742 a_expr
= firrtl_is_signed
? "SInt(1)" : "UInt(1)";
743 extract_y_bits
= true;
744 // Is the shift amount constant?
745 auto b_sig
= cell
->getPort("\\B");
746 if (b_sig
.is_fully_const()) {
748 int shiftAmount
= b_sig
.as_int();
749 if (shiftAmount
< 0) {
750 log_error("Negative power exponent - %d: %s.%s\n", shiftAmount
, log_id(module
), log_id(cell
));
752 b_expr
= std::to_string(shiftAmount
);
753 firrtl_width
= a_width
+ shiftAmount
;
756 // Convert from FIRRTL left shift semantics.
757 b_expr
= gen_dshl(b_expr
, b_width
);
758 firrtl_width
= a_width
+ (1 << b_width
) - 1;
761 log_error("Non power 2: %s.%s\n", log_id(module
), log_id(cell
));
765 if (!cell
->parameters
.at("\\B_SIGNED").as_bool()) {
766 b_expr
= "asUInt(" + b_expr
+ ")";
770 // Deal with $xnor == ~^ (not xor)
771 if (primop
== "xnor") {
772 expr
= stringf("not(xor(%s, %s))", a_expr
.c_str(), b_expr
.c_str());
774 expr
= stringf("%s(%s, %s)", primop
.c_str(), a_expr
.c_str(), b_expr
.c_str());
777 // Deal with FIRRTL's "shift widens" semantics, or the need to widen the FIRRTL result.
778 // If the operation is signed, the FIRRTL width will be 1 one bit larger.
779 if (extract_y_bits
) {
780 expr
= stringf("bits(%s, %d, 0)", expr
.c_str(), y_width
- 1);
781 } else if (firrtl_is_signed
&& (firrtl_width
+ 1) < y_width
) {
782 expr
= stringf("pad(%s, %d)", expr
.c_str(), y_width
);
785 if ((firrtl_is_signed
&& !always_uint
))
786 expr
= stringf("asUInt(%s)", expr
.c_str());
788 cell_exprs
.push_back(stringf(" %s <= %s %s\n", y_id
.c_str(), expr
.c_str(), cellFileinfo
.c_str()));
789 register_reverse_wire_map(y_id
, cell
->getPort("\\Y"));
794 if (cell
->type
.in("$mux"))
796 int width
= cell
->parameters
.at("\\WIDTH").as_int();
797 string a_expr
= make_expr(cell
->getPort("\\A"));
798 string b_expr
= make_expr(cell
->getPort("\\B"));
799 string s_expr
= make_expr(cell
->getPort("\\S"));
800 wire_decls
.push_back(stringf(" wire %s: UInt<%d> %s\n", y_id
.c_str(), width
, cellFileinfo
.c_str()));
802 string expr
= stringf("mux(%s, %s, %s)", s_expr
.c_str(), b_expr
.c_str(), a_expr
.c_str());
804 cell_exprs
.push_back(stringf(" %s <= %s %s\n", y_id
.c_str(), expr
.c_str(), cellFileinfo
.c_str()));
805 register_reverse_wire_map(y_id
, cell
->getPort("\\Y"));
810 if (cell
->type
.in("$mem"))
812 string mem_id
= make_id(cell
->name
);
813 int abits
= cell
->parameters
.at("\\ABITS").as_int();
814 int width
= cell
->parameters
.at("\\WIDTH").as_int();
815 int size
= cell
->parameters
.at("\\SIZE").as_int();
816 memory
m(cell
, mem_id
, abits
, size
, width
);
817 int rd_ports
= cell
->parameters
.at("\\RD_PORTS").as_int();
818 int wr_ports
= cell
->parameters
.at("\\WR_PORTS").as_int();
820 Const initdata
= cell
->parameters
.at("\\INIT");
821 for (State bit
: initdata
.bits
)
822 if (bit
!= State::Sx
)
823 log_error("Memory with initialization data: %s.%s\n", log_id(module
), log_id(cell
));
825 Const rd_clk_enable
= cell
->parameters
.at("\\RD_CLK_ENABLE");
826 Const wr_clk_enable
= cell
->parameters
.at("\\WR_CLK_ENABLE");
827 Const wr_clk_polarity
= cell
->parameters
.at("\\WR_CLK_POLARITY");
829 int offset
= cell
->parameters
.at("\\OFFSET").as_int();
831 log_error("Memory with nonzero offset: %s.%s\n", log_id(module
), log_id(cell
));
833 for (int i
= 0; i
< rd_ports
; i
++)
835 if (rd_clk_enable
[i
] != State::S0
)
836 log_error("Clocked read port %d on memory %s.%s.\n", i
, log_id(module
), log_id(cell
));
838 SigSpec addr_sig
= cell
->getPort("\\RD_ADDR").extract(i
*abits
, abits
);
839 SigSpec data_sig
= cell
->getPort("\\RD_DATA").extract(i
*width
, width
);
840 string addr_expr
= make_expr(addr_sig
);
841 string
name(stringf("%s.r%d", m
.name
.c_str(), i
));
842 bool clk_enable
= false;
843 bool clk_parity
= true;
844 bool transparency
= false;
845 SigSpec ena_sig
= RTLIL::SigSpec(RTLIL::State::S1
, 1);
846 SigSpec clk_sig
= RTLIL::SigSpec(RTLIL::State::S0
, 1);
847 read_port
rp(name
, clk_enable
, clk_parity
, transparency
, clk_sig
, ena_sig
, addr_sig
);
848 m
.add_memory_read_port(rp
);
849 cell_exprs
.push_back(rp
.gen_read(indent
.c_str()));
850 register_reverse_wire_map(stringf("%s.data", name
.c_str()), data_sig
);
853 for (int i
= 0; i
< wr_ports
; i
++)
855 if (wr_clk_enable
[i
] != State::S1
)
856 log_error("Unclocked write port %d on memory %s.%s.\n", i
, log_id(module
), log_id(cell
));
858 if (wr_clk_polarity
[i
] != State::S1
)
859 log_error("Negedge write port %d on memory %s.%s.\n", i
, log_id(module
), log_id(cell
));
861 string
name(stringf("%s.w%d", m
.name
.c_str(), i
));
862 bool clk_enable
= true;
863 bool clk_parity
= true;
864 bool transparency
= false;
865 SigSpec addr_sig
=cell
->getPort("\\WR_ADDR").extract(i
*abits
, abits
);
866 string addr_expr
= make_expr(addr_sig
);
867 SigSpec data_sig
=cell
->getPort("\\WR_DATA").extract(i
*width
, width
);
868 string data_expr
= make_expr(data_sig
);
869 SigSpec clk_sig
= cell
->getPort("\\WR_CLK").extract(i
);
870 string clk_expr
= make_expr(clk_sig
);
872 SigSpec wen_sig
= cell
->getPort("\\WR_EN").extract(i
*width
, width
);
873 string wen_expr
= make_expr(wen_sig
[0]);
875 for (int i
= 1; i
< GetSize(wen_sig
); i
++)
876 if (wen_sig
[0] != wen_sig
[i
])
877 log_error("Complex write enable on port %d on memory %s.%s.\n", i
, log_id(module
), log_id(cell
));
879 SigSpec mask_sig
= RTLIL::SigSpec(RTLIL::State::S1
, 1);
880 write_port
wp(name
, clk_enable
, clk_parity
, transparency
, clk_sig
, wen_sig
[0], addr_sig
, mask_sig
);
881 m
.add_memory_write_port(wp
);
882 cell_exprs
.push_back(stringf("%s%s.data <= %s\n", indent
.c_str(), name
.c_str(), data_expr
.c_str()));
883 cell_exprs
.push_back(wp
.gen_write(indent
.c_str()));
889 if (cell
->type
.in("$memwr", "$memrd", "$meminit"))
891 std::string cell_type
= fid(cell
->type
);
892 std::string mem_id
= make_id(cell
->parameters
["\\MEMID"].decode_string());
893 int abits
= cell
->parameters
.at("\\ABITS").as_int();
894 int width
= cell
->parameters
.at("\\WIDTH").as_int();
895 memory
*mp
= nullptr;
896 if (cell
->type
== "$meminit" ) {
897 log_error("$meminit (%s.%s.%s) currently unsupported\n", log_id(module
), log_id(cell
), mem_id
.c_str());
899 // It's a $memwr or $memrd. Remember the read/write port parameters for the eventual FIRRTL memory definition.
900 auto addrSig
= cell
->getPort("\\ADDR");
901 auto dataSig
= cell
->getPort("\\DATA");
902 auto enableSig
= cell
->getPort("\\EN");
903 auto clockSig
= cell
->getPort("\\CLK");
904 Const clk_enable
= cell
->parameters
.at("\\CLK_ENABLE");
905 Const clk_polarity
= cell
->parameters
.at("\\CLK_POLARITY");
907 // Do we already have an entry for this memory?
908 if (memories
.count(mem_id
) == 0) {
909 memory
m(cell
, mem_id
, abits
, 0, width
);
912 mp
= &memories
.at(mem_id
);
914 bool transparency
= false;
915 string data_expr
= make_expr(dataSig
);
916 if (cell
->type
.in("$memwr")) {
917 portNum
= (int) mp
->write_ports
.size();
918 write_port
wp(stringf("%s.w%d", mem_id
.c_str(), portNum
), clk_enable
.as_bool(), clk_polarity
.as_bool(), transparency
, clockSig
, enableSig
, addrSig
, dataSig
);
919 mp
->add_memory_write_port(wp
);
920 cell_exprs
.push_back(stringf("%s%s.data <= %s\n", indent
.c_str(), wp
.name
.c_str(), data_expr
.c_str()));
921 cell_exprs
.push_back(wp
.gen_write(indent
.c_str()));
922 } else if (cell
->type
.in("$memrd")) {
923 portNum
= (int) mp
->read_ports
.size();
924 read_port
rp(stringf("%s.r%d", mem_id
.c_str(), portNum
), clk_enable
.as_bool(), clk_polarity
.as_bool(), transparency
, clockSig
, enableSig
, addrSig
);
925 mp
->add_memory_read_port(rp
);
926 cell_exprs
.push_back(rp
.gen_read(indent
.c_str()));
927 register_reverse_wire_map(stringf("%s.data", rp
.name
.c_str()), dataSig
);
933 if (cell
->type
.in("$dff"))
935 bool clkpol
= cell
->parameters
.at("\\CLK_POLARITY").as_bool();
937 log_error("Negative edge clock on FF %s.%s.\n", log_id(module
), log_id(cell
));
939 int width
= cell
->parameters
.at("\\WIDTH").as_int();
940 string expr
= make_expr(cell
->getPort("\\D"));
941 string clk_expr
= "asClock(" + make_expr(cell
->getPort("\\CLK")) + ")";
943 wire_decls
.push_back(stringf(" reg %s: UInt<%d>, %s %s\n", y_id
.c_str(), width
, clk_expr
.c_str(), cellFileinfo
.c_str()));
945 cell_exprs
.push_back(stringf(" %s <= %s %s\n", y_id
.c_str(), expr
.c_str(), cellFileinfo
.c_str()));
946 register_reverse_wire_map(y_id
, cell
->getPort("\\Q"));
951 // This may be a parameterized module - paramod.
952 if (cell
->type
.begins_with("$paramod"))
954 process_instance(cell
, wire_exprs
);
957 if (cell
->type
== "$shiftx") {
958 // assign y = a[b +: y_width];
959 // We'll extract the correct bits as part of the primop.
961 string a_expr
= make_expr(cell
->getPort("\\A"));
962 // Get the initial bit selector
963 string b_expr
= make_expr(cell
->getPort("\\B"));
964 wire_decls
.push_back(stringf(" wire %s: UInt<%d>\n", y_id
.c_str(), y_width
));
966 if (cell
->getParam("\\B_SIGNED").as_bool()) {
967 // Use validif to constrain the selection (test the sign bit)
968 auto b_string
= b_expr
.c_str();
969 int b_sign
= cell
->parameters
.at("\\B_WIDTH").as_int() - 1;
970 b_expr
= stringf("validif(not(bits(%s, %d, %d)), %s)", b_string
, b_sign
, b_sign
, b_string
);
972 string expr
= stringf("dshr(%s, %s)", a_expr
.c_str(), b_expr
.c_str());
974 cell_exprs
.push_back(stringf(" %s <= %s\n", y_id
.c_str(), expr
.c_str()));
975 register_reverse_wire_map(y_id
, cell
->getPort("\\Y"));
978 if (cell
->type
== "$shift") {
979 // assign y = a >> b;
980 // where b may be negative
982 string a_expr
= make_expr(cell
->getPort("\\A"));
983 string b_expr
= make_expr(cell
->getPort("\\B"));
984 auto b_string
= b_expr
.c_str();
986 wire_decls
.push_back(stringf(" wire %s: UInt<%d>\n", y_id
.c_str(), y_width
));
988 if (cell
->getParam("\\B_SIGNED").as_bool()) {
989 // We generate a left or right shift based on the sign of b.
990 std::string dshl
= stringf("bits(dshl(%s, %s), 0, %d)", a_expr
.c_str(), gen_dshl(b_expr
, b_width
).c_str(), y_width
);
991 std::string dshr
= stringf("dshr(%s, %s)", a_expr
.c_str(), b_string
);
992 expr
= stringf("mux(%s < 0, %s, %s)",
998 expr
= stringf("dshr(%s, %s)", a_expr
.c_str(), b_string
);
1000 cell_exprs
.push_back(stringf(" %s <= %s\n", y_id
.c_str(), expr
.c_str()));
1001 register_reverse_wire_map(y_id
, cell
->getPort("\\Y"));
1004 if (cell
->type
== "$pos") {
1007 string a_expr
= make_expr(cell
->getPort("\\A"));
1008 // Verilog appears to treat the result as signed, so if the result is wider than "A",
1010 if (a_width
< y_width
) {
1011 a_expr
= stringf("pad(%s, %d)", a_expr
.c_str(), y_width
);
1013 wire_decls
.push_back(stringf(" wire %s: UInt<%d>\n", y_id
.c_str(), y_width
));
1014 cell_exprs
.push_back(stringf(" %s <= %s\n", y_id
.c_str(), a_expr
.c_str()));
1015 register_reverse_wire_map(y_id
, cell
->getPort("\\Y"));
1018 log_error("Cell type not supported: %s (%s.%s)\n", log_id(cell
->type
), log_id(module
), log_id(cell
));
1021 for (auto conn
: module
->connections())
1023 string y_id
= next_id();
1024 int y_width
= GetSize(conn
.first
);
1025 string expr
= make_expr(conn
.second
);
1027 wire_decls
.push_back(stringf(" wire %s: UInt<%d>\n", y_id
.c_str(), y_width
));
1028 cell_exprs
.push_back(stringf(" %s <= %s\n", y_id
.c_str(), expr
.c_str()));
1029 register_reverse_wire_map(y_id
, conn
.first
);
1032 for (auto wire
: module
->wires())
1035 std::string wireFileinfo
= getFileinfo(wire
->attributes
);
1037 if (wire
->port_input
)
1041 bool is_valid
= false;
1042 bool make_unconn_id
= false;
1044 while (cursor
< wire
->width
)
1046 int chunk_width
= 1;
1049 SigBit
start_bit(wire
, cursor
);
1051 if (reverse_wire_map
.count(start_bit
))
1053 pair
<string
, int> start_map
= reverse_wire_map
.at(start_bit
);
1055 while (cursor
+chunk_width
< wire
->width
)
1057 SigBit
stop_bit(wire
, cursor
+chunk_width
);
1059 if (reverse_wire_map
.count(stop_bit
) == 0)
1062 pair
<string
, int> stop_map
= reverse_wire_map
.at(stop_bit
);
1063 stop_map
.second
-= chunk_width
;
1065 if (start_map
!= stop_map
)
1071 new_expr
= stringf("bits(%s, %d, %d)", start_map
.first
.c_str(),
1072 start_map
.second
+ chunk_width
- 1, start_map
.second
);
1077 if (unconn_id
.empty()) {
1078 unconn_id
= next_id();
1079 make_unconn_id
= true;
1081 new_expr
= unconn_id
;
1087 expr
= "cat(" + new_expr
+ ", " + expr
+ ")";
1089 cursor
+= chunk_width
;
1093 if (make_unconn_id
) {
1094 wire_decls
.push_back(stringf(" wire %s: UInt<1> %s\n", unconn_id
.c_str(), wireFileinfo
.c_str()));
1095 // `invalid` is a firrtl construction for simulation so we will not
1096 // tag it with a @[fileinfo] tag as it doesn't directly correspond to
1097 // a specific line of verilog code.
1098 wire_decls
.push_back(stringf(" %s is invalid\n", unconn_id
.c_str()));
1100 wire_exprs
.push_back(stringf(" %s <= %s %s\n", make_id(wire
->name
), expr
.c_str(), wireFileinfo
.c_str()));
1102 if (make_unconn_id
) {
1105 // `invalid` is a firrtl construction for simulation so we will not
1106 // tag it with a @[fileinfo] tag as it doesn't directly correspond to
1107 // a specific line of verilog code.
1108 wire_decls
.push_back(stringf(" %s is invalid\n", make_id(wire
->name
)));
1112 for (auto str
: port_decls
)
1117 for (auto str
: wire_decls
)
1122 // If we have any memory definitions, output them.
1123 for (auto kv
: memories
) {
1124 memory
&m
= kv
.second
;
1125 f
<< stringf(" mem %s:\n", m
.name
.c_str());
1126 f
<< stringf(" data-type => UInt<%d>\n", m
.width
);
1127 f
<< stringf(" depth => %d\n", m
.size
);
1128 for (int i
= 0; i
< (int) m
.read_ports
.size(); i
+= 1) {
1129 f
<< stringf(" reader => r%d\n", i
);
1131 for (int i
= 0; i
< (int) m
.write_ports
.size(); i
+= 1) {
1132 f
<< stringf(" writer => w%d\n", i
);
1134 f
<< stringf(" read-latency => %d\n", m
.read_latency
);
1135 f
<< stringf(" write-latency => %d\n", m
.write_latency
);
1136 f
<< stringf(" read-under-write => undefined\n");
1140 for (auto str
: cell_exprs
)
1145 for (auto str
: wire_exprs
)
1150 struct FirrtlBackend
: public Backend
{
1151 FirrtlBackend() : Backend("firrtl", "write design to a FIRRTL file") { }
1152 void help() YS_OVERRIDE
1154 // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
1156 log(" write_firrtl [options] [filename]\n");
1158 log("Write a FIRRTL netlist of the current design.\n");
1159 log("The following commands are executed by this command:\n");
1163 void execute(std::ostream
*&f
, std::string filename
, std::vector
<std::string
> args
, RTLIL::Design
*design
) YS_OVERRIDE
1165 size_t argidx
= args
.size(); // We aren't expecting any arguments.
1167 // If we weren't explicitly passed a filename, use the last argument (if it isn't a flag).
1168 if (filename
== "") {
1169 if (argidx
> 0 && args
[argidx
- 1][0] != '-') {
1170 // extra_args and friends need to see this argument.
1172 filename
= args
[argidx
];
1175 extra_args(f
, filename
, args
, argidx
);
1177 if (!design
->full_selection())
1178 log_cmd_error("This command only operates on fully selected designs!\n");
1180 log_header(design
, "Executing FIRRTL backend.\n");
1183 Pass::call(design
, stringf("pmuxtree"));
1188 // Get the top module, or a reasonable facsimile - we need something for the circuit name.
1189 Module
*top
= design
->top_module();
1190 Module
*last
= nullptr;
1191 // Generate module and wire names.
1192 for (auto module
: design
->modules()) {
1193 make_id(module
->name
);
1195 if (top
== nullptr && module
->get_bool_attribute("\\top")) {
1198 for (auto wire
: module
->wires())
1200 make_id(wire
->name
);
1206 auto circuitFileinfo
= getFileinfo(top
->attributes
);
1207 *f
<< stringf("circuit %s: %s\n", make_id(top
->name
), circuitFileinfo
.c_str());
1209 for (auto module
: design
->modules())
1211 FirrtlWorker
worker(module
, *f
, design
);
1220 PRIVATE_NAMESPACE_END