Merge pull request #2116 from whitequark/cxxrtl-vcd

cxxrtl: add a VCD writer using debug information
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whitequark 2020-06-07 20:32:00 +00:00 committed by GitHub
commit 210d129d9a
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7 changed files with 419 additions and 3 deletions

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@ -1,2 +1,2 @@
OBJS += backends/cxxrtl/cxxrtl.o
OBJS += backends/cxxrtl/cxxrtl_backend.o

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@ -728,6 +728,8 @@ struct debug_item : ::cxxrtl_object {
MEMORY = CXXRTL_MEMORY,
};
debug_item(const ::cxxrtl_object &object) : cxxrtl_object(object) {}
template<size_t Bits>
debug_item(value<Bits> &item) {
static_assert(sizeof(item) == value<Bits>::chunks * sizeof(chunk_t),

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@ -1851,10 +1851,15 @@ struct CxxrtlWorker {
else
f << "#include <backends/cxxrtl/cxxrtl.h>\n";
f << "\n";
f << "#ifdef CXXRTL_INCLUDE_CAPI_IMPL\n";
f << "#if defined(CXXRTL_INCLUDE_CAPI_IMPL) || \\\n";
f << " defined(CXXRTL_INCLUDE_VCD_CAPI_IMPL)\n";
f << "#include <backends/cxxrtl/cxxrtl_capi.cc>\n";
f << "#endif\n";
f << "\n";
f << "#if defined(CXXRTL_INCLUDE_VCD_CAPI_IMPL)\n";
f << "#include <backends/cxxrtl/cxxrtl_vcd_capi.cc>\n";
f << "#endif\n";
f << "\n";
f << "using namespace cxxrtl_yosys;\n";
f << "\n";
f << "namespace " << design_ns << " {\n";

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@ -26,6 +26,11 @@ struct _cxxrtl_handle {
cxxrtl::debug_items objects;
};
// Private function for use by other units of the C API.
const cxxrtl::debug_items &cxxrtl_debug_items_from_handle(cxxrtl_handle handle) {
return handle->objects;
}
cxxrtl_handle cxxrtl_create(cxxrtl_toplevel design) {
cxxrtl_handle handle = new _cxxrtl_handle;
handle->module = std::move(design->module);
@ -49,7 +54,7 @@ cxxrtl_object *cxxrtl_get(cxxrtl_handle handle, const char *name) {
}
void cxxrtl_enum(cxxrtl_handle handle, void *data,
void (*callback)(void *data, const char *name, struct cxxrtl_object *object)) {
void (*callback)(void *data, const char *name, cxxrtl_object *object)) {
for (auto &it : handle->objects)
callback(data, it.first.c_str(), static_cast<cxxrtl_object*>(&it.second));
}

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@ -0,0 +1,214 @@
/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2020 whitequark <whitequark@whitequark.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#ifndef CXXRTL_VCD_H
#define CXXRTL_VCD_H
#include <backends/cxxrtl/cxxrtl.h>
namespace cxxrtl {
class vcd_writer {
struct variable {
size_t ident;
size_t width;
chunk_t *curr;
size_t prev_off;
};
std::vector<std::string> current_scope;
std::vector<variable> variables;
std::vector<chunk_t> cache;
bool streaming = false;
void emit_timescale(unsigned number, const std::string &unit) {
assert(!streaming);
assert(number == 1 || number == 10 || number == 100);
assert(unit == "s" || unit == "ms" || unit == "us" ||
unit == "ns" || unit == "ps" || unit == "fs");
buffer += "$timescale " + std::to_string(number) + " " + unit + " $end\n";
}
void emit_scope(const std::vector<std::string> &scope) {
assert(!streaming);
while (current_scope.size() > scope.size() ||
(current_scope.size() > 0 &&
current_scope[current_scope.size() - 1] != scope[current_scope.size() - 1])) {
buffer += "$upscope $end\n";
current_scope.pop_back();
}
while (current_scope.size() < scope.size()) {
buffer += "$scope module " + scope[current_scope.size()] + " $end\n";
current_scope.push_back(scope[current_scope.size()]);
}
}
void emit_ident(size_t ident) {
do {
buffer += '!' + ident % 94; // "base94"
ident /= 94;
} while (ident != 0);
}
void emit_var(const variable &var, const std::string &type, const std::string &name) {
assert(!streaming);
buffer += "$var " + type + " " + std::to_string(var.width) + " ";
emit_ident(var.ident);
buffer += " " + name + " $end\n";
}
void emit_enddefinitions() {
assert(!streaming);
buffer += "$enddefinitions $end\n";
streaming = true;
}
void emit_time(uint64_t timestamp) {
assert(streaming);
buffer += "#" + std::to_string(timestamp) + "\n";
}
void emit_scalar(const variable &var) {
assert(streaming);
assert(var.width == 1);
buffer += (*var.curr ? '1' : '0');
emit_ident(var.ident);
buffer += '\n';
}
void emit_vector(const variable &var) {
assert(streaming);
buffer += 'b';
for (size_t bit = var.width - 1; bit != (size_t)-1; bit--) {
bool bit_curr = var.curr[bit / (8 * sizeof(chunk_t))] & (1 << (bit % (8 * sizeof(chunk_t))));
buffer += (bit_curr ? '1' : '0');
}
buffer += ' ';
emit_ident(var.ident);
buffer += '\n';
}
void append_variable(size_t width, chunk_t *curr) {
const size_t chunks = (width + (sizeof(chunk_t) * 8 - 1)) / (sizeof(chunk_t) * 8);
variables.emplace_back(variable { variables.size(), width, curr, cache.size() });
cache.insert(cache.end(), &curr[0], &curr[chunks]);
}
bool test_variable(const variable &var) {
const size_t chunks = (var.width + (sizeof(chunk_t) * 8 - 1)) / (sizeof(chunk_t) * 8);
if (std::equal(&var.curr[0], &var.curr[chunks], &cache[var.prev_off])) {
return false;
} else {
std::copy(&var.curr[0], &var.curr[chunks], &cache[var.prev_off]);
return true;
}
}
static std::vector<std::string> split_hierarchy(const std::string &hier_name) {
std::vector<std::string> hierarchy;
size_t prev = 0;
while (true) {
size_t curr = hier_name.find_first_of(' ', prev + 1);
if (curr > hier_name.size())
curr = hier_name.size();
if (curr > prev + 1)
hierarchy.push_back(hier_name.substr(prev, curr - prev));
if (curr == hier_name.size())
break;
prev = curr + 1;
}
return hierarchy;
}
public:
std::string buffer;
void timescale(unsigned number, const std::string &unit) {
emit_timescale(number, unit);
}
void add(const std::string &hier_name, const debug_item &item) {
std::vector<std::string> scope = split_hierarchy(hier_name);
std::string name = scope.back();
scope.pop_back();
emit_scope(scope);
switch (item.type) {
// Not the best naming but oh well...
case debug_item::VALUE:
append_variable(item.width, item.curr);
emit_var(variables.back(), "wire", name);
break;
case debug_item::WIRE:
append_variable(item.width, item.curr);
emit_var(variables.back(), "reg", name);
break;
case debug_item::MEMORY: {
const size_t stride = (item.width + (sizeof(chunk_t) * 8 - 1)) / (sizeof(chunk_t) * 8);
for (size_t index = 0; index < item.depth; index++) {
chunk_t *nth_curr = &item.curr[stride * index];
std::string nth_name = name + '[' + std::to_string(index) + ']';
append_variable(item.width, nth_curr);
emit_var(variables.back(), "reg", nth_name);
}
break;
}
}
}
template<class Filter>
void add(const debug_items &items, const Filter &filter) {
// `debug_items` is a map, so the items are already sorted in an order optimal for emitting
// VCD scope sections.
for (auto &it : items)
if (filter(it.first, it.second))
add(it.first, it.second);
}
void add(const debug_items &items) {
this->template add(items, [](const std::string &, const debug_item &) {
return true;
});
}
void add_without_memories(const debug_items &items) {
this->template add(items, [](const std::string &, const debug_item &item) {
return item.type == debug_item::VALUE || item.type == debug_item::WIRE;
});
}
void sample(uint64_t timestamp) {
bool first_sample = !streaming;
if (first_sample) {
emit_scope({});
emit_enddefinitions();
}
emit_time(timestamp);
for (auto var : variables)
if (test_variable(var) || first_sample) {
if (var.width == 1)
emit_scalar(var);
else
emit_vector(var);
}
}
};
}
#endif

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@ -0,0 +1,83 @@
/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2020 whitequark <whitequark@whitequark.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
// This file is a part of the CXXRTL C API. It should be used together with `cxxrtl_vcd_capi.h`.
#include <backends/cxxrtl/cxxrtl_vcd.h>
#include <backends/cxxrtl/cxxrtl_vcd_capi.h>
extern const cxxrtl::debug_items &cxxrtl_debug_items_from_handle(cxxrtl_handle handle);
struct _cxxrtl_vcd {
cxxrtl::vcd_writer writer;
bool flush = false;
};
cxxrtl_vcd cxxrtl_vcd_create() {
return new _cxxrtl_vcd;
}
void cxxrtl_vcd_destroy(cxxrtl_vcd vcd) {
delete vcd;
}
void cxxrtl_vcd_timescale(cxxrtl_vcd vcd, int number, const char *unit) {
vcd->writer.timescale(number, unit);
}
void cxxrtl_vcd_add(cxxrtl_vcd vcd, const char *name, cxxrtl_object *object) {
// Note the copy. We don't know whether `object` came from a design (in which case it is
// an instance of `debug_item`), or from user code (in which case it is an instance of
// `cxxrtl_object`), so casting the pointer wouldn't be safe.
vcd->writer.add(name, debug_item(*object));
}
void cxxrtl_vcd_add_from(cxxrtl_vcd vcd, cxxrtl_handle handle) {
vcd->writer.add(cxxrtl_debug_items_from_handle(handle));
}
void cxxrtl_vcd_add_from_if(cxxrtl_vcd vcd, cxxrtl_handle handle, void *data,
int (*filter)(void *data, const char *name,
const cxxrtl_object *object)) {
vcd->writer.add(cxxrtl_debug_items_from_handle(handle),
[=](const std::string &name, const debug_item &item) {
return filter(data, name.c_str(), static_cast<const cxxrtl_object*>(&item));
});
}
void cxxrtl_vcd_add_from_without_memories(cxxrtl_vcd vcd, cxxrtl_handle handle) {
vcd->writer.add_without_memories(cxxrtl_debug_items_from_handle(handle));
}
void cxxrtl_vcd_sample(cxxrtl_vcd vcd, uint64_t time) {
if (vcd->flush) {
vcd->writer.buffer.clear();
vcd->flush = false;
}
vcd->writer.sample(time);
}
void cxxrtl_vcd_read(cxxrtl_vcd vcd, const char **data, size_t *size) {
if (vcd->flush) {
vcd->writer.buffer.clear();
vcd->flush = false;
}
*data = vcd->writer.buffer.c_str();
*size = vcd->writer.buffer.size();
vcd->flush = true;
}

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@ -0,0 +1,107 @@
/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2020 whitequark <whitequark@whitequark.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#ifndef CXXRTL_VCD_CAPI_H
#define CXXRTL_VCD_CAPI_H
// This file is a part of the CXXRTL C API. It should be used together with `cxxrtl_vcd_capi.cc`.
//
// The CXXRTL C API for VCD writing makes it possible to insert virtual probes into designs and
// dump waveforms to Value Change Dump files.
#include <stddef.h>
#include <stdint.h>
#include <backends/cxxrtl/cxxrtl_capi.h>
#ifdef __cplusplus
extern "C" {
#endif
// Opaque reference to a VCD writer.
typedef struct _cxxrtl_vcd *cxxrtl_vcd;
// Create a VCD writer.
cxxrtl_vcd cxxrtl_vcd_create();
// Release all resources used by a VCD writer.
void cxxrtl_vcd_destroy(cxxrtl_vcd vcd);
// Set VCD timescale.
//
// The `number` must be 1, 10, or 100, and the `unit` must be one of `"s"`, `"ms"`, `"us"`, `"ns"`,
// `"ps"`, or `"fs"`.
//
// Timescale can only be set before the first call to `cxxrtl_vcd_sample`.
void cxxrtl_vcd_timescale(cxxrtl_vcd vcd, int number, const char *unit);
// Schedule a specific CXXRTL object to be sampled.
//
// The `name` is a full hierarchical name as described for `cxxrtl_get`; it does not need to match
// the original name of `object`, if any. The `object` must outlive the VCD writer, but there are
// no other requirements; if desired, it can be provided by user code, rather than come from
// a design.
//
// Objects can only be scheduled before the first call to `cxxrtl_vcd_sample`.
void cxxrtl_vcd_add(cxxrtl_vcd vcd, const char *name, struct cxxrtl_object *object);
// Schedule all CXXRTL objects in a simulation.
//
// The design `handle` must outlive the VCD writer.
//
// Objects can only be scheduled before the first call to `cxxrtl_vcd_sample`.
void cxxrtl_vcd_add_from(cxxrtl_vcd vcd, cxxrtl_handle handle);
// Schedule CXXRTL objects in a simulation that match a given predicate.
//
// For every object in the simulation, `filter` is called with the provided `data`, the full
// hierarchical name of the object (see `cxxrtl_get` for details), and the object description.
// The object will be sampled if the predicate returns a non-zero value.
//
// Objects can only be scheduled before the first call to `cxxrtl_vcd_sample`.
void cxxrtl_vcd_add_from_if(cxxrtl_vcd vcd, cxxrtl_handle handle, void *data,
int (*filter)(void *data, const char *name,
const struct cxxrtl_object *object));
// Schedule all CXXRTL objects in a simulation except for memories.
//
// The design `handle` must outlive the VCD writer.
//
// Objects can only be scheduled before the first call to `cxxrtl_vcd_sample`.
void cxxrtl_vcd_add_from_without_memories(cxxrtl_vcd vcd, cxxrtl_handle handle);
// Sample all scheduled objects.
//
// First, `time` is written to the internal buffer. Second, the values of every signal changed since
// the previous call to `cxxrtl_vcd_sample` (all values if this is the first call) are written to
// the internal buffer. The contents of the buffer can be retrieved with `cxxrtl_vcd_read`.
void cxxrtl_vcd_sample(cxxrtl_vcd vcd, uint64_t time);
// Retrieve buffered VCD data.
//
// The pointer to the start of the next chunk of VCD data is assigned to `*data`, and the length
// of that chunk is assigned to `*size`. The pointer to the data is valid until the next call to
// `cxxrtl_vcd_sample` or `cxxrtl_vcd_read`. Once all of the buffered data has been retrieved,
// this function will always return zero sized chunks.
void cxxrtl_vcd_read(cxxrtl_vcd vcd, const char **data, size_t *size);
#ifdef __cplusplus
}
#endif
#endif