sc_time.cc revision 13124 
1/*
2 * Copyright 2018 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#include <vector>
31
32#include "base/logging.hh"
33#include "base/types.hh"
34#include "python/pybind11/pybind.hh"
35#include "systemc/core/python.hh"
36#include "systemc/ext/core/sc_time.hh"
37
38namespace sc_core
39{
40
41namespace
42{
43
44const char *TimeUnitNames[] = {
45    [SC_FS] = "fs",
46    [SC_PS] = "ps",
47    [SC_NS] = "ns",
48    [SC_US] = "us",
49    [SC_MS] = "ms",
50    [SC_SEC] = "s"
51};
52
53double TimeUnitScale[] = {
54    [SC_FS] = 1.0e-15,
55    [SC_PS] = 1.0e-12,
56    [SC_NS] = 1.0e-9,
57    [SC_US] = 1.0e-6,
58    [SC_MS] = 1.0e-3,
59    [SC_SEC] = 1.0
60};
61
62bool timeFixed = false;
63bool pythonReady = false;
64
65struct SetInfo
66{
67    SetInfo(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu) :
68        time(time), d(d), tu(tu)
69    {}
70
71    ::sc_core::sc_time *time;
72    double d;
73    ::sc_core::sc_time_unit tu;
74};
75std::vector<SetInfo> toSet;
76
77void
78setWork(sc_time *time, double d, ::sc_core::sc_time_unit tu)
79{
80    //XXX Assuming the time resolution is 1ps.
81    double scale = TimeUnitScale[tu] / TimeUnitScale[SC_PS];
82    // Accellera claims there is a linux bug, and that these next two
83    // lines work around them.
84    volatile double tmp = d * scale + 0.5;
85    *time = sc_time::from_value(static_cast<uint64_t>(tmp));
86}
87
88void
89fixTime()
90{
91    auto ticks = pybind11::module::import("m5.ticks");
92    auto fix_global_frequency = ticks.attr("fixGlobalFrequency");
93    fix_global_frequency();
94
95    for (auto &t: toSet)
96        setWork(t.time, t.d, t.tu);
97    toSet.clear();
98}
99
100void
101set(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu)
102{
103    // Only fix time once.
104    if (!timeFixed) {
105        timeFixed = true;
106
107        // If we've run, python is working and we haven't fixed time yet.
108        if (pythonReady)
109            fixTime();
110    }
111    if (pythonReady) {
112        // Time should be working. Set up this sc_time.
113        setWork(time, d, tu);
114    } else {
115        // Time isn't set up yet. Defer setting up this sc_time.
116        toSet.emplace_back(time, d, tu);
117    }
118}
119
120class TimeSetter : public ::sc_gem5::PythonReadyFunc
121{
122  public:
123    TimeSetter() : ::sc_gem5::PythonReadyFunc() {}
124
125    void
126    run() override
127    {
128        // Record that we've run and python/pybind should be usable.
129        pythonReady = true;
130
131        // If time is already fixed, let python know.
132        if (timeFixed)
133            fixTime();
134    }
135} timeSetter;
136
137double defaultUnit = 1.0e-9;
138
139} // anonymous namespace
140
141sc_time::sc_time() : val(0) {}
142
143sc_time::sc_time(double d, sc_time_unit tu)
144{
145    val = 0;
146    if (d != 0)
147        set(this, d, tu);
148}
149
150sc_time::sc_time(const sc_time &t)
151{
152    val = t.val;
153}
154
155sc_time::sc_time(double d, bool scale)
156{
157    //XXX Assuming the time resolution is 1ps.
158    if (scale)
159        set(this, d * defaultUnit, SC_SEC);
160    else
161        set(this, d, SC_PS);
162}
163
164sc_time::sc_time(sc_dt::uint64 v, bool scale)
165{
166    //XXX Assuming the time resolution is 1ps.
167    if (scale)
168        set(this, static_cast<double>(v) * defaultUnit, SC_SEC);
169    else
170        set(this, static_cast<double>(v), SC_PS);
171}
172
173sc_time &
174sc_time::operator = (const sc_time &t)
175{
176    val = t.val;
177    return *this;
178}
179
180sc_dt::uint64
181sc_time::value() const
182{
183    return val;
184}
185
186double
187sc_time::to_double() const
188{
189    return static_cast<double>(val);
190}
191double
192sc_time::to_seconds() const
193{
194    double d = to_double();
195    //XXX Assuming the time resolution is 1ps.
196    double scale = TimeUnitScale[SC_PS] / TimeUnitScale[SC_SEC];
197    return d * scale;
198}
199
200const std::string
201sc_time::to_string() const
202{
203    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
204    return "";
205}
206
207bool
208sc_time::operator == (const sc_time &t) const
209{
210    return val == t.val;
211}
212
213bool
214sc_time::operator != (const sc_time &t) const
215{
216    return val != t.val;
217}
218
219bool
220sc_time::operator < (const sc_time &t) const
221{
222    return val < t.val;
223}
224
225bool
226sc_time::operator <= (const sc_time &t) const
227{
228    return val <= t.val;
229}
230
231bool
232sc_time::operator > (const sc_time &t) const
233{
234    return val > t.val;
235}
236
237bool
238sc_time::operator >= (const sc_time &t) const
239{
240    return val >= t.val;
241}
242
243sc_time &
244sc_time::operator += (const sc_time &t)
245{
246    val += t.val;
247    return *this;
248}
249
250sc_time &
251sc_time::operator -= (const sc_time &t)
252{
253    val -= t.val;
254    return *this;
255}
256
257sc_time &
258sc_time::operator *= (double d)
259{
260    val = static_cast<int64_t>(static_cast<double>(val) * d + 0.5);
261    return *this;
262}
263
264sc_time &
265sc_time::operator /= (double d)
266{
267    val = static_cast<int64_t>(static_cast<double>(val) / d + 0.5);
268    return *this;
269}
270
271void
272sc_time::print(std::ostream &os) const
273{
274    if (val == 0) {
275        os << "0 s";
276    } else {
277        //XXX Assuming the time resolution is 1ps.
278        sc_time_unit tu = SC_PS;
279        uint64_t scaled = val;
280        while (tu < SC_SEC && (scaled % 1000) == 0) {
281            tu = (sc_time_unit)((int)tu + 1);
282            scaled /= 1000;
283        }
284
285        os << scaled << ' ' << TimeUnitNames[tu];
286    }
287}
288
289sc_time
290sc_time::from_value(sc_dt::uint64 u)
291{
292    sc_time t;
293    t.val = u;
294    return t;
295}
296
297sc_time
298sc_time::from_seconds(double d)
299{
300    sc_time t;
301    set(&t, d, SC_SEC);
302    return t;
303}
304
305sc_time
306sc_time::from_string(const char *str)
307{
308    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
309    return sc_time();
310}
311
312const sc_time
313operator + (const sc_time &a, const sc_time &b)
314{
315    return sc_time::from_value(a.value() + b.value());
316}
317
318const sc_time
319operator - (const sc_time &a, const sc_time &b)
320{
321    return sc_time::from_value(a.value() - b.value());
322}
323
324const sc_time
325operator * (const sc_time &t, double d)
326{
327    volatile double tmp = static_cast<double>(t.value()) * d + 0.5;
328    return sc_time::from_value(static_cast<int64_t>(tmp));
329}
330
331const sc_time
332operator * (double d, const sc_time &t)
333{
334    volatile double tmp = d * static_cast<double>(t.value()) + 0.5;
335    return sc_time::from_value(static_cast<int64_t>(tmp));
336}
337
338const sc_time
339operator / (const sc_time &t, double d)
340{
341    volatile double tmp = static_cast<double>(t.value()) / d + 0.5;
342    return sc_time::from_value(static_cast<int64_t>(tmp));
343}
344
345double
346operator / (const sc_time &t1, const sc_time &t2)
347{
348    return t1.to_double() / t2.to_double();
349}
350
351std::ostream &
352operator << (std::ostream &os, const sc_time &t)
353{
354    t.print(os);
355    return os;
356}
357
358const sc_time SC_ZERO_TIME;
359
360void
361sc_set_time_resolution(double, sc_time_unit)
362{
363    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
364}
365
366sc_time
367sc_get_time_resolution()
368{
369    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
370    return sc_time();
371}
372
373const sc_time &
374sc_max_time()
375{
376    static const sc_time MaxScTime = sc_time::from_value(MaxTick);
377    return MaxScTime;
378}
379
380void
381sc_set_default_time_unit(double d, sc_time_unit tu)
382{
383    defaultUnit = d * TimeUnitScale[tu];
384}
385
386sc_time
387sc_get_default_time_unit()
388{
389    return sc_time(defaultUnit, SC_SEC);
390}
391
392sc_time_tuple::sc_time_tuple(const sc_time &)
393{
394    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
395}
396
397bool
398sc_time_tuple::has_value() const
399{
400    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
401    return false;
402}
403
404sc_dt::uint64
405sc_time_tuple::value() const
406{
407    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
408    return 0;
409}
410
411const char *
412sc_time_tuple::unit_symbol() const
413{
414    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
415    return "";
416}
417
418double
419sc_time_tuple::to_double() const
420{
421    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
422    return 0.0;
423}
424
425std::string
426sc_time_tuple::to_string() const
427{
428    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
429    return "";
430}
431
432} // namespace sc_core
433