diff --git a/dcalc/DmpCeff.cc b/dcalc/DmpCeff.cc index 60cd9383..3468d836 100644 --- a/dcalc/DmpCeff.cc +++ b/dcalc/DmpCeff.cc @@ -66,6 +66,17 @@ enum DmpFunc { y20, y50, ipi }; static const char *dmp_func_index_strings[] = {"y20", "y50", "Ipi"}; +class DmpError : public Exception +{ +public: + DmpError(const char *what); + virtual ~DmpError() {} + virtual const char *what() const noexcept { return what_; } + +private: + const char *what_; +}; + static double gateModelRd(const LibertyCell *cell, GateTableModel *gate_model, @@ -75,7 +86,7 @@ gateModelRd(const LibertyCell *cell, float related_out_cap, const Pvt *pvt, bool pocv_enabled); -static bool +static void evalDmpEqnsState(void *state); static void evalVoEqns(void *state, @@ -94,16 +105,15 @@ findRoot(void (*func)(void *state, double x, double &y, double &dy), double x1, double x2, double x_tol, - int max_iter, - const char *&error); -static const char * + int max_iter); +static void newtonRaphson(const int max_iter, double x[], const int n, const double x_tol, // eval(state) is called to fill fvec and fjac. // Returns false if fails. - bool (*eval)(void *state), + void (*eval)(void *state), void *state, // Temporaries supplied by caller. double *fvec, @@ -116,7 +126,7 @@ luSolve(double **a, const int size, const int *index, double b[]); -static const char * +static void luDecomp(double **a, const int size, int *index, @@ -154,7 +164,7 @@ public: // Given x_ as a vector of input parameters, fill fvec_ with the // equations evaluated at x_ and fjac_ with the jabobian evaluated at x_. - virtual bool evalDmpEqns() = 0; + virtual void evalDmpEqns() = 0; // Output response to vs(t) ramp driving pi model load. double vo(double t); double dVoDt(double t); @@ -165,7 +175,7 @@ public: protected: // Find driver parameters t0, delta_t, Ceff. - const char *findDriverParams(double ceff); + void findDriverParams(double ceff); void gateCapDelaySlew(double cl, double &delay, double &slew); @@ -189,13 +199,11 @@ protected: void showX(); void showFvec(); void showJacobian(); - const char *findDriverDelaySlew(double &delay, - double &slew); - double findVoCrossing(double vth, - const char *&error); + void findDriverDelaySlew(double &delay, + double &slew); + double findVoCrossing(double vth); void showVo(); - bool findVlCrossing(double vth, - double &t); + double findVlCrossing(double vth); void showVl(); void fail(const char *reason); @@ -334,7 +342,7 @@ DmpAlg::init(const LibertyLibrary *drvr_library, // Find Ceff, delta_t and t0 for the driver. // Return error msg on failure. -const char * +void DmpAlg::findDriverParams(double ceff) { x_[DmpParam::ceff] = ceff; @@ -344,29 +352,23 @@ DmpAlg::findDriverParams(double ceff) double t0 = t_vth + log(1.0 - vth_) * rd_ * ceff - vth_ * dt; x_[DmpParam::dt] = dt; x_[DmpParam::t0] = t0; - const char *error = newtonRaphson(100, x_, nr_order_, driver_param_tol, - evalDmpEqnsState, - this, fvec_, fjac_, index_, p_, scale_); - if (error) - return error; - else { - t0_ = x_[DmpParam::t0]; - dt_ = x_[DmpParam::dt]; - debugPrint3(debug_, "dmp_ceff", 3, " t0 = %s dt = %s ceff = %s\n", - units_->timeUnit()->asString(t0_), - units_->timeUnit()->asString(dt_), - units_->capacitanceUnit()->asString(x_[DmpParam::ceff])); - if (debug_->check("dmp_ceff", 4)) - showVo(); - return nullptr; - } + newtonRaphson(100, x_, nr_order_, driver_param_tol, evalDmpEqnsState, + this, fvec_, fjac_, index_, p_, scale_); + t0_ = x_[DmpParam::t0]; + dt_ = x_[DmpParam::dt]; + debugPrint3(debug_, "dmp_ceff", 3, " t0 = %s dt = %s ceff = %s\n", + units_->timeUnit()->asString(t0_), + units_->timeUnit()->asString(dt_), + units_->capacitanceUnit()->asString(x_[DmpParam::ceff])); + if (debug_->check("dmp_ceff", 4)) + showVo(); } -static bool +static void evalDmpEqnsState(void *state) { DmpAlg *alg = reinterpret_cast(state); - return alg->evalDmpEqns(); + alg->evalDmpEqns(); } void @@ -427,12 +429,9 @@ DmpAlg::dy(double t, double &dydcl) { double t1 = t - t0; -#if 0 if (t1 <= 0.0) dydt0 = dyddt = dydcl = 0.0; - else -#endif -if (t1 <= dt) { + else if (t1 <= dt) { dydt0 = -y0dt(t1, cl) / dt; dyddt = -y0(t1, cl) / (dt * dt); dydcl = y0dcl(t1, cl) / dt; @@ -488,34 +487,24 @@ DmpAlg::showJacobian() } } -// Return error msg on failure. -const char * +void DmpAlg::findDriverDelaySlew(double &delay, double &slew) { const char *error = nullptr; - delay = findVoCrossing(vth_, error); - if (error) - return error; - double tl = findVoCrossing(vl_, error); - if (error) - return error; - double th = findVoCrossing(vh_, error); - if (error) - return error; + delay = findVoCrossing(vth_); + double tl = findVoCrossing(vl_); + double th = findVoCrossing(vh_); slew = (th - tl) / slew_derate_; - return nullptr; } // Find t such that vo(t)=v. -// Return true if successful. double -DmpAlg::findVoCrossing(double vth, - const char *&error) +DmpAlg::findVoCrossing(double vth) { v_cross_ = vth; double ub = voCrossingUpperBound(); - return findRoot(evalVoEqns, this, t0_, ub, vth_time_tol, find_root_max_iter, error); + return findRoot(evalVoEqns, this, t0_, ub, vth_time_tol, find_root_max_iter); } static void @@ -570,28 +559,27 @@ DmpAlg::loadDelaySlew(const Pin *, ArcDelay &delay, Slew &slew) { - if (elmore == 0.0) { - delay = 0.0; - slew = gate_slew_; - } - else if (elmore < gate_slew_ * 1e-3) { - // Elmore delay is small compared to driver slew. + if (!driver_valid_ + || elmore == 0.0 + // Elmore delay is small compared to driver slew. + || elmore < gate_slew_ * 1e-3) { delay = elmore; + // solve v=1-exp(-t/rc) for t, elmore_slew_factor_ = t(vh) - t(vl) + // slew = elmore * (log(vh_) - log(vl_)) + // slew = elmore * elmore_slew_factor_; slew = gate_slew_; } else { - elmore_ = elmore; - p3_ = 1.0 / elmore; - if (driver_valid_ - && debug_->check("dmp_ceff", 4)) - showVl(); // Use the driver thresholds and rely on thresholdAdjust to // convert the delay and slew to the load's thresholds. - double tl, th, load_delay; - if (driver_valid_ - && findVlCrossing(vth_, load_delay) - && findVlCrossing(vl_, tl) - && findVlCrossing(vh_, th)) { + try { + if (debug_->check("dmp_ceff", 4)) + showVl(); + elmore_ = elmore; + p3_ = 1.0 / elmore; + double load_delay = findVlCrossing(vth_); + double tl = findVlCrossing(vl_); + double th = findVlCrossing(vh_); // Measure delay from Vo, the load dependent source excitation. double delay1 = load_delay - vo_delay_; double slew1 = (th - tl) / slew_derate_; @@ -600,7 +588,7 @@ DmpAlg::loadDelaySlew(const Pin *, if (-delay1 > vth_time_tol * vo_delay_) fail("load delay less than zero"); // Use elmore delay. - delay1 = 1.0 / p3_; + delay1 = elmore; } if (slew1 < gate_slew_) { // Only report a problem if the difference is significant. @@ -611,30 +599,24 @@ DmpAlg::loadDelaySlew(const Pin *, delay = delay1; slew = slew1; } - else { + catch (DmpError &error) { // Failed - use elmore delay and driver slew. delay = elmore_; // solve v=1-exp(-t/rc) for t, elmore_slew_factor_ = t(vh) - t(vl) // slew = elmore * (log(vh_) - log(vl_)) - slew = gate_slew_ + elmore * elmore_slew_factor_; + slew = elmore * elmore_slew_factor_; } } } // Find t such that vl(t)=v. // Return true if successful. -bool -DmpAlg::findVlCrossing(double vth, - double &t) +double +DmpAlg::findVlCrossing(double vth) { v_cross_ = vth; double ub = vlCrossingUpperBound(); - const char *error; - t = findRoot(evalVlEqns, this, t0_, ub, vth_time_tol, find_root_max_iter, - error); - if (error) - fail("findVlCrossing: Vl(t) did not cross threshold"); - return (error == nullptr); + return findRoot(evalVlEqns, this, t0_, ub, vth_time_tol, find_root_max_iter); } double @@ -725,7 +707,7 @@ public: double elmore, ArcDelay &delay, Slew &slew); - virtual bool evalDmpEqns(); + virtual void evalDmpEqns(); virtual double voCrossingUpperBound(); private: @@ -779,10 +761,9 @@ DmpCap::loadDelaySlew(const Pin *, slew = gate_slew_; } -bool +void DmpCap::evalDmpEqns() { - return true; } double @@ -836,11 +817,11 @@ public: double c1); virtual void gateDelaySlew(double &delay, double &slew); - virtual bool evalDmpEqns(); + virtual void evalDmpEqns(); virtual double voCrossingUpperBound(); private: - const char *findDriverParamsPi(); + void findDriverParamsPi(); virtual double v0(double t); virtual double dv0dt(double t); double ipiIceff(double t0, @@ -924,14 +905,8 @@ void DmpPi::gateDelaySlew(double &delay, double &slew) { - const char *error = findDriverParamsPi(); - if (error) { - fail(error); - // Driver calculation failed - use Ceff=c1+c2. - ceff_ = c1_ + c2_; - gateCapDelaySlew(ceff_, delay, slew); - } - else { + try { + findDriverParamsPi(); ceff_ = x_[DmpParam::ceff]; driver_valid_ = true; double table_slew; @@ -941,38 +916,50 @@ DmpPi::gateDelaySlew(double &delay, // Vo slew is more accurate than table // (-8% max, -3% avg vs -32% max, -12% avg). // Need Vo delay to measure load wire delay waveform. - const char *error = findDriverDelaySlew(vo_delay_, slew); - if (error) { - fail(error); + try { + findDriverDelaySlew(vo_delay_, slew); + } + catch (DmpError &error) { + fail(error.what()); // Fall back to table slew. slew = table_slew; } } + catch (DmpError &error) { + fail(error.what()); + // Driver calculation failed - use Ceff=c1+c2. + driver_valid_ = false; + ceff_ = c1_ + c2_; + gateCapDelaySlew(ceff_, delay, slew); + } // Save for wire delay calc. gate_slew_ = slew; } -const char * +void DmpPi::findDriverParamsPi() { - const char *error; - error = findDriverParams(c2_ + c1_); - if (error) - error = findDriverParams(c2_); - return error; + try { + findDriverParams(c2_ + c1_); + } + catch (DmpError &) { + findDriverParams(c2_); + } } // Given x_ as a vector of input parameters, fill fvec_ with the // equations evaluated at x_ and fjac_ with the jacobian evaluated at x_. -bool +void DmpPi::evalDmpEqns() { double t0 = x_[DmpParam::t0]; double dt = x_[DmpParam::dt]; double ceff = x_[DmpParam::ceff]; - if (ceff > (c1_ + c2_) || ceff < 0.0) - return false; + if (ceff < 0.0) + throw DmpError("eqn eval failed: ceff < 0"); + if (ceff > (c1_ + c2_)) + throw DmpError("eqn eval failed: ceff > c2 + c1"); double t_vth, t_vl, slew; gateDelays(ceff, t_vth, t_vl, slew); @@ -981,7 +968,7 @@ DmpPi::evalDmpEqns() ceff_time = 1.4 * dt; if (dt <= 0.0) - return false; + throw DmpError("eqn eval failed: dt < 0"); double exp_p1_dt = exp(-p1_ * dt); double exp_p2_dt = exp(-p2_ * dt); @@ -1021,7 +1008,6 @@ DmpPi::evalDmpEqns() showJacobian(); debug_->print(".................\n"); } - return true; } // Eqn 13, Eqn 14. @@ -1090,7 +1076,7 @@ class DmpOnePole : public DmpAlg { public: DmpOnePole(StaState *sta); - virtual bool evalDmpEqns(); + virtual void evalDmpEqns(); virtual double voCrossingUpperBound(); }; @@ -1099,7 +1085,7 @@ DmpOnePole::DmpOnePole(StaState *sta) : { } -bool +void DmpOnePole::evalDmpEqns() { double t0 = x_[DmpParam::t0]; @@ -1133,7 +1119,6 @@ DmpOnePole::evalDmpEqns() showJacobian(); debug_->print(".................\n"); } - return true; } double @@ -1291,19 +1276,15 @@ findRoot(void (*func)(void *state, double x, double &y, double &dy), double x1, double x2, double x_tol, - int max_iter, - const char *&error) + int max_iter) { double y1, y2, dy; func(state, x1, y1, dy); func(state, x2, y2, dy); - if ((y1 > 0.0 && y2 > 0.0) || (y1 < 0.0 && y2 < 0.0)) { - error = "findRoot: initial bounds do not surround a root"; - return 0.0; - } + if ((y1 > 0.0 && y2 > 0.0) || (y1 < 0.0 && y2 < 0.0)) + throw DmpError("findRoot: initial bounds do not surround a root"); - error = nullptr; if (y1 == 0.0) return x1; @@ -1346,20 +1327,19 @@ findRoot(void (*func)(void *state, double x, double &y, double &dy), else x2 = root; } - error = "findRoot: max iterations exceeded"; - return 0.0; + throw DmpError("findRoot: max iterations exceeded"); } // Newton-Raphson iteration to find zeros of a function. // x_tol is percentage that all changes in x must be less than (1.0 = 100%). // Eval(state) is called to fill fvec and fjac (returns false if fails). // Return error msg on failure. -static const char * +static void newtonRaphson(const int max_iter, double x[], const int size, const double x_tol, - bool (*eval)(void *state), + void (*eval)(void *state), void *state, // Temporaries supplied by caller. double *fvec, @@ -1369,29 +1349,23 @@ newtonRaphson(const int max_iter, double *scale) { for (int k = 0; k < max_iter; k++) { - if (!eval(state)) - return "Newton-Raphson eval failed"; - + eval(state); for (int i = 0; i < size; i++) // Right-hand side of linear equations. p[i] = -fvec[i]; - const char *error = luDecomp(fjac, size, index, scale); - if (error) - return error; - else { - luSolve(fjac, size, index, p); + luDecomp(fjac, size, index, scale); + luSolve(fjac, size, index, p); - bool all_under_x_tol = true; - for (int i = 0; i < size; i++) { - if (abs(p[i]) > abs(x[i]) * x_tol) - all_under_x_tol = false; - x[i] += p[i]; - } - if (all_under_x_tol) - return nullptr; + bool all_under_x_tol = true; + for (int i = 0; i < size; i++) { + if (abs(p[i]) > abs(x[i]) * x_tol) + all_under_x_tol = false; + x[i] += p[i]; } + if (all_under_x_tol) + return; } - return "Newton-Raphson max iterations exceeded"; + throw DmpError("Newton-Raphson max iterations exceeded"); } // luDecomp, luSolve based on MatClass from C. R. Birchenhall, @@ -1406,7 +1380,7 @@ newtonRaphson(const int max_iter, // Replaces a[0..size-1][0..size-1] by the LU decomposition. // index[0..size-1] is an output vector of the row permutations. // Return error msg on failure. -const char * +void luDecomp(double **a, const int size, int *index, @@ -1423,7 +1397,7 @@ luDecomp(double **a, big = temp; } if (big == 0.0) - return "LU decomposition: no non-zero row element"; + throw DmpError("LU decomposition: no non-zero row element"); scale[i] = 1.0 / big; } int size_1 = size - 1; @@ -1473,7 +1447,6 @@ luDecomp(double **a, a[i][j] *= pivot; } } - return nullptr; } // Solves the set of size linear equations a*x=b, assuming A is LU form @@ -1789,4 +1762,10 @@ DmpCeffDelayCalc::copyState(const StaState *sta) dmp_zero_c2_->copyState(sta); } +DmpError::DmpError(const char *what) : + what_(what) +{ + //printf("DmpError %s\n", what); +} + } // namespace