1 #include <typeinfo>
2 #include <iostream>
3 #include <Eigen/Core>
4 #include "BenchTimer.h"
5 using namespace Eigen;
6 using namespace std;
7 
8 template<typename T>
sqsumNorm(T & v)9 EIGEN_DONT_INLINE typename T::Scalar sqsumNorm(T& v)
10 {
11   return v.norm();
12 }
13 
14 template<typename T>
stableNorm(T & v)15 EIGEN_DONT_INLINE typename T::Scalar stableNorm(T& v)
16 {
17   return v.stableNorm();
18 }
19 
20 template<typename T>
hypotNorm(T & v)21 EIGEN_DONT_INLINE typename T::Scalar hypotNorm(T& v)
22 {
23   return v.hypotNorm();
24 }
25 
26 template<typename T>
blueNorm(T & v)27 EIGEN_DONT_INLINE typename T::Scalar blueNorm(T& v)
28 {
29   return v.blueNorm();
30 }
31 
32 template<typename T>
lapackNorm(T & v)33 EIGEN_DONT_INLINE typename T::Scalar lapackNorm(T& v)
34 {
35   typedef typename T::Scalar Scalar;
36   int n = v.size();
37   Scalar scale = 0;
38   Scalar ssq = 1;
39   for (int i=0;i<n;++i)
40   {
41     Scalar ax = std::abs(v.coeff(i));
42     if (scale >= ax)
43     {
44       ssq += numext::abs2(ax/scale);
45     }
46     else
47     {
48       ssq = Scalar(1) + ssq * numext::abs2(scale/ax);
49       scale = ax;
50     }
51   }
52   return scale * std::sqrt(ssq);
53 }
54 
55 template<typename T>
twopassNorm(T & v)56 EIGEN_DONT_INLINE typename T::Scalar twopassNorm(T& v)
57 {
58   typedef typename T::Scalar Scalar;
59   Scalar s = v.array().abs().maxCoeff();
60   return s*(v/s).norm();
61 }
62 
63 template<typename T>
bl2passNorm(T & v)64 EIGEN_DONT_INLINE typename T::Scalar bl2passNorm(T& v)
65 {
66   return v.stableNorm();
67 }
68 
69 template<typename T>
divacNorm(T & v)70 EIGEN_DONT_INLINE typename T::Scalar divacNorm(T& v)
71 {
72   int n =v.size() / 2;
73   for (int i=0;i<n;++i)
74     v(i) = v(2*i)*v(2*i) + v(2*i+1)*v(2*i+1);
75   n = n/2;
76   while (n>0)
77   {
78     for (int i=0;i<n;++i)
79       v(i) = v(2*i) + v(2*i+1);
80     n = n/2;
81   }
82   return std::sqrt(v(0));
83 }
84 
85 namespace Eigen {
86 namespace internal {
87 #ifdef EIGEN_VECTORIZE
plt(const Packet4f & a,Packet4f & b)88 Packet4f plt(const Packet4f& a, Packet4f& b) { return _mm_cmplt_ps(a,b); }
plt(const Packet2d & a,Packet2d & b)89 Packet2d plt(const Packet2d& a, Packet2d& b) { return _mm_cmplt_pd(a,b); }
90 
pandnot(const Packet4f & a,Packet4f & b)91 Packet4f pandnot(const Packet4f& a, Packet4f& b) { return _mm_andnot_ps(a,b); }
pandnot(const Packet2d & a,Packet2d & b)92 Packet2d pandnot(const Packet2d& a, Packet2d& b) { return _mm_andnot_pd(a,b); }
93 #endif
94 }
95 }
96 
97 template<typename T>
pblueNorm(const T & v)98 EIGEN_DONT_INLINE typename T::Scalar pblueNorm(const T& v)
99 {
100   #ifndef EIGEN_VECTORIZE
101   return v.blueNorm();
102   #else
103   typedef typename T::Scalar Scalar;
104 
105   static int nmax = 0;
106   static Scalar b1, b2, s1m, s2m, overfl, rbig, relerr;
107   int n;
108 
109   if(nmax <= 0)
110   {
111     int nbig, ibeta, it, iemin, iemax, iexp;
112     Scalar abig, eps;
113 
114     nbig  = std::numeric_limits<int>::max();            // largest integer
115     ibeta = std::numeric_limits<Scalar>::radix; //NumTraits<Scalar>::Base;                    // base for floating-point numbers
116     it    = std::numeric_limits<Scalar>::digits; //NumTraits<Scalar>::Mantissa;                // number of base-beta digits in mantissa
117     iemin = std::numeric_limits<Scalar>::min_exponent;  // minimum exponent
118     iemax = std::numeric_limits<Scalar>::max_exponent;  // maximum exponent
119     rbig  = std::numeric_limits<Scalar>::max();         // largest floating-point number
120 
121     // Check the basic machine-dependent constants.
122     if(iemin > 1 - 2*it || 1+it>iemax || (it==2 && ibeta<5)
123       || (it<=4 && ibeta <= 3 ) || it<2)
124     {
125       eigen_assert(false && "the algorithm cannot be guaranteed on this computer");
126     }
127     iexp  = -((1-iemin)/2);
128     b1    = std::pow(ibeta, iexp);  // lower boundary of midrange
129     iexp  = (iemax + 1 - it)/2;
130     b2    = std::pow(ibeta,iexp);   // upper boundary of midrange
131 
132     iexp  = (2-iemin)/2;
133     s1m   = std::pow(ibeta,iexp);   // scaling factor for lower range
134     iexp  = - ((iemax+it)/2);
135     s2m   = std::pow(ibeta,iexp);   // scaling factor for upper range
136 
137     overfl  = rbig*s2m;          // overfow boundary for abig
138     eps     = std::pow(ibeta, 1-it);
139     relerr  = std::sqrt(eps);      // tolerance for neglecting asml
140     abig    = 1.0/eps - 1.0;
141     if (Scalar(nbig)>abig)  nmax = abig;  // largest safe n
142     else                    nmax = nbig;
143   }
144 
145   typedef typename internal::packet_traits<Scalar>::type Packet;
146   const int ps = internal::packet_traits<Scalar>::size;
147   Packet pasml = internal::pset1<Packet>(Scalar(0));
148   Packet pamed = internal::pset1<Packet>(Scalar(0));
149   Packet pabig = internal::pset1<Packet>(Scalar(0));
150   Packet ps2m = internal::pset1<Packet>(s2m);
151   Packet ps1m = internal::pset1<Packet>(s1m);
152   Packet pb2  = internal::pset1<Packet>(b2);
153   Packet pb1  = internal::pset1<Packet>(b1);
154   for(int j=0; j<v.size(); j+=ps)
155   {
156     Packet ax = internal::pabs(v.template packet<Aligned>(j));
157     Packet ax_s2m = internal::pmul(ax,ps2m);
158     Packet ax_s1m = internal::pmul(ax,ps1m);
159     Packet maskBig = internal::plt(pb2,ax);
160     Packet maskSml = internal::plt(ax,pb1);
161 
162 //     Packet maskMed = internal::pand(maskSml,maskBig);
163 //     Packet scale = internal::pset1(Scalar(0));
164 //     scale = internal::por(scale, internal::pand(maskBig,ps2m));
165 //     scale = internal::por(scale, internal::pand(maskSml,ps1m));
166 //     scale = internal::por(scale, internal::pandnot(internal::pset1(Scalar(1)),maskMed));
167 //     ax = internal::pmul(ax,scale);
168 //     ax = internal::pmul(ax,ax);
169 //     pabig = internal::padd(pabig, internal::pand(maskBig, ax));
170 //     pasml = internal::padd(pasml, internal::pand(maskSml, ax));
171 //     pamed = internal::padd(pamed, internal::pandnot(ax,maskMed));
172 
173 
174     pabig = internal::padd(pabig, internal::pand(maskBig, internal::pmul(ax_s2m,ax_s2m)));
175     pasml = internal::padd(pasml, internal::pand(maskSml, internal::pmul(ax_s1m,ax_s1m)));
176     pamed = internal::padd(pamed, internal::pandnot(internal::pmul(ax,ax),internal::pand(maskSml,maskBig)));
177   }
178   Scalar abig = internal::predux(pabig);
179   Scalar asml = internal::predux(pasml);
180   Scalar amed = internal::predux(pamed);
181   if(abig > Scalar(0))
182   {
183     abig = std::sqrt(abig);
184     if(abig > overfl)
185     {
186       eigen_assert(false && "overflow");
187       return rbig;
188     }
189     if(amed > Scalar(0))
190     {
191       abig = abig/s2m;
192       amed = std::sqrt(amed);
193     }
194     else
195     {
196       return abig/s2m;
197     }
198 
199   }
200   else if(asml > Scalar(0))
201   {
202     if (amed > Scalar(0))
203     {
204       abig = std::sqrt(amed);
205       amed = std::sqrt(asml) / s1m;
206     }
207     else
208     {
209       return std::sqrt(asml)/s1m;
210     }
211   }
212   else
213   {
214     return std::sqrt(amed);
215   }
216   asml = std::min(abig, amed);
217   abig = std::max(abig, amed);
218   if(asml <= abig*relerr)
219     return abig;
220   else
221     return abig * std::sqrt(Scalar(1) + numext::abs2(asml/abig));
222   #endif
223 }
224 
225 #define BENCH_PERF(NRM) { \
226   float af = 0; double ad = 0; std::complex<float> ac = 0; \
227   Eigen::BenchTimer tf, td, tcf; tf.reset(); td.reset(); tcf.reset();\
228   for (int k=0; k<tries; ++k) { \
229     tf.start(); \
230     for (int i=0; i<iters; ++i) { af += NRM(vf); } \
231     tf.stop(); \
232   } \
233   for (int k=0; k<tries; ++k) { \
234     td.start(); \
235     for (int i=0; i<iters; ++i) { ad += NRM(vd); } \
236     td.stop(); \
237   } \
238   /*for (int k=0; k<std::max(1,tries/3); ++k) { \
239     tcf.start(); \
240     for (int i=0; i<iters; ++i) { ac += NRM(vcf); } \
241     tcf.stop(); \
242   } */\
243   std::cout << #NRM << "\t" << tf.value() << "   " << td.value() <<  "    " << tcf.value() << "\n"; \
244 }
245 
check_accuracy(double basef,double based,int s)246 void check_accuracy(double basef, double based, int s)
247 {
248   double yf = basef * std::abs(internal::random<double>());
249   double yd = based * std::abs(internal::random<double>());
250   VectorXf vf = VectorXf::Ones(s) * yf;
251   VectorXd vd = VectorXd::Ones(s) * yd;
252 
253   std::cout << "reference\t" << std::sqrt(double(s))*yf << "\t" << std::sqrt(double(s))*yd << "\n";
254   std::cout << "sqsumNorm\t" << sqsumNorm(vf) << "\t" << sqsumNorm(vd) << "\n";
255   std::cout << "hypotNorm\t" << hypotNorm(vf) << "\t" << hypotNorm(vd) << "\n";
256   std::cout << "blueNorm\t" << blueNorm(vf) << "\t" << blueNorm(vd) << "\n";
257   std::cout << "pblueNorm\t" << pblueNorm(vf) << "\t" << pblueNorm(vd) << "\n";
258   std::cout << "lapackNorm\t" << lapackNorm(vf) << "\t" << lapackNorm(vd) << "\n";
259   std::cout << "twopassNorm\t" << twopassNorm(vf) << "\t" << twopassNorm(vd) << "\n";
260   std::cout << "bl2passNorm\t" << bl2passNorm(vf) << "\t" << bl2passNorm(vd) << "\n";
261 }
262 
check_accuracy_var(int ef0,int ef1,int ed0,int ed1,int s)263 void check_accuracy_var(int ef0, int ef1, int ed0, int ed1, int s)
264 {
265   VectorXf vf(s);
266   VectorXd vd(s);
267   for (int i=0; i<s; ++i)
268   {
269     vf[i] = std::abs(internal::random<double>()) * std::pow(double(10), internal::random<int>(ef0,ef1));
270     vd[i] = std::abs(internal::random<double>()) * std::pow(double(10), internal::random<int>(ed0,ed1));
271   }
272 
273   //std::cout << "reference\t" << internal::sqrt(double(s))*yf << "\t" << internal::sqrt(double(s))*yd << "\n";
274   std::cout << "sqsumNorm\t"  << sqsumNorm(vf)  << "\t" << sqsumNorm(vd)  << "\t" << sqsumNorm(vf.cast<long double>()) << "\t" << sqsumNorm(vd.cast<long double>()) << "\n";
275   std::cout << "hypotNorm\t"  << hypotNorm(vf)  << "\t" << hypotNorm(vd)  << "\t" << hypotNorm(vf.cast<long double>()) << "\t" << hypotNorm(vd.cast<long double>()) << "\n";
276   std::cout << "blueNorm\t"   << blueNorm(vf)   << "\t" << blueNorm(vd)   << "\t" << blueNorm(vf.cast<long double>()) << "\t" << blueNorm(vd.cast<long double>()) << "\n";
277   std::cout << "pblueNorm\t"  << pblueNorm(vf)  << "\t" << pblueNorm(vd)  << "\t" << blueNorm(vf.cast<long double>()) << "\t" << blueNorm(vd.cast<long double>()) << "\n";
278   std::cout << "lapackNorm\t" << lapackNorm(vf) << "\t" << lapackNorm(vd) << "\t" << lapackNorm(vf.cast<long double>()) << "\t" << lapackNorm(vd.cast<long double>()) << "\n";
279   std::cout << "twopassNorm\t" << twopassNorm(vf) << "\t" << twopassNorm(vd) << "\t" << twopassNorm(vf.cast<long double>()) << "\t" << twopassNorm(vd.cast<long double>()) << "\n";
280 //   std::cout << "bl2passNorm\t" << bl2passNorm(vf) << "\t" << bl2passNorm(vd) << "\t" << bl2passNorm(vf.cast<long double>()) << "\t" << bl2passNorm(vd.cast<long double>()) << "\n";
281 }
282 
main(int argc,char ** argv)283 int main(int argc, char** argv)
284 {
285   int tries = 10;
286   int iters = 100000;
287   double y = 1.1345743233455785456788e12 * internal::random<double>();
288   VectorXf v = VectorXf::Ones(1024) * y;
289 
290 // return 0;
291   int s = 10000;
292   double basef_ok = 1.1345743233455785456788e15;
293   double based_ok = 1.1345743233455785456788e95;
294 
295   double basef_under = 1.1345743233455785456788e-27;
296   double based_under = 1.1345743233455785456788e-303;
297 
298   double basef_over = 1.1345743233455785456788e+27;
299   double based_over = 1.1345743233455785456788e+302;
300 
301   std::cout.precision(20);
302 
303   std::cerr << "\nNo under/overflow:\n";
304   check_accuracy(basef_ok, based_ok, s);
305 
306   std::cerr << "\nUnderflow:\n";
307   check_accuracy(basef_under, based_under, s);
308 
309   std::cerr << "\nOverflow:\n";
310   check_accuracy(basef_over, based_over, s);
311 
312   std::cerr << "\nVarying (over):\n";
313   for (int k=0; k<1; ++k)
314   {
315     check_accuracy_var(20,27,190,302,s);
316     std::cout << "\n";
317   }
318 
319   std::cerr << "\nVarying (under):\n";
320   for (int k=0; k<1; ++k)
321   {
322     check_accuracy_var(-27,20,-302,-190,s);
323     std::cout << "\n";
324   }
325 
326   y = 1;
327   std::cout.precision(4);
328   int s1 = 1024*1024*32;
329   std::cerr << "Performance (out of cache, " << s1 << "):\n";
330   {
331     int iters = 1;
332     VectorXf vf = VectorXf::Random(s1) * y;
333     VectorXd vd = VectorXd::Random(s1) * y;
334     VectorXcf vcf = VectorXcf::Random(s1) * y;
335     BENCH_PERF(sqsumNorm);
336     BENCH_PERF(stableNorm);
337     BENCH_PERF(blueNorm);
338     BENCH_PERF(pblueNorm);
339     BENCH_PERF(lapackNorm);
340     BENCH_PERF(hypotNorm);
341     BENCH_PERF(twopassNorm);
342     BENCH_PERF(bl2passNorm);
343   }
344 
345   std::cerr << "\nPerformance (in cache, " << 512 << "):\n";
346   {
347     int iters = 100000;
348     VectorXf vf = VectorXf::Random(512) * y;
349     VectorXd vd = VectorXd::Random(512) * y;
350     VectorXcf vcf = VectorXcf::Random(512) * y;
351     BENCH_PERF(sqsumNorm);
352     BENCH_PERF(stableNorm);
353     BENCH_PERF(blueNorm);
354     BENCH_PERF(pblueNorm);
355     BENCH_PERF(lapackNorm);
356     BENCH_PERF(hypotNorm);
357     BENCH_PERF(twopassNorm);
358     BENCH_PERF(bl2passNorm);
359   }
360 }
361