[boost] uBLAS gcc performance question

From: Simon J. Julier (sjulier_at_[hidden])
Date: 2002-06-25 08:10:28

Does anybody know a "good" set of command line options which should be used 
to compile uBLAS? I compiled the benchmarks using cygwin gcc 3.1, running 
under Win2k with the "-O2" option. I see a significant difference in 
performance. The last test from bench1, multiplying 100x100 matrices 
together, gives the following results:

C array
elapsed: 0.06 s, 94.8906 Mflops
c_matrix safe
elapsed: 0.541 s, 10.5239 Mflops
c_matrix fast
elapsed: 0.54 s, 10.5434 Mflops
matrix<bounded_array> safe
elapsed: 2.324 s, 2.44984 Mflops
matrix<bounded_array> fast
elapsed: 2.333 s, 2.44039 Mflops
matrix<unbounded_array> safe
elapsed: 2.444 s, 2.32956 Mflops
matrix<unbounded_array> fast
elapsed: 2.463 s, 2.31159 Mflops
matrix<std::vector> safe
elapsed: 2.474 s, 2.30131 Mflops
matrix<std::vector> fast
elapsed: 2.493 s, 2.28377 Mflops

The absolute values of the Mflops reflect the fact that I'm using a slow 
computer (Pentium II, 333MHz). However, the ratio of the Mflops is fairly 
consistent across all of the tests.

Any suggestions would be welcome.

Cheers,

Simon

A=3D[=0A   4.6526e-01   5.1705e-01   2.0033e+00=0A   5.1705e-01   7.7208e-01=
   4.6114e+00=0A   2.0033e+00   4.6114e+00  =
 4.8358e+01];=0A=0AA=3DA(1:2,1:2);=0A=0AB=3D[=0A   9.9836e-01  -3.1359e-02=
=0A  -3.1359e-02   4.0164e-01];=0A=0A%A=3Deye(2);=0A=0A%B=3D[1 0;0=
 2];=0A=0A=0A=0A[xa,ya]=3Dcovpts([0;0],A,40);=0A[xb,yb]=3Dcovpts([0;0],B,40)=
;=0A=0Afigure(1)=0Ahold off=0Aplot(xa,ya)=0Ahold=
 on=0Aplot(xb,yb)=0An=3D8;=0A=0AD=3Dinv(inv(A)+inv(B));=0Atrace(D)=0A=0A[xd,=
yd]=3Dcovpts([0;0],D,40);=0A=0Aplot(xd,yd,':');=0A=
 =0A[d,D]=3DbinGI([0;0],A,[0;0],B,eye(2));=0Atrace(D)=0A=0A[xd,yd]=3Dcovpts(=
[0;0],D,40);=0A=0Aplot(xd,yd,'--');=0A=0Astop=0A=0A=0A%handle=3Dget(gca);=0A=
%plot_handles=3Dget(handle,'Children');=0A=0A=0Afor a =3D 0:1:n=0A	for b =3D=
 0 : 0.25 : 1.0=0A	c =3D 2 * pi * a / n;=0A	T =3D b*[cos(c) -sin(c); sin(c)=
 cos(c)];=0A	C =3D sqrtm(A) * T * sqrtm(B);=0A	if min(eig([A C;C'=
 B])<0)=0A		eig([A C;C' B])=0A	end;=0A	S =3D A + B - C - C';=0A	W =3D (A -=
 C) * pinv(S);=0A	D =3D A - W * S * W';=0A	if=
 (b=3D=3D0)=0A=
        =
        plot(xd,yd,'-','Linewidth',1.5);=0A=
        =
        %plot_handles=3Dget(handle,'Children');=0A=
        =
        %set(plot_handles(1),'LineWidth',1);=0A=
        =
        %set(plot_handles(2),'LineWidth',1);=0A=
        =
        %set(plot_handles(3),'LineWidth',1);=0A=
        else=0A		plot(xd,yd,'--');=0A	end;=0A	drawnow;=0A	end;=0Aend;=0A=0Afor a =
=3D0 : 0.25 : 0,=0A	D =3D inv(a*inv(A) +(1-a)*inv(B));=0A	[xd,yd]=3Dcovpts([=
0;0],D,40);=0A	plot(xd,yd,'r');=0A	drawnow;=0Aend;=0A