Sjlj vs dwarf2 on mingw for octave

[Tatsuro MATSUOKA]

Hello
According to README-gcc-tdm.txt in MiGW GCC by TDM, there exists the following 
description,

***********
Until recently, only SJLJ has been available for the Windows
platform. This affects you, the end user, primarily in programs that throw and
catch exceptions. Programs which utilize the DW2 unwind method handle exceptions
much more quickly than programs which utilize the SJLJ method. However, the DW2
method increases code size by a noticeable amount, and additionally cannot yet
unwind (pass exceptions) through "foreign" stack frames: stack frames compiled
by another non-DW2-enabled compiler, such as OS DLLs in a Windows callback.
***********


I have tested this the following the code, 


#script testOregoB.m
function dx = oregonator_m (x, t)

  dx = zeros (3, 1);

  dx(1) = 77.27*(x(2) - x(1)*x(2) + x(1) - 8.375e-06*x(1)^2);
  dx(2) = (x(3) - x(1)*x(2) - x(2)) / 77.27;
  dx(3) = 0.161*(x(1) - x(3));

end

% The test of `oregonator'.
x0 = [ 4; 1.1; 4 ];
%t = [0, logspace (-1, log10(303), 150), logspace (log10(304), log10(500), 
150)];
%t=linspace(0,500,1000);
t=0:0.5:500;
ts=cputime();
y = lsode ('oregonator_m', x0, t);
cputime()-ts
plot (t',y(:,1),"",t',y(:,2),"",t',y(:,3));
#*******end of script

Sjlj octave-3.0.4RC7
octave.exe:2> testOregoB
ans =  1.5469

Dwarfs octave-3.0.4RC5
octave:3> testOregoB
ans =  1.1875

Optimizing option
export FFLAGS='-O3 -fomit-frame-pointer'
export CFLAGS='-O3 -fomit-frame-pointer'
export CXXFLAGS='-O3 -fomit-frame-pointer'

For Benjamin Binary of octave-3.0.2
> testOregoB
ans =  1.2344

That is near to 3.0.4RC5 with dwarf2 because Benjamin's binaries are built by 
GCC-4.3.0-TDM-dw2.
The speed of binaries built with dw2 is 25 to 30 % faster than that of sjlj.

This is a just record so that I would not like to say dw2 EH is better than 
sjlj EH.

Regards

Tatsuro  



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