[Halld-offline] stl vector

[David Lawrence]

Hi Paul,

     I actually tried your code on my 2.33GHz Core 2 duo laptop running 
OS X 10.5 and got a much larger discrepancy. However, when I turned on 
optimization, the discrepancy disappeared. Have you tried this test with 
optimization turned on?


No Optimization
--------------
1:13.83 STL
0:04.83 double array

-O
--------------
0:03.63 STL
0:03.64 double array

-O2
--------------
0:03.68 STL
0:03.64 double array



Full transcript of session is below.

Regards,
-Dave

STL-vector
-------------------
wifi-80-86:STLTest>g++ stl-test.cc -o stl-test
wifi-80-86:STLTest>time ./stl-test
sumXsq = 2.69986e+17
71.068u 0.584s 1:13.83 97.0%    0+0k 0+0io 0pf+0w
wifi-80-86:STLTest>g++ -O stl-test.cc -o stl-test
wifi-80-86:STLTest>time ./stl-test
sumXsq = 2.69986e+17
3.498u 0.031s 0:03.63 96.9%    0+0k 0+0io 0pf+0w
wifi-80-86:STLTest>g++ -O2 stl-test.cc -o stl-test
wifi-80-86:STLTest>time ./stl-test
sumXsq = 2.69986e+17
3.496u 0.033s 0:03.68 95.6%    0+0k 0+0io 0pf+0w


double with malloc
-----------------
wifi-80-86:STLTest>g++ stl-test.cc -o stl-test
wifi-80-86:STLTest>time ./stl-test
sumXsq = 0
4.674u 0.036s 0:04.83 97.3%    0+0k 0+0io 0pf+0w
wifi-80-86:STLTest>g++ -O stl-test.cc -o stl-test
wifi-80-86:STLTest>time ./stl-test
sumXsq = 0
3.498u 0.032s 0:03.64 96.7%    0+0k 0+0io 0pf+0w
wifi-80-86:STLTest>g++ -O2 stl-test.cc -o stl-test
wifi-80-86:STLTest>time ./stl-test
sumXsq = 0
3.489u 0.027s 0:03.64 96.1%    0+0k 0+0io 0pf+0w


On 5/9/11 11:58 AM, Paul Eugenio wrote:
> g++     stl-test.cc   -o stl-test