Numerical discrepancy between 2 project configurations in fltpnt ('Debug' vs 'float')

[D.Mihai]

I am running C code compiled and linked in two different configurations of the same 'project' with exactly the same settings (source/header files, include directories, libraries, additional dependencies, etc.). The two configurations are 'Debug' and 'float'; both are in floating point arithmetic, which is selected in preprocessing (a macro that selects fixed or floating point arithmetic is not defined, leading to compiling/linking in floating point). The numerical results differ between the two runs; e.g., an array element that is a complex-number structure (with two float members---real and imag) shows significantly different numeric values after the two runs.

Has anybody come across a similar problem? I would appreciate any insight, or suggestions for where to look---thank you in advance.

[Andrew Hain]

Hallo.

Are there any differences in optimisation or preprocessor symbols?

[D.Mihai]

Hello, I was away from the site (lost password; had to see to other tasks), sorry for the silence...

Preprocessor Definitions are "WIN32;_DEBUG;_CONSOLE" in 'Debug' and none in 'float'.

Optimizations are disabled in 'Debug' and "Maximize Speed (/O2)" in 'float'.

[Paul McKenzie]

Has anybody come across a similar problem? I would appreciate any insight, or suggestions for where to look---thank you in advance.

Maybe it's a bug in your program.

Regards,

Paul McKenzie

[D.Mihai]

Thank you, I will look again into it.

Regards,

Mihai Ionescu

[cilu]

I am running C code compiled and linked in two different configurations of the same 'project' with exactly the same settings (source/header files, include directories, libraries, additional dependencies, etc.). The two configurations are 'Debug' and 'float'; both are in floating point arithmetic, which is selected in preprocessing (a macro that selects fixed or floating point arithmetic is not defined, leading to compiling/linking in floating point). The numerical results differ between the two runs; e.g., an array element that is a complex-number structure (with two float members---real and imag) shows significantly different numeric values after the two runs.

Has anybody come across a similar problem? I would appreciate any insight, or suggestions for where to look---thank you in advance.

I suggest reading this FAQ: http://www.codeguru.com/forum/showthread.php?t=323835.