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[Solved] Default compiler flags [message #40147]

Fri, 21 June 2013 09:57

keltor
Messages: 73
Registered: February 2012

Member

Hello all,

I have been working on a program to make some numerical simulations. The other day, just for kicks, I decided to port a part of it into our beloved U++, simply because I like TheIde. I have witnessed, much to my dismay, that the program, compiled in U++, is slower than the exact same program compiled with Code::Blocks, almost by a factor of two!

Edit: Actually, I made a blunder: I was comparing 64-bit code to 32-bit. So it's not a factor of two, but it's still noticeable.

The reason, it seems, is simply that U++ adds default flags depending on the type of compilation (Optimal/Size/Speed) that interfere with the optimisations that I have selected myself. For instance, in Speed mode, U++ chooses -Gy (function-level optimisation), which seems to collide with my choice of -GA (whole-program optimisation). And sadly, it adds the default options at the end of the compilation command, thus overriding the ones I specify.

Does anyone know of a way to tame U++ into accepting my optimisations?

Thanks,

Kel

[Updated on: Tue, 01 October 2013 16:13]

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