Slow Epiphany

[AndyC]

[aolofsson]

99% sure that you are fetching instructions from external memory directly without realizing it. Please use e-objdump -D "your.elf" to see where your code is placed.
For example, with the constants you used, pretty sure that they get called in as doubles without a n f specifier. i.e. 1.0f If this is the case, then there will be lots of messy double/float conversion (and this code is read from DRAM!)
Andreas

[AndyC]

Hi Andreas,

Thanks very much for the pointers, I will have a look.

Andy

[AndyC]

[AndyC]

[aolofsson]

[sebraa]

I did the same mistake and solved it by the -fsingle-precision-constants compiler option.

[AndyC]

Another nice tip, thanks!

[notzed]

Don't put data in text. Text is code. Data is data.

Oh and don't put your automatic variables in a section either. They should just end up in registers or at worst spill to the stack.

[AndyC]

Hi,

Thanks for the pointers.

I thought it wouldn't matter if I put them in the text section due to the way the epiphany works, why would there be a difference between .text and .data on the epiphany?

The variables were just put in a section as I was trying to make sure the linker was not putting them in slow ram when I was trying to work out why it was going slow.

Cheers

Andy