Example: In-line maths calculation, in internal memory

[Dr.BeauWebber]

[Dr.BeauWebber]

[shodruk]

[Hoernchen]

[Dr.BeauWebber]

[aolofsson]

More often than not, when things run really slow, it's because code is being fetched out of external. Any PC address above 0x000xxxxx is going to slow things down by >100X.

Can you try this just to make sure all the critical code is running out of local?

1.) e-ojdump -D "your_epiphany.elf" > dump (tar and attach)
2.) e-run --trace "your_epiphany.elf" > trace (tar and attach)

Thanks,
Andreas

[Dr.BeauWebber]

Ah, thanks.
Ben has asked to reclaim access to their hardware, but I assume I can do this test on other hosts :
Can I just do the objdump and trace from a simple a.out file, as opposed to creating the actual Epiphany .elf files ?
I certainly get assembly code when I try.
If not, I am building a test Arm installation on a Raspberry Pi, to help validate the latest changes to the aplc compiler, and I could recreate the Epiphany code there.

[ysapir]

a.out is just the default name for the executable generated by the gnu compilers, if you don't specify an explicit name.

In your question, do you mean if you could analyze the executable generated by ARM/x86 compiler instead of Epiphany compiler? If so, the answer is obviously no, since the binaries are different between platforms and there is limited amount of info that you can learn from that. However, you don't really need the actual hardware to do your test. You can work with the cross-build tools on your PC (esdk.4.13.04.24). e-objdump will work on the executable generated by e-gcc on any platform. e-run is a simulator, thus no need for the hardware.

[Dr.BeauWebber]

[ysapir]

A quick look at your objdump listing shows that all of your code is being run from external memory. Also note that for the specific code you attached, no LDF was used in compilation, so all addresses are resolved using the default linker LDF, where ext. mem is at 0x80000000. I am surprised if you manage to run this executable on a real hardware.