Re: [hatari-devel] Feature request/idea: cycle counting

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Le 31/01/2018 à 02:11, Miro Kropáček a écrit :

On 31 January 2018 at 10:25, Eero Tamminen <oak@xxxxxxxxxxxxxx <mailto:oak@xxxxxxxxxxxxxx>> wrote:

    Hatari already provides that info:

That's true  but this is not what I'm after, at least the use case is different here -- I'm not after profiling of existing code. I just want to write something and know which variant is the fastest without looking into instruction timing tables. Sure, I can do that via the profiling feature but it's so time consuming that it's easier to look it up in the docs, especially if I want to compare one or two instructions. :)


When I want to check that some instructions are correctly emulated cycle-wise, or if I want to see how many cycles a group of instructions is needing in some code, I'm using the cycles already availabe in --trace cpu_disasm.

for example :

cpu video_cyc= 40780 332@ 79 : 00014566 224c MOVEA.L A4,A1 cpu video_cyc= 40784 336@ 79 : 00014568 d2dd ADDA.W (A5)+ [1530],A1

the value after video_cys is the global cycle position since the start of the current VBL. So here we can see that "MOVEA.L A4,A1" takes 40784-40780 cycles.
This works well as long as all the instructions are in the same VBL.

Is that the kind of values you're looking for ?


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