Branch predictor in cv32e40p core will take more time.

[Attaullah786]

I integrated code of branch predictor in cv32e40p core and try to simulate hello world test in it but it will not give the tests also did not give the error.

[pascalgouedo]

Hi, You have to move cv32e40p directory somewhere else and use following option when launching make command: CV_CORE_PATH=<your path>/cv32e40p

[MikeOpenHWGroup]

Hi @Attaullah786, did @pascalgouedo answer your question? If so, please close this Issue. If you do not comment within one week, this Issue will be closed.

[Attaullah786]

Thanks for your answer. When i run the hello world test there is no information about CPI for the test cases. Kindly give me insight about the test cases that gave clock cycles. Thanks

[MikeOpenHWGroup]

Hi @Attaullah786'

there is no information about CPI for the test cases

What do you mean by "CPI"?

Kindly give me insight about the test cases that gave clock cycles.

We have no testcases that track clock cycles and there is no function in the testbench that does this. We do not have any verification requirements to measure clock cycles, so this was not added. Why do you need it?

[pascalgouedo]

Even if clock cycles are not useful for verification purpose, we do measure them in the benchmarks.

You can find a simple example of that in matmul_32b_int one.

[Attaullah786]

I implemented a dynamic w but branch predictor in cv32e40p core. Now I have to analyze whether the branch predictor reduced the execution time for some branch instructions or not. So I need that execution time. Is there any process in the core already to find it?

[MikeOpenHWGroup]

The CV32E40P implements the mcycle and minstret CSRs. Your test-program could query these.

[pascalgouedo]

I implemented a dynamic w but branch predictor in cv32e40p core. Now I have to analyze whether the branch predictor reduced the execution time for some branch instructions or not. So I need that execution time. Is there any process in the core already to find it?

Already answered above with matmul_32b_int example. To characterize your branch predictor, I advise you to use Embench Iot 0.5 that you can launch on uvm test-bench.