[Bug report] Kronos overcounts the retired instructions

[flaviens]

Hi there!

Bug description

I think I found a bug not described in the issues and PRs in this repo. minstret seems to overcount.

Example snippet

The stored value of t0 should be 0, however with Kronos it is 1.

  .section ".text.init","ax",@progbits
  .globl _start
  .align 2
_start:

  li a0, 0x10

  csrrw zero, minstret, zero
  csrrw t0, minstret, zero

  sw t0, (a0)
  sw zero, (zero)

infinite_loop0:
  j infinite_loop0

Notes

The same bug is found in BOOM and Vexriscv.

Thanks!