[Qemu-devel] [PATCH] ppc32 guests: fix computation of XER.{CA, OV} in addme, subfme, mullwo

[Julian Seward]

For ppc32 guests, computation of XER.CA and XER.OV in some obscure
cases is incorrect.  At least, it doesn't produce the same results
as a real MPC7447, and doesn't appear to be in accordance with the
instruction set documentation.

The attached patch fixes it:

* addme{o}{.}, subfme{o}{.}: compute XER.CA correctly

* mullwo{.}: sign extend arguments before doing 64-bit
  multiply, so as to make the XER.OV computation correct

I suspect the handling of the 64-bit equivalents is similarly borked,
but I haven't checked so far.

J

qemu-ppc32-fix-xer-ca-obscure-cases.diff
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