[Qemu-ppc] [PATCH] Fix QEMU PPC e500v1 efscmp* instructions

[Imran, Talha]

Hi Everyone,

Please find attached a patch which fixes handling in QEMU PPC e500v1 for efscmp*
instructions. This was the cause of over 400 FAILs for this CPU while running
GCC testsuite, which have been fixed.

Value for Condition Registers (CR) being set in QEMU was different from
the value observed on hardware.

I have not managed to find a documentation describing the behaviour of
e500 cores for these instructions. However, the behaviour on
MPC8548-CDS target was observed by dumping registers to stdout, while
running executables from uboot.

These instructions are used by GCC only when compiling for te500v1 multilib; hence no
effect on other PPC CPUs (603, 7400 etc.)

A comparison of GCC v5.2.0 testsuite results summary (number of FAILs) is as follows:

CPU = te500v1
without patch: 699
with patch: 193

CPU = e500v2
without patch: 225
with patch: 225

Is this OK to commit? Comments and suggestions are welcome.

Thanks,
Talha Imran

ppc-efscmpgt.patch
Description: ppc-efscmpgt.patch