Re: [PATCH v2 10/16] tests/tcg: add generic version of float_convs

[Richard Henderson]

On 9/20/19 3:15 AM, Alex Bennée wrote:
> I can't figure out what is meant to be going on with CONVERT_BITS. It
> seems to be implying there is a direct relationship between status flags
> and the exception disable bits. But that is confusing because integer
> overflow (IOV) and float overflow (OVF) are different flags bit I assume
> both suppressed by Overflow Disable (OVFD).

I had failed to notice that the kernel routine plays with INV and not IOV for
the emulation of CVTTQ, so it's the SWCR_TRAP_ENABLE_INV bit that controls
whether CVTTQ/S raises a signal.

Will fix.

> Why are we doing this magic 32 bit shuffling anyway? Is it purely to
> save 32 bits of a mostly empty lower half of the FPCR register?

Yes.  Which is not a great answer, but it was done years ago and there's little
point in changing it back now.


r~