The initial implementation of the MVE VRMLALDAVH and VRMLSLDAVH
insns had some bugs:
* the 32x32 multiply of elements was being done as 32x32->32,
not 32x32->64
* we were incorrectly maintaining the accumulator in its full
72-bit form across all 4 beats of the insn; in the pseudocode
it is squashed back into the 64 bits of the RdaHi:RdaLo
registers after each beat
In particular, fixing the second of these allows us to recast
the implementation to avoid 128-bit arithmetic entirely.
Since the element size here is always 4, we can also drop the
parameterization of ESIZE to make the code a little more readable.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-3-peter.maydell@linaro.org