The Arm ARM specifies that for Thumb encodings of the various plain
store insns, if the Rn field is 1111 then we must UNDEF. This is
different from the Arm encodings, where this case is either
UNPREDICTABLE or has well-defined behaviour. The exclusive stores,
store-release and STRD do not have this UNDEF case for any encoding.
Enforce the UNDEF for this case in the Thumb plain store insns.
Fixes: https://bugs.launchpad.net/qemu/+bug/1922887
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210408162402.5822-1-peter.maydell@linaro.org
8196fe9d83