target/arm/translate-a64: Fix mishandling of size in FCMLA decode

In disas_simd_indexed(), for the case of "complex fp", each indexable
element is a complex pair, so the total size is twice that indicated
in the 'size' field in the encoding. We were trying to do this
"double the size" operation with a left shift by 1, but this is
incorrect because the 'size' field is a MO_8/MO_16/MO_32/MO_64
value, and doubling the size should be done by a simple increment.

This meant we were mishandling FCMLA (by element) of values where
the real and imaginary parts are 32-bit floats, and would incorrectly
UNDEF this encoding. (No other insns take this code path, and for
16-bit floats it happens that 1 << 1 and 1 + 1 are both the same).

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190129140411.682-3-peter.maydell@linaro.org

0 files changed, 0 insertions, 0 deletions