Bastian Koppelmann
b00aa8ecbc
Add helpers:
* madd64_q_ssov: multiply two 32 bit q-format number, add them with a
64 bit q-format number and saturate.
* madd32_q_add_ssov: add two 64 bit q-format numbers and return a 32 bit
result.
* maddr_q_ssov: multiplay two 32 bit q-format numbers, add a 32 bit
q-format number and saturate.
* maddr_q: multiplay two 32 bit q-format numbers and add a 32 bit
q-format number.
Note: madd instructions in the q format can behave strange, e.g.
0x1 + (0x80000000 * 0x80000000) << 1 for 32 bit signed values does not cause an
overflow on the guest, because all intermediate results should be handled as if
they are indefinitely precise. We handle this by inverting the overflow bit for
all cases: a + (0x80000000 * 0x80000000) << 1.
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Read the documentation in qemu-doc.html or on http://wiki.qemu-project.org - QEMU team