The only commands that have the 5th bit required to address XR16 are S32M2I/S32I2M.
I can split it out into a separate utility function and put a conditional into the S32M2I/S32I2M functions if you are more comfortable with that. -----Original Message----- From: Aleksandar Markovic <amarko...@wavecomp.com> Sent: Tuesday, August 28, 2018 12:53 PM To: Janeczek, Craig <jancr...@amazon.com>; qemu-devel@nongnu.org Cc: aurel...@aurel32.net Subject: Re: [PATCH v3 3/8] target/mips: Add MXU instructions S32I2M and S32M2I > > This does not handle the case xra == XR16. > I do not see where the case is un-handled. XR16 maps to index 15 in the > mxu_gpr array. But, XR16 has its own rules for read/write, and you are treating it just as a regular register.