On 4/11/21 10:08 PM, David Gibson wrote:
Not directly related to what you're trying to accomplish here, but the whole vscr_sat thing looks really weird. I have no idea why we're splitting out the storage of VSCR[SAT] for the TCG case at all. If you wanted to clean that up as a preliminary, I'd be grateful.
That's about efficiently implementing the vector saturation instructions in TCG. See GEN_VXFORM_SAT in translate/vmx-impl.c.inc.
The SAT bit is represented as a vector that e.g. compares the result of addition with the result of saturating addition. We don't need to resolve that to a single bit until the VSCR register is read.
r~