The RVV kernel generation script uses the provided LMUL to increase the number of accumulator registers.
Since the effect of the LMUL is to group together the vector registers into larger ones, it actually should be used as a multiplier in the calculation of vlenmax.
At the moment, no matter what LMUL is provided, the generated kernels would only set the maximum number of vector elements equal to VLEN/SEW.
Commit changes the use of LMUL to properly adjust vlenmax. Note that an increase in LMUL results in a decrease in the number of effective vector registers.
* fix multiple numerical stability and corner case issues
* add a script to generate arbitrary gemm kernel shapes
* add a generic zvl256b target to demonstrate large gemm kernel unrolls
Octavian Maghiar
Sergei Lewis