# [DRAFT] Twin Multiply and Add Doubleword

VA-Form

* madded RT,RA,RB,RC

Pseudo-code:

    <!-- SVP64: RA,RB,RC,RT have EXTRA2, RS as below   -->
    <!-- bit 8 of EXTRA is clear: RS.[s|v]=RT.[s|v]+VL -->
    <!-- bit 8 of EXTRA is set  : RS.[s|v]=RC.[s|v]    -->
    prod[0:127] <- (RA) * (RB)
    sum[0:127] <- EXTZ(RC) + prod
    RT <- sum[64:127]
    RS <- sum[0:63]

Special Registers Altered:

    None

# [DRAFT] Twin Divide/Modulo Quad Unsigned

VA-Form

* divmod2du   RT,RA,RB,RC

Pseudo-code:

    <!-- SVP64: RA,RB,RC,RT have EXTRA2, RS as below   -->
    <!-- bit 8 of EXTRA is clear: RS.[s|v]=RT.[s|v]+VL -->
    <!-- bit 8 of EXTRA is set  : RS.[s|v]=RC.[s|v]    -->
    if ((RA) <u (RB)) & ((RB) != [0]*XLEN) then
        dividend[0:(XLEN*2)-1] <- (RC) || (RA)
        divisor[0:(XLEN*2)-1] <- [0]*XLEN || (RB)
        result <- dividend / divisor
        modulo <- dividend % divisor
        RT <- result[XLEN:(XLEN*2)-1]
        RS <- modulo[XLEN:(XLEN*2)-1]
        overflow <- 0
    else
        overflow <- 1
        RT <- [1]*XLEN
        RS <- [0]*XLEN

Special Registers Altered:

    None