ref: a7f1bb9a9e1720b22d1fbed16e7527fa2cd0d82c
dir: /sys/src/libc/mips/vlop.s/
TEXT _mulv(SB), $0 MOVW 8(FP), R2 MOVW 4(FP), R3 MOVW 16(FP), R4 MOVW 12(FP), R5 MULU R4, R2 MOVW LO, R6 MOVW HI, R7 MULU R3, R4 MOVW LO, R8 ADDU R8, R7 MULU R2, R5 MOVW LO, R8 ADDU R8, R7 MOVW R6, 4(R1) MOVW R7, 0(R1) RET