ref: f5688dd6c9bfb6cee00f2c5e5f190d7a2ffaa6c6
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