/* * Signed 64-bit integer multiply. * * For JIT: op1 in r0/r1, op2 in r2/r3, return in r0/r1 * * Consider WXxYZ (r1r0 x r3r2) with a long multiply: * WX * x YZ * -------- * ZW ZX * YW YX * * The low word of the result holds ZX, the high word holds * (ZW+YX) + (the high overflow from ZX). YW doesn't matter because * it doesn't fit in the low 64 bits. * * Unlike most ARM math operations, multiply instructions have * restrictions on using the same register more than once (Rd and Rm * cannot be the same). */ /* mul-long vAA, vBB, vCC */ mul ip, r2, r1 @ ip<- ZxW umull r9, r10, r2, r0 @ r9/r10 <- ZxX mla r2, r0, r3, ip @ r2<- YxX + (ZxW) add r10, r2, r10 @ r10<- r10 + low(ZxW + (YxX)) mov r0,r9 mov r1,r10 bx lr