"Ron Nicholson" <[EMAIL PROTECTED]> wrote in message news:108293@palm-dev-forum... > >One other point to note is that the DB processor cannot multiply 32 bit > >integers. This is emulated transparently by the compiler, so it isn't > >immediately obvious. Watch out for 32 bit multiplies. > Actually, the 68000 CPU core cannot do any hardware multiplies; > all multiplies are emulated. There are 68k 16x32 MULU and MULS > instructions, but they emulated in microcode by double pumping > the 16-bit adder, and thus takes 40 or 42 clock cycles to complete.
Err.. I'd say you're nitpicking here. IIRC many of the 68k instructions take more than 10 cycles to complete, I just wouldn't call them "emulated" if the CPU natively knows what to do with them. What I'm talking about is 32x32 multiplies which effectively take a several hundred clock cycles to execute. (IIRC, CW creates an inline function which includes at least three MUL* opcodes.) Alan -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
