On Sat, May 21, 2016 at 08:59:55PM -0400, Alvin Starr wrote:
Microcode also helped with reusing gates. For example coding a multiply instruction as a loop of adds and shifts. now days most processors have ripple multipliers.
Sure speeds up multiplies though.
The x86 although popular is not the best example of a CISC design. The National Semiconductor NS32000 which I believe was the first production 32bit microprocessor. The current x86 64bit is just the last of a long set of patches from the 8086.
I would change that to 4004.
I believe the last original CPU design from intel was the iAPX 432.
Maybe. And even though it flopped they still insisted on trying such a design in the Itanium again. And again it flopped and didn't work. When will intel learn that compile time scheduling is NEVER going to happen in general purpose use?
Intel had plans to dead end the x86 in favour if the Itanium as the step up to 64bit but AMD scuttled those plays by designing a 64 but instruction set addition.
The Itanium being an awful design probably did most of the damage.
A number of Risc processors still live on mostly in embedded applications.. MIPS. ARM. Power(IBM)
Well IBM in the server and HPC market, Freescale (well NXP now) in the embedded market. Well AppliedMicro does a bit of powerpc still too.
It was a shame to see the end of the Alpha it was a nice processor and opened the door to NUMA interprocessor interconnects that just came into the the Intel world.
Unfortunately a case of horrible management and being too worried about hurting sales of your former product even though your compretitors didn't mind hurting it at all. -- Len Sorensen