3 ms·
of course what you do is run the 32-bit decoders and 16-bit decoders in parallel making the same internal instruction bundle formats - then you fuse those bundl
by Taniwha 6y ago
of course what you do is run the 32-bit decoders and 16-bit decoders in parallel making the same internal instruction bundle formats - then you fuse those bundles.
BTW your analysis ignores that in the compressed ISA you can have 4-byte instructions aligned on a 2 byte boundary
- imtringued 6y agoThat kind of destroys most benefits of fixed length instructions. I expected compressed instructions to be aligned on 4 bytes which means your 32bit decoder merely has to have a 2x 16bit fallback but nope, now you gotta decode with a 2byte granularity and join two 2 byte instruction pieces into a 4 byte instruction.
- Taniwha 6y agoYes but it's just a 2:1 mux in the path, it's not like you need twice as many 32bit decoders