[Date Prev][Date Next][Thread Prev][Thread Next]
- Subject: Re: Towards a faster interpreter
- From: Dibyendu Majumdar <mobile@...>
- Date: Thu, 8 Dec 2016 18:37:35 +0000
On 8 December 2016 at 16:47, Roberto Ierusalimschy
>> I have been thinking of ways of making the Ravi interpreter faster
>> without having to resort to assembly code etc. So far one of the areas
>> I have not really looked at is how to improve the bytecode decoding.
>> The main issue is that the operands B and C require an extra bit
>> compared to operand A, so we cannot make them all 8 bits...
> Given a 32- or 64-bit machine, why decoding 8-bit operands would be
> faster/better than 9-bit ones?
I don't know whether the extracting the operands itself will be any
faster. One option might be to map the instruction directly to a
struct as each component will be 8 bytes, but I don't know if that is
better. But there should definitely be savings in the macros RKB() and
RKC() if the opcode itself encoded whether the operand is a constant
I suppose that until I implement and test the performance of various
alternatives it will not be clear whether the changes are worthwhile.