RISC-V Bootstrap problems

[juzhe.zhong@rivai.ai]

>> It's highly unlikely we'll switch from the mechanisms we're using.
>>They're pretty deeply embedded into how all the ports are developed and
>>work.

We just take a look at the build file. It seems that the functions generated by define_insn 
are so many. Do we have the chance optimize it?
I believe the tablegen mechanism in LLVM is well optimized in case of generated files and functions
so that they won't be affected to much as instructions go up.

Thanks.


juzhe.zhong@rivai.ai
 
From: Jeff Law
Date: 2023-05-25 12:07
To: juzhe.zhong@rivai.ai; kito.cheng
CC: jeffreyalaw; palmer; vineetg; Kito.cheng; gcc-patches; Patrick O'Neill; macro
Subject: Re: RISC-V Bootstrap problems
 
 
On 5/24/23 21:54, juzhe.zhong@rivai.ai wrote:
>  >> IIRC LLVM is using the table driven mechanism, so it's less impact 
> on the
>>>compilation time when the instruction becomes more and more.
> Oh, I see. Could you share more details ?
> Maybe we can support this in GCC.
It's highly unlikely we'll switch from the mechanisms we're using. 
They're pretty deeply embedded into how all the ports are developed and 
work.
 
The first step is to figure out what's exploding.  I strongly suspect 
we'll be able to see this in a cross, but again, the magnitude will be 
smaller.
 
jeff