Re: [f-cpu] Instruction census

[cedric <cedric.bail@free.fr>]

Hi,

>   98104 instructions total
>   13079 move            13.3% ( 13.3% total)
>   10846 load            11.0% ( 24.3% total)
>    3545 storei           3.6% ( 78.1% total)
>    3533 loadi            3.6% ( 81.7% total)
>    3459 store            3.5% ( 85.3% total)

>   21383 lsu             21.7% ( 21.7% total)

	Did you use the new register allocator for this test ? I hope it will change 
a lot of result for RISC CPU, and perhaps it will remove some loadi/storei, 
but I don't know the impact for load/store (Did you have an idea why we have 
3 time more load than store, but loadi and storei are very close) .

> Goals for optimization (IMHO):
> 	- reduce number of load/store instructions

Perhaps it's more easy for loadi/storei, but I really want to know where all 
this load came from.

> 	- increase number of conditional moves (in favor of jmp{cc})
> 	- avoid shift-and-add where mul/mac is faster

Hum, what about a "mac"shift instruction ?

> 	- make use of divrem[s] instruction
> 	- make use of SIMD instructions

I think that gcc support SIMD only for string function, it's really hard to 
give a real SIMD support to gcc.

Cedric
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