[patch] RFC: Hook for insn costs?

[Richard Henderson]

On 07/17/2017 12:20 AM, Richard Biener wrote:
> On Sun, Jul 16, 2017 at 12:51 AM, Segher Boessenkool
>> Now what should it take as input?  An rtx_insn, or just the pattern
>> (as insn_rtx_cost does)?
> 
> Is there any useful info on the other operands of an rtx_insn?  If not
> then passing in the pattern (a rtx) might be somewhat more flexible.
> Of course it's then way easier to confuse rtx_cost and insn_cost ...

A lot of really complex by-hand pattern matching goes away if you know the 
instruction is valid, and you can look up an insn attribute.  That suggests 
passing the insn and not the PATTERN.


r~