register allocation

[Daniel Berlin]

On May 2, 2004, at 9:27 AM, Qiong Cai wrote:

> Hi,
>
> I'm going to study register allocation in GCC.

What do you mean "study"?

To be honest, we already know a lot about GCC register allocation, it's 
shortcomings, etc.
This is true for both allocators.

>   Currently GCC has
> two register allocators.  Here some questions:

> * Is there any performance results(eg. spec2k results) available for
> these two allocators?
Yes, for various platforms.
Check the mailing list archives.

> * Besides those ra*.[c,h] files, is tthere any other source files 
> related
> to register allocation?
local-alloc, global-alloc (the "old" allocator)


> * Which function, if available, calcuate the register pressure,
> which is the defined as the max number of live variable for a basic 
> block?
>
None.

> Many thanks.
>
> Qiong