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Re: Improving reload inheritance code generation and predictability
- From: Bernd Schmidt <bernds at codesourcery dot com>
- To: Jeff Law <law at redhat dot com>
- Cc: gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 18 Nov 2010 20:34:32 +0100
- Subject: Re: Improving reload inheritance code generation and predictability
- References: <4CE53C3D.6020001@redhat.com>
On 11/18/2010 03:46 PM, Jeff Law wrote:
> Basically we start searching forward in the stream from the current insn
> needing a reload noting uses of spill regs as we go.
Isn't this quadratic in the number of insns?
> The further away
> from the insn needing reloads the spill reg is used the more desirable
> that spill reg becomes. If we can't find all the spill regs before
> reaching the end of the block, the remaining spill regs are considered
> the most desirable and we allocate these stragglers in the round-robin
> fashion.
Ideally we'd allocate the valuable ones only to reloads which we know
we'll want to inherit in the future.
Bernd