[LLVMdev] [PATCH] Spill Comments

Dan Gohman gohman at apple.com
Mon Sep 14 10:22:42 PDT 2009

Hi Dave,

On Sep 11, 2009, at 3:31 PM, David Greene wrote:

> Attached is a patch to print asm comments for spill information.
> We've discussed the mechanisms before but I wanted to run the
> patch by everyone before I start to commit pieces.

The Offset->FrameIndex mapping seems rather heavy-weight, as
any expense is incurred even when AsmVerbose is off.   Would it
be possible to use MachineMemOperands instead? In theory,
they should already be preserving the needed information.  If
they're not sufficient, could they be improved?

There is work going on to improve the register allocator's ability
to use rematerlialization.  In a world where the register allocator
can aggressively remat misc. loads, will it still be interesting to
identify spill reloads?

You mentioned at one point that you have some scripts which
know how to read some of these comments.  Would it be
possible for you to include these scripts with the patch so that
others can consider your patch in context?


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