[llvm-commits] Patch for review: Speeding up ScheduleDAG computations

[Roman Levenstein]

Hi Evan,

2008/3/6, Evan Cheng <evan.cheng at apple.com>:
>  > There is still one moment, where I'm not quite sure, but in any case
>  > it is not worse than in the repository. It is related to Dan's comment
>  > about updates of PredSU->CycleBound in the CapturePred function. I
>  > inserted for now the following comment:
>  > // TODO: Check that PredSU is not in the AvailableQueue at this
>  > moment!
>  > The problem is that currently there is no way to check if a node in
>  > the AvailableQueue, AFAIK. But if it is, then the node should be
>  > removed and inserted back into the queue to preserve the ordering. All
>  > tests compile without problems, but I'd still like to be sure that
>  > when this comment line is reached, the node is not in the queue.
>
>
> There is a way. When a node is inserted into the AvailableQueue, the
>  isAvailable field is set to true. Can you update the patch?

Yes. I know this method. But if you look at the implementation of the
CapturePred, it already checks for isAvailable and removes  the node
conditionally, if it is not isPending. So, the question is, can it
happen, that after those conditional checks the node is not removed
yet, i.e. the node has isAvailable set, and isPending set and is in
the queue?

>  >
>  >> CodeGen/X86/2007-07-03-GR64ToVR64.ll
>  >
>  > OK. This one is not a real failure. Basically, the names of registers
>  > are swapped (see below), as far as I understand. Without my changes
>  > %rdi should be loaded into %mm1 and %rsi into %mm0.
>  >
>  >        .text
>  >        .align  16
>  >        .globl  foo
>  >        .type   foo, at function
>  > foo:
>  >        movd    %rdi, %mm0
>  >        movd    %rsi, %mm1
>  >        paddusw %mm1, %mm0
>  >        movq    %mm0, R
>  >        emms
>  >        ret
>  >        .size   foo, .-foo
>
>
> Yes, that's silly. Please change the run lines to grep for movd and
>  paddusw instead.

Will do.

- Roman