[llvm-commits] [PATCH] 64 functional units

Evan Cheng evan.cheng at apple.com
Tue Jun 19 11:48:29 PDT 2012


Are you sure this is the right way to go? That's a lot of functional units and this change is probably increasing LLVM's memory foot print.

The InstrStage data structure is already poorly packed even before this change:
  unsigned Cycles_;  ///< Length of stage in machine cycles
  unsigned Units_;   ///< Choice of functional units
  int NextCycles_;   ///< Number of machine cycles to next stage
  ReservationKinds Kind_; ///< Kind of the FU reservation

We probably want to reduce the size of Cycles_ and NextCycles_ down to i16. This change is not helping. :-(

Evan

On Jun 18, 2012, at 7:34 PM, Hal Finkel wrote:

> On Mon, 18 Jun 2012 02:19:51 -0700
> Bill Wendling <wendling at apple.com> wrote:
> 
>> This looks fine.'
>> -bw
> 
> Thanks! r158679.
> 
> -Hal
> 
>> 
>> On Jun 13, 2012, at 7:04 AM, Hal Finkel wrote:
>> 
>>> Please review the attached patch which changes the datatype used to
>>> hold the function-units bitmask from unsigned to uint64_t. In order
>>> to describe some of the recent PowerPC chips (with all of their
>>> relevant multi-stage pipelines), I need more than 32 FUs.
>>> 
>>> Thanks again,
>>> Hal 
>>> 
>>> -- 
>>> Hal Finkel
>>> Postdoctoral Appointee
>>> Leadership Computing Facility
>>> Argonne National Laboratory
>>> <64units_patch.patch>_______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>> 
> 
> 
> 
> -- 
> Hal Finkel
> Postdoctoral Appointee
> Leadership Computing Facility
> Argonne National Laboratory
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