llvm dev - May 2015 - [LLVMdev] MVT (machine value type) for MachineOperand

Hi,

I am writing a small tool to gather some static statistics on machine code
using LLVMs MachineInstr, etc., infrastructure.
My current goal is to count the number of bytes of integer and floating
point data being processed per iteration of a loop.
Now I've ran into the problem that I can't find any obvious way to get
the
actual type of a MachineOperand.

After some digging I noticed that the selection DAG has some type
information and I had a look at the TableGen records that contain this type
info. I started looking into how I could generate some descriptor tables
with that information but TableGen is quite a handfull, and I'd like to
avoid this if I can.

Did I overlook some easy way to get at type information at the
MachineOperand level?

Thanks.
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For the registers on register operands you can query MachineRegisterInfor for
their Class. The registerclass should have a list of possible types (usually
with the same size in bits) assigned.

- Matthias
> On May 28, 2015, at 8:11 AM, Fabian Gruber <fabian.gruber at
fadeopolis.com> wrote:
> 
> Hi,
> 
> I am writing a small tool to gather some static statistics on machine code
using LLVMs MachineInstr, etc., infrastructure.
> My current goal is to count the number of bytes of integer and floating
point data being processed per iteration of a loop.
> Now I've ran into the problem that I can't find any obvious way to
get the actual type of a MachineOperand.
> 
> After some digging I noticed that the selection DAG has some type
information and I had a look at the TableGen records that contain this type
info. I started looking into how I could generate some descriptor tables with
that information but TableGen is quite a handfull, and I'd like to avoid
this if I can.
> 
> Did I overlook some easy way to get at type information at the
MachineOperand level?
> 
> Thanks.
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Unfortunately looking at the register classes is not enough for my use case.
Some vector registers for example can hold both scalars and packed vectors.
This would lead my estimation being wrong by factor between 2 and 4x.
In many cases this also does not allow me to distinguish floating point and
integer computation.
On 29 May 2015 01:07, "Matthias Braun" <mbraun at apple.com>
wrote:
> For the registers on register operands you can query MachineRegisterInfor
> for their Class. The registerclass should have a list of possible types
> (usually with the same size in bits) assigned.
>
> - Matthias
>
> > On May 28, 2015, at 8:11 AM, Fabian Gruber <fabian.gruber at
fadeopolis.com>
> wrote:
> >
> > Hi,
> >
> > I am writing a small tool to gather some static statistics on machine
> code using LLVMs MachineInstr, etc., infrastructure.
> > My current goal is to count the number of bytes of integer and
floating
> point data being processed per iteration of a loop.
> > Now I've ran into the problem that I can't find any obvious
way to get
> the actual type of a MachineOperand.
> >
> > After some digging I noticed that the selection DAG has some type
> information and I had a look at the TableGen records that contain this type
> info. I started looking into how I could generate some descriptor tables
> with that information but TableGen is quite a handfull, and I'd like to
> avoid this if I can.
> >
> > Did I overlook some easy way to get at type information at the
> MachineOperand level?
> >
> > Thanks.
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
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