[cfe-dev] [Mesa-dev] 3 element vectors in opencl 1.1+

[Jan Vesely]

On Tue, 2014-04-22 at 14:40 -0700, Matt Arsenault wrote:
> On 04/22/2014 02:35 PM, Tom Stellard wrote:
> > On Mon, Apr 21, 2014 at 10:02:27PM -0400, Jan Vesely wrote:
> >> Hi,
> >>
> >> I ran into a problem caused by this part of the OCL specs (6.1.5
> >> Alignment of Types):
> >> "For 3-component vector data types, the size of the data type is 4 *
> >> sizeof(component)."
> >>
> >> and the corresponding part of Khronos cl_platform.h (with all types, not
> >> just float):
> >> /* cl_float3 is identical in size, alignment and behavior to cl_float4.
> >> See section 6.1.5. */
> >> typedef  cl_float4  cl_float3;
> >>
> >> So when I try to run kernel that takes 3 element vectors as arguments I
> >> get 'invalid arg size' error.
> >>
> >> Not sure whether this is best solved in clang, libclc or clover. I tried
> >> changing float3 to have 4 elements in libclc, it caused clang to
> >> complain in thousand places. I don't think this can be handled cleanly
> >> in clang, unless we add something like __attribute__((padding)).
> >>
> >> I have attached a workaround that I use now.
> >>
> > You may want to ask this question on the pocl mailing list as they
> > have likely solved this issue already.  Ideally, TD.getTypeStoreSize
> > would return the correct value.  Also, maybe look at the DataLayout
> > description for R600 and see if there is a way to specify the
> > correct type size.
> >
> > -Tom
> I think this is what v96:128 is for

according to [0], it specifies only alignment, not size. I could not
find an __attribute__ that would change size either.

It should be possible to have ADMGPUDataLayout: public DataLayout class
that would intercept the call and fix the reported value, but I think it
would only move the hack to different place.

I have added pocl-devel list as suggested.

regards,
Jan

[0]http://llvm.org/docs/LangRef.html#data-layout

> 
> 
> >
> >> any advice welcome,
> >> Jan
> >>
> >> -- 
> >> Jan Vesely <jan.vesely at rutgers.edu>
> >> diff --git a/src/gallium/state_trackers/clover/llvm/invocation.cpp b/src/gallium/state_trackers/clover/llvm/invocation.cpp
> >> index a81bdf8..71ee01f 100644
> >> --- a/src/gallium/state_trackers/clover/llvm/invocation.cpp
> >> +++ b/src/gallium/state_trackers/clover/llvm/invocation.cpp
> >> @@ -62,6 +62,8 @@
> >>   #include <llvm/IR/DataLayout.h>
> >>   #endif
> >>   
> >> +#include <llvm/Support/Debug.h>
> >> +
> >>   #include "pipe/p_state.h"
> >>   #include "util/u_memory.h"
> >>   
> >> @@ -309,6 +311,13 @@ namespace {
> >>   
> >>               llvm::Type *arg_type = arg.getType();
> >>               unsigned arg_size = TD.getTypeStoreSize(arg_type);
> >> +            if (arg_type->isVectorTy() &&
> >> +               ::llvm::cast<::llvm::VectorType>(arg_type)->getNumElements() == 3) {
> >> +               ::llvm::dbgs() << "Fixing argument type: " << *arg_type
> >> +                              << " size: " << arg_size << "->"
> >> +                              << (arg_size / 3) * 4 << "\n";
> >> +               arg_size = (arg_size / 3) * 4;
> >> +            }
> >>   
> >>               llvm::Type *target_type = arg_type->isIntegerTy() ?
> >>                  TD.getSmallestLegalIntType(mod->getContext(), arg_size * 8) :
> >
> >
> >
> >> _______________________________________________
> >> mesa-dev mailing list
> >> mesa-dev at lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
> > _______________________________________________
> > cfe-dev mailing list
> > cfe-dev at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
> 

-- 
Jan Vesely <jan.vesely at rutgers.edu>
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