[Libclc-dev] architecture-specific builtins and OpenCL

[Matt Arsenault]

> On Nov 11, 2014, at 10:42 AM, Tom Stellard <tom at stellard.net> wrote:
> 
> On Tue, Nov 11, 2014 at 01:37:06PM -0500, Richard Gorton wrote:
>> grep reverse ./include/llvm/IR/IntrinsicsCogE.td ./tools/clang/include/clang/Basic/BuiltinsCogE.def
>> ./include/llvm/IR/IntrinsicsCogE.td:def int_coge_reverse: GCCBuiltin<"__builtin_coge_reverse">,
>> ./tools/clang/include/clang/Basic/BuiltinsCogE.def:BUILTIN(__builtin_coge_reverse,     "ULLiULLi", "nc")
>> 
>> unsigned long (uint64_t) as the input and result.  Removing the 'kernel' keyword does not improve matters; the following .cl file also crashes
> 
> Does it still crash in the same place?
> 
> -Tom
> 

This crash looks vaguely familiar. The builtins don’t understand address spaces, and I remember in an older version clang would accept the implicit address space cast to a builtin, and 3.4 stopped allowing bitcast to be used. The clang problem was probably fixed later than that


>> void fred(unsigned long *in, unsigned long* where, int id)
>> {
>>    where[id] = __builtin_coge_reverse(in[id]);
>> }
>> 
>> (I did not use any of the #pragmas or include <CL/cl.h>)
>> 
>> Regards,
>> 	Richard
>> 	rcgorton at cog-e.com
>> 
>> 
>> 
>> 
>> On Nov 11, 2014, at 1:09 PM, Tom Stellard <tom at stellard.net> wrote:
>> 
>>> On Tue, Nov 11, 2014 at 01:01:16PM -0500, Richard Gorton wrote:
>>>> I originally posted this to llvmdev,but it strikes me that this might be a better place to make the query.
>>>> 
>>>> 
>>>>> I'm trying to ascertain whether or not it is possible to use architecture-specific builtins (LLVM3.4.2) in OpenCL:
>>>>> 
>>>>> This compiles cleanly for my target when it has a .c extension:
>>>>> 
>>>>> void fred(unsigned long* in, unsigned long* where)
>>>>> {
>>>>>  *where = __builtin_coge_reverse(*in);
>>>>> }
>>>>> 
>>>>> But this variant crashes very early when it is a .cl file:
>>>>> void kernel fred(unsigned long *in, unsigned long* where)
>>>>> {
>>> 
>>> I just realized you are passing private pointers to your kernel.  This is
>>> not allowed in OpenCL.  Does it work if you drop the kernel attribute?
>>> 
>>> -Tom
>>> 
>>>>>  *where = __builtin_coge_reverse(*in);
>>>>> }
>>>>> 
>>>>> 
>>>>> 
>>>>> I'm not even sure how to go about determining the source of problem - it crashes before generating any IR (-mllvm -print-after-all)
>>>>> 
>>>>> clang: /localspace/rcgorton/svn/Compiler/trunk/LLVM3_4/llvm-3.4.2.src/lib/IR/Instructions.cpp:2352: static llvm::CastInst* llvm::CastInst::Create(llvm::Instruction::CastOps, llvm::Value*, llvm::Type*, const llvm::Twine&, llvm::Instruction*): Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
>>>>> 
>>>>> Is there a document somewhere which describes how to use various front-end-dumping switches?  Is there a better way to attack this?
>>>>> 
>>>>> Thanks in advance,
>>>>> 
>>>>> 	Richard
>>>>> 	rcgorton at cog-e.com
>>>> 
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> 
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