[Mesa-dev] [PATCH] clover: Pass image attributes to the kernel

Zoltán Gilián zoltan.gilian at gmail.com
Sun Jul 26 14:37:50 PDT 2015


> Why?  Your module::argument::image_size and ::image_format cases don't
> touch the explicit_arg iterator at all AFAICT, so it will be left
> pointing one past the last general semantic argument

Ok, my mistake, I didn't think this through.

> Hmmm...  So you only need it as padding?  Wouldn't it be possible for
> you to declare samplers to be 0 bytes?

Maybe it can be done by changing the type of the sampler arg from i32
to an empty struct. I'll have to try this, I don't know if it will
work.

On Sun, Jul 26, 2015 at 2:40 PM, Francisco Jerez <currojerez at riseup.net> wrote:
> Zoltán Gilián <zoltan.gilian at gmail.com> writes:
>
>>> auto img = dynamic_cast<image_argument &>(**(explicit_arg - 1))
>>
>> Ok, so it should be (explicit_arg - 2) for the image format, I
>> presume.
>
> Why?  Your module::argument::image_size and ::image_format cases don't
> touch the explicit_arg iterator at all AFAICT, so it will be left
> pointing one past the last general semantic argument
>
>> This will be incorrect, however, if the targets that need implicit
>> argument for format metadata are indeed a strict superset of the ones
>> that need dimension, as you mentioned before. The targets that only
>> need format will break this code. Should I swap the order of the
>> format and dimension implicit args to make this approach work under
>> the aforementioned assumption?
>>
> Why would it be incorrect?  The kernel::_args vector explicit_arg
> iterates in contains explicit arguments only so it shouldn't make a
> difference in which order you emit them as long as you don't interleave
> other explicit arguments in between.
>
>>> It also seems like you've got rid of the static casts you had
>>> previously?
>>
>> That is a mistake, I'll fix it.
>>
>>> My expectation here was that the compiler would be able to hard-code
>>> sampler indices in the shader without the API passing any actual data in
>>> the input buffer.  Doesn't that work for you?
>>
>> Yes, that's correct, but this is also the case with images. If image
>> index is uploaded explicitly, I don't see why it can't be done with
>> sampler indices. But probably it's a better idea to send the sampler
>> value rather than the index, in case the kernel needs it (e.g. the
>> normalized or non-normalized nature of texture coordinates may have to
>> be specified in the fetch instruction itself, and not by hardware
>> registers), so I'll definitely change this.
>
> Some hardware (e.g. Intel's) will need an index (which can probably be
> hardcoded in the shader for now) into a table of sampler configurations
> which can be set-up later on by the driver at state-emit time.  In any
> case we can always add a new argument semantic enum later on for the
> target to select sampler config vs index if different drivers turn out
> to need different things.
>
>> But the bigger problem is, that the byte offsets of the kernel
>> arguments are computed considering the sampler argument too, so the
>> binary expects it to be present in the input vector. Furthermore I
>> can't erase the sampler argument from the IR, because it is needed to
>> make it possible for get_kernel_args to detect the sampler. But if
>> sampler_argument::bind doesn't append 4 bytes (clang compiles
>> sampler_t to i32) to the input vector, the binary will try to load the
>> following arguments from wrong locations.
>
> Hmmm...  So you only need it as padding?  Wouldn't it be possible for
> you to declare samplers to be 0 bytes?
>
>>
>>> I don't think it's a good idea to use such obvious names for the
>>> implicit argument types. Couldn't they collide with some type declared
>> by the user that happens to have the same name?  How about
>> "__clover_image_size" or something similar?
>>
>> Indeed, that's a good point. I'd go with something like
>> "__opencl_image_*" or "__llvm_image_*", because these strings will be
>> added to llvm, and non-clover code may depend on them in the future.
>>
> Sounds good to me.
>
>>> (Identifiers starting with
>>> double underscore are reserved for the implementation at least on C and
>>> GLSL, not sure about OpenCL-C)
>>
>> I believe this is true for OpenCL C too, since it is an extension to
>> C99. Identifiers starting with double underscores are reserved in C99.
>>
> IIRC identifiers starting with double underscore and single underscore
> followed by some upper-case letter were reserved even in the original
> ANSI C spec.
>
>> On Sat, Jul 25, 2015 at 1:06 PM, Francisco Jerez <currojerez at riseup.net> wrote:
>>> Zoltan Gilian <zoltan.gilian at gmail.com> writes:
>>>
>>>> Read-only and write-only image arguments are recognized and
>>>> distinguished.
>>>> Attributes of the image arguments are passed to the kernel as implicit
>>>> arguments.
>>>> ---
>>>>  src/gallium/state_trackers/clover/core/kernel.cpp  |  46 ++++++-
>>>>  src/gallium/state_trackers/clover/core/kernel.hpp  |  13 +-
>>>>  src/gallium/state_trackers/clover/core/memory.cpp  |   2 +-
>>>>  src/gallium/state_trackers/clover/core/module.hpp  |   4 +-
>>>>  .../state_trackers/clover/llvm/invocation.cpp      | 147 ++++++++++++++++++++-
>>>>  5 files changed, 198 insertions(+), 14 deletions(-)
>>>>
>>>> diff --git a/src/gallium/state_trackers/clover/core/kernel.cpp b/src/gallium/state_trackers/clover/core/kernel.cpp
>>>> index 0756f06..1a6c28f 100644
>>>> --- a/src/gallium/state_trackers/clover/core/kernel.cpp
>>>> +++ b/src/gallium/state_trackers/clover/core/kernel.cpp
>>>> @@ -158,13 +158,18 @@ kernel::exec_context::bind(intrusive_ptr<command_queue> _q,
>>>>     auto margs = find(name_equals(kern.name()), m.syms).args;
>>>>     auto msec = find(type_equals(module::section::text), m.secs);
>>>>     auto explicit_arg = kern._args.begin();
>>>> +   image_argument *last_image_arg = nullptr;
>>>>
>>>>     for (auto &marg : margs) {
>>>>        switch (marg.semantic) {
>>>> -      case module::argument::general:
>>>> +      case module::argument::general: {
>>>> +         auto image_arg = dynamic_cast<image_argument*>(explicit_arg->get());
>>>> +         if (image_arg) {
>>>> +            last_image_arg = image_arg;
>>>> +         }
>>>>           (*(explicit_arg++))->bind(*this, marg);
>>>>           break;
>>>> -
>>>> +      }
>>>>        case module::argument::grid_dimension: {
>>>>           const cl_uint dimension = grid_offset.size();
>>>>           auto arg = argument::create(marg);
>>>> @@ -182,6 +187,36 @@ kernel::exec_context::bind(intrusive_ptr<command_queue> _q,
>>>>           }
>>>>           break;
>>>>        }
>>>> +      case module::argument::image_size: {
>>>> +         assert(last_image_arg);
>>>> +         auto img = last_image_arg->get();
>>>
>>> Instead of carrying around an extra variable during the loop, you could
>>> achieve the same effect more locally by doing:
>>>
>>> |            auto img = dynamic_cast<image_argument &>(**(explicit_arg - 1))
>>> |                       .get();
>>>
>>> The cast to reference would also make sure that the argument is of the
>>> specified type or otherwise throw std::bad_cast which is as good as an
>>> assertion failure.
>>>
>>>> +         std::vector<cl_uint> image_size({
>>>> +               img->width(),
>>>> +               img->height(),
>>>> +               img->depth()});
>>>
>>> Parentheses are not necessary around the curly braces, you could just:
>>>
>>> |         std::vector<cl_uint> image_size {
>>> |               img->width(),
>>> |               img->height(),
>>> |               img->depth()
>>> |         };
>>>
>>> It also seems like you've got rid of the static casts you had
>>> previously?  These image methods return a size_t value which may be of
>>> different size than cl_uint and cause a warning.
>>>
>>>> +         for (auto x: image_size) {
>>>
>>> Leave a space around the colon for consistency, also in the cases below.
>>>
>>>> +            auto arg = argument::create(marg);
>>>> +
>>>> +            arg->set(sizeof(x), &x);
>>>> +            arg->bind(*this, marg);
>>>> +         }
>>>> +         break;
>>>> +      }
>>>> +      case module::argument::image_format: {
>>>> +         assert(last_image_arg);
>>>> +         auto img = last_image_arg->get();
>>>> +         cl_image_format fmt = img->format();
>>>> +         std::vector<cl_uint> image_format({
>>>> +               fmt.image_channel_data_type,
>>>> +               fmt.image_channel_order});
>>>
>>> Same comments apply here.
>>>
>>>> +         for (auto x: image_format) {
>>>> +            auto arg = argument::create(marg);
>>>> +
>>>> +            arg->set(sizeof(x), &x);
>>>> +            arg->bind(*this, marg);
>>>> +         }
>>>> +         break;
>>>> +      }
>>>>        }
>>>>     }
>>>>
>>>> @@ -532,6 +567,13 @@ kernel::sampler_argument::set(size_t size, const void *value) {
>>>>  void
>>>>  kernel::sampler_argument::bind(exec_context &ctx,
>>>>                                 const module::argument &marg) {
>>>> +   auto v = bytes(ctx.samplers.size());
>>>> +
>>>> +   extend(v, module::argument::zero_ext, marg.target_size);
>>>> +   byteswap(v, ctx.q->device().endianness());
>>>> +   align(ctx.input, marg.target_align);
>>>> +   insert(ctx.input, v);
>>>> +
>>>
>>> My expectation here was that the compiler would be able to hard-code
>>> sampler indices in the shader without the API passing any actual data in
>>> the input buffer.  Doesn't that work for you?
>>>
>>>>     st = s->bind(*ctx.q);
>>>>     ctx.samplers.push_back(st);
>>>>  }
>>>> diff --git a/src/gallium/state_trackers/clover/core/kernel.hpp b/src/gallium/state_trackers/clover/core/kernel.hpp
>>>> index d6432a4..007ffcc 100644
>>>> --- a/src/gallium/state_trackers/clover/core/kernel.hpp
>>>> +++ b/src/gallium/state_trackers/clover/core/kernel.hpp
>>>> @@ -190,7 +190,14 @@ namespace clover {
>>>>           pipe_surface *st;
>>>>        };
>>>>
>>>> -      class image_rd_argument : public argument {
>>>> +      class image_argument : public argument {
>>>> +      public:
>>>> +         const image *get() const { return img; }
>>>
>>> Please write the return statement on its own line for consistency.
>>>
>>>> +      protected:
>>>> +         image *img;
>>>> +      };
>>>> +
>>>> +      class image_rd_argument : public image_argument {
>>>>        public:
>>>>           virtual void set(size_t size, const void *value);
>>>>           virtual void bind(exec_context &ctx,
>>>> @@ -198,11 +205,10 @@ namespace clover {
>>>>           virtual void unbind(exec_context &ctx);
>>>>
>>>>        private:
>>>> -         image *img;
>>>>           pipe_sampler_view *st;
>>>>        };
>>>>
>>>> -      class image_wr_argument : public argument {
>>>> +      class image_wr_argument : public image_argument {
>>>>        public:
>>>>           virtual void set(size_t size, const void *value);
>>>>           virtual void bind(exec_context &ctx,
>>>> @@ -210,7 +216,6 @@ namespace clover {
>>>>           virtual void unbind(exec_context &ctx);
>>>>
>>>>        private:
>>>> -         image *img;
>>>>           pipe_surface *st;
>>>>        };
>>>>
>>>> diff --git a/src/gallium/state_trackers/clover/core/memory.cpp b/src/gallium/state_trackers/clover/core/memory.cpp
>>>> index 055336a..b852e68 100644
>>>> --- a/src/gallium/state_trackers/clover/core/memory.cpp
>>>> +++ b/src/gallium/state_trackers/clover/core/memory.cpp
>>>> @@ -189,7 +189,7 @@ image2d::image2d(clover::context &ctx, cl_mem_flags flags,
>>>>                   const cl_image_format *format, size_t width,
>>>>                   size_t height, size_t row_pitch,
>>>>                   void *host_ptr) :
>>>> -   image(ctx, flags, format, width, height, 0,
>>>> +   image(ctx, flags, format, width, height, 1,
>>>>           row_pitch, 0, height * row_pitch, host_ptr) {
>>>>  }
>>>>
>>>> diff --git a/src/gallium/state_trackers/clover/core/module.hpp b/src/gallium/state_trackers/clover/core/module.hpp
>>>> index 9d65688..5db0548 100644
>>>> --- a/src/gallium/state_trackers/clover/core/module.hpp
>>>> +++ b/src/gallium/state_trackers/clover/core/module.hpp
>>>> @@ -72,7 +72,9 @@ namespace clover {
>>>>           enum semantic {
>>>>              general,
>>>>              grid_dimension,
>>>> -            grid_offset
>>>> +            grid_offset,
>>>> +            image_size,
>>>> +            image_format
>>>>           };
>>>>
>>>>           argument(enum type type, size_t size,
>>>> diff --git a/src/gallium/state_trackers/clover/llvm/invocation.cpp b/src/gallium/state_trackers/clover/llvm/invocation.cpp
>>>> index 967284d..e5cd59c 100644
>>>> --- a/src/gallium/state_trackers/clover/llvm/invocation.cpp
>>>> +++ b/src/gallium/state_trackers/clover/llvm/invocation.cpp
>>>> @@ -340,18 +340,91 @@ namespace {
>>>>        PM.run(*mod);
>>>>     }
>>>>
>>>> +   // Kernel metadata
>>>> +
>>>> +   const llvm::MDNode *
>>>> +   get_kernel_metadata(const llvm::Function *kernel_func) {
>>>> +      auto mod = kernel_func->getParent();
>>>> +      auto kernels_node = mod->getNamedMetadata("opencl.kernels");
>>>> +      if (!kernels_node) {
>>>> +         return nullptr;
>>>> +      }
>>>> +
>>>> +      const llvm::MDNode *kernel_node = nullptr;
>>>> +      for (unsigned i = 0; i < kernels_node->getNumOperands(); ++i) {
>>>> +#if HAVE_LLVM >= 0x0306
>>>> +         auto func = llvm::mdconst::dyn_extract<llvm::Function>(
>>>> +#else
>>>> +         auto func = llvm::dyn_cast<llvm::Function>(
>>>> +#endif
>>>> +                                    kernels_node->getOperand(i)->getOperand(0));
>>>> +         if (func == kernel_func) {
>>>> +            kernel_node = kernels_node->getOperand(i);
>>>> +            break;
>>>> +         }
>>>> +      }
>>>> +
>>>> +      return kernel_node;
>>>> +   }
>>>> +
>>>> +   llvm::MDNode*
>>>> +   node_from_op_checked(const llvm::MDOperand &md_operand,
>>>> +                        llvm::StringRef expect_name,
>>>> +                        unsigned expect_num_args)
>>>> +   {
>>>> +      auto node = llvm::cast<llvm::MDNode>(md_operand);
>>>> +      assert(node->getNumOperands() == expect_num_args &&
>>>> +             "Wrong number of operands.");
>>>> +
>>>> +      auto str_node = llvm::cast<llvm::MDString>(node->getOperand(0));
>>>> +      assert(str_node->getString() == expect_name &&
>>>> +             "Wrong metadata node name.");
>>>> +
>>>> +      return node;
>>>> +   }
>>>> +
>>>> +   struct kernel_arg_md {
>>>> +      llvm::StringRef type_name;
>>>> +      llvm::StringRef access_qual;
>>>> +      kernel_arg_md(llvm::StringRef type_name_, llvm::StringRef access_qual_):
>>>> +         type_name(type_name_), access_qual(access_qual_) {}
>>>> +   };
>>>> +
>>>> +   std::vector<kernel_arg_md>
>>>> +   get_kernel_arg_md(const llvm::Function *kernel_func) {
>>>> +      auto num_args = kernel_func->getArgumentList().size();
>>>> +
>>>> +      auto kernel_node = get_kernel_metadata(kernel_func);
>>>> +      auto aq = node_from_op_checked(kernel_node->getOperand(2),
>>>> +                                     "kernel_arg_access_qual", num_args + 1);
>>>> +      auto ty = node_from_op_checked(kernel_node->getOperand(3),
>>>> +                                     "kernel_arg_type", num_args + 1);
>>>> +
>>>> +      auto res = std::vector<kernel_arg_md>();
>>>> +      res.reserve(num_args);
>>>
>>> std::vector<kernel_arg_md> res;
>>>
>>>> +      for (unsigned i = 0; i < num_args; ++i) {
>>>> +         res.push_back(kernel_arg_md(
>>>> +            llvm::cast<llvm::MDString>(ty->getOperand(i+1))->getString(),
>>>> +            llvm::cast<llvm::MDString>(aq->getOperand(i+1))->getString()));
>>>> +      }
>>>> +
>>>> +      return res;
>>>> +   }
>>>> +
>>>>     std::vector<module::argument>
>>>>     get_kernel_args(const llvm::Module *mod, const std::string &kernel_name,
>>>>                     const clang::LangAS::Map &address_spaces) {
>>>>
>>>>        std::vector<module::argument> args;
>>>>        llvm::Function *kernel_func = mod->getFunction(kernel_name);
>>>> +      assert(kernel_func && "Kernel name not found in module.");
>>>> +      auto arg_md = get_kernel_arg_md(kernel_func);
>>>>
>>>>        llvm::DataLayout TD(mod);
>>>> +      llvm::Type *size_type =
>>>> +         TD.getSmallestLegalIntType(mod->getContext(), sizeof(cl_uint) * 8);
>>>>
>>>> -      for (llvm::Function::const_arg_iterator I = kernel_func->arg_begin(),
>>>> -                                      E = kernel_func->arg_end(); I != E; ++I) {
>>>> -         const llvm::Argument &arg = *I;
>>>> +      for (const auto &arg: kernel_func->args()) {
>>>>
>>>>           llvm::Type *arg_type = arg.getType();
>>>>           const unsigned arg_store_size = TD.getTypeStoreSize(arg_type);
>>>> @@ -369,6 +442,68 @@ namespace {
>>>>           unsigned target_size = TD.getTypeStoreSize(target_type);
>>>>           unsigned target_align = TD.getABITypeAlignment(target_type);
>>>>
>>>> +         llvm::StringRef type_name = arg_md[arg.getArgNo()].type_name;
>>>> +         llvm::StringRef access_qual = arg_md[arg.getArgNo()].access_qual;
>>>> +
>>>> +         // Image
>>>> +         bool is_image2d = type_name == "image2d_t";
>>>> +         bool is_image3d = type_name == "image3d_t";
>>>
>>> These should be marked const.
>>>
>>>> +         if (is_image2d || is_image3d) {
>>>> +            bool is_write_only = access_qual == "write_only";
>>>> +            bool is_read_only = access_qual == "read_only";
>>>> +
>>>
>>> And these too.
>>>
>>>> +            typename module::argument::type marg_type;
>>>> +            if (is_image2d && is_read_only) {
>>>> +               marg_type = module::argument::image2d_rd;
>>>> +            } else if (is_image2d && is_write_only) {
>>>> +               marg_type = module::argument::image2d_wr;
>>>> +            } else if (is_image3d && is_read_only) {
>>>> +               marg_type = module::argument::image3d_rd;
>>>> +            } else if (is_image3d && is_write_only) {
>>>> +               marg_type = module::argument::image3d_wr;
>>>> +            } else {
>>>> +               assert(0 && "Wrong image access qualifier");
>>>> +            }
>>>> +
>>>> +            args.push_back(module::argument(marg_type,
>>>> +                                            arg_store_size, target_size,
>>>> +                                            target_align,
>>>> +                                            module::argument::zero_ext));
>>>> +            continue;
>>>> +         }
>>>> +
>>>> +         // Sampler
>>>> +         if (type_name == "sampler_t") {
>>>> +            args.push_back(module::argument(module::argument::sampler,
>>>> +                                            arg_store_size, target_size,
>>>> +                                            target_align,
>>>> +                                            module::argument::zero_ext));
>>>> +            continue;
>>>> +         }
>>>> +
>>>> +         // Image size implicit argument
>>>> +         if (type_name == "image_size") {
>>>
>>> I don't think it's a good idea to use such obvious names for the
>>> implicit argument types.  Couldn't they collide with some type declared
>>> by the user that happens to have the same name?  How about
>>> "__clover_image_size" or something similar?  (Identifiers starting with
>>> double underscore are reserved for the implementation at least on C and
>>> GLSL, not sure about OpenCL-C)
>>>
>>>> +            args.push_back(module::argument(module::argument::scalar,
>>>> +                                            sizeof(cl_uint),
>>>> +                                            TD.getTypeStoreSize(size_type),
>>>> +                                            TD.getABITypeAlignment(size_type),
>>>> +                                            module::argument::zero_ext,
>>>> +                                            module::argument::image_size));
>>>> +            continue;
>>>> +         }
>>>> +
>>>> +         // Image format implicit argument
>>>> +         if (type_name == "image_format") {
>>>> +            args.push_back(module::argument(module::argument::scalar,
>>>> +                                            sizeof(cl_uint),
>>>> +                                            TD.getTypeStoreSize(size_type),
>>>> +                                            TD.getABITypeAlignment(size_type),
>>>> +                                            module::argument::zero_ext,
>>>> +                                            module::argument::image_format));
>>>> +            continue;
>>>> +         }
>>>> +
>>>> +         // Other types
>>>>           if (llvm::isa<llvm::PointerType>(arg_type) && arg.hasByValAttr()) {
>>>>              arg_type =
>>>>                    llvm::dyn_cast<llvm::PointerType>(arg_type)->getElementType();
>>>> @@ -413,9 +548,6 @@ namespace {
>>>>        // Append implicit arguments.  XXX - The types, ordering and
>>>>        // vector size of the implicit arguments should depend on the
>>>>        // target according to the selected calling convention.
>>>> -      llvm::Type *size_type =
>>>> -         TD.getSmallestLegalIntType(mod->getContext(), sizeof(cl_uint) * 8);
>>>> -
>>>>        args.push_back(
>>>>           module::argument(module::argument::scalar, sizeof(cl_uint),
>>>>                            TD.getTypeStoreSize(size_type),
>>>> @@ -744,6 +876,9 @@ clover::compile_program_llvm(const std::string &source,
>>>>           std::vector<char> code = compile_native(mod, triple, processor,
>>>>                                                   get_debug_flags() & DBG_ASM,
>>>>                                                   r_log);
>>>> +         // Target-specific passes may alter functions
>>>> +         kernels.clear();
>>>> +         find_kernels(mod, kernels);
>>>
>>> Bah...  To make this sort of mistake impossible I'd get rid of the
>>> "kernels" argument of optimize() and build_module_native/llvm(), and
>>> make them call find_kernels() directly.  It would also be nice to have
>>> find_kernels() return its result as return value instead of returning
>>> void, so you could declare kernel arrays as const and initialize them at
>>> the same point.
>>>
>>>>           m = build_module_native(code, mod, kernels, address_spaces, r_log);
>>>>           break;
>>>>        }
>>>> --
>>>> 2.4.6


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