r298369 - [OpenCL] Added diagnostic for checking length of vector

[Bruno Cardoso Lopes via cfe-commits]

Hi Egor,

On Tue, Mar 21, 2017 at 6:20 AM, Egor Churaev via cfe-commits
<cfe-commits at lists.llvm.org> wrote:
> Author: echuraev
> Date: Tue Mar 21 08:20:57 2017
> New Revision: 298369
>
> URL: http://llvm.org/viewvc/llvm-project?rev=298369&view=rev
> Log:
> [OpenCL] Added diagnostic for checking length of vector
>
> Reviewers: Anastasia, cfe-commits
>
> Reviewed By: Anastasia
>
> Subscribers: bader, yaxunl
>
> Differential Revision: https://reviews.llvm.org/D30937
>
> Added:
>     cfe/trunk/test/SemaOpenCL/vector_swizzle_length.cl
> Modified:
>     cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>     cfe/trunk/lib/Sema/SemaExprMember.cpp
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=298369&r1=298368&r2=298369&view=diff
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Mar 21 08:20:57 2017
> @@ -8236,6 +8236,8 @@ def err_opencl_ptrptr_kernel_param : Err
>  def err_kernel_arg_address_space : Error<
>    "pointer arguments to kernel functions must reside in '__global', "
>    "'__constant' or '__local' address space">;
> +def err_opencl_ext_vector_component_invalid_length : Error<
> +  "vector component access has invalid length %0.  Supported: 1,2,3,4,8,16.">;
>  def err_opencl_function_variable : Error<
>    "%select{non-kernel function|function scope}0 variable cannot be declared in %1 address space">;
>  def err_static_function_scope : Error<
>
> Modified: cfe/trunk/lib/Sema/SemaExprMember.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprMember.cpp?rev=298369&r1=298368&r2=298369&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaExprMember.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaExprMember.cpp Tue Mar 21 08:20:57 2017
> @@ -284,6 +284,14 @@ IsRGBA(char c) {
>    }
>  }
>
> +// OpenCL v1.1, s6.1.7
> +// The component swizzle length must be in accordance with the acceptable
> +// vector sizes.
> +static bool IsValidOpenCLComponentSwizzleLength(unsigned len)
> +{
> +  return (len >= 1 && len <= 4) || len == 8 || len == 16;
> +}
> +
>  /// Check an ext-vector component access expression.
>  ///
>  /// VK should be set in advance to the value kind of the base
> @@ -376,6 +384,19 @@ CheckExtVectorComponent(Sema &S, QualTyp
>      }
>    }
>
> +  if (!HalvingSwizzle) {
> +    unsigned SwizzleLength = CompName->getLength();
> +
> +    if (HexSwizzle)
> +      SwizzleLength--;
> +
> +    if (IsValidOpenCLComponentSwizzleLength(SwizzleLength) == false) {
> +      S.Diag(OpLoc, diag::err_opencl_ext_vector_component_invalid_length)
> +        << SwizzleLength << SourceRange(CompLoc);
> +      return QualType();
> +    }
> +  }
> +
>    // The component accessor looks fine - now we need to compute the actual type.
>    // The vector type is implied by the component accessor. For example,
>    // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc.
>
> Added: cfe/trunk/test/SemaOpenCL/vector_swizzle_length.cl
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaOpenCL/vector_swizzle_length.cl?rev=298369&view=auto
> ==============================================================================
> --- cfe/trunk/test/SemaOpenCL/vector_swizzle_length.cl (added)
> +++ cfe/trunk/test/SemaOpenCL/vector_swizzle_length.cl Tue Mar 21 08:20:57 2017
> @@ -0,0 +1,10 @@
> +// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only
> +
> +typedef float float8 __attribute__((ext_vector_type(8)));
> +
> +void foo() {
> +    float8 f2 = (float8)(0, 0, 0, 0, 0, 0, 0, 0);
> +
> +    f2.s01234; // expected-error {{vector component access has invalid length 5.  Supported: 1,2,3,4,8,16}}
> +    f2.xyzxy; // expected-error {{vector component access has invalid length 5.  Supported: 1,2,3,4,8,16}}
> +}

Sorry for the necromancy here, but I wonder if we should only make
this if LangOpts.OpenCL in on. Is there an initial intent for not to?

The rationale is that we have given users support for ext_vector_type
without OpenCL mode with arbitrary vectors lengths not defined in
"6.1.2 Built-In Vector Data Types", that said it makes sense to
support the component notation for those. I'm happy to fix it, I just
need to know if this covers some background I'm not aware of.

Thanks,

-- 
Bruno Cardoso Lopes
http://www.brunocardoso.cc