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Diffstat (limited to 'docs/ReleaseNotes.rst')
| -rw-r--r-- | docs/ReleaseNotes.rst | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index 13766f0404..55ef35d2f6 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -116,7 +116,41 @@ Clang's support for building native Windows programs ... C Language Changes in Clang --------------------------- -- ... +- Added near complete support for implicit scalar to vector conversion, a GNU + C/C++ language extension. With this extension, the following code is + considered valid: + +.. code-block:: c + + typedef unsigned v4i32 __attribute__((vector_size(16))); + + v4i32 foo(v4i32 a) { + // Here 5 is implicitly casted to an unsigned value and replicated into a + // vector with as many elements as 'a'. + return a + 5; + } + +The implicit conversion of a scalar value to a vector value--in the context of +a vector expression--occurs when: + +- The type of the vector is that of a ``__attribute__((vector_size(size)))`` + vector, not an OpenCL ``__attribute__((ext_vector_type(size)))`` vector type. + +- The scalar value can be casted to that of the vector element's type without + the loss of precision based on the type of the scalar and the type of the + vector's elements. + +- For compile time constant values, the above rule is weakened to consider the + value of the scalar constant rather than the constant's type. + +- Floating point constants with precise integral representations are not + implicitly converted to integer values, this is for compatability with GCC. + + +Currently the basic integer and floating point types with the following +operators are supported: ``+``, ``/``, ``-``, ``*``, ``%``, ``>``, ``<``, +``>=``, ``<=``, ``==``, ``!=``, ``&``, ``|``, ``^`` and the corresponding +assignment operators where applicable. ... @@ -128,6 +162,10 @@ C11 Feature Support C++ Language Changes in Clang ----------------------------- +- As mentioned in `C Language Changes in Clang`_, Clang's support for + implicit scalar to vector conversions also applies to C++. Additionally + the following operators are also supported: ``&&`` and ``||``. + ... C++1z Feature Support |