[clang] cd256c8 - Add documentation for compound assignment and type conversion of matrix types

[Saurabh Jha via cfe-commits]

Author: Saurabh Jha
Date: 2021-06-24T15:50:58+01:00
New Revision: cd256c8bcc9723f0ce7a32957f26600c966fa07c

URL: https://github.com/llvm/llvm-project/commit/cd256c8bcc9723f0ce7a32957f26600c966fa07c
DIFF: https://github.com/llvm/llvm-project/commit/cd256c8bcc9723f0ce7a32957f26600c966fa07c.diff

LOG: Add documentation for compound assignment and type conversion of matrix types

Added: 
    

Modified: 
    clang/docs/LanguageExtensions.rst

Removed: 
    


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diff  --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
index c60b8b39e1c9e..f9e1208634b91 100644
--- a/clang/docs/LanguageExtensions.rst
+++ b/clang/docs/LanguageExtensions.rst
@@ -523,6 +523,63 @@ float matrices and add the result to a third 4x4 matrix.
     return a + b * c;
   }
 
+The matrix type extension also supports operations on a matrix and a scalar.
+
+.. code-block:: c++
+
+  typedef float m4x4_t __attribute__((matrix_type(4, 4)));
+
+  m4x4_t f(m4x4_t a) {
+    return (a + 23) * 12;
+  }
+
+The matrix type extension supports division on a matrix and a scalar but not on a matrix and a matrix.
+
+.. code-block:: c++
+  typedef float m4x4_t __attribute__((matrix_type(4, 4)));
+
+  m4x4_t f(m4x4_t a) {
+    a = a / 3.0;
+    return a;
+  }
+
+The matrix type extension supports compound assignments for addition, subtraction, and multiplication between matrices
+and between a matrix and a scalar, provided their types are consistent.
+
+.. code-block:: c++
+
+  typedef float m4x4_t __attribute__((matrix_type(4, 4)));
+
+  m4x4_t f(m4x4_t a, m4x4_t b) {
+    a += b;
+    a -= b;
+    a *= b;
+    a += 23;
+    a -= 12;
+    return a;
+  }
+
+The matrix type extension supports explicit casts. Implicit type conversion between matrix types is not allowed.
+
+.. code-block:: c++
+
+  typedef int ix5x5 __attribute__((matrix_type(5, 5)));
+  typedef float fx5x5 __attribute__((matrix_type(5, 5)));
+
+  fx5x5 f1(ix5x5 i, fx5x5 f) {
+    return (fx5x5) i;
+  }
+
+
+  template <typename X>
+  using matrix_4_4 = X __attribute__((matrix_type(4, 4)));
+
+  void f2() {
+    matrix_5_5<double> d;
+    matrix_5_5<int> i;
+    i = (matrix_5_5<int>)d;
+    i = static_cast<matrix_5_5<int>>(d);
+  }
 
 Half-Precision Floating Point
 =============================