[docs][mips] 10.0 Release notes

MIPS specific part of LLVM 10.0 Release notes for LLVM, Clang and LLD.

Differential Revision: https://reviews.llvm.org/D73108

Author: atanasyan

clang/docs/ReleaseNotes.rst

@@ -110,6 +110,9 @@ Non-comprehensive list of changes in this release
   Clang-specific flag ``-flax-vector-conversions=all``. In a future release of
   Clang, we intend to change the default to ``-fno-lax-vector-conversions``.
 
+* Improved support for ``octeon`` MIPS-family CPU. Added ``octeon+`` to
+  the list of of CPUs accepted by the driver.
+
 New Compiler Flags
 ------------------
 

lld/docs/ReleaseNotes.rst

@@ -30,6 +30,14 @@ ELF Improvements
   with GNU now. (`r375051
   <https://github.com/llvm/llvm-project/commit/48993d5ab9413f0e5b94dfa292a233ce55b09e3e>`_)
 
+* New ``elf32btsmipn32_fbsd`` and ``elf32ltsmipn32_fbsd`` emulations
+  are supported.
+
+* Relax MIPS ``jalr``and ``jr`` instructions marked by the ``R_MIPS_JALR``
+  relocation.
+
+* Reduced size of linked MIPS binaries.
+
 COFF Improvements
 -----------------
 

llvm/docs/ReleaseNotes.rst

@@ -124,8 +124,22 @@ Changes to the ARM Backend
 Changes to the MIPS Target
 --------------------------
 
- During this release ...
-
+* Improved support for ``octeon`` and added support for ``octeon+``
+  MIPS-family CPU.
+* ``min``, ``max``, ``umin``, ``umax`` atomics now supported on MIPS targets.
+* Now PC-relative relocations are generated for ``.eh_frame`` sections when
+  possible. That allows to link MIPS binaries without having to pass the
+  ``-Wl,-z,notext`` option.
+* Fix evaluating J-format branch (``j``, ``jal``, ...) targets when the
+  instruction is not in the first 256 MB region.
+* Fixed ``jal``, ``sc``, ``scs``, ``ll``, ``lld``, ``la``, ``lw``, ``sw``
+  instructions expanding. Now they accept more types of expression as arguments,
+  correctly handle load/store for ``XGOT`` model, expand using less instructions
+  or registers.
+* Initial MIPS support has been added to ``llvm-exegesis``.
+* Generates ``_mcount`` calls using proper MIPS ABI.
+* Improved support of GlobalISel instruction selection framework. This feature
+  is still in experimental state for MIPS targets though.
 
 Changes to the PowerPC Target
 -----------------------------