[GC Docs] Update LangRef to link to Statepoint docs

Add a brief section linking to the experimental statepoint intrinsics analogous to the one we have linking to patchpoint.

While I'm here, cleanup some wording about what the gc "name" attribute actually means.  It's not the name of a *collector* it's the name of the *strategy* which may be compatible with multiple collectors.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230576 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/GarbageCollection.rst b/docs/GarbageCollection.rst
index 5d1588a7fe41e45efa4e62de2c5ecb5f01888926..a1557fcdb0994f993ac76b3b256f5be013ce85e1 100644 (file)
--- a/docs/GarbageCollection.rst
+++ b/docs/GarbageCollection.rst
@@ -386,6 +386,8 @@ greater performance impact since pointer reads are more frequent than writes.
 
 .. _plugin:
 
+.. _builtin-gc-strategies:
+
 Built In GC Strategies
 ======================
 

diff --git a/docs/LangRef.rst b/docs/LangRef.rst
index 6b72e74d54dc657687ec0fc2d3918f809d5fa6be..6706552be868e4b965b5f3871095556397c30dfd 100644 (file)
--- a/docs/LangRef.rst
+++ b/docs/LangRef.rst
@@ -1014,19 +1014,22 @@ Currently, only the following parameter attributes are defined:
 
 .. _gc:
 
-Garbage Collector Names
------------------------
+Garbage Collector Strategy Names
+--------------------------------
 
-Each function may specify a garbage collector name, which is simply a
+Each function may specify a garbage collector strategy name, which is simply a
 string:
 
 .. code-block:: llvm
 
     define void @f() gc "name" { ... }
 
-The compiler declares the supported values of *name*. Specifying a
-collector will cause the compiler to alter its output in order to
-support the named garbage collection algorithm.
+The supported values of *name* includes those :ref:`built in to LLVM 
+<builtin-gc-strategies>` and any provided by loaded plugins.  Specifying a GC
+strategy will cause the compiler to alter its output in order to support the 
+named garbage collection algorithm.  Note that LLVM itself does not contain a 
+garbage collector, this functionality is restricted to generating machine code
+which can interoperate with a collector provided externally.  
 
 .. _prefixdata:
 
@@ -7113,11 +7116,18 @@ stack <int_gcroot>`, as well as garbage collector implementations that
 require :ref:`read <int_gcread>` and :ref:`write <int_gcwrite>` barriers.
 Front-ends for type-safe garbage collected languages should generate
 these intrinsics to make use of the LLVM garbage collectors. For more
-details, see `Accurate Garbage Collection with
-LLVM <GarbageCollection.html>`_.
+details, see `Garbage Collection with LLVM <GarbageCollection.html>`_.
+
+Experimental Statepoint Intrinsics
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-The garbage collection intrinsics only operate on objects in the generic
-address space (address space zero).
+LLVM provides an second experimental set of intrinsics for describing garbage
+collection safepoints in compiled code.  These intrinsics are an alternative 
+to the ``llvm.gcroot`` intrinsics, but are compatible with the ones for 
+:ref:`read <int_gcread>` and :ref:`write <int_gcwrite>` barriers.  The 
+differences in approach are covered in the `Garbage Collection with LLVM 
+<GarbageCollection.html>`_ documentation.  The intrinsics themselves are 
+described in :doc:`Statepoints`.
 
 .. _int_gcroot: