Update documentation for unroll pragmas on loops with runtime trip counts.

This change updates the documentation for the loop unrolling pragma behavior
change in r242047. Specifically, with that change "#pragma unroll" will not
unroll loops with a runtime trip count.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@242048 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/LanguageExtensions.rst b/docs/LanguageExtensions.rst
index 0b4775ba6ad4f2aad615ace193082bfbbacc082b..6a4dd5ccbf3c7db9f01ca877fd82d70bfdf188cf 100644 (file)
--- a/docs/LanguageExtensions.rst
+++ b/docs/LanguageExtensions.rst
@@ -1991,10 +1991,10 @@ compile time. Partial unrolling replicates the loop body within the loop and
 reduces the trip count.
 
 If ``unroll(full)`` is specified the unroller will attempt to fully unroll the
-loop if the trip count is known at compile time. If the loop count is not known
-or the fully unrolled code size is greater than the limit specified by the
-`-pragma-unroll-threshold` command line option the loop will be partially
-unrolled subject to the same limit.
+loop if the trip count is known at compile time. If the fully unrolled code size
+is greater than an internal limit the loop will be partially unrolled up to this
+limit. If the loop count is not known at compile time the loop will not be
+unrolled.
 
 .. code-block:: c++
 
@@ -2006,7 +2006,7 @@ unrolled subject to the same limit.
 The unroll count can be specified explicitly with ``unroll_count(_value_)`` where
 _value_ is a positive integer. If this value is greater than the trip count the
 loop will be fully unrolled. Otherwise the loop is partially unrolled subject
-to the `-pragma-unroll-threshold` limit.
+to the same code size limit as with ``unroll(full)``.
 
 .. code-block:: c++