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In unroll pragma syntax and loop hint metadata, change "enable" forms to a new form using the string "full".

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213772 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Mark Heffernan
2014-07-23 17:31:37 +00:00
parent b1365e35cc
commit e8d7ebcd5a
4 changed files with 65 additions and 103 deletions
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40
docs/LangRef.rst
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@@ -2987,20 +2987,6 @@ identification metadata. The ``llvm.loop.unroll`` metadata are only
optimization hints and the unrolling will only be performed if the
optimizer believes it is safe to do so.
'``llvm.loop.unroll.enable``' Metadata
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This metadata either disables loop unrolling or suggests that the loop
be unrolled fully. The first operand is the string
``llvm.loop.unroll.enable`` and the second operand is a bit. If the
bit operand value is 0 loop unrolling is disabled. A value of 1
indicates that the loop should be fully unrolled. For example:
.. code-block:: llvm
!0 = metadata !{ metadata !"llvm.loop.unroll.enable", i1 0 }
!1 = metadata !{ metadata !"llvm.loop.unroll.enable", i1 1 }
'``llvm.loop.unroll.count``' Metadata
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -3016,12 +3002,26 @@ example:
If the trip count of the loop is less than the unroll count the loop
will be partially unrolled.
If a loop has both a ``llvm.loop.unroll.enable`` metadata and
``llvm.loop.unroll.count`` metadata the behavior depends upon the
value of the ``llvm.loop.unroll.enable`` operand. If the value is 0,
the loop will not be unrolled. If the value is 1, the loop will be
unrolled with a factor determined by the ``llvm.loop.unroll.count``
operand effectively ignoring the ``llvm.loop.unroll.enable`` metadata.
'``llvm.loop.unroll.disable``' Metadata
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This metadata either disables loop unrolling. The metadata has a single operand
which is the string ``llvm.loop.unroll.disable``. For example:
.. code-block:: llvm
!0 = metadata !{ metadata !"llvm.loop.unroll.disable" }
'``llvm.loop.unroll.full``' Metadata
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This metadata either suggests that the loop should be unrolled fully. The
metadata has a single operand which is the string ``llvm.loop.unroll.disable``.
For example:
.. code-block:: llvm
!0 = metadata !{ metadata !"llvm.loop.unroll.full" }
'``llvm.mem``'
^^^^^^^^^^^^^^^