the first parameter. This is not a valid attribute for return
values.
+``align <n>``
+ This indicates that the pointer value may be assumed by the optimizer to
+ have the specified alignment.
+
+ Note that this attribute has additional semantics when combined with the
+ ``byval`` attribute.
+
.. _noalias:
``noalias``
passed in is non-null, or the callee must ensure that the returned pointer
is non-null.
+``dereferenceable(<n>)``
+ This indicates that the parameter or return pointer is dereferenceable. This
+ attribute may only be applied to pointer typed parameters. A pointer that
+ is dereferenceable can be loaded from speculatively without a risk of
+ trapping. The number of bytes known to be dereferenceable must be provided
+ in parentheses. It is legal for the number of bytes to be less than the
+ size of the pointee type. The ``nonnull`` attribute does not imply
+ dereferenceability (consider a pointer to one element past the end of an
+ array), however ``dereferenceable(<n>)`` does imply ``nonnull`` in
+ ``addrspace(0)`` (which is the default address space).
+
.. _gc:
Garbage Collector Names
!0 = metadata !{ metadata !0 }
!1 = metadata !{ metadata !1 }
-The loop identifier metadata can be used to specify additional per-loop
-metadata. Any operands after the first operand can be treated as user-defined
-metadata. For example the ``llvm.loop.vectorize.unroll`` metadata is understood
-by the loop vectorizer to indicate how many times to unroll the loop:
+The loop identifier metadata can be used to specify additional
+per-loop metadata. Any operands after the first operand can be treated
+as user-defined metadata. For example the ``llvm.loop.unroll.count``
+suggests an unroll factor to the loop unroller:
.. code-block:: llvm
br i1 %exitcond, label %._crit_edge, label %.lr.ph, !llvm.loop !0
...
!0 = metadata !{ metadata !0, metadata !1 }
- !1 = metadata !{ metadata !"llvm.loop.vectorize.unroll", i32 2 }
+ !1 = metadata !{ metadata !"llvm.loop.unroll.count", i32 4 }
+
+'``llvm.loop.vectorize``' and '``llvm.loop.interleave``'
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Metadata prefixed with ``llvm.loop.vectorize`` or ``llvm.loop.interleave`` are
+used to control per-loop vectorization and interleaving parameters such as
+vectorization width and interleave count. These metadata should be used in
+conjunction with ``llvm.loop`` loop identification metadata. The
+``llvm.loop.vectorize`` and ``llvm.loop.interleave`` metadata are only
+optimization hints and the optimizer will only interleave and vectorize loops if
+it believes it is safe to do so. The ``llvm.mem.parallel_loop_access`` metadata
+which contains information about loop-carried memory dependencies can be helpful
+in determining the safety of these transformations.
+
+'``llvm.loop.interleave.count``' Metadata
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This metadata suggests an interleave count to the loop interleaver.
+The first operand is the string ``llvm.loop.interleave.count`` and the
+second operand is an integer specifying the interleave count. For
+example:
+
+.. code-block:: llvm
+
+ !0 = metadata !{ metadata !"llvm.loop.interleave.count", i32 4 }
+
+Note that setting ``llvm.loop.interleave.count`` to 1 disables interleaving
+multiple iterations of the loop. If ``llvm.loop.interleave.count`` is set to 0
+then the interleave count will be determined automatically.
+
+'``llvm.loop.vectorize.enable``' Metadata
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This metadata selectively enables or disables vectorization for the loop. The
+first operand is the string ``llvm.loop.vectorize.enable`` and the second operand
+is a bit. If the bit operand value is 1 vectorization is enabled. A value of
+0 disables vectorization:
+
+.. code-block:: llvm
+
+ !0 = metadata !{ metadata !"llvm.loop.vectorize.enable", i1 0 }
+ !1 = metadata !{ metadata !"llvm.loop.vectorize.enable", i1 1 }
+
+'``llvm.loop.vectorize.width``' Metadata
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This metadata sets the target width of the vectorizer. The first
+operand is the string ``llvm.loop.vectorize.width`` and the second
+operand is an integer specifying the width. For example:
+
+.. code-block:: llvm
+
+ !0 = metadata !{ metadata !"llvm.loop.vectorize.width", i32 4 }
+
+Note that setting ``llvm.loop.vectorize.width`` to 1 disables
+vectorization of the loop. If ``llvm.loop.vectorize.width`` is set to
+0 or if the loop does not have this metadata the width will be
+determined automatically.
+
+'``llvm.loop.unroll``'
+^^^^^^^^^^^^^^^^^^^^^^
+
+Metadata prefixed with ``llvm.loop.unroll`` are loop unrolling
+optimization hints such as the unroll factor. ``llvm.loop.unroll``
+metadata should be used in conjunction with ``llvm.loop`` loop
+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
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This metadata suggests an unroll factor to the loop unroller. The
+first operand is the string ``llvm.loop.unroll.count`` and the second
+operand is a positive integer specifying the unroll factor. For
+example:
+
+.. code-block:: llvm
+
+ !0 = metadata !{ metadata !"llvm.loop.unroll.count", i32 4 }
+
+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.mem``'
^^^^^^^^^^^^^^^
!1 = metadata !{ metadata !1 } ; an identifier for the inner loop
!2 = metadata !{ metadata !2 } ; an identifier for the outer loop
-'``llvm.loop.vectorize``'
-^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Metadata prefixed with ``llvm.loop.vectorize`` is used to control per-loop
-vectorization parameters such as vectorization factor and unroll factor.
-
-``llvm.loop.vectorize`` metadata should be used in conjunction with
-``llvm.loop`` loop identification metadata.
-
-'``llvm.loop.vectorize.unroll``' Metadata
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-This metadata instructs the loop vectorizer to unroll the specified
-loop exactly ``N`` times.
-
-The first operand is the string ``llvm.loop.vectorize.unroll`` and the second
-operand is an integer specifying the unroll factor. For example:
-
-.. code-block:: llvm
-
- !0 = metadata !{ metadata !"llvm.loop.vectorize.unroll", i32 4 }
-
-Note that setting ``llvm.loop.vectorize.unroll`` to 1 disables
-unrolling of the loop.
-
-If ``llvm.loop.vectorize.unroll`` is set to 0 then the amount of
-unrolling will be determined automatically.
-
-'``llvm.loop.vectorize.width``' Metadata
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-This metadata sets the target width of the vectorizer to ``N``. Without
-this metadata, the vectorizer will choose a width automatically.
-Regardless of this metadata, the vectorizer will only vectorize loops if
-it believes it is valid to do so.
-
-The first operand is the string ``llvm.loop.vectorize.width`` and the
-second operand is an integer specifying the width. For example:
-
-.. code-block:: llvm
-
- !0 = metadata !{ metadata !"llvm.loop.vectorize.width", i32 4 }
-
-Note that setting ``llvm.loop.vectorize.width`` to 1 disables
-vectorization of the loop.
-
-If ``llvm.loop.vectorize.width`` is set to 0 then the width will be
-determined automatically.
-
Module Flags Metadata
=====================
::
- declare i16 @llvm.convert.to.fp16(float %a)
+ declare i16 @llvm.convert.to.fp16.f32(float %a)
+ declare i16 @llvm.convert.to.fp16.f64(double %a)
Overview:
"""""""""
-The '``llvm.convert.to.fp16``' intrinsic function performs a conversion
-from single precision floating point format to half precision floating
-point format.
+The '``llvm.convert.to.fp16``' intrinsic function performs a conversion from a
+conventional floating point type to half precision floating point format.
Arguments:
""""""""""
Semantics:
""""""""""
-The '``llvm.convert.to.fp16``' intrinsic function performs a conversion
-from single precision floating point format to half precision floating
-point format. The return value is an ``i16`` which contains the
-converted number.
+The '``llvm.convert.to.fp16``' intrinsic function performs a conversion from a
+conventional floating point format to half precision floating point format. The
+return value is an ``i16`` which contains the converted number.
Examples:
"""""""""
.. code-block:: llvm
- %res = call i16 @llvm.convert.to.fp16(float %a)
+ %res = call i16 @llvm.convert.to.fp16.f32(float %a)
store i16 %res, i16* @x, align 2
.. _int_convert_from_fp16:
::
- declare float @llvm.convert.from.fp16(i16 %a)
+ declare float @llvm.convert.from.fp16.f32(i16 %a)
+ declare double @llvm.convert.from.fp16.f64(i16 %a)
Overview:
"""""""""
projects / oota-llvm.git / blobdiff