}
; Named metadata
- !0 = metadata !{i32 42, null, metadata !"string"}
+ !0 = !{i32 42, null, !"string"}
!foo = !{!0}
This example is made up of a :ref:`global variable <globalvars>` named
Syntax::
; Some unnamed metadata nodes, which are referenced by the named metadata.
- !0 = metadata !{metadata !"zero"}
- !1 = metadata !{metadata !"one"}
- !2 = metadata !{metadata !"two"}
+ !0 = !{!"zero"}
+ !1 = !{!"one"}
+ !2 = !{!"two"}
; A named metadata.
!name = !{!0, !1, !2}
having to print large zero initializers (e.g. for large arrays) and
is always exactly equivalent to using explicit zero initializers.
**Metadata node**
- A metadata node is a structure-like constant with :ref:`metadata
- type <t_metadata>`. For example:
- "``metadata !{ i32 0, metadata !"test" }``". Unlike other
- constants that are meant to be interpreted as part of the
- instruction stream, metadata is a place to attach additional
+ A metadata node is a constant tuple without types. For example:
+ "``!{!0, !{!2, !0}, !"test"}``". Metadata can reference constant values,
+ for example: "``!{!0, i32 0, i8* @global, i64 (i64)* @function, !"str"}``".
+ Unlike other typed constants that are meant to be interpreted as part of
+ the instruction stream, metadata is a place to attach additional
information such as debug info.
Global Variable and Function Addresses
.. _metadata:
-Metadata Nodes and Metadata Strings
------------------------------------
+Metadata
+========
LLVM IR allows metadata to be attached to instructions in the program
that can convey extra information about the code to the optimizers and
code generator. One example application of metadata is source-level
debug information. There are two metadata primitives: strings and nodes.
-All metadata has the ``metadata`` type and is identified in syntax by a
-preceding exclamation point ('``!``').
+
+Metadata does not have a type, and is not a value. If referenced from a
+``call`` instruction, it uses the ``metadata`` type.
+
+All metadata are identified in syntax by a exclamation point ('``!``').
+
+Metadata Nodes and Metadata Strings
+-----------------------------------
A metadata string is a string surrounded by double quotes. It can
contain any character by escaping non-printable characters with
.. code-block:: llvm
- !{ metadata !"test\00", i32 10}
+ !{ !"test\00", i32 10}
A :ref:`named metadata <namedmetadatastructure>` is a collection of
metadata nodes, which can be looked up in the module symbol table. For
.. code-block:: llvm
- !foo = metadata !{!4, !3}
+ !foo = !{!4, !3}
Metadata can be used as function arguments. Here ``llvm.dbg.value``
function is using two metadata arguments:
.. code-block:: llvm
- !0 = metadata !{ metadata !"an example type tree" }
- !1 = metadata !{ metadata !"int", metadata !0 }
- !2 = metadata !{ metadata !"float", metadata !0 }
- !3 = metadata !{ metadata !"const float", metadata !2, i64 1 }
+ !0 = !{ !"an example type tree" }
+ !1 = !{ !"int", !0 }
+ !2 = !{ !"float", !0 }
+ !3 = !{ !"const float", !2, i64 1 }
The first field is an identity field. It can be any value, usually a
metadata string, which uniquely identifies the type. The most important
.. code-block:: llvm
- !4 = metadata !{ i64 0, i64 4, metadata !1, i64 8, i64 4, metadata !2 }
+ !4 = !{ i64 0, i64 4, !1, i64 8, i64 4, !2 }
This describes a struct with two fields. The first is at offset 0 bytes
with size 4 bytes, and has tbaa tag !1. The second is at offset 8 bytes
.. code-block:: llvm
; Two scope domains:
- !0 = metadata !{metadata !0}
- !1 = metadata !{metadata !1}
+ !0 = !{!0}
+ !1 = !{!1}
; Some scopes in these domains:
- !2 = metadata !{metadata !2, metadata !0}
- !3 = metadata !{metadata !3, metadata !0}
- !4 = metadata !{metadata !4, metadata !1}
+ !2 = !{!2, !0}
+ !3 = !{!3, !0}
+ !4 = !{!4, !1}
; Some scope lists:
- !5 = metadata !{metadata !4} ; A list containing only scope !4
- !6 = metadata !{metadata !4, metadata !3, metadata !2}
- !7 = metadata !{metadata !3}
+ !5 = !{!4} ; A list containing only scope !4
+ !6 = !{!4, !3, !2}
+ !7 = !{!3}
; These two instructions don't alias:
%0 = load float* %c, align 4, !alias.scope !5
.. code-block:: llvm
- !0 = metadata !{ float 2.5 } ; maximum acceptable inaccuracy is 2.5 ULPs
+ !0 = !{ float 2.5 } ; maximum acceptable inaccuracy is 2.5 ULPs
'``range``' Metadata
^^^^^^^^^^^^^^^^^^^^
%d = invoke i8 @bar() to label %cont
unwind label %lpad, !range !3 ; Can only be -2, -1, 3, 4 or 5
...
- !0 = metadata !{ i8 0, i8 2 }
- !1 = metadata !{ i8 255, i8 2 }
- !2 = metadata !{ i8 0, i8 2, i8 3, i8 6 }
- !3 = metadata !{ i8 -2, i8 0, i8 3, i8 6 }
+ !0 = !{ i8 0, i8 2 }
+ !1 = !{ i8 255, i8 2 }
+ !2 = !{ i8 0, i8 2, i8 3, i8 6 }
+ !3 = !{ i8 -2, i8 0, i8 3, i8 6 }
'``llvm.loop``'
^^^^^^^^^^^^^^^
.. code-block:: llvm
- !0 = metadata !{ metadata !0 }
- !1 = metadata !{ metadata !1 }
+ !0 = !{!0}
+ !1 = !{!1}
The loop identifier metadata can be used to specify additional
per-loop metadata. Any operands after the first operand can be treated
br i1 %exitcond, label %._crit_edge, label %.lr.ph, !llvm.loop !0
...
- !0 = metadata !{ metadata !0, metadata !1 }
- !1 = metadata !{ metadata !"llvm.loop.unroll.count", i32 4 }
+ !0 = !{!0, !1}
+ !1 = !{!"llvm.loop.unroll.count", i32 4}
'``llvm.loop.vectorize``' and '``llvm.loop.interleave``'
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: llvm
- !0 = metadata !{ metadata !"llvm.loop.interleave.count", i32 4 }
+ !0 = !{!"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
.. code-block:: llvm
- !0 = metadata !{ metadata !"llvm.loop.vectorize.enable", i1 0 }
- !1 = metadata !{ metadata !"llvm.loop.vectorize.enable", i1 1 }
+ !0 = !{!"llvm.loop.vectorize.enable", i1 0}
+ !1 = !{!"llvm.loop.vectorize.enable", i1 1}
'``llvm.loop.vectorize.width``' Metadata
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: llvm
- !0 = metadata !{ metadata !"llvm.loop.vectorize.width", i32 4 }
+ !0 = !{!"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
.. code-block:: llvm
- !0 = metadata !{ metadata !"llvm.loop.unroll.count", i32 4 }
+ !0 = !{!"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.
.. code-block:: llvm
- !0 = metadata !{ metadata !"llvm.loop.unroll.disable" }
+ !0 = !{!"llvm.loop.unroll.disable"}
'``llvm.loop.unroll.full``' Metadata
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: llvm
- !0 = metadata !{ metadata !"llvm.loop.unroll.full" }
+ !0 = !{!"llvm.loop.unroll.full"}
'``llvm.mem``'
^^^^^^^^^^^^^^^
for.end:
...
- !0 = metadata !{ metadata !0 }
+ !0 = !{!0}
It is also possible to have nested parallel loops. In that case the
memory accesses refer to a list of loop identifier metadata nodes instead of
outer.for.end: ; preds = %for.body
...
- !0 = metadata !{ metadata !1, metadata !2 } ; a list of loop identifiers
- !1 = metadata !{ metadata !1 } ; an identifier for the inner loop
- !2 = metadata !{ metadata !2 } ; an identifier for the outer loop
+ !0 = !{!1, !2} ; a list of loop identifiers
+ !1 = !{!1} ; an identifier for the inner loop
+ !2 = !{!2} ; an identifier for the outer loop
Module Flags Metadata
=====================
.. code-block:: llvm
- !0 = metadata !{ i32 1, metadata !"foo", i32 1 }
- !1 = metadata !{ i32 4, metadata !"bar", i32 37 }
- !2 = metadata !{ i32 2, metadata !"qux", i32 42 }
- !3 = metadata !{ i32 3, metadata !"qux",
- metadata !{
- metadata !"foo", i32 1
+ !0 = !{ i32 1, !"foo", i32 1 }
+ !1 = !{ i32 4, !"bar", i32 37 }
+ !2 = !{ i32 2, !"qux", i32 42 }
+ !3 = !{ i32 3, !"qux",
+ !{
+ !"foo", i32 1
}
}
!llvm.module.flags = !{ !0, !1, !2, !3 }
::
- metadata !{ metadata !"foo", i32 1 }
+ !{ !"foo", i32 1 }
The behavior is to emit an error if the ``llvm.module.flags`` does not
contain a flag with the ID ``!"foo"`` that has the value '1' after linking is
linker options, presumably to link against ``libz`` and the ``Cocoa``
framework::
- !0 = metadata !{ i32 6, metadata !"Linker Options",
- metadata !{
- metadata !{ metadata !"-lz" },
- metadata !{ metadata !"-framework", metadata !"Cocoa" } } }
+ !0 = !{ i32 6, !"Linker Options",
+ !{
+ !{ !"-lz" },
+ !{ !"-framework", !"Cocoa" } } }
!llvm.module.flags = !{ !0 }
The metadata encoding as lists of lists of options, as opposed to a collapsed
enum is the smallest type which can represent all of its values::
!llvm.module.flags = !{!0, !1}
- !0 = metadata !{i32 1, metadata !"short_wchar", i32 1}
- !1 = metadata !{i32 1, metadata !"short_enum", i32 0}
+ !0 = !{i32 1, !"short_wchar", i32 1}
+ !1 = !{i32 1, !"short_enum", i32 0}
.. _intrinsicglobalvariables:
declare i64 @llvm.read_register.i64(metadata)
declare void @llvm.write_register.i32(metadata, i32 @value)
declare void @llvm.write_register.i64(metadata, i64 @value)
- !0 = metadata !{metadata !"sp\00"}
+ !0 = !{!"sp\00"}
Overview:
"""""""""
This instrinsic does *not* empty the instruction pipeline. Modifications
of the current function are outside the scope of the intrinsic.
+'``llvm.instrprof_increment``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+ declare void @llvm.instrprof_increment(i8* <name>, i64 <hash>,
+ i32 <num-counters>, i32 <index>)
+
+Overview:
+"""""""""
+
+The '``llvm.instrprof_increment``' intrinsic can be emitted by a
+frontend for use with instrumentation based profiling. These will be
+lowered by the ``-instrprof`` pass to generate execution counts of a
+program at runtime.
+
+Arguments:
+""""""""""
+
+The first argument is a pointer to a global variable containing the
+name of the entity being instrumented. This should generally be the
+(mangled) function name for a set of counters.
+
+The second argument is a hash value that can be used by the consumer
+of the profile data to detect changes to the instrumented source, and
+the third is the number of counters associated with ``name``. It is an
+error if ``hash`` or ``num-counters`` differ between two instances of
+``instrprof_increment`` that refer to the same name.
+
+The last argument refers to which of the counters for ``name`` should
+be incremented. It should be a value between 0 and ``num-counters``.
+
+Semantics:
+""""""""""
+
+This intrinsic represents an increment of a profiling counter. It will
+cause the ``-instrprof`` pass to generate the appropriate data
+structures and the code to increment the appropriate value, in a
+format that can be written out by a compiler runtime and consumed via
+the ``llvm-profdata`` tool.
+
Standard C Library Intrinsics
-----------------------------
projects / oota-llvm.git / blobdiff