an optional :ref:`garbage collector name <gc>`, an optional :ref:`prefix <prefixdata>`,
an optional :ref:`prologue <prologuedata>`,
an optional :ref:`personality <personalityfn>`,
+an optional list of attached :ref:`metadata <metadata>`,
an opening curly brace, a list of basic blocks, and a closing curly brace.
LLVM function declarations consist of the "``declare``" keyword, an
<ResultType> @<FunctionName> ([argument list])
[unnamed_addr] [fn Attrs] [section "name"] [comdat [($name)]]
[align N] [gc] [prefix Constant] [prologue Constant]
- [personality Constant] { ... }
+ [personality Constant] (!name !N)* { ... }
The argument list is a comma separated sequence of arguments where each
argument is of the following form:
Syntax::
- @<Name> = [Linkage] [Visibility] [DLLStorageClass] [ThreadLocal] [unnamed_addr] alias <AliaseeTy> @<Aliasee>
+ @<Name> = [Linkage] [Visibility] [DLLStorageClass] [ThreadLocal] [unnamed_addr] alias <AliaseeTy>
, <AliaseeTy>* @<Aliasee>
The linkage must be one of ``private``, ``internal``, ``linkonce``, ``weak``,
``linkonce_odr``, ``weak_odr``, ``external``. Note that some system linkers
This function attribute indicates that the function never returns
normally. This produces undefined behavior at runtime if the
function ever does dynamically return.
+``norecurse``
+ This function attribute indicates that the function does not call itself
+ either directly or indirectly down any possible call path. This produces
+ undefined behavior at runtime if the function ever does recurse.
``nounwind``
This function attribute indicates that the function never raises an
exception. If the function does raise an exception, its runtime
incorrect and will change program semantics.
Syntax::
+
operand bundle set ::= '[' operand bundle ']'
operand bundle ::= tag '(' [ bundle operand ] (, bundle operand )* ')'
bundle operand ::= SSA value
restrictions, LLVM does not need to have special knowledge of the
operand bundle to not miscompile programs containing it.
- - The bundle operands for an unknown operand bundle escape in unknown
- ways before control is transferred to the callee or invokee.
-
- - Calls and invokes with operand bundles have unknown read / write
- effect on the heap on entry and exit (even if the call target is
- ``readnone`` or ``readonly``).
-
- - An operand bundle at a call site cannot change the implementation
- of the called function. Inter-procedural optimizations work as
- usual as long as they take into account the first two properties.
+- The bundle operands for an unknown operand bundle escape in unknown
+ ways before control is transferred to the callee or invokee.
+- Calls and invokes with operand bundles have unknown read / write
+ effect on the heap on entry and exit (even if the call target is
+ ``readnone`` or ``readonly``), unless they're overriden with
+ callsite specific attributes.
+- An operand bundle at a call site cannot change the implementation
+ of the called function. Inter-procedural optimizations work as
+ usual as long as they take into account the first two properties.
.. _moduleasm:
symbols get a ``_`` prefix.
* ``w``: Windows COFF prefix: Similar to Mach-O, but stdcall and fastcall
functions also get a suffix based on the frame size.
+ * ``x``: Windows x86 COFF prefix: Similar to Windows COFF, but use a ``_``
+ prefix for ``__cdecl`` functions.
``n<size1>:<size2>:<size3>...``
This specifies a set of native integer widths for the target CPU in
bits. For example, it might contain ``n32`` for 32-bit PowerPC,
call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
-Metadata can be attached with an instruction. Here metadata ``!21`` is
-attached to the ``add`` instruction using the ``!dbg`` identifier:
+Metadata can be attached to an instruction. Here metadata ``!21`` is attached
+to the ``add`` instruction using the ``!dbg`` identifier:
.. code-block:: llvm
%indvar.next = add i64 %indvar, 1, !dbg !21
+Metadata can also be attached to a function definition. Here metadata ``!22``
+is attached to the ``foo`` function using the ``!dbg`` identifier:
+
+.. code-block:: llvm
+
+ define void @foo() !dbg !22 {
+ ret void
+ }
+
More information about specific metadata nodes recognized by the
optimizers and code generator is found below.
DISubprogram
""""""""""""
-``DISubprogram`` nodes represent functions from the source language. The
-``variables:`` field points at :ref:`variables <DILocalVariable>` that must be
-retained, even if their IR counterparts are optimized out of the IR. The
-``type:`` field must point at an :ref:`DISubroutineType`.
+``DISubprogram`` nodes represent functions from the source language. A
+``DISubprogram`` may be attached to a function definition using ``!dbg``
+metadata. The ``variables:`` field points at :ref:`variables <DILocalVariable>`
+that must be retained, even if their IR counterparts are optimized out of
+the IR. The ``type:`` field must point at an :ref:`DISubroutineType`.
.. code-block:: llvm
- !0 = !DISubprogram(name: "foo", linkageName: "_Zfoov", scope: !1,
- file: !2, line: 7, type: !3, isLocal: true,
- isDefinition: false, scopeLine: 8, containingType: !4,
- virtuality: DW_VIRTUALITY_pure_virtual, virtualIndex: 10,
- flags: DIFlagPrototyped, isOptimized: true,
- function: void ()* @_Z3foov,
- templateParams: !5, declaration: !6, variables: !7)
+ define void @_Z3foov() !dbg !0 {
+ ...
+ }
+
+ !0 = distinct !DISubprogram(name: "foo", linkageName: "_Zfoov", scope: !1,
+ file: !2, line: 7, type: !3, isLocal: true,
+ isDefinition: false, scopeLine: 8,
+ containingType: !4,
+ virtuality: DW_VIRTUALITY_pure_virtual,
+ virtualIndex: 10, flags: DIFlagPrototyped,
+ isOptimized: true, templateParams: !5,
+ declaration: !6, variables: !7)
.. _DILexicalBlock:
""""""""""
The first operand of an '``extractvalue``' instruction is a value of
-:ref:`struct <t_struct>` or :ref:`array <t_array>` type. The operands are
+:ref:`struct <t_struct>` or :ref:`array <t_array>` type. The other operands are
constant indices to specify which value to extract in a similar manner
as indices in a '``getelementptr``' instruction.
projects / oota-llvm.git / blobdiff