-.. _bitcode_format:
-
.. role:: raw-html(raw)
:format: html
provides a mechanism for the file to self-describe "abbreviations", which are
effectively size optimizations for the content.
-LLVM IR files may be optionally embedded into a `wrapper`_ structure that makes
-it easy to embed extra data along with LLVM IR files.
+LLVM IR files may be optionally embedded into a `wrapper`_ structure, or in a
+`native object file`_. Both of these mechanisms make it easy to embed extra
+data along with LLVM IR files.
This document first describes the LLVM bitstream format, describes the wrapper
format, then describes the record structure used by LLVM IR files.
* Abbreviations, which specify compression optimizations for the file.
-Note that the :doc:`llvm-bcanalyzer <CommandGuide/llvm-bcanalyzer>`
-tool can be used to dump and inspect arbitrary bitstreams, which is very useful
-for understanding the encoding.
+Note that the :doc:`llvm-bcanalyzer <CommandGuide/llvm-bcanalyzer>` tool can be
+used to dump and inspect arbitrary bitstreams, which is very useful for
+understanding the encoding.
.. _magic number:
in bytes of the stream. CPUType is a target-specific value that can be used to
encode the CPU of the target.
+.. _native object file:
+
+Native Object File Wrapper Format
+=================================
+
+Bitcode files for LLVM IR may also be wrapped in a native object file
+(i.e. ELF, COFF, Mach-O). The bitcode must be stored in a section of the
+object file named ``.llvmbc``. This wrapper format is useful for accommodating
+LTO in compilation pipelines where intermediate objects must be native object
+files which contain metadata in other sections.
+
+Not all tools support this format.
+
.. _encoding of LLVM IR:
LLVM IR Encoding
MODULE_CODE_GLOBALVAR Record
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-``[GLOBALVAR, pointer type, isconst, initid, linkage, alignment, section, visibility, threadlocal, unnamed_addr]``
+``[GLOBALVAR, pointer type, isconst, initid, linkage, alignment, section, visibility, threadlocal, unnamed_addr, dllstorageclass]``
The ``GLOBALVAR`` record (code 7) marks the declaration or definition of a
global variable. The operand fields are:
* ``weak_odr``: code 10
* ``linkonce_odr``: code 11
* ``available_externally``: code 12
- * ``linker_private``: code 13
+ * deprecated : code 13
+ * deprecated : code 14
* alignment*: The logarithm base 2 of the variable's requested alignment, plus 1
* *unnamed_addr*: If present and non-zero, indicates that the variable has
``unnamed_addr``
+.. _bcdllstorageclass:
+
+* *dllstorageclass*: If present, an encoding of the DLL storage class of this variable:
+
+ * ``default``: code 0
+ * ``dllimport``: code 1
+ * ``dllexport``: code 2
+
.. _FUNCTION:
MODULE_CODE_FUNCTION Record
^^^^^^^^^^^^^^^^^^^^^^^^^^^
-``[FUNCTION, type, callingconv, isproto, linkage, paramattr, alignment, section, visibility, gc]``
+``[FUNCTION, type, callingconv, isproto, linkage, paramattr, alignment, section, visibility, gc, prologuedata, dllstorageclass, comdat, prefixdata]``
The ``FUNCTION`` record (code 8) marks the declaration or definition of a
function. The operand fields are:
* ``ccc``: code 0
* ``fastcc``: code 8
* ``coldcc``: code 9
+ * ``webkit_jscc``: code 12
+ * ``anyregcc``: code 13
+ * ``preserve_mostcc``: code 14
+ * ``preserve_allcc``: code 15
* ``x86_stdcallcc``: code 64
* ``x86_fastcallcc``: code 65
* ``arm_apcscc``: code 66
* *unnamed_addr*: If present and non-zero, indicates that the function has
``unnamed_addr``
+* *prologuedata*: If non-zero, the value index of the prologue data for this function,
+ plus 1.
+
+* *dllstorageclass*: An encoding of the
+ :ref:`dllstorageclass<bcdllstorageclass>` of this function
+
+* *comdat*: An encoding of the COMDAT of this function
+
+* *prefixdata*: If non-zero, the value index of the prefix data for this function,
+ plus 1.
+
+
MODULE_CODE_ALIAS Record
^^^^^^^^^^^^^^^^^^^^^^^^
-``[ALIAS, alias type, aliasee val#, linkage, visibility]``
+``[ALIAS, alias type, aliasee val#, linkage, visibility, dllstorageclass]``
The ``ALIAS`` record (code 9) marks the definition of an alias. The operand
fields are
* *visibility*: If present, an encoding of the `visibility`_ of the alias
+* *dllstorageclass*: If present, an encoding of the
+ :ref:`dllstorageclass<bcdllstorageclass>` of the alias
+
MODULE_CODE_PURGEVALS Record
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
VALUE_SYMTAB_BLOCK Contents
---------------------------
-The ``VALUE_SYMTAB_BLOCK`` block (id 14) ...
+The ``VALUE_SYMTAB_BLOCK`` block (id 14) ...
.. _METADATA_BLOCK: