exists for defining a dll interface, the compiler, assembler and linker know
it is externally referenced and must refrain from deleting the symbol.
-Named Types
------------
+Structure Types
+---------------
+
+LLVM IR allows you to specify both "identified" and "literal" :ref:`structure
+types <t_struct>`. Literal types are uniqued structurally, but identified types
+are never uniqued. An :ref:`opaque structural type <t_opaque>` can also be used
+to forward declare a type which is not yet available.
-LLVM IR allows you to specify name aliases for certain types. This can
-make it easier to read the IR and make the IR more condensed
-(particularly when recursive types are involved). An example of a name
-specification is:
+An example of a identified structure specification is:
.. code-block:: llvm
%mytype = type { %mytype*, i32 }
-You may give a name to any :ref:`type <typesystem>` except
-":ref:`void <t_void>`". Type name aliases may be used anywhere a type is
-expected with the syntax "%mytype".
-
-Note that type names are aliases for the structural type that they
-indicate, and that you can therefore specify multiple names for the same
-type. This often leads to confusing behavior when dumping out a .ll
-file. Since LLVM IR uses structural typing, the name is not part of the
-type. When printing out LLVM IR, the printer will pick *one name* to
-render all types of a particular shape. This means that if you have code
-where two different source types end up having the same LLVM type, that
-the dumper will sometimes print the "wrong" or unexpected type. This is
-an important design point and isn't going to change.
+Prior to the LLVM 3.0 release, identified types were structurally uniqued. Only
+literal types are uniqued in recent versions of LLVM.
.. _globalvars:
define [linkage] [visibility] [DLLStorageClass]
[cconv] [ret attrs]
<ResultType> @<FunctionName> ([argument list])
- [fn Attrs] [section "name"] [align N]
+ [unnamed_addr] [fn Attrs] [section "name"] [align N]
[gc] [prefix Constant] { ... }
.. _langref_aliases:
An argument allocation may be used by a call at most once because
the call may deallocate it. The ``inalloca`` attribute cannot be
used in conjunction with other attributes that affect argument
- storage, like ``inreg``, ``nest``, ``sret``, or ``byval``.
+ storage, like ``inreg``, ``nest``, ``sret``, or ``byval``. The
+ ``inalloca`` attribute also disables LLVM's implicit lowering of
+ large aggregate return values, which means that frontend authors
+ must lower them with ``sret`` pointers.
When the call site is reached, the argument allocation must have
been the most recent stack allocation that is still live, or the
- Calls to alloca() with variable sizes or constant sizes greater than
``ssp-buffer-size``.
+ Variables that are identified as requiring a protector will be arranged
+ on the stack such that they are adjacent to the stack protector guard.
+
If a function that has an ``ssp`` attribute is inlined into a
function that doesn't have an ``ssp`` attribute, then the resulting
function will have an ``ssp`` attribute.
stack smashing protector. This overrides the ``ssp`` function
attribute.
+ Variables that are identified as requiring a protector will be arranged
+ on the stack such that they are adjacent to the stack protector guard.
+ The specific layout rules are:
+
+ #. Large arrays and structures containing large arrays
+ (``>= ssp-buffer-size``) are closest to the stack protector.
+ #. Small arrays and structures containing small arrays
+ (``< ssp-buffer-size``) are 2nd closest to the protector.
+ #. Variables that have had their address taken are 3rd closest to the
+ protector.
+
If a function that has an ``sspreq`` attribute is inlined into a
function that doesn't have an ``sspreq`` attribute or which has an
``ssp`` or ``sspstrong`` attribute, then the resulting function will have
- Calls to alloca().
- Local variables that have had their address taken.
+ Variables that are identified as requiring a protector will be arranged
+ on the stack such that they are adjacent to the stack protector guard.
+ The specific layout rules are:
+
+ #. Large arrays and structures containing large arrays
+ (``>= ssp-buffer-size``) are closest to the stack protector.
+ #. Small arrays and structures containing small arrays
+ (``< ssp-buffer-size``) are 2nd closest to the protector.
+ #. Variables that have had their address taken are 3rd closest to the
+ protector.
+
This overrides the ``ssp`` function attribute.
If a function that has an ``sspstrong`` attribute is inlined into a
* - ``ppc_fp128``
- 128-bit floating point value (two 64-bits)
-.. _t_x86mmx:
-
-X86mmx Type
-"""""""""""
+X86_mmx Type
+""""""""""""
:Overview:
-The x86mmx type represents a value held in an MMX register on an x86
+The x86_mmx type represents a value held in an MMX register on an x86
machine. The operations allowed on it are quite limited: parameters and
return values, load and store, and bitcast. User-specified MMX
instructions are represented as intrinsic or asm calls with arguments
::
- x86mmx
+ x86_mmx
.. _t_pointer:
followed by 4 hexadecimal digits. All hexadecimal formats are big-endian
(sign bit at the left).
-There are no constants of type x86mmx.
+There are no constants of type x86_mmx.
.. _complexconstants:
for.body:
...
- %0 = load i32* %arrayidx, align 4, !llvm.mem.parallel_loop_access !0
+ %val0 = load i32* %arrayidx, !llvm.mem.parallel_loop_access !0
...
- store i32 %0, i32* %arrayidx4, align 4, !llvm.mem.parallel_loop_access !0
+ store i32 %val0, i32* %arrayidx1, !llvm.mem.parallel_loop_access !0
...
br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !0
.. code-block:: llvm
outer.for.body:
- ...
+ ...
+ %val1 = load i32* %arrayidx3, !llvm.mem.parallel_loop_access !2
+ ...
+ br label %inner.for.body
inner.for.body:
...
- %0 = load i32* %arrayidx, align 4, !llvm.mem.parallel_loop_access !0
+ %val0 = load i32* %arrayidx1, !llvm.mem.parallel_loop_access !0
...
- store i32 %0, i32* %arrayidx4, align 4, !llvm.mem.parallel_loop_access !0
+ store i32 %val0, i32* %arrayidx2, !llvm.mem.parallel_loop_access !0
...
br i1 %exitcond, label %inner.for.end, label %inner.for.body, !llvm.loop !1
inner.for.end:
...
- %0 = load i32* %arrayidx, align 4, !llvm.mem.parallel_loop_access !0
- ...
- store i32 %0, i32* %arrayidx4, align 4, !llvm.mem.parallel_loop_access !0
+ store i32 %val1, i32* %arrayidx4, !llvm.mem.parallel_loop_access !2
...
br i1 %exitcond, label %outer.for.end, label %outer.for.body, !llvm.loop !2
::
- <result> = alloca
<type>[, inalloca][, <ty> <NumElements>][, align <alignment>] ; yields {type*}:result
+ <result> = alloca
[inalloca] <type> [, <ty> <NumElements>] [, align <alignment>] ; yields {type*}:result
Overview:
"""""""""
""""""""""
This function returns the same values as the libm ``fma`` functions
-would.
+would, and does not set errno.
'``llvm.fabs.*``' Intrinsic
^^^^^^^^^^^^^^^^^^^^^^^^^^^
not be performed between the multiplication and addition steps if the
code generator fuses the operations. Fusion is not guaranteed, even if
the target platform supports it. If a fused multiply-add is required the
-corresponding llvm.fma.\* intrinsic function should be used instead.
+corresponding llvm.fma.\* intrinsic function should be used
+instead. This never sets errno, just as '``llvm.fma.*``'.
Examples:
"""""""""
Syntax:
"""""""
+This is an overloaded intrinsic. You can use ``llvm.expect`` on any
+integer bit width.
+
::
+ declare i1 @llvm.expect.i1(i1 <val>, i1 <expected_val>)
declare i32 @llvm.expect.i32(i32 <val>, i32 <expected_val>)
declare i64 @llvm.expect.i64(i64 <val>, i64 <expected_val>)
projects / oota-llvm.git / blobdiff