(``STB_LOCAL`` in the case of ELF) in the object file. This
corresponds to the notion of the '``static``' keyword in C.
``available_externally``
- Globals with "``available_externally``" linkage are never emitted
- into the object file corresponding to the LLVM module. They exist to
- allow inlining and other optimizations to take place given knowledge
- of the definition of the global, which is known to be somewhere
- outside the module. Globals with ``available_externally`` linkage
- are allowed to be discarded at will, and are otherwise the same as
- ``linkonce_odr``. This linkage type is only allowed on definitions,
- not declarations.
+ Globals with "``available_externally``" linkage are never emitted into
+ the object file corresponding to the LLVM module. From the linker's
+ perspective, an ``available_externally`` global is equivalent to
+ an external declaration. They exist to allow inlining and other
+ optimizations to take place given knowledge of the definition of the
+ global, which is known to be somewhere outside the module. Globals
+ with ``available_externally`` linkage are allowed to be discarded at
+ will, and allow inlining and other optimizations. This linkage type is
+ only allowed on definitions, not declarations.
``linkonce``
Globals with "``linkonce``" linkage are merged with other globals of
the same name when linkage occurs. This can be used to implement
thread execution pattern under certain parallel execution models.
Transformations that are execution model agnostic may not make the execution
of a convergent operation control dependent on any additional values.
+``inaccessiblememonly``
+ This attribute indicates that the function may only access memory that
+ is not accessible by the module being compiled. This is a weaker form
+ of ``readnone``.
+``inaccessiblemem_or_argmemonly``
+ This attribute indicates that the function may only access memory that is
+ either not accessible by the module being compiled, or is pointed to
+ by its pointer arguments. This is a weaker form of ``argmemonly``
``inlinehint``
This attribute indicates that the source code contained a hint that
inlining this function is desirable (such as the "inline" keyword in
semantically equivalent to composing the caller's deoptimization
continuation after the callee's deoptimization continuation.
+Funclet Operand Bundles
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Funclet operand bundles are characterized by the ``"funclet"``
+operand bundle tag. These operand bundles indicate that a call site
+is within a particular funclet. There can be at most one
+``"funclet"`` operand bundle attached to a call site and it must have
+exactly one bundle operand.
+
.. _moduleasm:
Module-Level Inline Assembly
The terminator instructions are: ':ref:`ret <i_ret>`',
':ref:`br <i_br>`', ':ref:`switch <i_switch>`',
':ref:`indirectbr <i_indirectbr>`', ':ref:`invoke <i_invoke>`',
-':ref:`resume <i_resume>`', ':ref:`catchpad <i_catchpad>`',
-':ref:`catchendpad <i_catchendpad>`',
+':ref:`resume <i_resume>`', ':ref:`catchswitch <i_catchswitch>`',
':ref:`catchret <i_catchret>`',
-':ref:`cleanupendpad <i_cleanupendpad>`',
':ref:`cleanupret <i_cleanupret>`',
-':ref:`terminatepad <i_terminatepad>`',
and ':ref:`unreachable <i_unreachable>`'.
.. _i_ret:
resume { i8*, i32 } %exn
-.. _i_catchpad:
+.. _i_catchswitch:
-'``catchpad``' Instruction
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+'``catchswitch``' Instruction
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Syntax:
"""""""
::
- <resultval> = catchpad [<args>*]
- to label <normal label> unwind label <exception label>
+ <resultval> = catchswitch within <parent> [ label <handler1>, label <handler2>, ... ] unwind to caller
+ <resultval> = catchswitch within <parent> [ label <handler1>, label <handler2>, ... ] unwind label <default>
Overview:
"""""""""
-The '``catchpad``' instruction is used by `LLVM's exception handling
-system <ExceptionHandling.html#overview>`_ to specify that a basic block
-is a catch block --- one where a personality routine attempts to transfer
-control to catch an exception.
-The ``args`` correspond to whatever information the personality
-routine requires to know if this is an appropriate place to catch the
-exception. Control is transfered to the ``exception`` label if the
-``catchpad`` is not an appropriate handler for the in-flight exception.
-The ``normal`` label should contain the code found in the ``catch``
-portion of a ``try``/``catch`` sequence. The ``resultval`` has the type
-:ref:`token <t_token>` and is used to match the ``catchpad`` to
-corresponding :ref:`catchrets <i_catchret>`.
+The '``catchswitch``' instruction is used by `LLVM's exception handling system
+<ExceptionHandling.html#overview>`_ to describe the set of possible catch handlers
+that may be executed by the :ref:`EH personality routine <personalityfn>`.
Arguments:
""""""""""
-The instruction takes a list of arbitrary values which are interpreted
-by the :ref:`personality function <personalityfn>`.
+The ``parent`` argument is the token of the funclet that contains the
+``catchswitch`` instruction. If the ``catchswitch`` is not inside a funclet,
+this operand may be the token ``none``.
-The ``catchpad`` must be provided a ``normal`` label to transfer control
-to if the ``catchpad`` matches the exception and an ``exception``
-label to transfer control to if it doesn't.
+The ``default`` argument is the label of another basic block beginning with a
+"pad" instruction, one of ``cleanuppad`` or ``catchswitch``.
+
+The ``handlers`` are a list of successor blocks that each begin with a
+:ref:`catchpad <i_catchpad>` instruction.
Semantics:
""""""""""
-When the call stack is being unwound due to an exception being thrown,
-the exception is compared against the ``args``. If it doesn't match,
-then control is transfered to the ``exception`` basic block.
-As with calling conventions, how the personality function results are
-represented in LLVM IR is target specific.
+Executing this instruction transfers control to one of the successors in
+``handlers``, if appropriate, or continues to unwind via the unwind label if
+present.
-The ``catchpad`` instruction has several restrictions:
-
-- A catch block is a basic block which is the unwind destination of
- an exceptional instruction.
-- A catch block must have a '``catchpad``' instruction as its
- first non-PHI instruction.
-- A catch block's ``exception`` edge must refer to a catch block or a
- catch-end block.
-- There can be only one '``catchpad``' instruction within the
- catch block.
-- A basic block that is not a catch block may not include a
- '``catchpad``' instruction.
-- A catch block which has another catch block as a predecessor may not have
- any other predecessors.
-- It is undefined behavior for control to transfer from a ``catchpad`` to a
- ``ret`` without first executing a ``catchret`` that consumes the
- ``catchpad`` or unwinding through its ``catchendpad``.
-- It is undefined behavior for control to transfer from a ``catchpad`` to
- itself without first executing a ``catchret`` that consumes the
- ``catchpad`` or unwinding through its ``catchendpad``.
+The ``catchswitch`` is both a terminator and a "pad" instruction, meaning that
+it must be both the first non-phi instruction and last instruction in the basic
+block. Therefore, it must be the only non-phi instruction in the block.
Example:
""""""""
.. code-block:: llvm
- ;; A catch block which can catch an integer.
- %tok = catchpad [i8** @_ZTIi]
- to label %int.handler unwind label %terminate
+ dispatch1:
+ %cs1 = catchswitch within none [label %handler0, label %handler1] unwind to caller
+ dispatch2:
+ %cs2 = catchswitch within %parenthandler [label %handler0] unwind label %cleanup
-.. _i_catchendpad:
+.. _i_catchpad:
-'``catchendpad``' Instruction
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+'``catchpad``' Instruction
+^^^^^^^^^^^^^^^^^^^^^^^^^^
Syntax:
"""""""
::
- catchendpad unwind label <nextaction>
- catchendpad unwind to caller
+ <resultval> = catchpad within <catchswitch> [<args>*]
Overview:
"""""""""
-The '``catchendpad``' instruction is used by `LLVM's exception handling
-system <ExceptionHandling.html#overview>`_ to communicate to the
-:ref:`personality function <personalityfn>` which invokes are associated
-with a chain of :ref:`catchpad <i_catchpad>` instructions; propagating an
-exception out of a catch handler is represented by unwinding through its
-``catchendpad``. Unwinding to the outer scope when a chain of catch handlers
-do not handle an exception is also represented by unwinding through their
-``catchendpad``.
-
-The ``nextaction`` label indicates where control should transfer to if
-none of the ``catchpad`` instructions are suitable for catching the
-in-flight exception.
-
-If a ``nextaction`` label is not present, the instruction unwinds out of
-its parent function. The
-:ref:`personality function <personalityfn>` will continue processing
-exception handling actions in the caller.
+The '``catchpad``' instruction is used by `LLVM's exception handling
+system <ExceptionHandling.html#overview>`_ to specify that a basic block
+begins a catch handler --- one where a personality routine attempts to transfer
+control to catch an exception.
Arguments:
""""""""""
-The instruction optionally takes a label, ``nextaction``, indicating
-where control should transfer to if none of the preceding
-``catchpad`` instructions are suitable for the in-flight exception.
+The ``catchswitch`` operand must always be a token produced by a
+:ref:`catchswitch <i_catchswitch>` instruction in a predecessor block. This
+ensures that each ``catchpad`` has exactly one predecessor block, and it always
+terminates in a ``catchswitch``.
+
+The ``args`` correspond to whatever information the personality routine
+requires to know if this is an appropriate handler for the exception. Control
+will transfer to the ``catchpad`` if this is the first appropriate handler for
+the exception.
+
+The ``resultval`` has the type :ref:`token <t_token>` and is used to match the
+``catchpad`` to corresponding :ref:`catchrets <i_catchret>` and other nested EH
+pads.
Semantics:
""""""""""
-When the call stack is being unwound due to an exception being thrown
-and none of the constituent ``catchpad`` instructions match, then
-control is transfered to ``nextaction`` if it is present. If it is not
-present, control is transfered to the caller.
+When the call stack is being unwound due to an exception being thrown, the
+exception is compared against the ``args``. If it doesn't match, control will
+not reach the ``catchpad`` instruction. The representation of ``args`` is
+entirely target and personality function-specific.
-The ``catchendpad`` instruction has several restrictions:
+Like the :ref:`landingpad <i_landingpad>` instruction, the ``catchpad``
+instruction must be the first non-phi of its parent basic block.
-- A catch-end block is a basic block which is the unwind destination of
- an exceptional instruction.
-- A catch-end block must have a '``catchendpad``' instruction as its
- first non-PHI instruction.
-- There can be only one '``catchendpad``' instruction within the
- catch-end block.
-- A basic block that is not a catch-end block may not include a
- '``catchendpad``' instruction.
-- Exactly one catch block may unwind to a ``catchendpad``.
-- It is undefined behavior to execute a ``catchendpad`` if none of the
- '``catchpad``'s chained to it have been executed.
-- It is undefined behavior to execute a ``catchendpad`` twice without an
- intervening execution of one or more of the '``catchpad``'s chained to it.
-- It is undefined behavior to execute a ``catchendpad`` if, after the most
- recent execution of the normal successor edge of any ``catchpad`` chained
- to it, some ``catchret`` consuming that ``catchpad`` has already been
- executed.
-- It is undefined behavior to execute a ``catchendpad`` if, after the most
- recent execution of the normal successor edge of any ``catchpad`` chained
- to it, any other ``catchpad`` or ``cleanuppad`` has been executed but has
- not had a corresponding
- ``catchret``/``cleanupret``/``catchendpad``/``cleanupendpad`` executed.
+The meaning of the tokens produced and consumed by ``catchpad`` and other "pad"
+instructions is described in the
+`Windows exception handling documentation <ExceptionHandling.html#wineh>`.
+
+Executing a ``catchpad`` instruction constitutes "entering" that pad.
+The pad may then be "exited" in one of three ways:
+
+1) explicitly via a ``catchret`` that consumes it. Executing such a ``catchret``
+ is undefined behavior if any descendant pads have been entered but not yet
+ exited.
+2) implicitly via a call (which unwinds all the way to the current function's caller),
+ or via a ``catchswitch`` or a ``cleanupret`` that unwinds to caller.
+3) implicitly via an unwind edge whose destination EH pad isn't a descendant of
+ the ``catchpad``. When the ``catchpad`` is exited in this manner, it is
+ undefined behavior if the destination EH pad has a parent which is not an
+ ancestor of the ``catchpad`` being exited.
Example:
""""""""
.. code-block:: llvm
- catchendpad unwind label %terminate
- catchendpad unwind to caller
+ dispatch:
+ %cs = catchswitch within none [label %handler0] unwind to caller
+ ;; A catch block which can catch an integer.
+ handler0:
+ %tok = catchpad within %cs [i8** @_ZTIi]
.. _i_catchret:
::
- catchret <value> to label <normal>
+ catchret from <token> to label <normal>
Overview:
"""""""""
Semantics:
""""""""""
-The '``catchret``' instruction ends the existing (in-flight) exception
-whose unwinding was interrupted with a
-:ref:`catchpad <i_catchpad>` instruction.
-The :ref:`personality function <personalityfn>` gets a chance to execute
-arbitrary code to, for example, run a C++ destructor.
-Control then transfers to ``normal``.
-It may be passed an optional, personality specific, value.
-
-It is undefined behavior to execute a ``catchret`` whose ``catchpad`` has
-not been executed.
-
-It is undefined behavior to execute a ``catchret`` if, after the most recent
-execution of its ``catchpad``, some ``catchret`` or ``catchendpad`` linked
-to the same ``catchpad`` has already been executed.
-
-It is undefined behavior to execute a ``catchret`` if, after the most recent
-execution of its ``catchpad``, any other ``catchpad`` or ``cleanuppad`` has
-been executed but has not had a corresponding
-``catchret``/``cleanupret``/``catchendpad``/``cleanupendpad`` executed.
-
-Example:
-""""""""
-
-.. code-block:: llvm
-
- catchret %catch label %continue
-
-.. _i_cleanupendpad:
-
-'``cleanupendpad``' Instruction
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Syntax:
-"""""""
-
-::
-
- cleanupendpad <value> unwind label <nextaction>
- cleanupendpad <value> unwind to caller
+The '``catchret``' instruction ends an existing (in-flight) exception whose
+unwinding was interrupted with a :ref:`catchpad <i_catchpad>` instruction. The
+:ref:`personality function <personalityfn>` gets a chance to execute arbitrary
+code to, for example, destroy the active exception. Control then transfers to
+``normal``.
-Overview:
-"""""""""
-
-The '``cleanupendpad``' instruction is used by `LLVM's exception handling
-system <ExceptionHandling.html#overview>`_ to communicate to the
-:ref:`personality function <personalityfn>` which invokes are associated
-with a :ref:`cleanuppad <i_cleanuppad>` instructions; propagating an exception
-out of a cleanup is represented by unwinding through its ``cleanupendpad``.
-
-The ``nextaction`` label indicates where control should unwind to next, in the
-event that a cleanup is exited by means of an(other) exception being raised.
-
-If a ``nextaction`` label is not present, the instruction unwinds out of
-its parent function. The
-:ref:`personality function <personalityfn>` will continue processing
-exception handling actions in the caller.
-
-Arguments:
-""""""""""
-
-The '``cleanupendpad``' instruction requires one argument, which indicates
-which ``cleanuppad`` it exits, and must be a :ref:`cleanuppad <i_cleanuppad>`.
-It also has an optional successor, ``nextaction``, indicating where control
-should transfer to.
-
-Semantics:
-""""""""""
-
-When and exception propagates to a ``cleanupendpad``, control is transfered to
-``nextaction`` if it is present. If it is not present, control is transfered to
-the caller.
-
-The ``cleanupendpad`` instruction has several restrictions:
-
-- A cleanup-end block is a basic block which is the unwind destination of
- an exceptional instruction.
-- A cleanup-end block must have a '``cleanupendpad``' instruction as its
- first non-PHI instruction.
-- There can be only one '``cleanupendpad``' instruction within the
- cleanup-end block.
-- A basic block that is not a cleanup-end block may not include a
- '``cleanupendpad``' instruction.
-- It is undefined behavior to execute a ``cleanupendpad`` whose ``cleanuppad``
- has not been executed.
-- It is undefined behavior to execute a ``cleanupendpad`` if, after the most
- recent execution of its ``cleanuppad``, some ``cleanupret`` or ``cleanupendpad``
- consuming the same ``cleanuppad`` has already been executed.
-- It is undefined behavior to execute a ``cleanupendpad`` if, after the most
- recent execution of its ``cleanuppad``, any other ``cleanuppad`` or
- ``catchpad`` has been executed but has not had a corresponding
- ``cleanupret``/``catchret``/``cleanupendpad``/``catchendpad`` executed.
+The ``token`` argument must be a token produced by a dominating ``catchpad``
+instruction. The ``catchret`` destroys the physical frame established by
+``catchpad``, so executing multiple returns on the same token without
+re-executing the ``catchpad`` will result in undefined behavior.
+See :ref:`catchpad <i_catchpad>` for more details.
Example:
""""""""
.. code-block:: llvm
- cleanupendpad %cleanup unwind label %terminate
- cleanupendpad %cleanup unwind to caller
+ catchret from %catch label %continue
.. _i_cleanupret:
::
- cleanupret <value> unwind label <continue>
- cleanupret <value> unwind to caller
+ cleanupret from <value> unwind label <continue>
+ cleanupret from <value> unwind to caller
Overview:
"""""""""
:ref:`cleanuppad <i_cleanuppad>` it transferred control to has ended.
It transfers control to ``continue`` or unwinds out of the function.
-It is undefined behavior to execute a ``cleanupret`` whose ``cleanuppad`` has
-not been executed.
-
-It is undefined behavior to execute a ``cleanupret`` if, after the most recent
-execution of its ``cleanuppad``, some ``cleanupret`` or ``cleanupendpad``
-consuming the same ``cleanuppad`` has already been executed.
-
-It is undefined behavior to execute a ``cleanupret`` if, after the most recent
-execution of its ``cleanuppad``, any other ``cleanuppad`` or ``catchpad`` has
-been executed but has not had a corresponding
-``cleanupret``/``catchret``/``cleanupendpad``/``catchendpad`` executed.
-
-Example:
-""""""""
-
-.. code-block:: llvm
-
- cleanupret %cleanup unwind to caller
- cleanupret %cleanup unwind label %continue
-
-.. _i_terminatepad:
-
-'``terminatepad``' Instruction
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Syntax:
-"""""""
-
-::
-
- terminatepad [<args>*] unwind label <exception label>
- terminatepad [<args>*] unwind to caller
-
-Overview:
-"""""""""
-
-The '``terminatepad``' instruction is used by `LLVM's exception handling
-system <ExceptionHandling.html#overview>`_ to specify that a basic block
-is a terminate block --- one where a personality routine may decide to
-terminate the program.
-The ``args`` correspond to whatever information the personality
-routine requires to know if this is an appropriate place to terminate the
-program. Control is transferred to the ``exception`` label if the
-personality routine decides not to terminate the program for the
-in-flight exception.
-
-Arguments:
-""""""""""
-
-The instruction takes a list of arbitrary values which are interpreted
-by the :ref:`personality function <personalityfn>`.
-
-The ``terminatepad`` may be given an ``exception`` label to
-transfer control to if the in-flight exception matches the ``args``.
-
-Semantics:
-""""""""""
-
-When the call stack is being unwound due to an exception being thrown,
-the exception is compared against the ``args``. If it matches,
-then control is transfered to the ``exception`` basic block. Otherwise,
-the program is terminated via personality-specific means. Typically,
-the first argument to ``terminatepad`` specifies what function the
-personality should defer to in order to terminate the program.
-
-The ``terminatepad`` instruction has several restrictions:
-
-- A terminate block is a basic block which is the unwind destination of
- an exceptional instruction.
-- A terminate block must have a '``terminatepad``' instruction as its
- first non-PHI instruction.
-- There can be only one '``terminatepad``' instruction within the
- terminate block.
-- A basic block that is not a terminate block may not include a
- '``terminatepad``' instruction.
+The unwind destination ``continue``, if present, must be an EH pad
+whose parent is either ``none`` or an ancestor of the ``cleanuppad``
+being returned from. This constitutes an exceptional exit from all
+ancestors of the completed ``cleanuppad``, up to but not including
+the parent of ``continue``.
+See :ref:`cleanuppad <i_cleanuppad>` for more details.
Example:
""""""""
.. code-block:: llvm
- ;; A terminate block which only permits integers.
- terminatepad [i8** @_ZTIi] unwind label %continue
+ cleanupret from %cleanup unwind to caller
+ cleanupret from %cleanup unwind label %continue
.. _i_unreachable:
execution of this ``load`` with other :ref:`volatile
operations <volatile>`.
-If the ``load`` is marked as ``atomic``, it takes an extra
-:ref:`ordering <ordering>` and optional ``singlethread`` argument. The
-``release`` and ``acq_rel`` orderings are not valid on ``load``
-instructions. Atomic loads produce :ref:`defined <memmodel>` results
-when they may see multiple atomic stores. The type of the pointee must
-be an integer type whose bit width is a power of two greater than or
-equal to eight and less than or equal to a target-specific size limit.
-``align`` must be explicitly specified on atomic loads, and the load has
-undefined behavior if the alignment is not set to a value which is at
-least the size in bytes of the pointee. ``!nontemporal`` does not have
-any defined semantics for atomic loads.
+If the ``load`` is marked as ``atomic``, it takes an extra :ref:`ordering
+<ordering>` and optional ``singlethread`` argument. The ``release`` and
+``acq_rel`` orderings are not valid on ``load`` instructions. Atomic loads
+produce :ref:`defined <memmodel>` results when they may see multiple atomic
+stores. The type of the pointee must be an integer, pointer, or floating-point
+type whose bit width is a power of two greater than or equal to eight and less
+than or equal to a target-specific size limit. ``align`` must be explicitly
+specified on atomic loads, and the load has undefined behavior if the alignment
+is not set to a value which is at least the size in bytes of the
+pointee. ``!nontemporal`` does not have any defined semantics for atomic loads.
The optional constant ``align`` argument specifies the alignment of the
operation (that is, the alignment of the memory address). A value of 0
execution of this ``store`` with other :ref:`volatile
operations <volatile>`.
-If the ``store`` is marked as ``atomic``, it takes an extra
-:ref:`ordering <ordering>` and optional ``singlethread`` argument. The
-``acquire`` and ``acq_rel`` orderings aren't valid on ``store``
-instructions. Atomic loads produce :ref:`defined <memmodel>` results
-when they may see multiple atomic stores. The type of the pointee must
-be an integer type whose bit width is a power of two greater than or
-equal to eight and less than or equal to a target-specific size limit.
-``align`` must be explicitly specified on atomic stores, and the store
-has undefined behavior if the alignment is not set to a value which is
-at least the size in bytes of the pointee. ``!nontemporal`` does not
-have any defined semantics for atomic stores.
+If the ``store`` is marked as ``atomic``, it takes an extra :ref:`ordering
+<ordering>` and optional ``singlethread`` argument. The ``acquire`` and
+``acq_rel`` orderings aren't valid on ``store`` instructions. Atomic loads
+produce :ref:`defined <memmodel>` results when they may see multiple atomic
+stores. The type of the pointee must be an integer, pointer, or floating-point
+type whose bit width is a power of two greater than or equal to eight and less
+than or equal to a target-specific size limit. ``align`` must be explicitly
+specified on atomic stores, and the store has undefined behavior if the
+alignment is not set to a value which is at least the size in bytes of the
+pointee. ``!nontemporal`` does not have any defined semantics for atomic stores.
The optional constant ``align`` argument specifies the alignment of the
operation (that is, the alignment of the memory address). A value of 0
::
- <result> = [tail | musttail | notail ] call [cconv] [ret attrs] <ty> [<fnty>*] <fnptrval>(<function args>) [fn attrs]
+ <result> = [tail | musttail | notail ] call [fast-math flags] [cconv] [ret attrs] <ty> [<fnty>*] <fnptrval>(<function args>) [fn attrs]
[ operand bundles ]
Overview:
``tail`` or ``musttail`` markers to the call. It is used to prevent tail
call optimization from being performed on the call.
+#. The optional ``fast-math flags`` marker indicates that the call has one or more
+ :ref:`fast-math flags <fastmath>`, which are optimization hints to enable
+ otherwise unsafe floating-point optimizations. Fast-math flags are only valid
+ for calls that return a floating-point scalar or vector type.
+
#. The optional "cconv" marker indicates which :ref:`calling
convention <callingconv>` the call should use. If none is
specified, the call defaults to using C calling conventions. The
::
- <resultval> = cleanuppad [<args>*]
+ <resultval> = cleanuppad
within <parent> [<args>*]
Overview:
"""""""""
information the :ref:`personality function <personalityfn>` requires to
execute the cleanup.
The ``resultval`` has the type :ref:`token <t_token>` and is used to
-match the ``cleanuppad`` to corresponding :ref:`cleanuprets <i_cleanupret>`
-and :ref:`cleanupendpads <i_cleanupendpad>`.
+match the ``cleanuppad`` to corresponding :ref:`cleanuprets <i_cleanupret>`.
+The ``parent`` argument is the token of the funclet that contains the
+``cleanuppad`` instruction. If the ``cleanuppad`` is not inside a funclet,
+this operand may be the token ``none``.
Arguments:
""""""""""
cleanup block.
- A basic block that is not a cleanup block may not include a
'``cleanuppad``' instruction.
-- All '``cleanupret``'s and '``cleanupendpad``'s which consume a ``cleanuppad``
- must have the same exceptional successor.
-- It is undefined behavior for control to transfer from a ``cleanuppad`` to a
- ``ret`` without first executing a ``cleanupret`` or ``cleanupendpad`` that
- consumes the ``cleanuppad``.
-- It is undefined behavior for control to transfer from a ``cleanuppad`` to
- itself without first executing a ``cleanupret`` or ``cleanupendpad`` that
- consumes the ``cleanuppad``.
+
+Executing a ``cleanuppad`` instruction constitutes "entering" that pad.
+The pad may then be "exited" in one of three ways:
+
+1) explicitly via a ``cleanupret`` that consumes it. Executing such a ``cleanupret``
+ is undefined behavior if any descendant pads have been entered but not yet
+ exited.
+2) implicitly via a call (which unwinds all the way to the current function's caller),
+ or via a ``catchswitch`` or a ``cleanupret`` that unwinds to caller.
+3) implicitly via an unwind edge whose destination EH pad isn't a descendant of
+ the ``cleanuppad``. When the ``cleanuppad`` is exited in this manner, it is
+ undefined behavior if the destination EH pad has a parent which is not an
+ ancestor of the ``cleanuppad`` being exited.
+
+It is undefined behavior for the ``cleanuppad`` to exit via an unwind edge which
+does not transitively unwind to the same destination as a constituent
+``cleanupret``.
Example:
""""""""
.. code-block:: llvm
- %tok = cleanuppad []
+ %tok = cleanuppad within %cs []
.. _intrinsics:
%r2 = call float @llvm.fmuladd.f32(float %a, float %b, float %c) ; yields float:r2 = (a * b) + c
-
-'``llvm.uabsdiff.*``' and '``llvm.sabsdiff.*``' Intrinsics
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Syntax:
-"""""""
-This is an overloaded intrinsic. The loaded data is a vector of any integer bit width.
-
-.. code-block:: llvm
-
- declare <4 x integer> @llvm.uabsdiff.v4i32(<4 x integer> %a, <4 x integer> %b)
-
-
-Overview:
-"""""""""
-
-The ``llvm.uabsdiff`` intrinsic returns a vector result of the absolute difference
-of the two operands, treating them both as unsigned integers. The intermediate
-calculations are computed using infinitely precise unsigned arithmetic. The final
-result will be truncated to the given type.
-
-The ``llvm.sabsdiff`` intrinsic returns a vector result of the absolute difference of
-the two operands, treating them both as signed integers. If the result overflows, the
-behavior is undefined.
-
-.. note::
-
- These intrinsics are primarily used during the code generation stage of compilation.
- They are generated by compiler passes such as the Loop and SLP vectorizers. It is not
- recommended for users to create them manually.
-
-Arguments:
-""""""""""
-
-Both intrinsics take two integer of the same bitwidth.
-
-Semantics:
-""""""""""
-
-The expression::
-
- call <4 x i32> @llvm.uabsdiff.v4i32(<4 x i32> %a, <4 x i32> %b)
-
-is equivalent to::
-
- %1 = zext <4 x i32> %a to <4 x i64>
- %2 = zext <4 x i32> %b to <4 x i64>
- %sub = sub <4 x i64> %1, %2
- %trunc = trunc <4 x i64> to <4 x i32>
-
-and the expression::
-
- call <4 x i32> @llvm.sabsdiff.v4i32(<4 x i32> %a, <4 x i32> %b)
-
-is equivalent to::
-
- %sub = sub nsw <4 x i32> %a, %b
- %ispos = icmp sge <4 x i32> %sub, zeroinitializer
- %neg = sub nsw <4 x i32> zeroinitializer, %sub
- %1 = select <4 x i1> %ispos, <4 x i32> %sub, <4 x i32> %neg
-
-
Half Precision Floating Point Intrinsics
----------------------------------------
projects / oota-llvm.git / blobdiff