If an attribute name has special characters such as '\01', it is not
properly printed in LLVM assembly language format. Since the format
expects the special characters are printed as it is, it has to contain
escape characters to make it printable.
Before:
attributes #0 = { ... "counting-function"="^A__gnu_mcount_nc" ...
After:
attributes #0 = { ... "counting-function"="\01__gnu_mcount_nc" ...
Reviewers: hfinkel, rengolin, rjmccall, compnerd
Subscribers: nemanjai, mcrosier, hans, shenhan, majnemer, llvm-commits
Differential Revision: https://reviews.llvm.org/D23792
llvm-svn: 280357
LLVM has an @llvm.eh.dwarf.cfa intrinsic, used to lower the GCC-compatible
__builtin_dwarf_cfa() builtin. As pointed out in PR26761, this is currently
broken on PowerPC (and likely on ARM as well). Currently, @llvm.eh.dwarf.cfa is
lowered using:
ADD(FRAMEADDR, FRAME_TO_ARGS_OFFSET)
where FRAME_TO_ARGS_OFFSET defaults to the constant zero. On x86,
FRAME_TO_ARGS_OFFSET is lowered to 2*SlotSize. This setup, however, does not
work for PowerPC. Because of the way that the stack layout works, the canonical
frame address is not exactly (FRAMEADDR + FRAME_TO_ARGS_OFFSET) on PowerPC
(there is a lower save-area offset as well), so it is not just a matter of
implementing FRAME_TO_ARGS_OFFSET for PowerPC (unless we redefine its
semantics -- We can do that, since it is currently used only for
@llvm.eh.dwarf.cfa lowering, but the better to directly lower the CFA construct
itself (since it can be easily represented as a fixed-offset FrameIndex)). Mips
currently does this, but by using a custom lowering for ADD that specifically
recognizes the (FRAMEADDR, FRAME_TO_ARGS_OFFSET) pattern.
This change introduces a ISD::EH_DWARF_CFA node, which by default expands using
the existing logic, but can be directly lowered by the target. Mips is updated
to use this method (which simplifies its implementation, and I suspect makes it
more robust), and updates PowerPC to do the same.
Fixes PR26761.
Differential Revision: https://reviews.llvm.org/D24038
llvm-svn: 280350
As discussed in https://reviews.llvm.org/D22666, our current mechanism to
support -pg profiling, where we insert calls to mcount(), or some similar
function, is fundamentally broken. We insert these calls in the frontend, which
means they get duplicated when inlining, and so the accumulated execution
counts for the inlined-into functions are wrong.
Because we don't want the presence of these functions to affect optimizaton,
they should be inserted in the backend. Here's a pass which would do just that.
The knowledge of the name of the counting function lives in the frontend, so
we're passing it here as a function attribute. Clang will be updated to use
this mechanism.
Differential Revision: https://reviews.llvm.org/D22825
llvm-svn: 280347
Summary:
This change promotes the 'isTailCall(...)' member function to
TargetInstrInfo as a query interface for determining on a per-target
basis whether a given MachineInstr is a tail call instruction. We build
upon this in the XRay instrumentation pass to emit special sleds for
tail call optimisations, where we emit the correct kind of sled.
The tail call sleds look like a mix between the function entry and
function exit sleds. Form-wise, the sled comes before the "jmp"
instruction that implements the tail call similar to how we do it for
the function entry sled. Functionally, because we know this is a tail
call, it behaves much like an exit sled -- i.e. at runtime we may use
the exit trampolines instead of a different kind of trampoline.
A follow-up change to recognise these sleds will be done in compiler-rt,
so that we can start intercepting these initially as exits, but also
have the option to have different log entries to more accurately reflect
that this is actually a tail call.
Reviewers: echristo, rSerge, majnemer
Subscribers: mehdi_amini, dberris, llvm-commits
Differential Revision: https://reviews.llvm.org/D23986
llvm-svn: 280334
Older versions of clang defined __has_cpp_attribute in C mode, but
would choke on scoped attributes, as per llvm.org/PR23435. Since we
support building with clang all the way back to 3.1, we have to work
around this issue.
llvm-svn: 280326
Previously we were assuming that any visitation of types would
necessarily be against a type we had binary data for. Reasonable
assumption when were just reading PDBs and dumping them, but once
we start writing PDBs from Yaml this breaks down, because we have
no binary data yet, only Yaml, and from that we need to read the
record kind and perform the switch based on that.
So this patch does that. Instead of having the visitor switch
on the kind that is already in the CVType record, we change the
visitTypeBegin() method to return the Kind, and switch on the
returned value. This way, the default implementation can still
return the value from the CVType, but the implementation which
visits Yaml records and serializes binary PDB type records can
use the field in the Yaml as the source of the switch.
llvm-svn: 280307
This reverts commit r280268, it causes all MSVC 2013 to ICE. This
appears to have been fixed in a later MSVC 2013 update, because I cannot
reproduce it locally. That said, all upstream LLVM bots are broken right
now, so I am reverting.
Also reverts dependent change r280275, "[Hexagon] Deal with undefs when
extending live intervals".
llvm-svn: 280301
We were kind of hacking this together before by embedding the
ability to forward requests into the TypeDeserializer. When
we want to start adding more different kinds of visitor callback
interfaces though, this doesn't scale well and is very inflexible.
So introduce the notion of a pipeline, which itself implements
the TypeVisitorCallbacks interface, but which contains an internal
list of other callbacks to invoke in sequence.
Also update the existing uses of CVTypeVisitor to use this new
pipeline class for deserializing records before visiting them
with another visitor.
llvm-svn: 280293
More preparation for dropping source types from MachineInstrs: regsters coming
out of already-selected code (i.e. non-generic instructions) don't have a type,
but that information is needed so we must add it manually.
This is done via a new G_TYPE instruction.
llvm-svn: 280292
Summary:
Current implementation of LI verifier isn't ideal and fails to detect
some cases when LI is incorrect. For instance, it checks that all
recorded loops are in a correct form, but it has no way to check if
there are no more other (unrecorded in LI) loops in the function. This
patch adds a way to detect such bugs.
Reviewers: chandlerc, sanjoy, hfinkel
Subscribers: llvm-commits, silvas, mzolotukhin
Differential Revision: https://reviews.llvm.org/D23437
llvm-svn: 280280
Summary:
Use MemorySSA, if requested, to do less conservative memory dependency
checking.
This change doesn't enable the MemorySSA enhanced EarlyCSE in the
default pipelines, so should be NFC.
Reviewers: dberlin, sanjoy, reames, majnemer
Subscribers: mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D19821
llvm-svn: 280279
This is a first step towards supporting deopt value lowering and reporting entirely with the register allocator. I hope to build on this in the near future to support live-on-return semantics, but I have a use case which allows me to test and investigate code quality with just the live-in semantics so I've chosen to start there. For those curious, my use cases is our implementation of the "__llvm_deoptimize" function we bind to @llvm.deoptimize. I'm choosing not to hard code that fact in the patch and instead make it configurable via function attributes.
The basic approach here is modelled on what is done for the "Live In" values on stackmaps and patchpoints. (A secondary goal here is to remove one of the last barriers to merging the pseudo instructions.) We start by adding the operands directly to the STATEPOINT SDNode. Once we've lowered to MI, we extend the remat logic used by the register allocator to fold virtual register uses into StackMap::Indirect entries as needed. This does rely on the fact that the register allocator rematerializes. If it didn't along some code path, we could end up with more vregs than physical registers and fail to allocate.
Today, we *only* fold in the register allocator. This can create some weird effects when combined with arguments passed on the stack because we don't fold them appropriately. I have an idea how to fix that, but it needs this patch in place to work on that effectively. (There's some weird interaction with the scheduler as well, more investigation needed.)
My near term plan is to land this patch off-by-default, experiment in my local tree to identify any correctness issues and then start fixing codegen problems one by one as I find them. Once I have the live-in lowering fully working (both correctness and code quality), I'm hoping to move on to the live-on-return semantics. Note: I don't have any *known* miscompiles with this patch enabled, but I'm pretty sure I'll find at least a couple. Thus, the "experimental" tag and the fact it's off by default.
Differential Revision: https://reviews.llvm.org/D24000
llvm-svn: 280250
types. This is the LLVM counterpart and it adds options that map onto FP
exceptions and denormal build attributes allowing better fp math library
selections.
Differential Revision: https://reviews.llvm.org/D24070
llvm-svn: 280246
Move the comparison function into the only place there it is used,
i.e. the call to std::stable_sort in CoverageMappingWriter::write().
Add sorting by region kinds as it is required to ensure stable order
in our tests and to simplify D23987.
Differential Revision: https://reviews.llvm.org/D24034
llvm-svn: 280198
Legalization ends up creating many G_SEQUENCE/G_EXTRACT pairs which leads to
inefficient codegen (even for -O0), so add a quick pass over the function to
remove them again.
llvm-svn: 280155
When binaries are compressed by UPX, information about symbol table
offset and symbol count remain unchanged (but became invalid due to
compression).
This causes failure in the constructor and the rest of the binary cannot
be processed.
Instead, reset symbol related information (symbol/string table pointers,
sizes) - this should disable the related iterators and functions while
the rest of the binary can still be processed.
Patch by Bandzi Michal!
llvm-svn: 280147
Add constants for additional GNU note types and the GNU Notes OS type id. This
is needed to support printing the notes in ELF binaries.
llvm-svn: 280130
Many lists want to override only allocation semantics, or callbacks for
iplist. Split these up to prevent code duplication.
- Specialize ilist_alloc_traits to change the implementations of
deleteNode() and createNode().
- One common desire is to do nothing deleteNode() and disable
createNode(). Specialize ilist_alloc_traits to inherit from
ilist_noalloc_traits for that behaviour.
- Specialize ilist_callback_traits to use the addNodeToList(),
removeNodeFromList(), and transferNodesFromList() callbacks.
As a drive-by, add some coverage to the callback-related unit tests.
llvm-svn: 280128
The existing code hard-coded a limit of 20 instructions for duplication
when a block ended with an indirect branch. Extract this as an option.
No functional change intended.
llvm-svn: 280125
Guarantee that ilist_traits<T>::transferNodesFromList is only called
when nodes are actually changing lists.
I also moved all the callbacks to occur *first*, before the operation.
This is the only choice for iplist<T>::merge, so we might as well be
consistent. I expect this to have no effect in practice, although it
simplifies the logic in both iplist<T>::transfer and iplist<T>::insert.
llvm-svn: 280122
This is a prep commit before splitting up ilist_node_traits and
updating/simplifying call sites.
- Move to top of file (I considered moving to a different file,
llvm/ADT/ilist_traits.h, but it's really not much code).
- Clang-format.
- Convert comments to doxygen, clean them up, and add TODOs for what I'm
doing next.
llvm-svn: 280109
Split out a new, low-level intrusive list type with clear semantics.
Unlike iplist (and ilist), all operations on simple_ilist are intrusive,
and simple_ilist never takes ownership of its nodes. This enables an
intuitive API that has the right defaults for intrusive lists.
- insert() takes references (not pointers!) to nodes (in iplist/ilist,
passing a reference will cause the node to be copied).
- erase() takes only iterators (like std::list), and does not destroy
the nodes.
- remove() takes only references and has the same behaviour as erase().
- clear() does not destroy the nodes.
- The destructor does not destroy the nodes.
- New API {erase,remove,clear}AndDispose() take an extra Disposer
functor for callsites that want to call some disposal routine (e.g.,
std::default_delete).
This list is not currently configurable, and has no callbacks.
The initial motivation was to fix iplist<>::sort to work correctly (even
with callbacks in ilist_traits<>). iplist<> uses simple_ilist<>::sort
directly. The new test in unittests/IR/ModuleTest.cpp crashes without
this commit.
Fixing sort() via a low-level layer provided a good opportunity to:
- Unit test the low-level functionality thoroughly.
- Modernize the API, largely inspired by other intrusive list
implementations.
Here's a sketch of a longer-term plan:
- Create BumpPtrList<>, a non-intrusive list implemented using
simple_ilist<>, and use it for the Token list in
lib/Support/YAMLParser.cpp. This will factor out the only real use of
createNode().
- Evolve the iplist<> and ilist<> APIs in the direction of
simple_ilist<>, making allocation/deallocation explicit at call sites
(similar to simple_ilist<>::eraseAndDispose()).
- Factor out remaining calls to createNode() and deleteNode() and remove
the customization from ilist_traits<>.
- Transition uses of iplist<>/ilist<> that don't need callbacks over to
simple_ilist<>.
llvm-svn: 280107
Or they were not instantiated as expected;
llvm::InnerAnalysisManagerProxy<llvm::AnalysisManager<llvm::Function>, llvm::LazyCallGraph::SCC>::PassID
llvm::InnerAnalysisManagerProxy<llvm::AnalysisManager<llvm::Function>, llvm::LazyCallGraph::SCC>::PassID
llvm-svn: 280105
This reverts commit r280016, and the followups of r280017, r280027,
r280051, r280058, and r280059.
MSVC's implementation of std::promise does not get along with
llvm::Error. It uses its promised value too much like a normal value
type.
llvm-svn: 280100
only) for Expected<T> so that it can interoperate with MSVC's std::future
implementation.
MSVC 2013's std::future implementation requires the wrapped type to be default
constructible.
Hopefully this will fix the bot breakage in
http://lab.llvm.org:8011/builders/clang-x86-win2008-selfhost/builds/9937 .
llvm-svn: 280058
The former is simply wrong -- the code will either never be used or will
always be used, rather than being dependent upon whether it's built with
debug assertions enabled.
The macro DEBUG isn't ever set by the llvm build system. But, the macro
DEBUG(X) is defined (unconditionally) if you happen to include
llvm/Support/Debug.h.
The code in Value.h which was erroneously protected by the #ifdef DEBUG
didn't even compile -- you can't cast<> from an LLVMOpaqueValue
directly. Fortunately, it was never invoked, as Core.cpp included
Value.h before Debug.h.
The conditionalized code in AArch64CollectLOH.cpp was previously always
used, as it includes Debug.h.
llvm-svn: 280056
behaviors, and add a callB (blacking call) primitive.
callB is a blocking call primitive for threaded code where the RPC responses are
being processed on a separate thread. (For single threaded code callST should
continue to be used instead).
No unit test yet: Last time I commited a threaded unit test it deadlocked on
one of the s390x builders. I'll try to re-enable that test first, and add a new
test if I can sort out the deadlock issue.
llvm-svn: 280051
I'm working on a lower-level intrusive list that can be used
stand-alone, and splitting the files up a bit will make the code easier
to organize. Explode the ilist headers in advance to improve blame
lists in the future.
- Move ilist_node_base from ilist_node.h to ilist_node_base.h.
- Move ilist_base from ilist.h to ilist_base.h.
- Move ilist_iterator from ilist.h to ilist_iterator.h.
- Move ilist_node_access from ilist.h to ilist_node.h to support
ilist_iterator.
- Update unit tests to #include smaller headers.
- Clang-format the moved things.
I noticed in transit that there is a simplify_type specialization for
ilist_iterator. Since there is no longer an implicit conversion from
ilist<T>::iterator to T*, this doesn't make sense (effectively it's a
form of implicit conversion). For now I've added a FIXME.
llvm-svn: 280047
Reverse iterators to doubly-linked lists can be simpler (and cheaper)
than std::reverse_iterator. Make it so.
In particular, change ilist<T>::reverse_iterator so that it is *never*
invalidated unless the node it references is deleted. This matches the
guarantees of ilist<T>::iterator.
(Note: MachineBasicBlock::iterator is *not* an ilist iterator, but a
MachineInstrBundleIterator<MachineInstr>. This commit does not change
MachineBasicBlock::reverse_iterator, but it does update
MachineBasicBlock::reverse_instr_iterator. See note at end of commit
message for details on bundle iterators.)
Given the list (with the Sentinel showing twice for simplicity):
[Sentinel] <-> A <-> B <-> [Sentinel]
the following is now true:
1. begin() represents A.
2. begin() holds the pointer for A.
3. end() represents [Sentinel].
4. end() holds the poitner for [Sentinel].
5. rbegin() represents B.
6. rbegin() holds the pointer for B.
7. rend() represents [Sentinel].
8. rend() holds the pointer for [Sentinel].
The changes are #6 and #8. Here are some properties from the old
scheme (which used std::reverse_iterator):
- rbegin() held the pointer for [Sentinel] and rend() held the pointer
for A;
- operator*() cost two dereferences instead of one;
- converting from a valid iterator to its valid reverse_iterator
involved a confusing increment; and
- "RI++->erase()" left RI invalid. The unintuitive replacement was
"RI->erase(), RE = end()".
With vector-like data structures these properties are hard to avoid
(since past-the-beginning is not a valid pointer), and don't impose a
real cost (since there's still only one dereference, and all iterators
are invalidated on erase). But with lists, this was a poor design.
Specifically, the following code (which obviously works with normal
iterators) now works with ilist::reverse_iterator as well:
for (auto RI = L.rbegin(), RE = L.rend(); RI != RE;)
fooThatMightRemoveArgFromList(*RI++);
Converting between iterator and reverse_iterator for the same node uses
the getReverse() function.
reverse_iterator iterator::getReverse();
iterator reverse_iterator::getReverse();
Why doesn't iterator <=> reverse_iterator conversion use constructors?
In order to catch and update old code, reverse_iterator does not even
have an explicit conversion from iterator. It wouldn't be safe because
there would be no reasonable way to catch all the bugs from the changed
semantic (see the changes at call sites that are part of this patch).
Old code used this API:
std::reverse_iterator::reverse_iterator(iterator);
iterator std::reverse_iterator::base();
Here's how to update from old code to new (that incorporates the
semantic change), assuming I is an ilist<>::iterator and RI is an
ilist<>::reverse_iterator:
[Old] ==> [New]
reverse_iterator(I) (--I).getReverse()
reverse_iterator(I) ++I.getReverse()
--reverse_iterator(I) I.getReverse()
reverse_iterator(++I) I.getReverse()
RI.base() (--RI).getReverse()
RI.base() ++RI.getReverse()
--RI.base() RI.getReverse()
(++RI).base() RI.getReverse()
delete &*RI, RE = end() delete &*RI++
RI->erase(), RE = end() RI++->erase()
=======================================
Note: bundle iterators are out of scope
=======================================
MachineBasicBlock::iterator, also known as
MachineInstrBundleIterator<MachineInstr>, is a wrapper to represent
MachineInstr bundles. The idea is that each operator++ takes you to the
beginning of the next bundle. Implementing a sane reverse iterator for
this is harder than ilist. Here are the options:
- Use std::reverse_iterator<MBB::i>. Store a handle to the beginning of
the next bundle. A call to operator*() runs a loop (usually
operator--() will be called 1 time, for unbundled instructions).
Increment/decrement just works. This is the status quo.
- Store a handle to the final node in the bundle. A call to operator*()
still runs a loop, but it iterates one time fewer (usually
operator--() will be called 0 times, for unbundled instructions).
Increment/decrement just works.
- Make the ilist_sentinel<MachineInstr> *always* store that it's the
sentinel (instead of just in asserts mode). Then the bundle iterator
can sniff the sentinel bit in operator++().
I initially tried implementing the end() option as part of this commit,
but updating iterator/reverse_iterator conversion call sites was
error-prone. I have a WIP series of patches that implements the final
option.
llvm-svn: 280032
Optional.
For void functions the return type of a nonblocking call changes from
Expected<future<Optional<bool>>> to Expected<future<Error>>, and for functions
returning T the return type changes from Expected<future<Optional<T>>> to
Expected<future<Expected<T>>>.
Inner results need to be checked (since the RPC connection may have dropped
out before a result came back) and Error/Expected provide stronger checking
requirements. It also allows us drop the crufty 'optionalToError' function and
just collapse Errors in the single-threaded call primitives.
llvm-svn: 280016
Instead of putting all possible requests into a single table, we can perform
the extremely dense lookup based on opcode and type-index in constant time
using multi-dimensional array-like things.
This roughly halves the time spent doing legalization, which was dominated by
queries against the Actions table.
llvm-svn: 280011
There should be no functional change here, I'm just making the implementation
of "frem" (to libcall) legalization easier for a followup.
llvm-svn: 279987
Summary: No functional changes, just refactoring to make D23947 simpler.
Reviewers: eugenis
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23954
llvm-svn: 279982
Summary:
[Coroutines] Part 9: Add cleanup subfunction.
This patch completes coroutine heap allocation elision. Now, the heap elision example from docs\Coroutines.rst compiles and produces expected result (see test/Transform/Coroutines/ex3.ll)
Intrinsic Changes:
* coro.free gets a token parameter tying it to coro.id to allow reliably discovering all coro.frees associated with a particular coroutine.
* coro.id gets an extra parameter that points back to a coroutine function. This allows to check whether a coro.id describes the enclosing function or it belongs to a different function that was later inlined.
CoroSplit now creates three subfunctions:
# f$resume - resume logic
# f$destroy - cleanup logic, followed by a deallocation code
# f$cleanup - just the cleanup code
CoroElide pass during devirtualization replaces coro.destroy with either f$destroy or f$cleanup depending whether heap elision is performed or not.
Other fixes, improvements:
* Fixed buglet in Shape::buildFrame that was not creating coro.save properly if coroutine has more than one suspend point.
* Switched to using variable width suspend index field (no longer limited to 32 bit index field can be as little as i1 or as large as i<whatever-size_t-is>)
Reviewers: majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23844
llvm-svn: 279971
Assuming the default FP env, we should not treat fdiv and frem any differently in terms of
trapping behavior than any other FP op. Ie, FP ops do not trap with the default FP env.
This matches how we treat these ops in IR with isSafeToSpeculativelyExecute(). There's a
similar bug in Constant::canTrap().
This bug manifests in PR29114:
https://llvm.org/bugs/show_bug.cgi?id=29114
...as a sequence of scalar divisions instead of a vector division on x86 for a <3 x float>
type.
Differential Revision: https://reviews.llvm.org/D23974
llvm-svn: 279970
switch to using one indirect stub manager per logical dylib rather than one per
input module.
LogicalDylib is a helper class used by the CompileOnDemandLayer to manage
symbol resolution between modules during lazy compilation. In particular, it
ensures that internal symbols resolve correctly even in the case where multiple
input modules contain the same internal symbol name (which must to be promoted
to external hidden linkage so that functions in any given module can be split
out by lazy compilation). LogicalDylib's resolution scheme (before this commit)
required one stub-manager per input module. This made recompilation of functions
(by adding a module containing a new definition) difficult, as the stub manager
for any given symbol was bound to the module that supplied the original
definition. By using one stubs manager for the whole logical dylib symbols can
be more easily replaced, although support for doing this is not included in this
patch (it will be implemented in a follow up).
llvm-svn: 279952
Fixed a bug in run-time checks for possible memory conflicts inside loop.
The bug is in Low <-> High boundaries calculation. The High boundary should be calculated as "last memory access pointer + element size".
Differential revision: https://reviews.llvm.org/D23176
llvm-svn: 279930
When global-isel fails on a MachineFunction MF, MF will be cleaned up
and given to SDISel.
Thanks to this fallback, we can already perform correctness test even if
we support only a small portion of the functions in a test.
llvm-svn: 279891
This is used to communicate that the instruction selection pipeline
failed at some point.
Another way to achieve that would be to have some kind of conditional
scheduling in the PassManager, such that we only schedule a pass based
on the success/failure of another one. The property approach has the
advantage of being lightweight and solve the problem at stake.
llvm-svn: 279885
Summary:
Have the cache pass back the path to the cache entry when it
is ready to be loaded, instead of a buffer.
For gold-plugin we can simply pass this file back to gold directly,
which avoids expensive writing of a separate tmp file. Ensure
the cache entry is not deleted on cleanup by adjusting the setting
of the IsTemporary flags.
Moved the loading of the buffer into llvm-lto2 to maintain current
behavior.
Reviewers: mehdi_amini
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23946
llvm-svn: 279883
By default, this hook tells GlobalISel to abort (report a fatal error)
when it encounters an error. The alternative will be to fall back on
SDISel.
This fall back will be removed when the bring-up of GlobalISel is over.
llvm-svn: 279879
This method allows to reset the state of a MachineFunction as if it was
just created. This will be used during the bring-up of GlobalISel to
provide a way to fallback on SelectionDAG. That way, we can start doing
correctness testing even if we are not able to select all functions via
the global instruction selector.
llvm-svn: 279876
Summary:
This is obviously an interesting case because it may motivate code
restructuring or LTO.
Reporting this requires instantiation of ORE in the loop where the call
sites are first gathered. I've checked compile-time
overhead *with* -Rpass-with-hotness and the worst slow-down was 6% in
mcf and quickly tailing off. As before without -Rpass-with-hotness
there is no overhead.
Because this could be a pretty noisy diagnostics, it is currently
qualified as 'verbose'. As of this patch, 'verbose' diagnostics are
only emitted with -Rpass-with-hotness, i.e. when the output is expected
to be filtered.
Reviewers: eraman, chandlerc, davidxl, hfinkel
Subscribers: tejohnson, Prazek, davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D23415
llvm-svn: 279860
We already have obtained a pointer to the underlying GlobalObject,
use it directly to find the comdat, rather than using the
GlobalValue::getComdat which will do the same thing again.
llvm-svn: 279856
MCContext already has many tasks, and separating CodeView out from it is
probably a good idea. The .cv_loc tracking was modelled on the DWARF
tracking which lived directly in MCContext.
Removes the inclusion of MCCodeView.h from MCContext.h, so now there are
only 10 build actions while I hack on CodeView support instead of 265.
llvm-svn: 279847
Summary: Dead store elimination gets very expensive when large numbers of instructions need to be analyzed. This patch limits the number of instructions analyzed per store to the value of the memdep-block-scan-limit parameter (which defaults to 100). This resulted in no observed difference in performance of the generated code, and no change in the statistics for the dead store elimination pass, but improved compilation time on some files by more than an order of magnitude.
Reviewers: dexonsmith, bruno, george.burgess.iv, dberlin, reames, davidxl
Subscribers: davide, chandlerc, dberlin, davidxl, eraman, tejohnson, mbodart, llvm-commits
Differential Revision: https://reviews.llvm.org/D15537
llvm-svn: 279833
We can't mark ORE (a function pass) preserved as required by the loop
passes because that is how we ensure that the required passes like
LazyBFI are all available any time ORE is used. See the new comments in
the patch.
Instead we use it directly just like the inliner does in D22694.
As expected there is some additional overhead after removing the caching
provided by analysis passes. The worst case, I measured was
LNT/CINT2006_ref/401.bzip2 which regresses by 12%. As before, this only
affects -Rpass-with-hotness and not default compilation.
llvm-svn: 279829
This function allows getting arbitrary sized block of random bytes.
Primary motivation is support for --build-id=uuid in lld.
Differential revision: https://reviews.llvm.org/D23671
llvm-svn: 279807
The assertion doesn't always hold true as sizeof(SDNodeBits) isn't equal
to sizeof(uint16_t) for some targets. For example, sizeof(SDNodeBits)
evaluates to 1, not 2, for ARM's APCS targets.
llvm-svn: 279797
MMI must match the function passed, and MF has a handle on MMI. Use that instead
of accepting it as separate argument. No Functional Change.
llvm-svn: 279701
Save the function in the class, and then don't pass it around. This reduces the
number of parameters and makes calls to member functions simpler.
No Functional Change.
llvm-svn: 279700
Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.
Differential Revision: http://reviews.llvm.org/D23850
llvm-svn: 279698
tracksSubRegLiveness only depends on the Subtarget and a cl::opt, there
is not need to change it or save/parse it in a .mir file.
Make the field const and move the initialization LiveIntervalAnalysis to the
MachineRegisterInfo constructor. Also cleanup some code and fix some
instances which better use MachineRegisterInfo::subRegLivenessEnabled() instead
of TargetSubtargetInfo::enableSubRegLiveness().
llvm-svn: 279676
Summary:
This patch implements readlane/readfirstlane intrinsics.
TODO: need to define a new register class to consider the case
that the source could be a vector register or M0.
Reviewed by:
arsenm and tstellarAMD
Differential Revision:
http://reviews.llvm.org/D22489
llvm-svn: 279660
In cases where .dwo/.dwp files are guaranteed to be available, skipping
the extra online (in the .o file) inline info can save a substantial
amount of space - see the original r221306 for more details there.
llvm-svn: 279650
The register allocator can split a live interval of a register into a set
of smaller intervals. After the allocation of registers is complete, the
rewriter will modify the IR to replace virtual registers with the corres-
ponding physical registers. At this stage, if a register corresponding
to a subregister of a virtual register is used, the rewriter will check
if that subregister is undefined, and if so, it will add the <undef> flag
to the machine operand. The function verifying liveness of the subregis-
ter would assume that it is undefined, unless any of the subranges of the
live interval proves otherwise.
The problem is that the live intervals created during splitting do not
have any subranges, even if the original parent interval did. This could
result in the <undef> flag placed on a register that is actually defined.
Differential Revision: http://reviews.llvm.org/D21189
llvm-svn: 279625
manager, including both plumbing and logic to handle function pass
updates.
There are three fundamentally tied changes here:
1) Plumbing *some* mechanism for updating the CGSCC pass manager as the
CG changes while passes are running.
2) Changing the CGSCC pass manager infrastructure to have support for
the underlying graph to mutate mid-pass run.
3) Actually updating the CG after function passes run.
I can separate them if necessary, but I think its really useful to have
them together as the needs of #3 drove #2, and that in turn drove #1.
The plumbing technique is to extend the "run" method signature with
extra arguments. We provide the call graph that intrinsically is
available as it is the basis of the pass manager's IR units, and an
output parameter that records the results of updating the call graph
during an SCC passes's run. Note that "...UpdateResult" isn't a *great*
name here... suggestions very welcome.
I tried a pretty frustrating number of different data structures and such
for the innards of the update result. Every other one failed for one
reason or another. Sometimes I just couldn't keep the layers of
complexity right in my head. The thing that really worked was to just
directly provide access to the underlying structures used to walk the
call graph so that their updates could be informed by the *particular*
nature of the change to the graph.
The technique for how to make the pass management infrastructure cope
with mutating graphs was also something that took a really, really large
number of iterations to get to a place where I was happy. Here are some
of the considerations that drove the design:
- We operate at three levels within the infrastructure: RefSCC, SCC, and
Node. In each case, we are working bottom up and so we want to
continue to iterate on the "lowest" node as the graph changes. Look at
how we iterate over nodes in an SCC running function passes as those
function passes mutate the CG. We continue to iterate on the "lowest"
SCC, which is the one that continues to contain the function just
processed.
- The call graph structure re-uses SCCs (and RefSCCs) during mutation
events for the *highest* entry in the resulting new subgraph, not the
lowest. This means that it is necessary to continually update the
current SCC or RefSCC as it shifts. This is really surprising and
subtle, and took a long time for me to work out. I actually tried
changing the call graph to provide the opposite behavior, and it
breaks *EVERYTHING*. The graph update algorithms are really deeply
tied to this particualr pattern.
- When SCCs or RefSCCs are split apart and refined and we continually
re-pin our processing to the bottom one in the subgraph, we need to
enqueue the newly formed SCCs and RefSCCs for subsequent processing.
Queuing them presents a few challenges:
1) SCCs and RefSCCs use wildly different iteration strategies at
a high level. We end up needing to converge them on worklist
approaches that can be extended in order to be able to handle the
mutations.
2) The order of the enqueuing need to remain bottom-up post-order so
that we don't get surprising order of visitation for things like
the inliner.
3) We need the worklists to have set semantics so we don't duplicate
things endlessly. We don't need a *persistent* set though because
we always keep processing the bottom node!!!! This is super, super
surprising to me and took a long time to convince myself this is
correct, but I'm pretty sure it is... Once we sink down to the
bottom node, we can't re-split out the same node in any way, and
the postorder of the current queue is fixed and unchanging.
4) We need to make sure that the "current" SCC or RefSCC actually gets
enqueued here such that we re-visit it because we continue
processing a *new*, *bottom* SCC/RefSCC.
- We also need the ability to *skip* SCCs and RefSCCs that get merged
into a larger component. We even need the ability to skip *nodes* from
an SCC that are no longer part of that SCC.
This led to the design you see in the patch which uses SetVector-based
worklists. The RefSCC worklist is always empty until an update occurs
and is just used to handle those RefSCCs created by updates as the
others don't even exist yet and are formed on-demand during the
bottom-up walk. The SCC worklist is pre-populated from the RefSCC, and
we push new SCCs onto it and blacklist existing SCCs on it to get the
desired processing.
We then *directly* update these when updating the call graph as I was
never able to find a satisfactory abstraction around the update
strategy.
Finally, we need to compute the updates for function passes. This is
mostly used as an initial customer of all the update mechanisms to drive
their design to at least cover some real set of use cases. There are
a bunch of interesting things that came out of doing this:
- It is really nice to do this a function at a time because that
function is likely hot in the cache. This means we want even the
function pass adaptor to support online updates to the call graph!
- To update the call graph after arbitrary function pass mutations is
quite hard. We have to build a fairly comprehensive set of
data structures and then process them. Fortunately, some of this code
is related to the code for building the cal graph in the first place.
Unfortunately, very little of it makes any sense to share because the
nature of what we're doing is so very different. I've factored out the
one part that made sense at least.
- We need to transfer these updates into the various structures for the
CGSCC pass manager. Once those were more sanely worked out, this
became relatively easier. But some of those needs necessitated changes
to the LazyCallGraph interface to make it significantly easier to
extract the changed SCCs from an update operation.
- We also need to update the CGSCC analysis manager as the shape of the
graph changes. When an SCC is merged away we need to clear analyses
associated with it from the analysis manager which we didn't have
support for in the analysis manager infrsatructure. New SCCs are easy!
But then we have the case that the original SCC has its shape changed
but remains in the call graph. There we need to *invalidate* the
analyses associated with it.
- We also need to invalidate analyses after we *finish* processing an
SCC. But the analyses we need to invalidate here are *only those for
the newly updated SCC*!!! Because we only continue processing the
bottom SCC, if we split SCCs apart the original one gets invalidated
once when its shape changes and is not processed farther so its
analyses will be correct. It is the bottom SCC which continues being
processed and needs to have the "normal" invalidation done based on
the preserved analyses set.
All of this is mostly background and context for the changes here.
Many thanks to all the reviewers who helped here. Especially Sanjoy who
caught several interesting bugs in the graph algorithms, David, Sean,
and others who all helped with feedback.
Differential Revision: http://reviews.llvm.org/D21464
llvm-svn: 279618
Re-apply this patch, hopefully I will get away without any warnings
in the constructor now.
This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.
This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.
Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.
Differential Revision: http://reviews.llvm.org/D23736
llvm-svn: 279602
Specifying isSSA is an extra line at best and results in invalid MI at
worst. Compute the value instead.
Differential Revision: http://reviews.llvm.org/D22722
llvm-svn: 279600
Change this pass constructor to just accept a const TargetMachine * and
use INITIALIZE_TM_PASS, that way we can get rid of the dummy
constructor. The pass will still fail when calling the default
constructor leading to TM == nullptr, this is no different than before
but is more in line what other codegen passes are doing and avoids the
dummy constructor.
llvm-svn: 279598
Summary:
In clang commit r268509 we started to invoke loop-unroll pass from the
driver even under -Os. However, we happen to not initialize optsize
thresholds properly, which si fixed with this change.
r268509 led to some big compile time regressions, because we started to
unroll some loops that we didn't unroll before. With this change I hope
to recover most of the regressions. We still are slightly slower than
before, because we do some checks here and there in loop-unrolling
before we bail out, but at least the slowdown is not that huge now.
Reviewers: hfinkel, chandlerc
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D23388
llvm-svn: 279585
Add the ability to plug a cache on the LTO API.
I tried to write such that a linker implementation can
control the cache backend. This is intrusive and I'm
not totally happy with it, but I can't figure out a
better design right now.
Differential Revision: https://reviews.llvm.org/D23599
llvm-svn: 279576
I want to compute the SSA property of .mir files automatically in
upcoming patches. The problem with this is that some inputs will be
reported as static single assignment with some passes claiming not to
support SSA form. In reality though those passes do not support PHI
instructions => Track the presence of PHI instructions separate from the
SSA property.
Differential Revision: https://reviews.llvm.org/D22719
llvm-svn: 279573
They really should have both types represented, but early variants were created
before MachineInstrs could have multiple types so they're rather ambiguous.
llvm-svn: 279567
Re-apply this commit with the deletion of a MachineFunction delegated to
a separate pass to avoid use after free when doing this directly in
AsmPrinter.
This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.
This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.
Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.
Differential Revision: http://reviews.llvm.org/D23736
llvm-svn: 279564
Instructions like G_ICMP have multiple types that may need to be legalized (the
boolean output and nearly arbitrary inputs in this case). So the legalizer must
be capable of deciding what to do for each of them separately.
llvm-svn: 279554
Summary:
I assume there was a use case, so maybe this strawman patch will help
clarifying if it is legit.
In any case the current situation is not legit: a ThinLTO compilation
should not trigger an unexpected full LTO compilation.
Right now, adding a --save-temps option triggers this and makes the
number of output differs.
Reviewers: tejohnson
Subscribers: pcc, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23600
llvm-svn: 279550
Summary:
This greatly simplifies our handling of SDNode::SubclassData.
NFC, hopefully. :)
See discussion in D23035 for discussion about the design API of these
bitfields.
Reviewers: chandlerc
Subscribers: llvm-commits, rnk
Differential Revision: https://reviews.llvm.org/D23036
llvm-svn: 279537
This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.
This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.
Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.
Differential Revision: http://reviews.llvm.org/D23736
llvm-svn: 279502
Separate algorithms in iplist<T> that don't depend on T into ilist_base,
and unit test them.
While I was adding unit tests for these algorithms anyway, I also added
unit tests for ilist_node_base and ilist_sentinel<T>.
To make the algorithms and unit tests easier to write, I also did the
following minor changes as a drive-by:
- encapsulate Prev/Next in ilist_node_base to so that algorithms are
easier to read, and
- update ilist_node_access API to take nodes by reference.
There should be no real functionality change here.
llvm-svn: 279484
Summary: Before the change, *Opt never actually gets updated by the end
of toNext(), so for every next time the loop has to start over from
child_begin(). This bug doesn't affect the correctness, since Visited prevents
it from re-entering the same node again; but it's slow.
Reviewers: dberris, dblaikie, dannyb
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23649
llvm-svn: 279482
Remove all the dead code around ilist_*sentinel_traits. This is a
follow-up to gutting them as part of r279314 (originally r278974),
staged to prevent broken builds in sub-projects.
Uses were removed from clang in r279457 and lld in r279458.
llvm-svn: 279473
Philip commented on r279113 to ask for better comments as to
when to use the different versions of getName. Its also possible
to assert in the simple case that we aren't an overloaded intrinsic
as those have to use the more capable version of getName.
Thanks for the comments Philip.
llvm-svn: 279466
Assembler directives .dtprelword, .dtpreldword, .tprelword, and
.tpreldword generates relocations R_MIPS_TLS_DTPREL32, R_MIPS_TLS_DTPREL64,
R_MIPS_TLS_TPREL32, and R_MIPS_TLS_TPREL64 respectively.
The main motivation for this patch is to be able to write test cases
for checking correctness of the LLD linker's behaviour.
Differential Revision: https://reviews.llvm.org/D23669
llvm-svn: 279439
It use to be non-const for the sole purpose of custom handling of
commons symbol. This is moved now in the regular LTO handling now
and such we can constify the callback.
llvm-svn: 279438
The gold-plugin was doing this internally, now the API is handling
commons correctly based on the given resolution.
Differential Revision: https://reviews.llvm.org/D23739
llvm-svn: 279417
Summary: Reduce store size to avoid leading and trailing zeros.
Reviewers: kcc, eugenis
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23648
llvm-svn: 279379
Summary:
We are going to combine poisoning of red zones and scope poisoning.
PR27453
Reviewers: kcc, eugenis
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23623
llvm-svn: 279373
unit for use in the PreservedAnalyses set.
This doesn't have any important functional change yet but it cleans
things up and makes the analysis substantially more efficient by
avoiding querying through the type erasure for every analysis.
I also think it makes it much easier to reason about how analyses are
preserved when walking across pass managers and across IR unit
abstractions.
Thanks to Sean and Mehdi both for the comments and suggestions.
Differential Revision: https://reviews.llvm.org/D23691
llvm-svn: 279360
- Always compile print() regardless of LLVM_ENABLE_DUMP. (We usually
only gard dump() functions with that).
- Only show the set properties to reduce output clutter.
- Remove the unused variant that even shows the unset properties.
- Fix comments
llvm-svn: 279338
Currently nodes_iterator may dereference to a NodeType* or a NodeType&. Make them all dereference to NodeType*, which is NodeRef later.
Differential Revision: https://reviews.llvm.org/D23704
Differential Revision: https://reviews.llvm.org/D23705
llvm-svn: 279326
This reverts commit r279053, reapplying r278974 after fixing PR29035
with r279104.
Note that r279312 has been committed in the meantime, and this has been
rebased on top of that. Otherwise it's identical to r278974.
Note for maintainers of out-of-tree code (that I missed in the original
message): if the new isKnownSentinel() assertion is firing from
ilist_iterator<>::operator*(), this patch has identified a bug in your
code. There are a few common patterns:
- Some IR-related APIs htake an IRUnit* that might be nullptr, and pass
in an incremented iterator as an insertion point. Some old code was
using "&*++I", which in the case of end() only worked by fluke. If
the IRUnit in question inherits from ilist_node_with_parent<>, you can
use "I->getNextNode()". Otherwise, use "List.getNextNode(*I)".
- In most other cases, crashes on &*I just need to check for I==end()
before dereferencing.
- There's also occasional code that sends iterators into a function, and
then starts calling I->getOperand() (or other API). Either check for
end() before the entering the function, or early exit.
Note for if the static_assert with HasObsoleteCustomization is firing
for you:
- r278513 has examples of how to stop using custom sentinel traits.
- r278532 removed ilist_nextprev_traits since no one was using it. See
lld's r278469 for the only migration I needed to do.
Original commit message follows.
----
This removes the undefined behaviour (UB) in ilist/ilist_node/etc.,
mainly by removing (gutting) the ilist_sentinel_traits customization
point and canonicalizing on a single, efficient memory layout. This
fixes PR26753.
The new ilist is a doubly-linked circular list.
- ilist_node_base has two ilist_node_base*: Next and Prev. Size-of: two
pointers.
- ilist_node<T> (size-of: two pointers) is a type-safe wrapper around
ilist_node_base.
- ilist_iterator<T> (size-of: two pointers) operates on an
ilist_node<T>*, and downcasts to T* on dereference.
- ilist_sentinel<T> (size-of: two pointers) is a wrapper around
ilist_node<T> that has some extra API for list management.
- ilist<T> (size-of: two pointers) has an ilist_sentinel<T>, whose
address is returned for end().
The new memory layout matches ilist_half_embedded_sentinel_traits<T>
exactly. The Head pointer that previously lived in ilist<T> is
effectively glued to the ilist_half_node<T> that lived in
ilist_half_embedded_sentinel_traits<T>, becoming the Next and Prev in
the ilist_sentinel_node<T>, respectively. sizeof(ilist<T>) is now the
size of two pointers, and there is never any additional storage for a
sentinel.
This is a much simpler design for a doubly-linked list, removing most of
the corner cases of list manipulation (add, remove, etc.). In follow-up
commits, I intend to move as many algorithms as possible into a
non-templated base class (ilist_base) to reduce code size.
Moreover, this fixes the UB in ilist_iterator/getNext/getPrev
operations. Previously, ilist_iterator<T> operated on a T*, even when
the sentinel was not of type T (i.e., ilist_embedded_sentinel_traits and
ilist_half_embedded_sentinel_traits). This added UB to all operations
involving end(). Now, ilist_iterator<T> operates on an ilist_node<T>*,
and only downcasts when the full type is guaranteed to be T*.
What did we lose? There used to be a crash (in some configurations) on
++end(). Curiously (via UB), ++end() would return begin() for users of
ilist_half_embedded_sentinel_traits<T>, but otherwise ++end() would
cause a nice dependable nullptr dereference, crashing instead of a
possible infinite loop. Options:
1. Lose that behaviour.
2. Keep it, by stealing a bit from Prev in asserts builds.
3. Crash on dereference instead, using the same technique.
Hans convinced me (because of the number of problems this and r278532
exposed on Windows) that we really need some assertion here, at least in
the short term. I've opted for #3 since I think it catches more bugs.
I added only a couple of unit tests to root out specific bugs I hit
during bring-up, but otherwise this is tested implicitly via the
extensive usage throughout LLVM.
Planned follow-ups:
- Remove ilist_*sentinel_traits<T>. Here I've just gutted them to
prevent build failures in sub-projects. Once I stop referring to them
in sub-projects, I'll come back and delete them.
- Add ilist_base and move algorithms there.
- Check and fix move construction and assignment.
Eventually, there are other interesting directions:
- Rewrite reverse iterators, so that rbegin().getNodePtr()==&*rbegin().
This allows much simpler logic when erasing elements during a reverse
traversal.
- Remove ilist_traits::createNode, by deleting the remaining API that
creates nodes. Intrusive lists shouldn't be creating nodes
themselves.
- Remove ilist_traits::deleteNode, by (1) asserting that lists are empty
on destruction and (2) changing API that calls it to take a Deleter
functor (intrusive lists shouldn't be in the memory management
business).
- Reconfigure the remaining callback traits (addNodeToList, etc.) to be
higher-level, pulling out a simple_ilist<T> that is much easier to
read and understand.
- Allow tags (e.g., ilist_node<T,tag1> and ilist_node<T,tag2>) so that T
can be a member of multiple intrusive lists.
llvm-svn: 279314
This spiritually reapplies r279012 (reverted in r279052) without the
r278974 parts. The differences:
- Only the HasGetNext trait exists here, so I've only cleaned up (and
tested) it. I still added HasObsoleteCustomization since I know
this will be expanding when r278974 is reapplied.
- I changed the unit tests to use static_assert to catch problems
earlier in the build.
- I added negative tests for the type traits.
Original commit message follows.
----
Change the ilist traits to use decltype instead of sizeof, and add
HasObsoleteCustomization so that additions to this list don't
need to be added in two places.
I suspect this will now work with MSVC, since the trait tested in
r278991 seems to work. If for some reason it continues to fail on
Windows I'll follow up by adding back the #ifndef _MSC_VER.
llvm-svn: 279312
Krzysztof Parzyszek