CFI instructions that set appropriate cfa offset and cfa register are now
inserted in emitEpilogue() in X86FrameLowering.
Majority of the changes in this patch:
1. Ensure that CFI instructions do not affect code generation.
2. Enable maintaining correct information about cfa offset and cfa register
in a function when basic blocks are reordered, merged, split, duplicated.
These changes are target independent and described below.
Changed CFI instructions so that they:
1. are duplicable
2. are not counted as instructions when tail duplicating or tail merging
3. can be compared as equal
Add information to each MachineBasicBlock about cfa offset and cfa register
that are valid at its entry and exit (incoming and outgoing CFI info). Add
support for updating this information when basic blocks are merged, split,
duplicated, created. Add a verification pass (CFIInfoVerifier) that checks
that outgoing cfa offset and register of predecessor blocks match incoming
values of their successors.
Incoming and outgoing CFI information is used by a late pass
(CFIInstrInserter) that corrects CFA calculation rule for a basic block if
needed. That means that additional CFI instructions get inserted at basic
block beginning to correct the rule for calculating CFA. Having CFI
instructions in function epilogue can cause incorrect CFA calculation rule
for some basic blocks. This can happen if, due to basic block reordering,
or the existence of multiple epilogue blocks, some of the blocks have wrong
cfa offset and register values set by the epilogue block above them.
Patch by Violeta Vukobrat.
Differential Revision: https://reviews.llvm.org/D18046
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306529 91177308-0d34-0410-b5e6-96231b3b80d8
It seems not all of our bots have a std::vector::erase() taking a
const_iterator (even though that seems to be part of C++11) attempt to
workaround.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304349 91177308-0d34-0410-b5e6-96231b3b80d8
After transforming FP to ST registers:
- Do not add the ST register to the livein lists, they are reserved so
we do not need to track their liveness.
- Remove the FP registers from the livein lists, they don't have defs or
uses anymore and so are not live.
- (The setKillFlags() call is moved to an earlier place as it relies on
the FP registers still being present in the livein list.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304342 91177308-0d34-0410-b5e6-96231b3b80d8
- Adapt MachineBasicBlock::getName() to have the same behavior as the IR
BasicBlock (Value::getName()).
- Add it to lib/CodeGen/CodeGen.cpp::initializeCodeGen so that it is linked in
the CodeGen library.
- MachineRegionInfoPass's name conflicts with RegionInfoPass's name ("region").
- MachineRegionInfo should depend on MachineDominatorTree,
MachinePostDominatorTree and MachineDominanceFrontier instead of their
respective IR versions.
- Since there were no tests for this, add a X86 MIR test.
Patch by Francis Visoiu Mistrih<fvisoiumistrih@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295518 91177308-0d34-0410-b5e6-96231b3b80d8
Inline spiller can decide to move a spill as early as possible in the basic block.
It will skip phis and label, but we also need to make sure it skips instructions
in the basic block prologue which restore exec mask.
Added isPositionLike callback in TargetInstrInfo to detect instructions which
shall be skipped in addition to common phis, labels etc.
Differential Revision: https://reviews.llvm.org/D27997
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292554 91177308-0d34-0410-b5e6-96231b3b80d8
Add an assert that checks whether liveins are up to date before they are
used.
- Do not print liveins into .mir files anymore in situations where they
are out of date anyway.
- The assert in the RegisterScavenger is superseded by the new one in
livein_begin().
- Skip parts of the liveness updating logic in IfConversion.cpp when
liveness isn't tracked anymore (just enough to avoid hitting the new
assert()).
Differential Revision: https://reviews.llvm.org/D27562
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291169 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This commits moves skipDebugInstructionsForward and
skipDebugInstructionsBackward from lib/CodeGen/IfConversion.cpp
to include/llvm/CodeGen/MachineBasicBlock.h and updates
some codgen files to use them.
This refactoring was suggested in https://reviews.llvm.org/D27688
and I thought it's best to do the refactoring in a separate
review, but I could also put both changes in a single review
if that's preferred.
Also, the names for the functions aren't the snappiest and
I would be happy to rename them if anybody has suggestions.
Reviewers: eli.friedman, iteratee, aprantl, MatzeB
Subscribers: MatzeB, llvm-commits
Differential Revision: https://reviews.llvm.org/D27782
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289933 91177308-0d34-0410-b5e6-96231b3b80d8
Specifically avoid implicit conversions from/to integral types to
avoid potential errors when changing the underlying type. For example,
a typical initialization of a "full" mask was "LaneMask = ~0u", which
would result in a value of 0x00000000FFFFFFFF if the type was extended
to uint64_t.
Differential Revision: https://reviews.llvm.org/D27454
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289820 91177308-0d34-0410-b5e6-96231b3b80d8
When a phi node is finally lowered to a machine instruction it is
important that the lowered "load" instruction is placed before the
associated DEBUG_VALUE entry describing the value loaded.
Renamed the existing SkipPHIsAndLabels to SkipPHIsLabelsAndDebug to
more fully describe that it also skips debug entries. Then used the
"new" function SkipPHIsAndLabels when the debug information should not
be skipped when placing the lowered "load" instructions so that it is
placed before the debug entries.
Differential Revision: https://reviews.llvm.org/D23760
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281727 91177308-0d34-0410-b5e6-96231b3b80d8
This is a prep commit before fixing MachineBasicBlock::reverse_iterator
invalidation semantics, ala r281167 for ilist::reverse_iterator. This
changes MachineBasicBlock::Instructions to track which node is the
sentinel regardless of LLVM_ENABLE_ABI_BREAKING_CHECKS.
There's almost no functionality change (aside from ABI). However, in
the rare configuration:
#if !defined(NDEBUG) && !defined(LLVM_ENABLE_ABI_BREAKING_CHECKS)
the isKnownSentinel() assertions in ilist_iterator<>::operator* suddenly
have teeth for MachineInstr. If these assertions start firing for your
out-of-tree backend, have a look at the suggestions in the commit
message for r279314, and at some of the commits leading up to it that
avoid dereferencing the end() iterator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281168 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280128 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280122 91177308-0d34-0410-b5e6-96231b3b80d8
The current MachineBasicBlock might be the last block, so FallThru may
be past the end(). Use getNextNode(), which will convert to nullptr,
rather than &*++, which is invalid if we reach the end().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278858 91177308-0d34-0410-b5e6-96231b3b80d8
If the result of the find is only used to compare against end(), just
use is_contained instead.
No functionality change is intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278469 91177308-0d34-0410-b5e6-96231b3b80d8
If the result of the find is only used to compare against end(), just
use is_contained instead.
No functionality change is intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278433 91177308-0d34-0410-b5e6-96231b3b80d8
After the block placement, if a block ends with a conditional branch, but the
next block is not its successor. The conditional branch should be changed to
unconditional branch. This patch fixes PR28307, PR28297, PR28402.
Differential Revision: http://reviews.llvm.org/D21811
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274470 91177308-0d34-0410-b5e6-96231b3b80d8
Change all the methods in LiveVariables that expect non-null
MachineInstr* to take MachineInstr& and update the call sites. This
clarifies the API, and designs away a class of iterator to pointer
implicit conversions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274319 91177308-0d34-0410-b5e6-96231b3b80d8
We didn't have logic to correctly handle CFGs where there was more than
one EH-pad successor (these are novel with WinEH).
There were situations where a register was live in one exceptional
successor but not another but the code as written would only consider
the first exceptional successor it found.
This resulted in split points which were insufficiently early if an
invoke was present.
This fixes PR27501.
N.B. This removes getLandingPadSuccessor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267412 91177308-0d34-0410-b5e6-96231b3b80d8
splitting edges.
MachineBasicBlock::SplitCriticalEdges will crash if a nullptr would have
been passed for the Pass argument. Do not allow that by turning this
argument into a reference.
The alternative would have been to make the Pass a truly optional
argument, but although this is easy to do, I was afraid users using it
like this would not be aware the livness information, dominator tree and
such would silently be broken.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267052 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce canSplitCriticalEdge, so that clients can now query whether or
not a critical edge can be split without actually needing to split it.
This may be useful when gathering information for cost models for
instance.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267046 91177308-0d34-0410-b5e6-96231b3b80d8
Update APIs in MachineInstrBundle.h to take and return MachineInstr&
instead of MachineInstr* when the instruction cannot be null. Besides
being a nice cleanup, this is tacking toward a fix for PR26753.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262141 91177308-0d34-0410-b5e6-96231b3b80d8
Take MachineInstr by reference instead of by pointer in SlotIndexes and
the SlotIndex wrappers in LiveIntervals. The MachineInstrs here are
never null, so this cleans up the API a bit. It also incidentally
removes a few implicit conversions from MachineInstrBundleIterator to
MachineInstr* (see PR26753).
At a couple of call sites it was convenient to convert to a range-based
for loop over MachineBasicBlock::instr_begin/instr_end, so I added
MachineBasicBlock::instrs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262115 91177308-0d34-0410-b5e6-96231b3b80d8
Change TargetInstrInfo API to take `MachineInstr&` instead of
`MachineInstr*` in the functions related to predicated instructions
(I'll try to come back later and get some of the rest). All of these
functions require non-null parameters already, so references are more
clear. As a bonus, this happens to factor away a host of implicit
iterator => pointer conversions.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261605 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds some missing calls to MBB::normalizeSuccProbs() in several
locations where it should be called. Those places are found by checking if the
sum of successors' probabilities is approximate one in MachineBlockPlacement
pass with some instrumented code (not in this patch).
Differential revision: http://reviews.llvm.org/D15259
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255455 91177308-0d34-0410-b5e6-96231b3b80d8
computeRegisterLiveness() was broken in that it reported dead for a
register even if a subregister was alive. I assume this was because the
results of analayzePhysRegs() are hard to understand with respect to
subregisters.
This commit: Changes the results of analyzePhysRegs (=struct
PhysRegInfo) to be clearly understandable, also renames the fields to
avoid silent breakage of third-party code (and improve the grammar).
Fix all (two) users of computeRegisterLiveness() in llvm: By reenabling
it and removing workarounds for the bug.
This fixes http://llvm.org/PR24535 and http://llvm.org/PR25033
Differential Revision: http://reviews.llvm.org/D15320
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255362 91177308-0d34-0410-b5e6-96231b3b80d8
Previously it is not allowed for each MBB to have successors with both known and
unknown probabilities. However, this may be too strict as at this stage we could
not always guarantee that. It is better to remove this restriction now, and I
will work on validating MBB's successors' probabilities first (for example,
check if the sum is approximate one).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254402 91177308-0d34-0410-b5e6-96231b3b80d8
(This is the second attempt to submit this patch. The first caused two assertion
failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687)
The patch in http://reviews.llvm.org/D13745 is broken into four parts:
1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.
This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.
All uses of weight-based interfaces are now updated to use probability-based
ones.
Differential revision: http://reviews.llvm.org/D14973
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254377 91177308-0d34-0410-b5e6-96231b3b80d8
and the follow-up r254356: "Fix a bug in MachineBlockPlacement that may cause assertion failure during BranchProbability construction."
Asserts were firing in Chromium builds. See PR25687.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254366 91177308-0d34-0410-b5e6-96231b3b80d8
The patch in http://reviews.llvm.org/D13745 is broken into four parts:
1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.
This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.
All uses of weight-based interfaces are now updated to use probability-based
ones.
Differential revision: http://reviews.llvm.org/D14973
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254348 91177308-0d34-0410-b5e6-96231b3b80d8
