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
These two functions are hard to reason about. This commit makes the code
more comprehensible:
- Use four distinct variables (OldIdxIn, OldIdxOut, NewIdxIn, NewIdxOut)
with a fixed value instead of a changing iterator I that points to
different things during the function.
- Remove the early explanation before the function in favor of more
detailed comments inside the function. Should have more/clearer comments now
stating which conditions are tested and which invariants hold at
different points in the functions.
The behaviour of the code was not changed.
I hope that this will make it easier to review the changes in
http://reviews.llvm.org/D9067 which I will adapt next.
Differential Revision: http://reviews.llvm.org/D16379
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258756 91177308-0d34-0410-b5e6-96231b3b80d8
The indexList's nodes are all allocated on a BumpPtrAllocator, so it's
more efficient to let them be freed when it goes away, rather than
deleting them directly. This is a follow up to r254794.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254808 91177308-0d34-0410-b5e6-96231b3b80d8
When a `SlotIndexes` is destroyed, `ileAllocator` will currently be
destructed before `IndexList`, but all of `IndexList`'s storage has
been allocated by `ileAllocator`. This means we'll call destructors on
garbage data, which is very bad. This can be avoided by putting the
BumpPtrAllocator earlier in the class than anything it allocates.
Unfortunately, I don't know how to test this. It depends very much on
memory layout, and the only evidence I have that this is actually
happening in practice are backtraces that might be explained by this.
By inspection though, the code is obviously dangerous/wrong, and this
is the right thing to do.
I'll follow up later with a patch that calls clearAndLeakNodesUnsafely
on the list, since there isn't much point in destructing them when
they're allocated in a BPA anyway, but I figured it makes sense to
commit the correctness fix separately from that optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254794 91177308-0d34-0410-b5e6-96231b3b80d8
Be honest about using iterator semantics in `SlotIndex::getNextSlot()`
and `SlotIndex::getPrevSlot()`. Instead of calling `getNextNode()` --
which is documented (but fails) to check for the sentinel -- call
`&*++getIterator()`.
This is (surprisingly!) a NFC commit. `ilist_traits<IndexListEntry>`
has an `ilist_half_node<IndexListEntry>` as a sentinel (and no other
fields), and so the layout of `ilist<IndexListEntry>` is:
--
struct ilist<IndexListEntry> {
ilist_half_node<IndexListEntry> Sentinel;
IndexListEntry *Head;
IndexListEntry *getHead() { return Head; }
IndexListEntry *getSentinel() { return cast<...>(&Sentinel); }
};
--
In memory, this happens to look just like:
--
struct ilist<IndexListEntry> {
ilist_node<IndexListEntry> Sentinel;
IndexListEntry *getHead() { return Sentinel.getNext(); }
IndexListEntry *getSentinel() { return cast<...>(&Sentinel); }
};
--
As a result, `ilist_node<IndexListEntry>::getNextNode()` that checks
`getNext()` of the possible sentinel will get a pointer to the head of
the list; it will never detect the sentinel, and will return the
sentinel itself instead of `nullptr` in the special cases.
Since `getNextNode()` and `getPrevNode()` don't work, just be honest
that we're not checking for the end/beginning of the list here. Since
this code works, I guess we must never go past the sentinel.
(It's possible we're just getting lucky, and the new code will get
"lucky" in the same situations. To properly fix that hypothetical bug,
we would need to check the iterator against `end()`/`begin()`.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252538 91177308-0d34-0410-b5e6-96231b3b80d8
Be explicit about changes between pointers and iterators, as with other
recent commits. This transitively removes implicit ilist iterator
conversions from about 20 source files in CodeGen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249869 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we have an explicit iterator over the idx2MBBMap in SlotIndices
we can use the fact that segments and the idx2MBBMap is sorted by
SlotIndex position so can advance both simultaneously instead of
starting from the beginning for each segment.
This complicates the code for the subregister case somewhat but should
be more efficient and has the advantage that we get the final lanemask
for each block immediately which will be important for a subsequent
change.
Removes the now unused SlotIndexes::findMBBLiveIns function.
Differential Revision: http://reviews.llvm.org/D12443
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247170 91177308-0d34-0410-b5e6-96231b3b80d8
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
BitVector/SmallBitVector::reference::operator bool remain implicit since
they model more exactly a bool, rather than something else that can be
boolean tested.
The most common (non-buggy) case are where such objects are used as
return expressions in bool-returning functions or as boolean function
arguments. In those cases I've used (& added if necessary) a named
function to provide the equivalent (or sometimes negative, depending on
convenient wording) test.
One behavior change (YAMLParser) was made, though no test case is
included as I'm not sure how to reach that code path. Essentially any
comparison of llvm::yaml::document_iterators would be invalid if neither
iterator was at the end.
This helped uncover a couple of bugs in Clang - test cases provided for
those in a separate commit along with similar changes to `operator bool`
instances in Clang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181868 91177308-0d34-0410-b5e6-96231b3b80d8
When the SlotIndexes pass was introduced it was intended to support insertion
of code during register allocation. Removal of code was a minor consideration
(and raised the question of what to do about dangling SlotIndex objects pointing
to the erased index), so I opted to keep all indexes around indefinitely and
simply null out those that weren't being used.
Nowadays people are moving more code around (e.g. via HandleMove), which means
more zombie indexes. I want to start killing off indexes when we're done with
them to reclaim the resources they use up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179834 91177308-0d34-0410-b5e6-96231b3b80d8
and removing instructions. The implementation seems more complicated than it
needs to be, but I couldn't find something simpler that dealt with all of the
corner cases.
Also add a call to repairIndexesInRange() from repairIntervalsInRange().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175601 91177308-0d34-0410-b5e6-96231b3b80d8
support for updating SlotIndexes to MachineBasicBlock::SplitCriticalEdge(). This
calls renumberIndexes() every time; it should be improved to only renumber
locally.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174851 91177308-0d34-0410-b5e6-96231b3b80d8
re-use that for SlotIndexes. This way other users who want half-open
semantics can share the implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171158 91177308-0d34-0410-b5e6-96231b3b80d8
AKA: Recompile *ALL* the source code!
This one went much better. No manual edits here. I spot-checked for
silliness and grep-checked for really broken edits and everything seemed
good. It all still compiles. Yell if you see something that looks goofy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169133 91177308-0d34-0410-b5e6-96231b3b80d8
It set NumLowBitAvailable = 3 which may not be true on all platforms. We only
ever use 2 bits (the default) so this assumption can be safely removed
Should fix PR12612.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155288 91177308-0d34-0410-b5e6-96231b3b80d8
for the life of me remember why I wrote it this way, but I can't see any good
reason for it now. This patch replaces the custom linked list with an ilist.
This change should preserve the existing numberings exactly, so no generated code
should change (if it does, file a bug!).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154904 91177308-0d34-0410-b5e6-96231b3b80d8
This allows the function to be inlined, and makes it suitable for use in
getInstructionIndex().
Also provide a const version. C++ is great for touch typing practice.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151782 91177308-0d34-0410-b5e6-96231b3b80d8
SlotIndexes are not assigned to instructions inside bundles, but it is
still valid to look up the index of those instructions.
The reverse getInstructionFromIndex() will return the first instruction
in the bundle.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151672 91177308-0d34-0410-b5e6-96231b3b80d8
Consider this code:
int h() {
int x;
try {
x = f();
g();
} catch (...) {
return x+1;
}
return x;
}
The variable x is undefined on the first edge to the landing pad, but it
has the f() return value on the second edge to the landing pad.
SplitAnalysis::getLastSplitPoint() would assume that the return value
from f() was live into the landing pad when f() throws, which is of
course impossible.
Detect these cases, and treat them as if the landing pad wasn't there.
This allows spill code to be inserted after the function call to f().
<rdar://problem/10664933>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147912 91177308-0d34-0410-b5e6-96231b3b80d8
The old naming scheme (load/use/def/store) can be traced back to an old
linear scan article, but the names don't match how slots are actually
used.
The load and store slots are not needed after the deferred spill code
insertion framework was deleted.
The use and def slots don't make any sense because we are using
half-open intervals as is customary in C code, but the names suggest
closed intervals. In reality, these slots were used to distinguish
early-clobber defs from normal defs.
The new naming scheme also has 4 slots, but the names match how the
slots are really used. This is a purely mechanical renaming, but some
of the code makes a lot more sense now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144503 91177308-0d34-0410-b5e6-96231b3b80d8
This gets rid of some of the gory splitting details in RAGreedy and
makes them available to future SplitKit clients.
Slightly generalize the functionality to support multi-way splitting.
Specifically, SplitEditor::splitLiveThroughBlock() supports switching
between different register intervals in a block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135307 91177308-0d34-0410-b5e6-96231b3b80d8
This makes a difference if a live interval is referring to a deleted
instruction. It can be important to insert an instruction before or after a
deleted instruction to avoid interference.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130686 91177308-0d34-0410-b5e6-96231b3b80d8
