This will be necessary to allow the global merge pass to attach
multiple debug info metadata nodes to global variables once we reverse
the edge from DIGlobalVariable to GlobalVariable.
Differential Revision: http://reviews.llvm.org/D20414
llvm-svn: 271358
This patch adds an IR, assembly and bitcode representation for metadata
attachments for globals. Future patches will port existing features to use
these new attachments.
Differential Revision: http://reviews.llvm.org/D20074
llvm-svn: 271348
This is part of solving PR27344:
https://llvm.org/bugs/show_bug.cgi?id=27344
CGP should undo the SimplifyCFG transform for the same reason that earlier patches have used this
same mechanism: it's possible that passes between SimplifyCFG and CGP may be able to optimize the
IR further with a select in place.
For the TLI hook default, >99% taken or not taken is chosen as the default threshold for a highly
predictable branch. Even the most limited HW branch predictors will be correct on this branch almost
all the time, so even a massive mispredict penalty perf loss would be overcome by the win from all
the times the branch was predicted correctly.
As a follow-up, we could make the default target hook less conservative by using the SchedMachineModel's
MispredictPenalty. Or we could just let targets override the default by implementing the hook with that
and other target-specific options. Note that trying to statically determine mispredict rates for
close-to-balanced profile weight data is generally impossible if the HW is sufficiently advanced. Ie,
50/50 taken/not-taken might still be 100% predictable.
Finally, note that this patch as-is will not solve PR27344 because the current __builtin_unpredictable()
branch weight default values are 4 and 64. A proposal to change that is in D19435.
Differential Revision: http://reviews.llvm.org/D19488
llvm-svn: 267572
Each reference to an unresolved MDNode is expensive, since the RAUW
support in MDNode uses a separate allocation and side map. Since
a distinct MDNode doesn't require its operands on creation (unlike
uniuqed nodes, there's no need to check for structural equivalence),
use nullptr for any of its unresolved operands. Besides reducing the
burden on MDNode maps, this can avoid allocating temporary MDNodes in
the first place.
We need some way to track operands. Invent DistinctMDOperandPlaceholder
for this purpose, which is a Metadata subclass that holds an ID and
points at its single user. DistinctMDOperandPlaceholder::replaceUseWith
is just like RAUW, but its name highlights that there is only ever
exactly one use.
There is no support for moving (or, obviously, copying) these. Move
support would be possible but expensive; leaving it unimplemented
prevents user error. In the BitcodeReader I originally considered
allocating on a BumpPtrAllocator and keeping a vector of pointers to
them, and then I realized that std::deque implements exactly this.
A couple of obvious follow-ups:
- Change ValueEnumerator to emit distinct nodes first to take more
advantage of this optimization. (How convenient... I think I might
have a couple of patches for this.)
- Change DIBuilder and its consumers (like CGDebugInfo in clang) to
use something like this when constructing debug info in the first
place.
llvm-svn: 267270
We never use the set-ness of SmallPtrSet for distinct nodes. Eventually
we may start garbage-collecting or reference-counting nodes (in which
cases we'd want to remove things from this collection, and a fast erase
would be valuable), but in the meantime a vector is sufficient.
llvm-svn: 266835
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
RAUW support on MDNode usually requires an extra allocation for
ReplaceableMetadataImpl. This is only strictly necessary if there are
tracking references to the MDNode. Make the construction of
ReplaceableMetadataImpl lazy, so that we don't get allocations if we
don't need them.
Since MDNode::isResolved now checks MDNode::isTemporary and
MDNode::NumUnresolved instead of whether a ReplaceableMetadataImpl is
allocated, the internal changes are intrusive (at various internal
checkpoints, isResolved now has a different answer).
However, there should be no real functionality change here; just
slightly lazier allocation behaviour. The external semantics should be
identical.
llvm-svn: 265279
Since we have moved to a model where functions are imported in bulk from
each source module after making summary-based importing decisions, there
is no longer a need to link metadata as a postpass, and all users have
been removed.
This essentially reverts r255909 and follow-on fixes.
llvm-svn: 264763
Summary:
Loading IR with debug info improves MDString::get() from 19ms to 10ms.
This is a rework of D16597 with adding an "emplace" method on the StringMap
to avoid requiring the MDString move ctor to be public.
Reviewers: dexonsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D17920
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 264386
This reverts commit r261030 and r261036.
(The revision was marked "approved" on phabricator, but some concerns
were raised on the mailing list. Thanks D. Blaikie for notifying me.)
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 261055
Summary: Loading IR with debug info improves MDString::get() from 19ms to 10ms.
Reviewers: dexonsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16597
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 261030
There is a legitimate use-case in clang where we need to replace a
temporary placeholder node with the temporary node that may be a
forward declaration.
<rdar://problem/24493203>
llvm-svn: 259973
Address review feedback from r255909.
Move body of resolveCycles(bool AllowTemps) to
resolveRecursivelyImpl(bool AllowTemps). Revert resolveCycles back
to asserting on temps, and add new resolveNonTemporaries interface
to invoke the new implementation with AllowTemps=true. Document
the differences between these interfaces, specifically the effect
on RAUW support and uniquing. Call appropriate interface from
ValueMapper.
llvm-svn: 257389
As suggested in review for r255909, rename MDMaterialized to AllowTemps,
and identify the name of the boolean flag being set in calls to
saveMetadataList.
llvm-svn: 256653
As suggested in review for r255909, add a way to ensure that temporary
MD used as keys in the MetadataToID map during ThinLTO importing are not
RAUWed.
Add support for marking an MDNode as not replaceable. Clear the new
CanReplace flag when adding a temporary MD node to the MetadataToID map
and clear it when destroying the map.
llvm-svn: 256648
header.
This is part of a series of patches to allow LLVM to check for complete
pointee types when computing its pointer traits. This is absolutely
necessary to get correct (or reproducible) results for things like how
many low bits are guaranteed to be zero.
The MetadataTracking helpers aren't actually independent. They rely on
constructing a PointerUnion between Metadata and MetadataAsValue
pointers, which requires know the alignment of pointers to those types
which requires them to be complete.
The .cpp file even defined a method declared in Metadata.h! These really
don't seem like something that is separable, and there is no real
layering problem with just placing them together.
llvm-svn: 256531
Summary:
Second patch split out from http://reviews.llvm.org/D14752.
Maps metadata as a post-pass from each module when importing complete,
suturing up final metadata to the temporary metadata left on the
imported instructions.
This entails saving the mapping from bitcode value id to temporary
metadata in the importing pass, and from bitcode value id to final
metadata during the metadata linking postpass.
Depends on D14825.
Reviewers: dexonsmith, joker.eph
Subscribers: davidxl, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D14838
llvm-svn: 255909
This would have suppressed bug 24578, about use-after-
destroy on User and MDNode. Rolled back suppression for
the sake of code cleanliness, in preferance for bug
tracking to keep track of this issue.
This reverts commit 6ff2baabc4625d5b0a8dccf76aa0f72d930ea6c0.
llvm-svn: 246484
Add `Function::setSubprogram()` and `Function::getSubprogram()`,
convenience methods to forward to `setMetadata()` and `getMetadata()`,
respectively, and deal in `DISubprogram` instead of `MDNode`.
Also add a verifier check to enforce that `!dbg` attachments are always
subprograms.
Originally (when I had the llvm-dev discussion back in April) I thought
I'd store a pointer directly on `llvm::Function` for these attachments
-- we frequently have debug info, and that's much cheaper than using map
in the context if there are no other function-level attachments -- but
for now I'm just using the generic infrastructure. Let's add the extra
complexity only if this shows up in a profile.
llvm-svn: 246339
and make it always preserve debug locations, since all callers wanted this
behavior anyway.
This is addressing a post-commit review feedback for r245589.
NFC (inside the LLVM tree).
llvm-svn: 245622
Instruction::dropUnknownMetadata(KnownSet) is supposed to preserve all
metadata in KnownSet, but the condition for DebugLocs was inverted.
Most users of dropUnknownMetadata() actually worked around this by not
adding LLVMContext::MD_dbg to their list of KnowIDs.
This is now made explicit.
llvm-svn: 245589
Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode. This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.
Almost all the testcases were updated with this script:
git grep -e '= !DICompileUnit' -l -- test |
grep -v test/Bitcode |
xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'
I imagine something similar should work for out-of-tree testcases.
llvm-svn: 243885
Adds static_asserts to ensure alignment of concatenated objects is
correct, and fixes them where they are not.
Also changes the definition of AlignOf to use constexpr, except on
MSVC, to avoid enum comparison warnings from GCC.
(There's not too much of this in llvm itself, most of the fun is in
clang).
This seems to make LLVM actually work without Bus Error on 32bit
sparc.
Differential Revision: http://reviews.llvm.org/D10271
llvm-svn: 239872
LLVMContext. Production builds of clang do not set names on most
Value's, so this is wasted space on almost all subclasses of Value.
This reduces the size of all Value subclasses by 8 bytes on 64 bit
hosts.
The one tricky part of this change is averting compile time regression
by keeping Value::hasName() fast. This required stealing bits out of
NumOperands.
With this change, peak memory usage on verify-uselistorder-nodbg.lto.bc
is decreased by approximately 2.3% (~3MB absolute on my machine).
llvm-svn: 238791
Add IR support for `Metadata` attachments. Assembly and bitcode support
will follow shortly, but for now we just have unit tests. This is part
of PR23340.
llvm-svn: 235783
Extract the set logic for metadata attachments from `Instruction` so it
can be reused for `Function` (PR23340).
This data structure makes a `SmallVector<>` look (a little) like a map,
just doing the bare minimum to support the `Instruction` (and soon,
`Function`) metadata API.
llvm-svn: 235769
Technically the operations are different -- the old logic moved items
from the back into the opened-up slots, instead of the usual
`remove_if()` logic of a slow and a fast iterator -- but unless a
profile tells us otherwise I prefer the simpler logic here. Regardless,
there shouldn't be an observable function change.
llvm-svn: 235767
Uniqued nodes have more complete registration with
`ReplaceableMetadataImpl` so that they can update themselves when
operands change. Fix a bug where `MDNode::replaceWithUniqued()` wasn't
enabling these callbacks.
The two most obvious ways missing callbacks causes problems is that
auto-resolution fails and re-uniquing (on changed operands) just doesn't
happen. I've added tests for both -- in both cases, I confirmed that
the final check was failing before the fix.
rdar://problem/20365935
llvm-svn: 233751
Update lib/IR and lib/Bitcode to use the new `DebugLoc` API. Added an
explicit conversion to `bool` (avoiding a conversion to `MDLocation`),
since a couple of these use cases need to handle broken code.
llvm-svn: 233585
Add new API for converting temporaries that may self-reference.
Self-referencing nodes are not allowed to be uniqued, so sending them
into `replaceWithUniqued()` is dangerous (and this commit adds
assertions that prevent it).
`replaceWithPermanent()` has similar semantics to `get()` followed by
calls to `replaceOperandWith()`. In particular, if there's a
self-reference, it returns a distinct node; otherwise, it returns a
uniqued one. Like `replaceWithUniqued()` and `replaceWithDistinct()`
(well, it calls out to them) it mutates the temporary node in place if
possible, only calling `replaceAllUsesWith()` on a uniquing collision.
llvm-svn: 228726
Summary:
The alias.scope metadata represents sets of things an instruction might
alias with. When generically combining the metadata from two
instructions the result must be the union of the original sets, because
the new instruction might alias with anything any of the original
instructions aliased with.
Reviewers: hfinkel
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7490
llvm-svn: 228525
Move debug-info-centred `Metadata` subclasses into their own
header/source file. A couple of private template functions are needed
from both `Metadata.cpp` and `DebugInfoMetadata.cpp`, so I've moved them
to `lib/IR/MetadataImpl.h`.
llvm-svn: 227835
These things are potentially used for non-DWARF data (see the discussion
in PR22235), so take the `Dwarf` out of the name. Since the new name
gives fewer clues, update the doxygen to properly describe what they
are.
llvm-svn: 226874
During `MDNode::deleteTemporary()`, call `replaceAllUsesWith(nullptr)`
to update all tracking references to `nullptr`.
This fixes PR22280, where inverted destruction order between tracking
references and the temporaries themselves caused a use-after-free in
`LLParser`.
An alternative fix would be to add an assertion that there are no users,
and continue to fix inverted destruction order in clients (like
`LLParser`), but instead I decided to make getting-teardown-right easy.
(If someone disagrees let me know.)
llvm-svn: 226866
Now that the clone methods used by `MapMetadata()` don't do any
remapping (and return a temporary), they make more sense as member
functions on `MDNode` (and subclasses).
llvm-svn: 226541
Rather than relying on updating switch statements correctly, detect
whether `setHash()` exists in the subclass. If so, call
`recalculateHash()` and `setHash(0)` appropriately.
llvm-svn: 226531
