Summary:
Before this change, AttributeLists stored a pair of index and
AttributeSet. This is memory efficient if most arguments do not have
attributes. However, it requires doing a search over the pairs to test
an argument or function attribute. Profiling shows that this loop was
0.76% of the time in 'opt -O2' of sqlite3.c, because LLVM constantly
tests values for nullability.
This was worth about 2.5% of mid-level optimization cycles on the
sqlite3 amalgamation. Here are the full perf results:
https://reviews.llvm.org/P7995
Here are just the before and after cycle counts:
```
$ perf stat -r 5 ./opt_before -O2 sqlite3.bc -o /dev/null
13,274,181,184 cycles # 3.047 GHz ( +- 0.28% )
$ perf stat -r 5 ./opt_after -O2 sqlite3.bc -o /dev/null
12,906,927,263 cycles # 3.043 GHz ( +- 0.51% )
```
This patch *does not* change the indices used to query attributes, as
requested by reviewers. Tracking whether an index is usable for array
indexing is a huge pain that affects many of the internal APIs, so it
would be good to come back later and do a cleanup to remove this
internal adjustment.
Reviewers: pete, chandlerc
Subscribers: javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D32819
llvm-svn: 303654
This patch extends llvm-ir to allow attributes to be set on global variables.
An RFC was sent out earlier by my colleague James Molloy: http://lists.llvm.org/pipermail/cfe-dev/2017-March/053100.html
A key part of that proposal was to extend LLVM-IR to carry attributes on global variables.
This generic feature could be useful for multiple purposes.
In our present context, it would be useful to carry user specified sections for bss/rodata/data.
Reviewed by: Jonathan Roelofs, Reid Kleckner
Differential Revision: https://reviews.llvm.org/D32009
llvm-svn: 302794
Remove the temporary, poorly named getSlotSet method which did the same
thing. Also remove getSlotNode, which is a hold-over from when we were
dealing with AttributeSetNode* instead of AttributeSet.
llvm-svn: 301267
Summary:
That API creates a temporary AttributeList to carry an index and a
single AttributeSet. We need to carry the index in addition to the set,
because that is how attribute groups are currently encoded.
NFC
Reviewers: pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32262
llvm-svn: 301245
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.
Rename AttributeSetImpl to AttributeListImpl to follow suit.
It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.
Reviewers: sanjoy, javed.absar, chandlerc, pete
Reviewed By: pete
Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits
Differential Revision: https://reviews.llvm.org/D31102
llvm-svn: 298393
We had various variants of defining dump() functions in LLVM. Normalize
them (this should just consistently implement the things discussed in
http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html
For reference:
- Public headers should just declare the dump() method but not use
LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
- The definition of a dump method should look like this:
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void MyClass::dump() {
// print stuff to dbgs()...
}
#endif
llvm-svn: 293359
I have an LTO snapshot (for which I don't have sources) that can't
be read back by LLVM. It seems the writer emitted broken bitcode
and this assertions aims at catching such cases.
llvm-svn: 274819
This change is motivated by an upcoming change to the metadata representation
used for CFI. The indirect function call checker needs type information for
external function declarations in order to correctly generate jump table
entries for such declarations. We currently associate such type information
with declarations using a global metadata node, but I plan [1] to move all
such metadata to global object attachments.
In bitcode, metadata attachments for function declarations appear in the
global metadata block. This seems reasonable to me because I expect metadata
attachments on declarations to be uncommon. In the long term I'd also expect
this to be the case for CFI, because we'd want to use some specialized bitcode
format for this metadata that could be read as part of the ThinLTO thin-link
phase, which would mean that it would not appear in the global metadata block.
To solve the lazy loaded metadata issue I was seeing with D20147, I use the
same bitcode representation for metadata attachments for global variables as I
do for function declarations. Since there's a use case for metadata attachments
in the global metadata block, we might as well use that representation for
global variables as well, at least until we have a mechanism for lazy loading
global variables.
In the assembly format, the metadata attachments appear after the "declare"
keyword in order to avoid a parsing ambiguity.
[1] http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html
Differential Revision: http://reviews.llvm.org/D21052
llvm-svn: 273336
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
Since forward references for uniqued node operands are expensive (and
those for distinct node operands are cheap due to
DistinctMDOperandPlaceholder), minimize forward references in uniqued
node operands.
Moreover, guarantee that when a cycle is broken by a distinct node, none
of the uniqued nodes have any forward references. In
ValueEnumerator::EnumerateMetadata, enumerate uniqued node subgraphs
first, delaying distinct nodes until all uniqued nodes have been
handled. This guarantees that uniqued nodes only have forward
references when there is a uniquing cycle (since r267276 changed
ValueEnumerator::organizeMetadata to partition distinct nodes in front
of uniqued nodes as a post-pass).
Note that a single uniqued subgraph can hit multiple distinct nodes at
its leaves. Ideally these would themselves be emitted in post-order,
but this commit doesn't attempt that; I think it requires an extra pass
through the edges, which I'm not convinced is worth it (since
DistinctMDOperandPlaceholder makes forward references quite cheap
between distinct nodes).
I've added two testcases:
- test/Bitcode/mdnodes-distinct-in-post-order.ll is just like
test/Bitcode/mdnodes-in-post-order.ll, except with distinct nodes
instead of uniqued ones. This confirms that, in the absence of
uniqued nodes, distinct nodes are still emitted in post-order.
- test/Bitcode/mdnodes-distinct-nodes-break-cycles.ll is the minimal
example where a naive post-order traversal would cause one uniqued
node to forward-reference another. IOW, it's the motivating test.
llvm-svn: 267278
When an operand of a distinct node hasn't been read yet, the reader can
use a DistinctMDOperandPlaceholder. This is much cheaper than forward
referencing from a uniqued node. Change
ValueEnumerator::organizeMetadata to partition distinct nodes and
uniqued nodes to reduce the overhead of cycles broken by distinct nodes.
Mehdi measured this for me; this removes most of the RAUW from the
importing step of -flto=thin, even after a WIP patch that removes
string-based DITypeRefs (introducing many more cycles to the metadata
graph).
llvm-svn: 267276
Mehdi's pattern recognition pulled this one out. This is cleaner with
std::find_if than with the strange helper function that took an iterator
by reference and updated it.
llvm-svn: 267271
Re-layer the functions in the new (i.e., newly correct) post-order
traversals in ValueEnumerator (r266947) and ValueMapper (r266949).
Instead of adding a node to the worklist in a helper function and
returning a flag to say what happened, return the node itself. This
makes the code way cleaner: the worklist is local to the main function,
there is no flag for an early loop exit (since we can cleanly bury the
loop), and it's perfectly clear when pointers into the worklist might be
invalidated.
I'm fixing both algorithms in the same commit to avoid repeating the
commit message; if you take the time to understand one the other should
be easy. The diff itself isn't entirely obvious since the traversals
have some noise (i.e., things to do), but here's the high-level change:
auto helper = [&WL](T *Op) { auto helper = [](T **&I, T **E) {
=> while (I != E) {
if (shouldVisit(Op)) { T *Op = *I++;
WL.push(Op, Op->begin()); if (shouldVisit(Op)) {
return true; return Op;
} }
return false; return nullptr;
}; };
=>
WL.push(S, S->begin()); WL.push(S, S->begin());
while (!empty()) { while (!empty()) {
auto *N = WL.top().N; auto *N = WL.top().N;
auto *&I = WL.top().I; auto *&I = WL.top().I;
bool DidChange = false;
while (I != N->end())
if (helper(*I++)) { => if (T *Op = helper(I, N->end()) {
DidChange = true; WL.push(Op, Op->begin());
break; continue;
} }
if (DidChange)
continue;
POT.push(WL.pop()); => POT.push(WL.pop());
} }
Thanks to Mehdi for helping me find a better way to layer this.
llvm-svn: 267099
Emit metadata nodes in post-order. The iterative algorithm from r266709
failed to maintain this property. After understanding my mistake, it
wasn't too hard to write a test with llvm-bcanalyzer (and I've actually
made this change once before: see r220340).
This also reverts the "noisy" testcase change from r266709. That should
have been more of a red flag :/.
Note: The same bug crept into the ValueMapper in r265456. I'm still
working on the fix.
llvm-svn: 266947
Use a worklist instead of recursing through MDNode operands in
ValueEnumerator. The actual record output order has changed slightly,
but otherwise there's no functionality change.
I had to update test/Bitcode/metadata-function-blocks.ll. I renumbered
nodes so they continue to match the implicit record ids.
llvm-svn: 266709
I have no idea how I chose two different spellings in the space of a
couple of weeks, but now I can't remember what to use where. Choose
"Worklist".
llvm-svn: 266582
This patch add support for GCC attribute((ifunc("resolver"))) for
targets that use ELF as object file format. In general ifunc is a
special kind of function alias with type @gnu_indirect_function. Patch
for Clang http://reviews.llvm.org/D15524
Differential Revision: http://reviews.llvm.org/D15525
llvm-svn: 265667
Whenever metadata is only referenced by a single function, emit the
metadata just in that function block. This should improve lazy-loading
by reducing the amount of metadata in the global block.
For now, this should catch all DILocations, and anything else that
happens to be referenced only by a single function.
It's also a first step toward a couple of possible future directions
(which this commit does *not* implement):
1. Some debug info metadata is only referenced from compile units and
individual functions. If we can drop the link from the compile
unit, this optimization will get more powerful.
2. Any uniqued metadata that isn't referenced globally can in theory be
emitted in every function block that references it (trading off
bitcode size and full-parse time vs. lazy-load time).
Note: this assumes the new BitcodeReader error checking from r265223.
The metadata stored in function blocks gets purged after parsing each
function, which means unresolved forward references will get lost.
Since all the global metadata should have already been resolved by the
time we get to the function metadata blocks we just need to check for
that case. (If for some reason we need to handle bitcode that fails the
checks in r265223, the fix is to store about-to-be-dropped unresolved
nodes in MetadataList::shrinkTo until they can be handled succesfully by
a future call to MetadataList::tryToResolveCycles.)
llvm-svn: 265226
Further unify the handling of function-local metadata with global
metadata, by exposing the same interface in ValueEnumerator. Both
contexts use the same accessors:
- getMDStrings(): get the strings for this block.
- getNonMDStrings(): get the non-strings for this block.
A future commit will start adding strings to the function-block.
llvm-svn: 265224
We don't really need a separate vector here; instead, point at a range
inside the main MDs array. This matches how r264551 references the
ranges of strings and non-strings.
llvm-svn: 264552
Spiritually reapply commit r264409 (reverted in r264410), albeit with a
bit of a redesign.
Firstly, avoid splitting the big blob into multiple chunks of strings.
r264409 imposed an arbitrary limit to avoid a massive allocation on the
shared 'Record' SmallVector. The bug with that commit only reproduced
when there were more than "chunk-size" strings. A test for this would
have been useless long-term, since we're liable to adjust the chunk-size
in the future.
Thus, eliminate the motivation for chunk-ing by storing the string sizes
in the blob. Here's the layout:
vbr6: # of strings
vbr6: offset-to-blob
blob:
[vbr6]: string lengths
[char]: concatenated strings
Secondly, make the output of llvm-bcanalyzer readable.
I noticed when debugging r264409 that llvm-bcanalyzer was outputting a
massive blob all in one line. Past a small number, the strings were
impossible to split in my head, and the lines were way too long. This
version adds support in llvm-bcanalyzer for pretty-printing.
<STRINGS abbrevid=4 op0=3 op1=9/> num-strings = 3 {
'abc'
'def'
'ghi'
}
From the original commit:
Inspired by Mehdi's similar patch, http://reviews.llvm.org/D18342, this
should (a) slightly reduce bitcode size, since there is less record
overhead, and (b) greatly improve reading speed, since blobs are super
cheap to deserialize.
llvm-svn: 264551
Optimize output of MDStrings in bitcode. This emits them in big blocks
(currently 1024) in a pair of records:
- BULK_STRING_SIZES: the sizes of the strings in the block, and
- BULK_STRING_DATA: a single blob, which is the concatenation of all
the strings.
Inspired by Mehdi's similar patch, http://reviews.llvm.org/D18342, this
should (a) slightly reduce bitcode size, since there is less record
overhead, and (b) greatly improve reading speed, since blobs are super
cheap to deserialize.
I needed to add support for blobs to streaming input to get the test
suite passing.
- StreamingMemoryObject::getPointer reads ahead and returns the
address of the blob.
- To avoid a possible reallocation of StreamingMemoryObject::Bytes,
BitstreamCursor::readRecord needs to move the call to JumpToEnd
forward so that getPointer is the last bitstream operation.
llvm-svn: 264409
Simplify ValueEnumerator and WriteModuleMetadata by shifting the logic
for the METADATA_GENERIC_DEBUG abbreviation into WriteGenericDINode.
(This is just like r264302, but for GenericDINode.)
The only change is that the abbreviation is emitted later in the
bitcode, just before the first `GenericDINode` record. This shouldn't
be observable though.
llvm-svn: 264303
Simplify ValueEnumerator and WriteModuleMetadata by shifting the logic
for the METADATA_LOCATION abbreviation into WriteDILocation.
The only change is that the abbreviation is emitted later in the
bitcode, just before the first `DILocation` record. This shouldn't be
observable though.
llvm-svn: 264302
Make personality functions, prefix data, and prologue data hungoff
operands of Function.
This is based on the email thread "[RFC] Clean up the way we store
optional Function data" on llvm-dev.
Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback!
Includes a fix to scrub value subclass data in dropAllReferences. Does not
use binary literals.
Differential Revision: http://reviews.llvm.org/D13829
llvm-svn: 256095
Make personality functions, prefix data, and prologue data hungoff
operands of Function.
This is based on the email thread "[RFC] Clean up the way we store
optional Function data" on llvm-dev.
Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback!
Includes a fix to scrub value subclass data in dropAllReferences.
Differential Revision: http://reviews.llvm.org/D13829
llvm-svn: 256093
Make personality functions, prefix data, and prologue data hungoff
operands of Function.
This is based on the email thread "[RFC] Clean up the way we store
optional Function data" on llvm-dev.
Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback!
Differential Revision: http://reviews.llvm.org/D13829
llvm-svn: 256090
Now LLVMBitWriter compiles without implicit ilist iterator conversions.
In these cases, the cleanest thing was to switch to range-based for
loops. Since there wasn't much noise I converted sub-loops and parent
loops as a drive-by.
llvm-svn: 250144
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!
llvm-svn: 240137
The personality routine currently lives in the LandingPadInst.
This isn't desirable because:
- All LandingPadInsts in the same function must have the same
personality routine. This means that each LandingPadInst beyond the
first has an operand which produces no additional information.
- There is ongoing work to introduce EH IR constructs other than
LandingPadInst. Moving the personality routine off of any one
particular Instruction and onto the parent function seems a lot better
than have N different places a personality function can sneak onto an
exceptional function.
Differential Revision: http://reviews.llvm.org/D10429
llvm-svn: 239940
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`. The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.
Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one. It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs. YMMV of
course.
Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py. I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three. It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).
Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.
llvm-svn: 236120
Add serialization support for function metadata attachments (added in
r235783). The syntax is:
define @foo() !attach !0 {
Metadata attachments are only allowed on functions with bodies. Since
they come before the `{`, they're not really part of the body; since
they require a body, they're not really part of the header. In
`LLParser` I gave them a separate function called from `ParseDefine()`,
`ParseOptionalFunctionMetadata()`.
In bitcode, I'm using the same `METADATA_ATTACHMENT` record used by
instructions. Instruction metadata attachments are included in a
special "attachment" block at the end of a `Function`. The attachment
records are laid out like this:
InstID (KindID MetadataID)+
Note that these records always have an odd number of fields. The new
code takes advantage of this to recognize function attachments (which
don't need an instruction ID):
(KindID MetadataID)+
This means we can use the same attachment block already used for
instructions.
This is part of PR23340.
llvm-svn: 235785
Canonicalize access to whether to preserve use-list order in bitcode on
a `bool` stored in `ValueEnumerator`. Next step, expose this as a
`bool` through `WriteBitcodeToFile()`.
llvm-svn: 234956
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
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
