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.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265226 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265224 91177308-0d34-0410-b5e6-96231b3b80d8
A ``swifterror`` attribute can be applied to a function parameter or an
AllocaInst.
This commit does not include any target-specific change. The target-specific
optimization will come as a follow-up patch.
Differential Revision: http://reviews.llvm.org/D18092
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265189 91177308-0d34-0410-b5e6-96231b3b80d8
Change writeFunctionMetadata to call writeMetadataRecords. For now
there's no functionality change, but makes it easy to serialize other
types of metadata in the function block in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264557 91177308-0d34-0410-b5e6-96231b3b80d8
To match writeMetadataRecords, writeNamedMetadata and
writeMetadataStrings, change:
WriteModuleMetadata => writeModuleMetadata
WriteFunctionLocalMetadata => writeFunctionMetadata
Write##CLASS => write##CLASS
The only major change is "FunctionLocal" => "Function". The point is to
be less specific, in preparation for emitting normal metadata records
inside function metadata blocks (currently we only emit
`LocalAsMetadata` there).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264556 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264552 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264551 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264409 91177308-0d34-0410-b5e6-96231b3b80d8
The motivation for MODULE_CODE_METADATA_VALUES was to enable an
-flto=thin scheme where:
1. First, one function is cherry-picked from a bitcode file.
2. Later, another function is cherry-picked.
3. Later, ...
4. Finally, the metadata needed by all the previous functions is
loaded.
This was abandoned in favour of:
1. Calculate the superset of functions needed from a Module.
2. Link all functions at once.
Delayed metadata reading no longer serves a purpose. It also adds
a few complication, since we can't count on metadata being properly
parsed when exiting the BitcodeReader. After discussing with Teresa, we
agreed to remove it.
The code that depended on this was removed/updated in r264326.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264378 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264303 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264302 91177308-0d34-0410-b5e6-96231b3b80d8
Split writeNamedMetadata out of WriteModuleMetadata to write named
metadata, and createNamedMetadataAbbrev for the abbreviation.
There should be no effective functionality change, although the layout
of the bitcode will change. Previously, the abbreviation was emitted at
the top of the block, but now it is delayed until immediately before the
named metadata records are emitted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264301 91177308-0d34-0410-b5e6-96231b3b80d8
Duncan P. N. Exon Smith
Mehdi Amini
Manman Ren
Teresa Johnson