There is no real reason the index has to have the concept of an
exporting Module. We should be able to have one single unique
instance of the Index, and it should be read-only after creation
for the whole ThinLTO processing.
The linker plugin should be able to process multiple modules (in
parallel or in sequence) with the same index.
The only reason the ExportingModule was present seems to be to
implement hasExportedFunctions() that is used by the Module linker
to decide what to do with the current Module.
For now I replaced it with a query to the map of Modules path to
see if this module was declared in the Index and consider that if
it is the case then it is probably exporting function.
On the long term the Linker interface needs to evolve and this
call should not be needed anymore.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 254581
Summary:
Several fixes to the handling of bitcode files without function summary
sections so that they are skipped during ThinLTO processing in llvm-lto
and the gold plugin when appropriate instead of aborting.
1 Don't assert when trying to add a FunctionInfo that doesn't have
a summary attached.
2 Skip FunctionInfo structures that don't have attached function summary
sections when trying to create the combined function summary.
3 In both llvm-lto and gold-plugin, check whether a bitcode file has
a function summary section before trying to parse the index, and skip
the bitcode file if it does not.
4 Fix hasFunctionSummaryInMemBuffer in BitcodeReader, which had a bug
where we returned to early while looking for the summary section.
Also added llvm-lto and gold-plugin based tests for cases where we
don't have function summaries in the bitcode file. I verified that
either the first couple fixes described above are enough to avoid the
crashes, or fixes 1,3,4. But have combined them all here for added
robustness.
Reviewers: joker.eph
Subscribers: llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D14903
llvm-svn: 253796
This assert was meant to execute at the end of parseMetadata, but
we return early and never reach the end of the function. Caught
by a compile-time warning since the function doesn't return a value
from that location.
llvm-svn: 253762
Summary:
This is split out from the ThinLTO metadata mapping patch
http://reviews.llvm.org/D14752.
To avoid needing to parse the module level metadata during function
importing, a new module-level record is added which holds the
number of module-level metadata values. This is required because
metadata value ids are assigned implicitly during parsing, and the
function-level metadata ids start after the module-level metadata ids.
I made a change to this version of the code compared to D14752
in order to add more consistent and thorough assertion checking of the
new record value. We now unconditionally use the record value to
initialize the MDValueList size, and handle it the same in parseMetadata
for all module level metadata cases (lazy loading or not).
Reviewers: dexonsmith, joker.eph
Subscribers: davidxl, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D14825
llvm-svn: 253668
Summary:
There are currently two blocks with the METADATA_BLOCK id at module
scope. The first has the module-level metadata values (consisting of
some combination of METADATA_* record codes except for METADATA_KIND).
The second consists only of METADATA_KIND records. The latter is used
only in the METADATA_ATTACHMENT block within function blocks (for
metadata attached to instructions).
For ThinLTO we want to delay the parsing of module level metadata
until all functions have been imported from that module (there is some
bookkeeping used to suture it up when we read it during a post-pass).
However, we do need the METADATA_KIND records when parsing the function
body during importing, since those kinds are used as described above.
To simplify identification and parsing of just the block containing
the metadata kinds, use a different block id (METADATA_KIND_BLOCK_ID).
Support older bitcode without the new block id as well.
Reviewers: dexonsmith, joker.eph
Subscribers: davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D14654
llvm-svn: 253154
Summary: Mimic parseTriple(); and exposes it to LTOModule.cpp
Reviewers: dexonsmith, rafael
Subscribers: llvm-commits
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 252442
This commit adds enums in LLVMBitCodes.h to improve readability and
maintainability. This is a follow-up to r252368 which was discussed
here:
http://reviews.llvm.org/D12923
llvm-svn: 252395
This marker prevents optimization passes from adding 'tail' or
'musttail' markers to a call. Is is used to prevent tail call
optimization from being performed on the call.
rdar://problem/22667622
Differential Revision: http://reviews.llvm.org/D12923
llvm-svn: 252368
This attribute allows the compiler to assume that the function never recurses into itself, either directly or indirectly (transitively). This can be used among other things to demote global variables to locals.
llvm-svn: 252282
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.
For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.
This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.
Since this is an IR change, a bitcode upgrade has been provided.
Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.
Differential Revision: http://reviews.llvm.org/D14265
llvm-svn: 252219
No test, since it would depend on what the compiler can optimize/reuse.
My next commit made this bug visible on Linux Release compiles with some
versions of gcc.
llvm-svn: 251909
This reverts commit r251837, due to a number of bot failures of the form:
/home/grosser/buildslave/perf-x86_64-penryn-O3-polly-fast/llvm.obj/tools/llvm-link/Release+Asserts/llvm-link.o:llvm-link.cpp:function
loadIndex(llvm::LLVMContext&, llvm::Module const*): error: undefined
reference to
'llvm::object::FunctionIndexObjectFile::create(llvm::MemoryBufferRef,
llvm::LLVMContext&, llvm::Module const*, bool)'
/home/grosser/buildslave/perf-x86_64-penryn-O3-polly-fast/llvm.obj/tools/llvm-link/Release+Asserts/llvm-link.o:llvm-link.cpp:function
loadIndex(llvm::LLVMContext&, llvm::Module const*): error: undefined
reference to 'llvm::object::FunctionIndexObjectFile::takeIndex()'
I'm not sure why these are happening - I added Object to the requred
libraries in tools/llvm-link/LLVMBuild.txt and the LLVM_LINK_COMPONENTS
in tools/llvm-link/CMakeLists.txt. Confirmed for my build that these
symbols come out of libLLVMObject.a. What am I missing?
llvm-svn: 251841
Summary:
Support for necessary linkage changes and symbol renaming during
ThinLTO function importing.
Also includes llvm-link support for manually importing functions
and associated llvm-link based tests.
Note that this does not include support for intelligently importing
metadata, which is currently imported duplicate times. That support will
be in the follow-on patch, and currently is ignored by the tests.
Reviewers: dexonsmith, joker.eph, davidxl
Subscribers: tobiasvk, tejohnson, llvm-commits
Differential Revision: http://reviews.llvm.org/D13515
llvm-svn: 251837
Use 10 bits to represent calling convention ID's instead of 13, and
update the bitcode compatibility tests accordingly. We now error-out in
the bitcode reader when we see bad calling conv ID's.
Thanks to rnk and dexonsmith for feedback!
Differential Revision: http://reviews.llvm.org/D13826
llvm-svn: 251452
Processing bitcode from a different LLVM version can lead to
unexpected behavior. The LLVM project guarantees autoupdating
bitcode from a previous minor revision for the same major, but
can't make any promise when reading bitcode generated from a
either a non-released LLVM, a vendor toolchain, or a "future"
LLVM release. This patch aims at being more user-friendly and
allows a bitcode produce to emit an optional block at the
beginning of the bitcode that will contains an opaque string
intended to describe the bitcode producer information. The
bitcode reader will dump this information alongside any error it
reports.
The optional block also includes an "epoch" number, monotonically
increasing when incompatible changes are made to the bitcode. The
reader will reject bitcode whose epoch is different from the one
expected.
Differential Revision: http://reviews.llvm.org/D13666
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 251325
Mehdi Amini
Teresa Johnson
Sanjoy Das
Akira Hatanaka
James Molloy
Peter Collingbourne
Filipe Cabecinhas
Vedant Kumar
Oleksiy Vyalov