Make sure ThinLTO with caching doesn't use non-atomic writes to the cache file (to prevent data races and cache files corruption).
1. Place temp file to the same place where the caching directory is (instead of creating it the directory pointed to by TMP/TEMP variable). This will help to prevent using non-atomic rename and falling back to non-atomic "direct" write to the cache file.
2. if rename failed do not write to the cache file directly (direct write to the file is non-atomic and could cause data race conditions).
3. if cache file doesn't exist (e.g., because 'rename' failed or because some other reasons), bypass using the cache altogether.
Differential Revision: https://reviews.llvm.org/D45076
llvm-svn: 328904
This reverts commit 1f3bd185c53beb6aa68446974b7e80837abd6ef0 (r326107)
because it fails
ThinLTO/X86/diagnostic-handler-remarks-with-hotness.ll.
llvm-svn: 326975
This wires up -pass-remarks-hotness-threshold to LTO and ThinLTO.
Next is to change the clang driver to pass this
with -fdiagnostics-hotness-threshold.
Differential Revision: https://reviews.llvm.org/D41465
llvm-svn: 326107
Summary:
ThinLTO indexing may decide to skip all objects. If we don't write something to
the list build system may consider this as failure or linker can reuse a file
from the previews build.
Reviewers: pcc, tejohnson
Subscribers: mehdi_amini, inglorion, eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D43415
llvm-svn: 325819
Summary:
With D43396, no clients use the Path parameter anymore.
Depends on D43396.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D43400
llvm-svn: 325619
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.
Third attempt - moved function from lambda to static function due to build failures.
llvm-svn: 325506
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.
Second attempt, since last patch caused stage2 build to fail (now using function_ref rather than std::function).
Reverted due to buildbot failures
llvm-svn: 325454
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.
Second attempt, since last patch caused stage2 build to fail (now using function_ref rather than std::function).
llvm-svn: 325448
It caused assertion failure
Assertion failed: (!DD.IsLambda && !MergeDD.IsLambda && "faked up lambda definition?"), function MergeDefinitionData, file /Users/buildslave/jenkins/workspace/clang-stage1-configure-RA/llvm/tools/clang/lib/Serialization/ASTReaderDecl.cpp, line 1675.
on the second stage build bots.
llvm-svn: 324932
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.
llvm-svn: 324854
As of r323633, this bit started controlling whether symbol definitions
appear in object files, and it also became sensitive to the prevailing
bit, so it needs to be included in the key.
Differential Revision: https://reviews.llvm.org/D43109
llvm-svn: 324711
Summary:
Removing the dropped symbols will prevent indirect call promotion in the
ThinLTO Backend from adding a new reference to a symbol, which can
result in linker unsats. This can happen when we compile with a sample
profile collected from one binary by used for another, which may have
profiled targets that aren't used in the new binary.
Note that until dropDeadSymbols handles variables and aliases (in
progress), we may not be able to remove the declaration and can still
have an issue.
Reviewers: grimar, davidxl
Subscribers: mehdi_amini, inglorion, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D42816
llvm-svn: 324299
Summary:
This complements the fixes in r323633 and r324075 which drop the
definitions of dead functions and variables, respectively.
Fixes PR36208.
Reviewers: grimar, rafael
Subscribers: mehdi_amini, llvm-commits, inglorion
Differential Revision: https://reviews.llvm.org/D42856
llvm-svn: 324242
This fixes PR36187.
Patch teaches ThinLTO to drop non-prevailing variables,
just like we recently did for functions (in r323633).
Differential revision: https://reviews.llvm.org/D42798
llvm-svn: 324075
Summary: ThinLTO may skip object for other reasons, e.g. if there is no summary.
Reviewers: pcc, eugenis
Subscribers: mehdi_amini, inglorion, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D42514
llvm-svn: 323818
Combine expression patterns to form expressions with fewer, simple instructions.
This pass does not modify the CFG.
For example, this pass reduce width of expressions post-dominated by TruncInst
into smaller width when applicable.
It differs from instcombine pass in that it contains pattern optimization that
requires higher complexity than the O(1), thus, it should run fewer times than
instcombine pass.
Differential Revision: https://reviews.llvm.org/D38313
llvm-svn: 323321
LTO sets dso_local as an optimization, so don't clear it.
This avoid clearing it from undefined hidden symbols, which would then
fail the verifier.
llvm-svn: 322814
Summary:
1. Use stream 0 only for combined module. Previously if combined module was not
processes ThinLTO used the stream for own output. However small changes in input,
could trigger combined module and shuffle outputs making life of llvm::LTO harder.
2. Always process combined module and write output to stream 0. Processing empty
combined module is cheap and allows llvm::LTO users to avoid implementing processing
which is already done in llvm::LTO.
Subscribers: mehdi_amini, inglorion, eraman, hiraditya
Differential Revision: https://reviews.llvm.org/D41267
llvm-svn: 320905
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
This requires a small change to TempFile: allowing a discard after a
failed keep.
With this the cache now handles signals and reuses a fd instead of
reopening the file.
llvm-svn: 318322
Summary:
LTO/Caching.cpp uses file rename to atomically set the value for a
cache key. On Windows, this fails when the destination file already
exists. Previously, LLVM would report_fatal_error in such
cases. However, because the old and the new value for the cache key
are supposed to be equivalent, it actually doesn't matter which one we
keep. This change makes it so that failing the rename when an openable
file with the desired name already exists causes us to report success
instead of fataling.
Reviewers: pcc, hans
Subscribers: mehdi_amini, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D39874
llvm-svn: 317899
Now that we have a way to mark GlobalValues as local we can use the symbol
resolutions that the linker plugin provides as part of lto/thinlto link
step to refine the compilers view on what symbols will end up being local.
Originally commited as r317374, but reverted in r317395 to update some missed
tests.
Differential Revision: https://reviews.llvm.org/D35702
llvm-svn: 317408
Now that we have a way to mark GlobalValues as local we can use the symbol
resolutions that the linker plugin provides as part of lto/thinlto link
step to refine the compilers view on what symbols will end up being local.
Differential Revision: https://reviews.llvm.org/D35702
llvm-svn: 317374
This is necessary because DCE is applied to full LTO modules. Without
this change, a reference from a dead ThinLTO global to a dead full
LTO global will result in an undefined reference at link time.
This problem is only observable when --gc-sections is disabled, or
when targeting COFF, as the COFF port of lld requires all symbols to
have a definition even if all references are dead (this is consistent
with link.exe).
This change also adds an EliminateAvailableExternally pass at -O0. This
is necessary to handle the situation on Windows where a non-prevailing
copy of a linkonce_odr function has an SEH filter function; any
such filters must be DCE'd because they will contain a call to the
llvm.localrecover intrinsic, passing as an argument the address of the
function that the filter belongs to, and llvm.localrecover requires
this function to be defined locally.
Fixes PR35142.
Differential Revision: https://reviews.llvm.org/D39484
llvm-svn: 317108
Ekaterina Romanova