Summary:
This change fixes PR36483. The bug was originally introduced by a change
that marked non-prevailing symbols dead. This broke LowerTypeTests
handling of available_externally functions, which are non-prevailing.
LowerTypeTests uses liveness information to avoid emitting thunks for
unused functions.
Marking available_externally functions dead is incorrect, the functions
are used though the function definitions are not. This change keeps them
live, and lets the EliminateAvailableExternally/GlobalDCE passes remove
them later instead.
(Reland with a suspected fix for a unit test failure I haven't been able
to reproduce locally)
Reviewers: pcc, tejohnson
Reviewed By: tejohnson
Subscribers: grimar, mehdi_amini, inglorion, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D43690
llvm-svn: 327360
Use isInlineViable to prevent inlining of functions with non-inlinable
constructs, in case cost analysis is skipped.
Reviewers: efriedma, sfertile, davide, davidxl
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D42846
llvm-svn: 327207
The retpoline mitigation for variant 2 of CVE-2017-5715 inhibits the
branch predictor, and as a result it can lead to a measurable loss of
performance. We can reduce the performance impact of retpolined virtual
calls by replacing them with a special construct known as a branch
funnel, which is an instruction sequence that implements virtual calls
to a set of known targets using a binary tree of direct branches. This
allows the processor to speculately execute valid implementations of the
virtual function without allowing for speculative execution of of calls
to arbitrary addresses.
This patch extends the whole-program devirtualization pass to replace
certain virtual calls with calls to branch funnels, which are
represented using a new llvm.icall.jumptable intrinsic. It also extends
the LowerTypeTests pass to recognize the new intrinsic, generate code
for the branch funnels (x86_64 only for now) and lay out virtual tables
as required for each branch funnel.
The implementation supports full LTO as well as ThinLTO, and extends the
ThinLTO summary format used for whole-program devirtualization to
support branch funnels.
For more details see RFC:
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120672.html
Differential Revision: https://reviews.llvm.org/D42453
llvm-svn: 327163
Summary:
This change fixes PR36483. The bug was originally introduced by a change
that marked non-prevailing symbols dead. This broke LowerTypeTests
handling of available_externally functions, which are non-prevailing.
LowerTypeTests uses liveness information to avoid emitting thunks for
unused functions.
Marking available_externally functions dead is incorrect, the functions
are used though the function definitions are not. This change keeps them
live, and lets the EliminateAvailableExternally/GlobalDCE passes remove
them later instead.
I've also enabled EliminateAvailableExternally for all optimization
levels, I believe it being disabled for O1 was an oversight.
Reviewers: pcc, tejohnson
Reviewed By: tejohnson
Subscribers: grimar, mehdi_amini, inglorion, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D43690
llvm-svn: 327041
This caused some links to fail with ThinLTO due to missing symbols as
well as causing some binaries to have failures at runtime. We're working
with the author to get a test case, but want to get the tree green
again.
Further, it appears to introduce a data race. While the test usage of
threads was disabled in r325361 & r325362, that isn't an acceptable fix.
I've reverted both of these as well. This code needs to be thread safe.
Test cases for this are already on the original commit thread.
llvm-svn: 326638
When the function has musttail call - its cc is fixed to be equal to the
cc of the musttail callee. In such case (and in the case of the musttail
callee), GlobalOpt should not change the cc to fastcc as it will break
the invariant.
This fixes PR36546
Patch by: Fedor Indutny (indutny)
Differential revision: https://reviews.llvm.org/D43859
llvm-svn: 326376
- Fix for bug 36078.
- Prevent the functionattrs, function-attrs, globalopt and argpromotion passes
from changing naked functions.
- These passes can perform some alterations to the functions that should not be
applied. An example is removing parameters that are seemingly not used because
they are only referenced in the inline assembly. Another example is marking
the function as fastcc.
llvm-svn: 325788
Summary:
Exposing getOffset and findFunctionSamples as members of
SampleProfile. They are intimately tied to design choices of the
sample profile format - using offsets instead of line numbers, and
traversing inlined functions stack, respectively.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43605
llvm-svn: 325747
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
Summary:
For symbols that has linkonce_odr linkage and unnamed_addr, it can be
auto hide by linker to avoid weak external symbols. Teach ThinLTO to
perform auto hide so it can safely promote linkonce_odr to weak symbols
without breaking this nice property.
Reviewers: tejohnson, mehdi_amini
Reviewed By: tejohnson
Subscribers: inglorion, eraman, rnk, pcc, llvm-commits
Differential Revision: https://reviews.llvm.org/D43130
llvm-svn: 324757
With fix: reimplemented.
Original commit message:
Recently introduced convertToDeclaration is very similar
to code used in filterModule function.
Patch reuses it to reduce duplication.
Differential revision: https://reviews.llvm.org/D42971
llvm-svn: 324574
Recently introduced convertToDeclaration is very similar
to code used in filterModule function.
Patch reuses it to reduce duplication.
Differential revision: https://reviews.llvm.org/D42971
llvm-svn: 324455
It is better to update pointer of the DISuprogram before we call RAUW for
still live arguments of the function, because with the change reviewed in
D42541 in RAUW we compare DISubprograms rather than functions itself.
Patch by Djordje Todorovic.
Differential Revision: https://reviews.llvm.org/D42794
llvm-svn: 324335
If the inline asm provides the definition of a symbol, this can result
in duplicate symbol errors.
Differential Revision: https://reviews.llvm.org/D42944
llvm-svn: 324313
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
Summary:
When creating the debug fragments for a SRA'd variable, use the types'
allocation sizes. This fixes issues where the pass would emit too small
fragments, placed at the wrong offset, for padded types.
An example of this is long double on x86. The type is represented using
x86_fp80, which is 10 bytes, but the value is aligned to 12/16 bytes.
The padding is included in the type's DW_AT_byte_size attribute;
therefore, the fragments should also include that. Newer GCC releases
(I tested 7.2.0) emit 12/16-byte pieces for long double. Earlier
releases, e.g. GCC 5.5.0, behaved as LLVM did, i.e. by emitting a
10-byte piece, followed by an empty 2/6-byte piece for the padding.
Failing to cover all `DW_AT_byte_size' bytes of a value with non-empty
pieces results in the value being printed as <optimized out> by GDB.
Patch by: David Stenberg
Reviewers: aprantl, JDevlieghere
Reviewed By: aprantl, JDevlieghere
Subscribers: llvm-commits
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D42807
llvm-svn: 324066
For very, very large global initializers which can be statically evaluated, the
code would create vectors of temporary Constants, modifying them in place,
before committing the resulting Constant aggregate to the global's initializer
value. This had effectively O(n^2) complexity in the size of the global
initializer and would cause memory and non-termination issues compiling some
workloads.
This change performs the static initializer evaluation and creation in batches,
once for each global in the evaluated IR memory. The existing code is maintained
as a last resort when the initializers are more complex than simple values in a
large aggregate. This should theoretically by NFC, no test as the example case
is massive. The existing test cases pass with this, as well as the llvm test
suite.
To give an example, consider the following C++ code adapted from the clang
regression tests:
struct S {
int n = 10;
int m = 2 * n;
S(int a) : n(a) {}
};
template<typename T>
struct U {
T *r = &q;
T q = 42;
U *p = this;
};
U<S> e;
The global static constructor for 'e' will need to initialize 'r' and 'p' of
the outer struct, while also initializing the inner 'q' structs 'n' and 'm'
members. This batch algorithm will simply use general CommitValueTo() method
to handle the complex nested S struct initialization of 'q', before
processing the outermost members in a single batch. Using CommitValueTo() to
handle member in the outer struct is inefficient when the struct/array is
very large as we end up creating and destroy constant arrays for each
initialization.
For the above case, we expect the following IR to be generated:
%struct.U = type { %struct.S*, %struct.S, %struct.U* }
%struct.S = type { i32, i32 }
@e = global %struct.U { %struct.S* gep inbounds (%struct.U, %struct.U* @e,
i64 0, i32 1),
%struct.S { i32 42, i32 84 }, %struct.U* @e }
The %struct.S { i32 42, i32 84 } inner initializer is treated as a complex
constant expression, while the other two elements of @e are "simple".
Differential Revision: https://reviews.llvm.org/D42612
llvm-svn: 323933
candidates with coldcc attribute.
This recommits r322721 reverted due to sanitizer memory leak build bot failures.
Original commit message:
This patch adds support for the coldcc calling convention for Power.
This changes the set of non-volatile registers. It includes a pass to stress
test the implementation by marking all static directly called functions with
the coldcc attribute through the option -enable-coldcc-stress-test. It also
includes an option, -ppc-enable-coldcc, to add the coldcc attribute to
functions which are cold at all call sites based on BlockFrequencyInfo when
the containing function does not call any non cold functions.
Differential Revision: https://reviews.llvm.org/D38413
llvm-svn: 323778
Summary:
The intent of this is to allow the code to be used with ThinLTO. In
Thinlink phase, a traditional Callgraph can not be computed even though
all the necessary information (nodes and edges of a call graph) is
available. This is due to the fact that CallGraph class is closely tied
to the IR. This patch first extends GraphTraits to add a CallGraphTraits
graph. This is then used to implement a version of counts propagation
on a generic callgraph.
Reviewers: davidxl
Subscribers: mehdi_amini, tejohnson, llvm-commits
Differential Revision: https://reviews.llvm.org/D42311
llvm-svn: 323475
It was reverted after buildbot regressions.
Original commit message:
This allows relative block frequency of call edges to be passed
to the thinlink stage where it will be used to compute synthetic
entry counts of functions.
llvm-svn: 323460
Summary:
When creating the debug fragments for a SRA'd struct, use the fields'
offsets, taken from the struct layout, as the offsets for the resulting
fragments. This fixes an issue where GlobalOpt would emit fragments with
incorrect offsets for padded fields.
This should solve PR36016.
Patch by David Stenberg.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42489
llvm-svn: 323411
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
Summary:
Currently, there is no way to extract a basic block from a function easily. This patch
extends llvm-extract to extract the specified basic block(s).
Reviewers: loladiro, rafael, bogner
Reviewed By: bogner
Subscribers: hintonda, mgorny, qcolombet, llvm-commits
Differential Revision: https://reviews.llvm.org/D41638
llvm-svn: 323266
Summary:
The class wraps a uint64_t and an enum to represent the type of profile
count (real and synthetic) with some helper methods.
Reviewers: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41883
llvm-svn: 322771
Vlad Tsyrklevich