Fix use-after-free bug in AffectedValueCallbackVH::allUsesReplacedWith
When transferring affected values in the cache from an old value, identified by
the value of the current callback, to the specified new value we might need to
insert a new entry into the DenseMap which constitutes the cache. Doing so
might delete the current callback object. Move the copying logic into a new
function, a member of the assumption cache itself, so that we don't run into UB
should the callback handle itself be removed mid-copy.
Hans Wennborg [Wed, 18 Jan 2017 00:12:25 +0000 (00:12 +0000)]
Merging r291968 and r291979:
------------------------------------------------------------------------
r291968 | dannyb | 2017-01-13 14:40:01 -0800 (Fri, 13 Jan 2017) | 23 lines
NewGVN: Move leaders around properly to ensure we have a canonical dominating leader. Fixes PR 31613.
Summary:
This is a testcase where phi node cycling happens, and because we do
not order the leaders by domination or anything similar, the leader
keeps changing.
Using std::set for the members is too expensive, and we actually don't
need them sorted all the time, only at leader changes.
We could keep both a set and a vector, and keep them mostly sorted and
resort as necessary, or use a set and a fibheap, but all of this seems
premature.
After running some statistics, we are able to avoid the vast majority
of sorting by keeping a "next leader" field. Most congruence classes only have
leader changes once or twice during GVN.
[cmake] Update SOVERSION for the new versioning scheme
Update SOVERSION to use just the major version number rather than
major+minor, to match the new versioning scheme where only major is used
to indicate API/ABI version.
Since two-digit SOVERSIONs were introduced post 3.9 branching, this
change does not risk any SOVERSION collisions. In the past,
two-component X.Y SOVERSIONs were shortly used but those will not
interfere with the new ones since the new versions start at 4.
Revert r291640 change to fold X86 comparison with atomic_load_add.
Even with the fix from r291630, this still causes problems. I get
widespread assertion failures in the Swift runtime's WeakRefCount::increment()
function. I sent a reduced testcase in reply to the commit.
------------------------------------------------------------------------
Revert r291503, "Lift the 10-type limit for AlignedCharArrayUnion", and followings.
r291503, "Lift the 10-type limit for AlignedCharArrayUnion"
r291514, "Fix MSVC build of AlignedCharArrayUnion"
r291515, "Revert the attempt to optimize the constexpr functions. MSVC does not handle this yet"
r291519, "Try once again to fix the MSVC build of AlignedCharArrayUnion"
They has been failing on i686-linux.
------------------------------------------------------------------------
Robert Lougher [Thu, 12 Jan 2017 20:34:35 +0000 (20:34 +0000)]
[DebugInfo] Handle same locations in DILocation::getMergedLocation
Revision 289661 introduced the function DILocation::getMergedLocation for
merging of debug locations. At the time is was simply a stub which always
returned no location. This patch modifies getMergedLocation to handle the
case where the two locations are the same or can't be discriminated.
Nikolai Bozhenov [Thu, 12 Jan 2017 19:54:27 +0000 (19:54 +0000)]
[X86] Replace AND+IMM64 with SRL/SHL
Emit SHRQ/SHLQ instead of ANDQ with a 64 bit constant mask if the result
is unused and the mask has only higher/lower bits set. For example, with
this patch LLVM emits
shrq $41, %rdi
je
instead of
movabsq $0xFFFFFE0000000000, %rcx
testq %rcx, %rdi
je
This reduces number of instructions, code size and register pressure.
The transformation is applied only for cases where the mask cannot be
encoded as an immediate value within TESTQ instruction.
[llvm-config] Fix obviously wrong code in parsing DyLib components.
The code parsing the string was using the offset returned from
StringRef::find() wrong, assuming it was relative to the staring
offset that is passed to the function, but the returned offset
is always relative to the beginning of the line.
This causes odd behaviour while parsing the component string.
Spotted thanks to the newly added test:
Nikolai Bozhenov [Thu, 12 Jan 2017 19:41:27 +0000 (19:41 +0000)]
[X86] Rename tests for bypassing slow division (NFC)
For tests on bypassing slow division there's no need to be
Atom-specific. The patch renames all tests on division bypassing
and makes their names more consistent:
atom-bypass-slow-division.ll -> bypass-slow-division-32.ll
(tests verifying correctness of divl-to-divb bypassing)
atom-bypass-slow-division-64.ll -> bypass-slow-division-64.ll
(tests verifying correctness of divq-to-divl bypassing)
slow-div.ll -> bypass-slow-division-tune.ll
(tests verifying that bypassing is enabled only when appropriate)
Nikolai Bozhenov [Thu, 12 Jan 2017 19:34:15 +0000 (19:34 +0000)]
[X86] Tune bypassing of slow division for Intel CPUs
64-bit integer division in Intel CPUs is extremely slow, much slower
than 32-bit division. On the other hand, 8-bit and 16-bit divisions
aren't any faster. The only important exception is Atom where DIV8
is fastest. Because of that, the patch
1) Enables bypassing of 64-bit division for Atom, Silvermont and
all big cores.
2) Modifies 64-bit bypassing to use 32-bit division instead of
16-bit one. This doesn't make the shorter division slower but
increases chances of taking it. Moreover, it's much more likely
to prove at compile-time that a value fits 32 bits and doesn't
require a run-time check (e.g. zext i32 to i64).
Switch some additional library call setup to be table driven. This
makes it more immediately obvious what the library call looks like.
This is important for ARM since the calling conventions for the builtins
change based on the target/libcall name. NFC
Daniel Sanders [Thu, 12 Jan 2017 16:11:23 +0000 (16:11 +0000)]
[globalisel] Move as much RegisterBank initialization to the constructor as possible
Summary:
The register bank is now entirely initialized in the constructor. However,
we still have the hardcoded number of register classes which will be
dealt with in the TableGen patch (D27338) since we do not have access
to this information to resolve this at this stage. The number of register
classes is known to the TRI and to TableGen but the RegisterBank
constructor is too early for the former and too late for the latter.
This will be fixed when the data is tablegen-erated.
Daniel Sanders [Thu, 12 Jan 2017 15:32:10 +0000 (15:32 +0000)]
[globalisel] Initialize RegisterBanks with static data.
Summary:
Refactor the RegisterBank initialization to use static data. This requires
GlobalISel implementations to rewrite calls to createRegisterBank() and
addRegBankCoverage() into a call to setRegBankData().
Out of tree targets can use diff 4 of D27807
(https://reviews.llvm.org/D27807?id=84117) to have addRegBankCoverage() dump
the register classes and other data that needs to be provided to
setRegBankData(). This is the method that was used to generate the static data
in this patch.
Tablegen-eration of this static data will follow after some refactoring.
Summary:
Memory Dependence Analysis was limited to return only local dependencies
for invariant.group handling. Now it returns NonLocal when it finds it
and then by asking getNonLocalPointerDependency we get found dep.
Thanks to this we are able to devirtualize loops!
void indirect(A &a, int n) {
for (int i = 0 ; i < n; i++)
a.foo();
}
void test(int n) {
A a;
indirect(a);
}
After inlining a.foo() will be changed to direct call, even if foo and A::A()
is external (but only if vtable definition is be available).
[XRay] Implement the `llvm-xray account` subcommand
Summary:
This is the third of a multi-part change to implement subcommands for
the `llvm-xray` tool.
Here we define the `account` subcommand which does simple function call
accounting, generating basic statistics on function calls we find in an
XRay log/trace. We support text output and csv output for this
subcommand.
This change also supports sorting, summing, and filtering the top N
results.
Part of this tool will later be turned into a library that could be used
for basic function call accounting.
Elad Cohen [Thu, 12 Jan 2017 06:49:03 +0000 (06:49 +0000)]
[X86][AVX512] Fix PR31515 - Do not flip vselect condition if it's not a vXi1 mask
r289653 added a case where `vselect <cond> <vector1> <all-zeros>`
is transformed to:
`vselect xor(cond, DAG.getConstant(1, DL, CondVT) <all-zeros> <vector1>`
This was not aimed to catch cases where Cond is not a vXi1
mask but it does. Moreover, when Cond type is VxiN (N > 1)
then xor(cond, DAG.getConstant(1, DL, CondVT) != NOT(cond).
This patch changes the above to xor with allones, and avoids
entering the case for non-mask Conds.
Chandler Carruth [Thu, 12 Jan 2017 03:49:07 +0000 (03:49 +0000)]
Make a test actually test what it set out to test.
This test seems to have largely been relying on asserts being tripped.
It had a very specific and somewhat uninteresting grep of the output,
but it never really did anything to cause SCEV to be preserved across
loop simplify, certainly not explicitly. And a later addition to it
actually added CHECK lines despite the test never running FileCheck.
Now we actually print SCEV before and after loop simplify to make sure
it is *changing* and being *updated*. Which seems to be much more likely
the point of the test.
Davide Italiano [Wed, 11 Jan 2017 23:41:24 +0000 (23:41 +0000)]
[NewGVN] Fixup store count for the `initial` congruency class.
It was always zero. When we move a store from `initial` to its
own congruency class, we end up with a negative store count, which
is obviously wrong.
Also, while here, change StoreCount to be signed so that the assertions
actually fire.
Zachary Turner [Wed, 11 Jan 2017 23:24:22 +0000 (23:24 +0000)]
[CodeView] Finish decoupling TypeDatabase from TypeDumper.
Previously the type dumper itself was passed around to a lot of different
places and manipulated in ways that were more appropriate on the type
database. For example, the entire TypeDumper was passed into the symbol
dumper, when all the symbol dumper wanted to do was lookup the name of a
TypeIndex so it could print it. That's what the TypeDatabase is for --
mapping type indices to names.
Another example is how if the user runs llvm-pdbdump with the option to
dump symbols but not types, we still have to visit all types so that we
can print minimal information about the type of a symbol, but just without
dumping full symbol records. The way we did this before is by hacking it
up so that we run everything through the type dumper with a null printer,
so that the output goes to /dev/null. But really, we don't need to dump
anything, all we want to do is build the type database. Since
TypeDatabaseVisitor now exists independently of TypeDumper, we can do
this. We just build a custom visitor callback pipeline that includes a
database visitor but not a dumper.
All the hackery around printers etc goes away. After this patch, we could
probably even delete the entire CVTypeDumper class since really all it is
at this point is a thin wrapper that hides the details of how to build a
useful visitation pipeline. It's not a priority though, so CVTypeDumper
remains for now.
After this patch we will be able to easily plug in a different style of
type dumper by only implementing the proper visitation methods to dump
one-line output and then sticking it on the pipeline.
Kuba Mracek [Wed, 11 Jan 2017 22:26:10 +0000 (22:26 +0000)]
[asan] Set alignment of __asan_global_* globals to sizeof(GlobalStruct)
When using profiling and ASan together (-fprofile-instr-generate -fcoverage-mapping -fsanitize=address), at least on Darwin, the section of globals that ASan emits (__asan_globals) is misaligned and starts at an odd offset. This really doesn't have anything to do with profiling, but it triggers the issue because profiling emits a string section, which can have arbitrary size. This patch changes the alignment to sizeof(GlobalStruct).
LowerTypeTests: Represent the memory region size with the constant size-1.
This means that we can use a shorter instruction sequence in the case where
the size is a power of two and on the boundary between two representations.
Daniel Berlin [Wed, 11 Jan 2017 20:22:36 +0000 (20:22 +0000)]
NewGVN: Fix PR31594, by tracking the store count of congruence
classes, and updating checking to allow for equivalence through
reachability.
(Sadly, the checking here is not perfect, and can't be made perfect,
so we'll have to disable it after we are satisfied with correctness.
Right now it is just "very unlikely" to happen.)
David Blaikie [Wed, 11 Jan 2017 19:47:16 +0000 (19:47 +0000)]
Make some operator bools explicit for sanity/safety.
There are a couple left in bool-like containers (BitVector, etc) where
the implicit conversions seem more suitable - though it might be worth
considering explicitifying those too.
The removed assert seems bogus - it's perfectly legal for the roots of the
vectorized subtrees to be equal even if the original scalar values aren't,
if the original scalars happen to be equivalent.
Ivan Krasin [Wed, 11 Jan 2017 16:54:04 +0000 (16:54 +0000)]
Revert rL291205 because it breaks Chrome tests under CFI.
Summary:
Revert LowerTypeTests: Split the pass in two: a resolution phase and a lowering phase.
This change separates how type identifiers are resolved from how intrinsic
calls are lowered. All information required to lower an intrinsic call
is stored in a new TypeIdLowering data structure. The idea is that this
data structure can either be initialized using the module itself during
regular LTO, or using the module summary in ThinLTO backends.
[ARM] Fix test CodeGen/ARM/fpcmp_ueq.ll broken by rL290616
Commit rL290616 (https://reviews.llvm.org/rL290616) changed a checking command
for the triple arm-apple-darwin in LLVM::CodeGen/ARM/fpcmp_ueq.ll. As a result
of the changes the test could fail for the valid generated code.
These changes fixes the test to check only instructions we would expect.
Hal Finkel [Wed, 11 Jan 2017 13:24:24 +0000 (13:24 +0000)]
Make processing @llvm.assume more efficient - Add affected values to the assumption cache
Here's my second try at making @llvm.assume processing more efficient. My
previous attempt, which leveraged operand bundles, r289755, didn't end up
working: it did make assume processing more efficient but eliminating the
assumption cache made ephemeral value computation too expensive. This is a
more-targeted change. We'll keep the assumption cache, but extend it to keep a
map of affected values (i.e. values about which an assumption might provide
some information) to the corresponding assumption intrinsics. This allows
ValueTracking and LVI to find assumptions relevant to the value being queried
without scanning all assumptions in the function. The fact that ValueTracking
started doing O(number of assumptions in the function) work, for every
known-bits query, has become prohibitively expensive in some cases.
As discussed during the review, this is a pragmatic fix that, longer term, will
likely be replaced by a more-principled solution (perhaps based on an extended
SSA form).
Chandler Carruth [Wed, 11 Jan 2017 09:43:56 +0000 (09:43 +0000)]
[PM] Separate the LoopAnalysisManager from the LoopPassManager and move
the latter to the Transforms library.
While the loop PM uses an analysis to form the IR units, the current
plan is to have the PM itself establish and enforce both loop simplified
form and LCSSA. This would be a layering violation in the analysis
library.
Fundamentally, the idea behind the loop PM is to *transform* loops in
addition to running passes over them, so it really seemed like the most
natural place to sink this was into the transforms library.
We can't just move *everything* because we also have loop analyses that
rely on a subset of the invariants. So this patch splits the the loop
infrastructure into the analysis management that has to be part of the
analysis library, and the transform-aware pass manager.
This also required splitting the loop analyses' printer passes out to
the transforms library, which makes sense to me as running these will
transform the code into LCSSA in theory.
I haven't split the unittest though because testing one component
without the other seems nearly intractable.
Chandler Carruth [Wed, 11 Jan 2017 09:20:24 +0000 (09:20 +0000)]
[PM] Take more drastic measures to work around MSVC's failure on this
code. If this doesn't work and I can't find someone to help who has MSVC
installed, I'll back everything out I guess. =[
Elad Cohen [Wed, 11 Jan 2017 09:11:48 +0000 (09:11 +0000)]
[X86] Fix PR30926 - Add patterns for (v)cvtsi2s{s,d} and (v)cvtsd2s{s,d}
The code emiited by Clang's intrinsics for (v)cvtsi2ss, (v)cvtsi2sd,
(v)cvtsd2ss and (v)cvtss2sd is lowered to a code sequence that includes
redundant (v)movss/(v)movsd instructions. This patch adds patterns for
optimizing these sequences.