Summary:
This patch will add loop metadata on the pre and post loops generated by IRCE.
Currently, we have metadata for disabling optimizations such as vectorization,
unrolling, loop distribution and LICM versioning (and confirmed that these
optimizations check for the metadata before proceeding with the transformation).
The pre and post loops generated by IRCE need not go through loop opts (since
these are slow paths).
Added two test cases as well.
Reviewers: sanjoy, reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26806
llvm-svn: 289588
We currently check if the exact trip count is known and is smaller than the
"tiny loop" bound. We should be checking the maximum bound on the trip count
instead.
Differential Revision: https://reviews.llvm.org/D27690
llvm-svn: 289583
Summary:
This is last in of a series of patches to evolve ADCE.cpp to support
removing of unnecessary control flow.
This patch adds the code to update the control and data flow graphs
to remove the dead control flow.
Also update unit tests to test the capability to remove dead,
may-be-infinite loop which is enabled by the switch
-adce-remove-loops.
Previous patches:
D23824 [ADCE] Add handling of PHI nodes when removing control flow
D23559 [ADCE] Add control dependence computation
D23225 [ADCE] Modify data structures to support removing control flow
D23065 [ADCE] Refactor anticipating new functionality (NFC)
D23102 [ADCE] Refactoring for new functionality (NFC)
Reviewers: dberlin, majnemer, nadav, mehdi_amini
Subscribers: llvm-commits, david2050, freik, twoh
Differential Revision: https://reviews.llvm.org/D24918
llvm-svn: 289548
Only the lower bits of the input element are used. And only the lower element can be undef since the upper bits are zeroed.
Have InstCombineCalls call SimplifyDemandedVectorElts for these intrinsics to reuse this support.
llvm-svn: 289523
Summary:
Since we don't break BBs for function calls. We might get some insane counts
(wrap of unsigned) in the presence of noreturn calls.
This patch sets these counts to zero instead of the wrapped number.
Reviewers: davidxl
Subscribers: xur, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D27602
llvm-svn: 289521
This patch ensures the correct minimum bit width during type-shrinking.
Previously when type-shrinking, we always sign-extended values back to their
original width. However, if we are going to sign-extend, and the sign bit is
unknown, we have to increase the minimum bit width by one bit so the
sign-extend will fill the upper bits correctly. If the sign bit is known to be
zero, we can perform a zero-extend instead. This should fix PR31243.
Reference: https://llvm.org/bugs/show_bug.cgi?id=31243
Differential Revision: https://reviews.llvm.org/D27466
llvm-svn: 289470
We could truncate the condition and then try to fold the add into the
original condition value causing wrong case constants to be used.
Move the offset transform ahead of the truncate transform and return
after each transform, so there's no chance of getting confused values.
Fix for:
https://llvm.org/bugs/show_bug.cgi?id=31260
llvm-svn: 289442
This teaches SimplifyDemandedElts that the FMA can be removed if the lower element isn't used. It also teaches it that if upper elements of the first operand aren't used then we can simplify them.
llvm-svn: 289377
These intrinsics don't read the upper elements of their first and second input. These are slightly different the the SSE version which does use the upper bits of its first element as passthru bits since the result goes to an XMM register. For AVX-512 the result goes to a mask register instead.
llvm-svn: 289371
These intrinsics don't read the upper bits of their second input. And the third input is the passthru for masking and that only uses the lower element as well.
llvm-svn: 289370
The motivating example is:
extern int patatino;
int goo() {
int x = 0;
for (int i = 0; i < 1000000; ++i) {
x *= patatino;
}
return x;
}
Currently SCCP will not realize that this function returns always zero,
therefore will try to unroll and vectorize the loop at -O3 producing an
awful lot of (useless) code. With this change, it will just produce:
0000000000000000 <g>:
xor %eax,%eax
retq
llvm-svn: 289175
When trying to vectorize trees that start at insertelement instructions
function tryToVectorizeList() uses vectorization factor calculated as
MinVecRegSize/ScalarTypeSize. But sometimes it does not work as tree
cost for this fixed vectorization factor is too high.
Patch tries to improve the situation. It tries different vectorization
factors from max(PowerOf2Floor(NumberOfVectorizedValues),
MinVecRegSize/ScalarTypeSize) to MinVecRegSize/ScalarTypeSize and tries
to choose the best one.
Differential Revision: https://reviews.llvm.org/D27215
llvm-svn: 289043
Replace @progbits in the section directive with %progbits, because "@" starts a comment on arm/thumb.
Use b.w branch instruction.
Use .thumb_function and .thumb_set for proper arm/thumb interwork. This way jumptable entry addresses on thumb have bit 0 set (correctly). This does not affect CFI check math, because the address of the jumptable start also has that bit set.
This does not work on thumbv5, because it does not support b.w, and the linker would not insert a veneer (trampoline?) to extend the range of b.n. We may need to do full-range plt-style jumptables on thumbv54, which are 12 bytes per entry. Another option is "push lr; bl; pop pc" (4 bytes) but that needs unwinding instructions, etc.
Differential Revision: https://reviews.llvm.org/D27499
llvm-svn: 289008
The fix committed in r288851 doesn't cover all the cases.
In particular, if we have an instruction with side effects
which has a no non-dbg use not depending on the bits, we still
perform RAUW destroying the dbg.value's first argument.
Prevent metadata from being replaced here to avoid the issue.
Differential Revision: https://reviews.llvm.org/D27534
llvm-svn: 288987
This patch attempts to scalarize the operand expressions of predicated
instructions if they were conditionally executed in the original loop. After
scalarization, the expressions will be sunk inside the blocks created for the
predicated instructions. The transformation essentially performs
un-if-conversion on the operands.
The cost model has been updated to determine if scalarization is profitable. It
compares the cost of a vectorized instruction, assuming it will be
if-converted, to the cost of the scalarized instruction, assuming that the
instructions corresponding to each vector lane will be sunk inside a predicated
block, possibly avoiding execution. If it's more profitable to scalarize the
entire expression tree feeding the predicated instruction, the expression will
be scalarized; otherwise, it will be vectorized. We only consider the cost of
the entire expression to accurately estimate the cost of the required
insertelement and extractelement instructions.
Differential Revision: https://reviews.llvm.org/D26083
llvm-svn: 288909
In the case of a fully redundant load LI dominated by an equivalent load V, GVN
should always preserve the original debug location of V. Otherwise, we risk to
introduce an incorrect stepping.
If V has debug info, then clearly it should not be modified. If V has a null
debugloc, then it is still potentially incorrect to propagate LI's debugloc
because LI may not post-dominate V.
Differential Revision: https://reviews.llvm.org/D27468
llvm-svn: 288903
When a function F is inlined, InlineFunction extends the debug location of every
instruction inlined from F by adding an InlinedAt.
However, if an instruction has a 'null' debug location, InlineFunction would
propagate the callsite debug location to it. This behavior existed since
revision 210459.
Revision 210459 was originally committed specifically to workaround the lack of
debug information for instructions inlined from intrinsic functions (which are
usually declared with attributes `__always_inline__, __nodebug__`).
The problem with revision 210459 is that it doesn't make any sort of distinction
between instructions inlined from a 'nodebug' function and instructions which
are inlined from a function built with debug info. This issue may lead to
incorrect stepping in the debugger.
This patch works under the assumption that a nodebug function does not have a
DISubprogram. When a function F is inlined into another function G,
InlineFunction checks if F has debug info associated with it.
For nodebug functions, the InlineFunction logic is unchanged (i.e. it would
still propagate the callsite debugloc to the inlined instructions). Otherwise,
InlineFunction no longer propagates the callsite debug location.
Differential Revision: https://reviews.llvm.org/D27462
llvm-svn: 288895
Requesting metadata for a global is a relatively expensive operation as it
involves a map lookup, but it's one that we need to do relatively frequently in
this pass to collect the list of type metadata nodes associated with a global.
This change improves the performance of type metadata queries by prebuilding
data structures that keep the global together with its list of type metadata,
and changing the pass to use that data structure wherever we were previously
passing global references around.
This change also eliminates some O(N^2) behavior by collecting the list of
globals associated with each type identifier during the first pass over the
list of globals rather than visiting each global to compute that list every
time we add a new type identifier.
Reduces pass runtime on a module containing Chrome's vtables from over 60s
to 0.9s.
Differential Revision: https://reviews.llvm.org/D27484
llvm-svn: 288859
BDCE has two phases:
1. It asks SimplifyDemandedBits if all the bits of an instruction are dead, and if so,
replaces all its uses with the constant zero.
2. Then, it asks SimplifyDemandedBits again if the instruction is really dead
(no side effects etc..) and if so, eliminates it.
Now, in 1) if all the bits of an instruction are dead, we may end up replacing a dbg use:
%call = tail call i32 (...) @g() #4, !dbg !15
tail call void @llvm.dbg.value(metadata i32 %call, i64 0, metadata !8, metadata !16), !dbg !17
->
%call = tail call i32 (...) @g() #4, !dbg !15
tail call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !8, metadata !16), !dbg !17
but not eliminating the call because it may have arbitrary side effects.
In other words, we lose some debug informations.
This patch fixes the problem making sure that BDCE does nothing with the instruction if
it has side effects and no non-dbg uses.
Differential Revision: https://reviews.llvm.org/D27471
llvm-svn: 288851
There are two cases handled here:
1) a branch on undef
2) a switch with an undef condition.
Both cases are currently handled by ResolvedUndefsIn. If we have
a branch on undef, we force its value to false (which is trivially
foldable). If we have a switch on undef, we force to the first
constant (which is also foldable).
llvm-svn: 288725
so we can stop using DW_OP_bit_piece with the wrong semantics.
The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html
The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.
Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.
Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809
llvm-svn: 288683
This solves a secondary problem seen in PR6137:
https://llvm.org/bugs/show_bug.cgi?id=6137#c6
This is similar to the bitwise logic op fold added with:
https://reviews.llvm.org/rL287707
And like that patch, I'm artificially restricting the
transform from vector <-> scalar types until we're sure
that the backend can handle that.
llvm-svn: 288584
For -O0 there might be unreachable BBs, which breaks the assumption that all the
BBs have an auxiliary data structure. In this patch, we add another interface
called findBBInfo() so that a nullptr can be returned for the unreachable BBs
(and the callers can ignore those BBs).
This fixes the bug reported
https://llvm.org/bugs/show_bug.cgi?id=31209
Differential Revision: https://reviews.llvm.org/D27280
llvm-svn: 288528
This reverts commit r288497, as it broke the AArch64 build of Compiler-RT's
builtins (twice: once in r288412 and once in r288497). We should investigate
this offline.
llvm-svn: 288508
When trying to vectorize trees that start at insertelement instructions
function tryToVectorizeList() uses vectorization factor calculated as
MinVecRegSize/ScalarTypeSize. But sometimes it does not work as tree
cost for this fixed vectorization factor is too high.
Patch tries to improve the situation. It tries different vectorization
factors from max(PowerOf2Floor(NumberOfVectorizedValues),
MinVecRegSize/ScalarTypeSize) to MinVecRegSize/ScalarTypeSize and tries
to choose the best one.
Differential Revision: https://reviews.llvm.org/D27215
llvm-svn: 288497
Now that PointerType is no longer a SequentialType, all SequentialTypes
have an associated number of elements, so we can move that information to
the base class, allowing for a number of simplifications.
Differential Revision: https://reviews.llvm.org/D27122
llvm-svn: 288464
As proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106640.html
This is for a couple of reasons:
- Values of type PointerType are unlike the other SequentialTypes (arrays
and vectors) in that they do not hold values of the element type. By moving
PointerType we can unify certain aspects of how the other SequentialTypes
are handled.
- PointerType will have no place in the SequentialType hierarchy once
pointee types are removed, so this is a necessary step towards removing
pointee types.
Differential Revision: https://reviews.llvm.org/D26595
llvm-svn: 288462
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.
Differential Revision: https://reviews.llvm.org/D26594
llvm-svn: 288458
Summary:
We were doing an optimization in the ThinLTO backends of importing
constant unnamed_addr globals unconditionally as a local copy (regardless
of whether the thin link decided to import them). This should be done in
the thin link instead, so that resulting exported references are marked
and promoted appropriately, but will need a summary enhancement to mark
these variables as constant unnamed_addr.
The function import logic during the thin link was trying to handle
this proactively, by conservatively marking all values referenced in
the initializer lists of exported global variables as also exported.
However, this only handled values referenced directly from the
initializer list of an exported global variable. If the value is itself
a constant unnamed_addr variable, we could end up exporting its
references as well. This caused multiple issues. The first is that the
transitively exported references weren't promoted. Secondly, some could
not be promoted/renamed (e.g. they had a section or other constraint).
recursively, instead of just adding the first level of initializer list
references to the ExportList directly.
Remove this optimization and the associated handling in the function
import backend. SPEC measurements indicate we weren't getting much
from it in any case.
Fixes PR31052.
Reviewers: mehdi_amini
Subscribers: krasin, llvm-commits
Differential Revision: https://reviews.llvm.org/D26880
llvm-svn: 288446
The instcombine code which folds loads and stores into their use types can trip up if the use is a bitcast to a type which we can't directly load or store in the IR. In principle, such types shouldn't exist, but in practice they do today. This is a workaround to avoid a bug while we work towards the long term goal.
Differential Revision: https://reviews.llvm.org/D24365
llvm-svn: 288415
This just extracts out the transfer rules for constant ranges into a single shared point. As it happens, neither bit of code actually overlaps in terms of the handled operators, but with this change that could easily be tweaked in the future.
I also want to have this separated out to make experimenting with a eager value info implementation and possibly a ValueTracking-like fixed depth recursion peephole version. There's no reason all four of these can't share a common implementation which reduces the chances of bugs.
Differential Revision: https://reviews.llvm.org/D27294
llvm-svn: 288413
When trying to vectorize trees that start at insertelement instructions
function tryToVectorizeList() uses vectorization factor calculated as
MinVecRegSize/ScalarTypeSize. But sometimes it does not work as tree
cost for this fixed vectorization factor is too high.
Patch tries to improve the situation. It tries different vectorization
factors from max(PowerOf2Floor(NumberOfVectorizedValues),
MinVecRegSize/ScalarTypeSize) to MinVecRegSize/ScalarTypeSize and tries
to choose the best one.
Differential Revision: https://reviews.llvm.org/D27215
llvm-svn: 288412
Currently when cost of scalar operations is evaluated the vector type is
used for scalar operations. Patch fixes this issue and fixes evaluation
of the vector operations cost.
Several test showed that vector cost model is too optimistic. It
allowed vectorization of 8 or less add/fadd operations, though scalar
code is faster. Actually, only for 16 or more operations vector code
provides better performance.
Differential Revision: https://reviews.llvm.org/D26277
llvm-svn: 288398
[recommitting after the fix in r288307]
This requires some changes to the opt-diag API. Hal and I have
discussed this at the Dev Meeting and came up with a streaming delimiter
(setExtraArgs) to solve this.
Arguments after this delimiter are only included in the optimization
records and not in the remarks printed in the compiler output. (Note,
how in the test the content of the YAML file changes but the remarks on
the compiler output don't.)
This implements the green GVN message with a bug fix at line
http://lab.llvm.org:8080/artifacts/opt-view_test-suite/build/SingleSource/Benchmarks/Dhrystone/CMakeFiles/dry.dir/html/_org_test-suite_SingleSource_Benchmarks_Dhrystone_dry.c.html#L446
The fix is that now we properly include the constant value in the
message: "load of type i32 eliminated in favor of 7"
Differential Revision: https://reviews.llvm.org/D26489
llvm-svn: 288380
This class represents a symbol table built from in-memory IR. It provides
access to GlobalValues and should only be used if such access is required
(e.g. in the LTO implementation). We will eventually change IRObjectFile
to read from a bitcode symbol table rather than using ModuleSymbolTable,
so it would not be able to expose the module.
Differential Revision: https://reviews.llvm.org/D27073
llvm-svn: 288319
If LoopInfo is available during GVN, BasicAA will use it. However
MergeBlockIntoPredecessor does not update LI as it merges blocks.
This didn't use to cause problems because LI was freed before
GVN/BasicAA. Now with OptimizationRemarkEmitter, the lifetime of LI is
extended so LI needs to be kept up-to-date during GVN.
Differential Revision: https://reviews.llvm.org/D27288
llvm-svn: 288307
Summary:
Fix a case when first register in a search has maximum
RegUses.getUsedByIndices(Reg).count()
Reviewers: qcolombet
Differential Revision: http://reviews.llvm.org/D26877
From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 288278
This implements PGO-driven loop peeling.
The basic idea is that when the average dynamic trip-count of a loop is known,
based on PGO, to be low, we can expect a performance win by peeling off the
first several iterations of that loop.
Unlike unrolling based on a known trip count, or a trip count multiple, this
doesn't save us the conditional check and branch on each iteration. However,
it does allow us to simplify the straight-line code we get (constant-folding,
etc.). This is important given that we know that we will usually only hit this
code, and not the actual loop.
This is currently disabled by default.
Differential Revision: https://reviews.llvm.org/D25963
llvm-svn: 288274
Michel Dänzer reported that r288051, "[StructurizeCFG] Use range-based
for loops", introduced a bug into rebuildSSA, wherein we were iterating
over an instruction's use list while modifying it, without taking care
to do this correctly.
llvm-svn: 288200
The flag was introduced because the optimization controlled by the flag initially caused regressions. All the regressions were fixed some time ago and the flag has been false for quite a while.
llvm-svn: 288154
Enable scalar hoisting at -Oz as it is safe to hoist scalars to a place
where they are partially needed.
Differential Revision: https://reviews.llvm.org/D27111
llvm-svn: 288141
Currently SLP vectorizer tries to vectorize a binary operation and dies
immediately after unsuccessful the first unsuccessfull attempt. Patch
tries to improve the situation, trying to vectorize all binary
operations of all children nodes in the binop tree.
Differential Revision: https://reviews.llvm.org/D25517
llvm-svn: 288115
This way, when the linker adds padding between globals, we can skip over
the zero padding bytes and reliably find the start of the next metadata
global.
llvm-svn: 288096
Preserving lifetime markers isn't as important as allowing promotion,
so just drop the lifetime markers if necessary.
This also fixes an assertion failure where other parts of SROA assumed
that lifetime markers never block promotion.
Fixes https://llvm.org/bugs/show_bug.cgi?id=29139.
Differential Revision: https://reviews.llvm.org/D24854
llvm-svn: 288074
Summary:
As far as I can tell, doing our own computations in
NearestCommonDominator is a false optimization -- DomTree will build up
what appears to be exactly this data when it decides it's worthwhile.
Moreover, by building the cache ourselves, we cannot take advantage of
the cache that the domtree might have available.
In addition, I am not convinced of the correctness of the original code.
In particular, setting ResultIndex = 1 on the first addBlock instead of
setting it to 0 is quite fishy. Similarly, it's not clear to me that
setting IndexMap[Node] = 0 for every node as we walk up the tree finding
a common parent is correct. But rather than ponder over these
questions, I'd rather just make the code do the obviously-correct thing.
This patch also changes the NearestCommonDominator API a bit, improving
the names and getting rid of the boolean parameter in addBlock -- see
http://jlebar.com/2011/12/16/Boolean_parameters_to_API_functions_considered_harmful..html
Reviewers: arsenm
Subscribers: aemerson, wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D26998
llvm-svn: 288050
Note that the non-splat lshr+lshr test folded, but that does not
work in general. Something is missing or wrong in computeKnownBits
as the non-splat shl+shl test still shows.
llvm-svn: 288005
There are other spots where we can use this; we're currently dropping
metadata in some places, and there are proposed changes where we will
want to propagate metadata.
IRBuilder's CreateSelect() already has a parameter like this, so this
change makes the regular 'Create' API line up with that.
llvm-svn: 287976
Summary:
The iterative algorithm for Loop Unswitching may render some of the branches unreachable in the unswitched loops.
Given the exponential nature of the algorithm, this is quite an overhead.
This patch fixes this problem by selectively unswitching only those branches within a loop that are reachable from the loop header.
Reviewers: Michael Zolothukin, Anna Thomas, Weiming Zhao.
Subscribers: llvm-commits.
Differential Revision: http://reviews.llvm.org/D26299
llvm-svn: 287925
analyses to have a common type which is enforced rather than using
a char object and a `void *` type when used as an identifier.
This has a number of advantages. First, it at least helps some of the
confusion raised in Justin Lebar's code review of why `void *` was being
used everywhere by having a stronger type that connects to documentation
about this.
However, perhaps more importantly, it addresses a serious issue where
the alignment of these pointer-like identifiers was unknown. This made
it hard to use them in pointer-like data structures. We were already
dodging this in dangerous ways to create the "all analyses" entry. In
a subsequent patch I attempted to use these with TinyPtrVector and
things fell apart in a very bad way.
And it isn't just a compile time or type system issue. Worse than that,
the actual alignment of these pointer-like opaque identifiers wasn't
guaranteed to be a useful alignment as they were just characters.
This change introduces a type to use as the "key" object whose address
forms the opaque identifier. This both forces the objects to have proper
alignment, and provides type checking that we get it right everywhere.
It also makes the types somewhat less mysterious than `void *`.
We could go one step further and introduce a truly opaque pointer-like
type to return from the `ID()` static function rather than returning
`AnalysisKey *`, but that didn't seem to be a clear win so this is just
the initial change to get to a reliably typed and aligned object serving
is a key for all the analyses.
Thanks to Richard Smith and Justin Lebar for helping pick plausible
names and avoid making this refactoring many times. =] And thanks to
Sean for the super fast review!
While here, I've tried to move away from the "PassID" nomenclature
entirely as it wasn't really helping and is overloaded with old pass
manager constructs. Now we have IDs for analyses, and key objects whose
address can be used as IDs. Where possible and clear I've shortened this
to just "ID". In a few places I kept "AnalysisID" to make it clear what
was being identified.
Differential Revision: https://reviews.llvm.org/D27031
llvm-svn: 287783
Summary:
The "getVectorizablePrefix" method would give up if it found an aliasing load for a store chain.
In practice, the aliasing load can be treated as a memory barrier and all stores that precede it
are a valid vectorizable prefix.
Issue found by volkan in D26962. Testcase is a pruned version of the one in the original patch.
Reviewers: jlebar, arsenm, tstellarAMD
Subscribers: mzolotukhin, wdng, nhaehnle, anna, volkan, llvm-commits
Differential Revision: https://reviews.llvm.org/D27008
llvm-svn: 287781
Summary:
No need to copy the RPOT vector before using it. Switch from std::map
to SmallDenseMap. Get rid of an unused variable (TempVisited). Get rid
of a typedef, RNVector, which is now used only once.
Differential Revision: https://reviews.llvm.org/D26997
llvm-svn: 287721
Summary:
"addRequired" and "addPreserved" look very similar when squished up next
to each other -- without the newline this code looked to me like it was
addRequired'ing DominatorTreeWrapperPass twice.
Reviewers: arsenm
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D26996
llvm-svn: 287720
Summary: Lets us get rid of one member variable too.
Reviewers: arsenm
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D26992
llvm-svn: 287716
We visit and/or, we try to derive a lattice value for the
instruction even if one of the operands is overdefined.
If the non-overdefined value is still 'unknown' just return and wait
for ResolvedUndefsIn to "plug in" the correct value. This simplifies
the logic a bit. While I'm here add tests for missing cases.
llvm-svn: 287709
In PR27925:
https://llvm.org/bugs/show_bug.cgi?id=27925
...we proposed adding this fold to eliminate a bitcast. In D20774, there was
some concern about changing the type of a bitwise op as well as creating
bitcasts that might not be free for a target. However, if we're strictly
eliminating an instruction (by limiting this to one-use ops), then we should
be able to do this in InstCombine.
But we're cautiously restricting the transform for now to vector types to
avoid possible backend problems. A transform to make sure the logic op is
legal for the target should be added to reverse this transform and improve
codegen.
Differential Revision: https://reviews.llvm.org/D26641
llvm-svn: 287707
Allow using an instruction other than a mul or phi as the base for
root-finding. For example, the included testcase includes a loop
which requires using a getelementptr as the base for root-finding.
Differential Revision: https://reviews.llvm.org/D26529
llvm-svn: 287588
This is a first step towards canonicalization and improved folding/codegen
for integer min/max as discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/106868.html
Here, we're just matching the simplest min/max patterns and adjusting the
icmp predicate while swapping the select operands.
I've included FIXME tests in test/Transforms/InstCombine/select_meta.ll
so it's easier to see how this might be extended (corresponds to the TODO
comment in the code). That's also why I'm using matchSelectPattern()
rather than a simpler check; once the backend is patched, we can just
remove some of the restrictions to allow the obfuscated min/max patterns
in the FIXME tests to be matched.
Differential Revision: https://reviews.llvm.org/D26525
llvm-svn: 287585
Summary:
This is similar to what was done for Darwin in rL264645 /
http://reviews.llvm.org/D16737, but it uses COFF COMDATs to achive the
same result instead of relying on new custom linker features.
As on MachO, this creates one metadata global per instrumented global.
The metadata global is placed in the custom .ASAN$GL section, which the
ASan runtime will iterate over during initialization. There are no other
references to the metadata, so normal linker dead stripping would
discard it. However, the metadata is put in a COMDAT group with the
instrumented global, so that it will be discarded if and only if the
instrumented global is discarded.
I didn't update the ASan ABI version check since this doesn't affect
non-Windows platforms, and the WinASan ABI isn't really stable yet.
Implementing this for ELF will require extending LLVM IR and MC a bit so
that we can use non-COMDAT section groups.
Reviewers: pcc, kcc, mehdi_amini, kubabrecka
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26770
llvm-svn: 287576
This patch fixes the non-determinism caused due to iterating SmallPtrSet's
which was uncovered due to the experimental "reverse iteration order " patch:
https://reviews.llvm.org/D26718
The following unit tests failed because of the undefined order of iteration.
LLVM :: Transforms/Util/MemorySSA/cyclicphi.ll
LLVM :: Transforms/Util/MemorySSA/many-dom-backedge.ll
LLVM :: Transforms/Util/MemorySSA/many-doms.ll
LLVM :: Transforms/Util/MemorySSA/phi-translation.ll
Reviewers: dberlin, mgrang
Subscribers: dberlin, llvm-commits, david2050
Differential Revision: https://reviews.llvm.org/D26704
llvm-svn: 287563
On some architectures (s390x, ppc64, sparc64, mips), C-level int is passed
as i32 signext instead of plain i32. Likewise, unsigned int may be passed
as i32, i32 signext, or i32 zeroext depending on the platform. Mark
__llvm_profile_instrument_target properly (its last parameter is unsigned
int).
This (together with the clang change) makes compiler-rt profile testsuite pass
on s390x.
Differential Revision: http://reviews.llvm.org/D21736
llvm-svn: 287534
insertUniqueBackedgeBlock in lib/Transforms/Utils/LoopSimplify.cpp now
propagates existing llvm.loop metadata to newly the added backedge.
llvm::TryToSimplifyUncondBranchFromEmptyBlock in lib/Transforms/Utils/Local.cpp
now propagates existing llvm.loop metadata to the branch instructions in the
predecessor blocks of the empty block that is removed.
Differential Revision: https://reviews.llvm.org/D26495
llvm-svn: 287341
This is a straightforward extension of the existing support for 32/64-bit element types. Just needed to add the additional instrinsics to the switches.
llvm-svn: 287316
This patch updates a bunch of places where add_dependencies was being explicitly called to add dependencies on intrinsics_gen to instead use the DEPENDS named parameter. This cleanup is needed for a patch I'm working on to add a dependency debugging mode to the build system.
llvm-svn: 287206
Summary:
For flat loop, even if it is hot, it is not a good idea to unroll in runtime, thus we set a lower partial unroll threshold.
For hot loop, we set a higher unroll threshold and allows expensive tripcount computation to allow more aggressive unrolling.
Reviewers: davidxl, mzolotukhin
Subscribers: sanjoy, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D26527
llvm-svn: 287186
This pass splits globals into elements using inrange annotations on
getelementptr indices.
Differential Revision: https://reviews.llvm.org/D22295
llvm-svn: 287178
Summary: These intrinsics have been unused for clang for a while. This patch removes them. We auto upgrade them to extractelements, a scalar operation and then an insertelement. This matches the sequence used by clangs intrinsic file.
Reviewers: zvi, delena, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26660
llvm-svn: 287083
Summary:
We don't do BypassSlowDivision when the denominator is a constant, but
we do do it when the numerator is a constant.
This patch makes two related changes to BypassSlowDivision when the
numerator is a constant:
* If the numerator is too large to fit into the bypass width, don't
bypass slow division (because we'll never run the smaller-width
code).
* If we bypass slow division where the numerator is a constant, don't
OR together the numerator and denominator when determining whether
both operands fit within the bypass width. We need to check only the
denominator.
Reviewers: tra
Subscribers: llvm-commits, jholewinski
Differential Revision: https://reviews.llvm.org/D26699
llvm-svn: 287062
This patch adds support for instrumenting masked loads and stores under
ASan, if they have a constant mask.
isInterestingMemoryAccess now supports returning a mask to be applied to
the loads, and instrumentMop will use it to generate additional checks.
Added tests for v4i32 v8i32, and v4p0i32 (~v4i64) for both loads and
stores (as well as a test to verify we don't add checks to non-constant
masks).
Differential Revision: https://reviews.llvm.org/D26230
llvm-svn: 287047
In RateRegister of existing LSR, if a formula contains a Reg which is a SCEVAddRecExpr,
and this SCEVAddRecExpr's loop is an outerloop, the formula will be marked as Loser
and dropped.
Suppose we have an IR that %for.body is outerloop and %for.body2 is innerloop. LSR only
handle inner loop now so only %for.body2 will be handled.
Using the logic above, formula like
reg(%array) + reg({1,+, %size}<%for.body>) + 1*reg({0,+,1}<%for.body2>) will be dropped
no matter what because reg({1,+, %size}<%for.body>) is a SCEVAddRecExpr type reg related
with outerloop. Only formula like
reg(%array) + 1*reg({{1,+, %size}<%for.body>,+,1}<nuw><nsw><%for.body2>) will be kept
because the SCEVAddRecExpr related with outerloop is folded into the initial value of the
SCEVAddRecExpr related with current loop.
But in some cases, we do need to share the basic induction variable
reg{0 ,+, 1}<%for.body2> among LSR Uses to reduce the final total number of induction
variables used by LSR, so we don't want to drop the formula like
reg(%array) + reg({1,+, %size}<%for.body>) + 1*reg({0,+,1}<%for.body2>) unconditionally.
From the existing comment, it tries to avoid considering multiple level loops at the same time.
However, existing LSR only handles innermost loop, so for any SCEVAddRecExpr with a loop other
than current loop, it is an invariant and will be simple to handle, and the formula doesn't have
to be dropped.
Differential Revision: https://reviews.llvm.org/D26429
llvm-svn: 286999
When both WidenIV::getWideRecurrence and WidenIV::getExtendedOperandRecurrence
return non-null but different WideAddRec, if getWideRecurrence is called
before getExtendedOperandRecurrence, we won't bother to call
getExtendedOperandRecurrence again. But As we know it is possible that after
SCEV folding, we cannot prove the legality using the SCEVAddRecExpr returned
by getWideRecurrence. Meanwhile if getExtendedOperandRecurrence returns non-null
WideAddRec, we know for sure that it is legal to do widening for current instruction.
So it is better to put getExtendedOperandRecurrence before getWideRecurrence, which
will increase the chance of successful widening.
Differential Revision: https://reviews.llvm.org/D26059
llvm-svn: 286987
The register usage algorithm incorrectly treats instructions whose value is
not used within the loop (e.g. those that do not produce a value).
The algorithm first calculates the usages within the loop. It iterates over
the instructions in order, and records at which instruction index each use
ends (in fact, they're actually recorded against the next index, as this is
when we want to delete them from the open intervals).
The algorithm then iterates over the instructions again, adding each
instruction in turn to a list of open intervals. Instructions are then
removed from the list of open intervals when they occur in the list of uses
ended at the current index.
The problem is, instructions which are not used in the loop are skipped.
However, although they aren't used, the last use of a value may have been
recorded against that instruction index. In this case, the use is not deleted
from the open intervals, which may then bump up the estimated register usage.
This patch fixes the issue by simply moving the "is used" check after the loop
which erases the uses at the current index.
Differential Revision: https://reviews.llvm.org/D26554
llvm-svn: 286969
This adds support for TSan C++ exception handling, where we need to add extra calls to __tsan_func_exit when a function is exitted via exception mechanisms. Otherwise the shadow stack gets corrupted (leaked). This patch moves and enhances the existing implementation of EscapeEnumerator that finds all possible function exit points, and adds extra EH cleanup blocks where needed.
Differential Revision: https://reviews.llvm.org/D26177
llvm-svn: 286893
Summary:
We have always speculatively promoted all renamable local values
(except const non-address taken variables) for both the exporting
and importing module. We would then internalize them back based on
the ThinLink results if they weren't actually exported. This is
inefficient, and results in unnecessary renames. It also meant we
had to check the non-renamability of a value in the summary, which
was already checked during function importing analysis in the ThinLink.
Made renameModuleForThinLTO (which does the promotion/renaming) instead
use the index when exporting, to avoid unnecessary renames/promotions.
For importing modules, we can simply promoted all values as any local
we import by definition is exported and needs promotion.
This required changes to the method used by the FunctionImport pass
(only invoked from 'opt' for testing) and when invoked from llvm-link,
since neither does a ThinLink. We simply conservatively mark all locals
in the index as promoted, which preserves the current aggressive
promotion behavior.
I also needed to change an llvm-lto based test where we had previously
been aggressively promoting values that weren't importable (aliasees),
but now will not promote.
Reviewers: mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26467
llvm-svn: 286871
Summary:
The change in r285513 to prevent exporting of locals used in
inline asm added all locals in the llvm.used set to the reference
set of functions containing inline asm. Since these locals were marked
NoRename, this automatically prevented importing of the function.
Unfortunately, this caused an explosion in the summary reference lists
in some cases. In my particular example, it happened for a large protocol
buffer generated C++ file, where many of the generated functions
contained an inline asm call. It was exacerbated when doing a ThinLTO
PGO instrumentation build, where the PGO instrumentation included
thousands of private __profd_* values that were added to llvm.used.
We really only need to include a single llvm.used local (NoRename) value
in the reference list of a function containing inline asm to block it
being imported. However, it seems cleaner to add a flag to the summary
that explicitly describes this situation, which is what this patch does.
Reviewers: mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26402
llvm-svn: 286840
Summary:
Unfolding selects was previously done with the help of a vector
of pointers that was then sorted to be able to remove duplicates.
As this sorting depends on the memory addresses, it was
non-deterministic. A SetVector is used now so that duplicates are
removed without the need of sorting first.
Reviewers: mgrang, efriedma
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26450
llvm-svn: 286807
All existing callers were manually extracting information out of an existing
GEP instruction and passing it to getGEPExpr(). Simplify the interface by
changing it to take a GEPOperator instead.
llvm-svn: 286751
Anna Thomas