9723 Commits

Author SHA1 Message Date
Florian Hahn
7d274aa9be [SCEV] Add support for x != 0 to CollectCondition.
Add support for NE predicates with 0 constants. Those can be translated
to UMaxExpr(x, 1).
2020-09-25 18:58:55 +01:00
Florian Hahn
b5a3b901c7 [SCEV] Add support for x == constant to CollectCondition.
Add support for EQ predicates with constant operand. In that case, using
the constant instead of an unknown expression should always be
beneficial.
2020-09-25 16:56:49 +01:00
Florian Hahn
8858340bd3 [SCEV] Swap operands if LHS is not unknown.
Currently we only use information from guards for unknown expressions.
Swap LHS/RHS and predicate, if LHS is not unknown.
2020-09-25 15:50:01 +01:00
Florian Hahn
df77ce7cad [SCEV] Extract code to collect conditions to lambda (NFC).
This makes re-using the common functionality easier in follow-up
patches.
2020-09-25 15:12:42 +01:00
Juneyoung Lee
92106641ae [ValueTracking] Make isGuaranteedNotToBeUndefOrPoison exit early when MetadataAsValue is given
It is set to conservatively return false, otherwise noundef attributes are added to function calls with metadata arguments.
2020-09-25 09:50:09 +09:00
Juneyoung Lee
1c45220028 [ValueTracking] Check uses of Argument if it is given to isGuaranteedNotToBeUndefOrPoison
This is a patch that allows isGuaranteedNotToBeUndefOrPoison to return more precise result
when an argument is given, by looking through its uses at the entry block (and following blocks as well, if it is checking poison only).

This is useful when there is a function call with noundef arguments at the entry block.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D88207
2020-09-25 08:57:57 +09:00
Andrew Litteken
f02c4c87b4 [IRSim] Adding wrapper pass for IRSimilarityIdentfier
This introduces an analysis pass that wraps IRSimilarityIdentifier,
and adds a printer pass to examine in what function similarities are
being found.

Test for what the printer pass can find are in
test/Analysis/IRSimilarityIdentifier.

Reviewed by: paquette, jroelofs

Differential Revision: https://reviews.llvm.org/D86973
2020-09-24 14:59:41 -05:00
Andrew Litteken
08d145e6d7 [IRSim][NFC] Removing dead variables from IRSimilarityIdentifier.cpp
As informed by danielkiss.

Follow up to Differential Revision: https://reviews.llvm.org/D86972
2020-09-24 11:43:33 -05:00
Matt Arsenault
d65a7003c4 OpaquePtr: Add helpers for sret to mirror byval
Sret should really have a type parameter like byval does.
2020-09-24 09:57:28 -04:00
Florian Hahn
d4ddf63fc4 [SCEV] Use loop guard info when computing the max BE taken count in howFarToZero.
For some expressions, we can use information from loop guards when
we are looking for a maximum. This patch applies information from
loop guards to the expression used to compute the maximum backedge
taken count in howFarToZero. It currently replaces an unknown
expression X with UMin(X, Y), if the loop is guarded by
X ult Y.

This patch is minimal in what conditions it applies, and there
are a few TODOs to generalize.

This partly addresses PR40961. We will also need an update to
LV to address it completely.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D67178
2020-09-24 11:06:55 +01:00
Andrew Litteken
b63bfc2030 [IRSim] Adding a basic similarity identifier.
This takes the mapped instructions from the IRInstructionMapper, and
passes it to the Suffix Tree to find the repeated substrings.  Within
each set of repeated substrings, the IRSimilarityCandidates are compared
against one another for structure, and ensuring that the operands in the
instructions are used in the same way.  Each of these structurally
similarity IRSimilarityCandidates are contained in a SimilarityGroup.

Tests checking for identifying identity of structure, different
isomorphic structure, and different
nonisomoprhic structure are found in
unittests/Analysis/IRSimilarityIdentifierTest.cpp.

Differential Revision: https://reviews.llvm.org/D86972
2020-09-24 02:05:25 -05:00
Andrew Litteken
beeceb92c0 [IRSim][NFC] Removing warning from IRSimilarityIdentifier 2020-09-24 00:26:32 -05:00
Andrew Litteken
d1aa143aa8 [IRSim] Adding structural comparison to IRSimilarityCandidate.
Just because sequences of instructions are similar to one another,
doesn't mean they are doing the same thing.

This introduces a structural check for the IRSimilarityCandidate that
compares two IRSimilarityCandidates against one another, and in each
instruction creates a mapping between the operands and results, or
checks that the existing mapping is valid.  If this check passes, it
means we have structurally similar IRSimilarityCandidates.

Tests for whether the candidates are found in
unittests/Analysis/IRSimilarityIdentifierTest.cpp.

Recommit of: b27db2bb68163fa5bcb4a8f631a305eb5adb44e5 for Differential
URL.

Differential Revision: https://reviews.llvm.org/D86971
2020-09-23 22:42:30 -05:00
Andrew Litteken
0a8e097e72 Revert "[IRSim] Adding structural comparison to IRSimilarityCandidate."
This reverts commit b27db2bb68163fa5bcb4a8f631a305eb5adb44e5.
2020-09-23 22:40:37 -05:00
Andrew Litteken
b27db2bb68 [IRSim] Adding structural comparison to IRSimilarityCandidate.
Just because sequences of instructions are similar to one another,
doesn't mean they are doing the same thing.

This introduces a structural check for the IRSimilarityCandidate that
compares two IRSimilarityCandidates against one another, and in each
instruction creates a mapping between the operands and results, or
checks that the existing mapping is valid.  If this check passes, it
means we have structurally similar IRSimilarityCandidates.

Tests for whether the candidates are found in
unittests/Analysis/IRSimilarityIdentifierTest.cpp.
2020-09-23 22:31:12 -05:00
Sam McCall
fa69b60806 [JSON] Add error reporting to fromJSON and ObjectMapper
Translating between JSON objects and C++ strutctures is common.
From experience in clangd, fromJSON/ObjectMapper work well and save a lot of
code, but aren't adopted elsewhere at least partly due to total lack of error
reporting beyond "ok"/"bad".

The recently-added error model should be rich enough for most applications.
It requires tracking the path within the root object and reporting local
errors at appropriate places.
To do this, we exploit the fact that the call graph of recursive
parse functions mirror the structure of the JSON itself.
The current path is represented as a linked list of segments, each of which is
on the stack as a parameter. Concretely, fromJSON now looks like:
  bool fromJSON(const Value&, T&, Path);

Beyond the signature change, this is reasonably unobtrusive: building
the path segments is mostly handled by ObjectMapper and the vector<T> fromJSON.
However the root caller of fromJSON must now create a Root object to
store the errors, which is a little clunky.

I've added high-level parse<T>(StringRef) -> Expected<T>, but it's not
general enough to be the primary interface I think (at least, not usable in
clangd).

All existing users (mostly just clangd) are updated in this patch,
making this change backwards-compatible is a bit hairy.

Differential Revision: https://reviews.llvm.org/D88103
2020-09-24 01:20:09 +02:00
Arthur Eubanks
6b1ce83a12 [NewPM][CGSCC] Handle newly added functions in updateCGAndAnalysisManagerForPass
This seems to fit the CGSCC updates model better than calling
addNewFunctionInto{Ref,}SCC() on newly created/outlined functions.
Now addNewFunctionInto{Ref,}SCC() are no longer necessary.

However, this doesn't work on newly outlined functions that aren't
referenced by the original function. e.g. if a() was outlined into b()
and c(), but c() is only referenced by b() and not by a(), this will
trigger an assert.

This also fixes an issue I was seeing with newly created functions not
having passes run on them.

Ran check-llvm with expensive checks.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D87798
2020-09-23 15:22:18 -07:00
Andrew Litteken
6ada9e516f [IRSim] Adding IRSimilarityCandidate that contains a region of IRInstructionData.
The IRSimilarityCandidate is a container to hold a region of
IRInstructions and offer interfaces for the starting instruction, ending
instruction, parent function, length.  It also assigns a global value
number for each unique instance of a value in the region.

It also contains an interface to compare two IRSimilarity as to whether
they have the same sequence of similar instructions.

Tests for whether the instructions are similar are found in
unittests/Analysis/IRSimilarityIdentifierTest.cpp.

Recommit of: 4944bb190fed8861d4d043eaf45e3c1e12aa2dc5

Differential Revision: https://reviews.llvm.org/D86970
2020-09-23 13:43:34 -05:00
Sanjay Patel
6189a8d9f5 [TTI] add wrapper for matching vector reduction to reduce code duplication; NFC
I'm not sure what this means, but the order in which we try
the matches makes a difference on at least 1 regression test...
2020-09-23 13:48:57 -04:00
Andrew Litteken
88bc59c300 Revert "[IRSim] Adding IRSimilarityCandidate that contains a region of IRInstructionData."
This reverts commit 4944bb190fed8861d4d043eaf45e3c1e12aa2dc5.
2020-09-22 21:02:34 -05:00
Andrew Litteken
4944bb190f [IRSim] Adding IRSimilarityCandidate that contains a region of IRInstructionData.
The IRSimilarityCandidate is a container to hold a region of
IRInstructions and offer interfaces for the starting instruction, ending
instruction, parent function, length.  It also assigns a global value
number for each unique instance of a value in the region.

It also contains an interface to compare two IRSimilarity as to whether
they have the same sequence of similar instructions.

Tests for whether the instructions are similar are found in
unittests/Analysis/IRSimilarityIdentifierTest.cpp.

Differential Revision: https://reviews.llvm.org/D86970
2020-09-22 18:42:31 -05:00
Stefanos Baziotis
89c1e35f3c [LoopInfo] empty() -> isInnermost(), add isOutermost()
Differential Revision: https://reviews.llvm.org/D82895
2020-09-22 23:28:51 +03:00
Max Kazantsev
e2703c021d [SCEV] Handle less predicates for FoundPred = NE
Currently these predicates are ignored, yet their handling is
pretty simple. I could not find a single test where it would
actually change something, but it's only because isImpliedCondOperands
is not smart enough to prove it further on. Yet the situation when
we come there with `less` predicate is pretty common.

Differential Revision: https://reviews.llvm.org/D87890
Reviewed By: fhahn
2020-09-22 18:56:35 +07:00
Meera Nakrani
a3d0dce260 [ARM][TTI] Prevents constants in a min(max) or max(min) pattern from being hoisted when in a loop
Changes TTI function getIntImmCostInst to take an additional Instruction parameter,
which enables us to be able to check it is part of a min(max())/max(min()) pattern that will match SSAT.
We can then mark the constant used as free to prevent it being hoisted so SSAT can still be generated.
Required minor changes in some non-ARM backends to allow for the optional parameter to be included.

Differential Revision: https://reviews.llvm.org/D87457
2020-09-22 11:54:10 +00:00
Max Kazantsev
16fde88dbd [SCEV] Support unsigned predicates in isKnownPredicateViaNoOverflow
SCEV should be able to prove facts like `x <u x+1<nuw>`.

Differential Revision: https://reviews.llvm.org/D88015
Reviewed By: lebedev.ri
2020-09-22 17:14:05 +07:00
Arthur Eubanks
9db0c572c1 [Delinearization][NewPM] Port delinearization to NPM
Also make tests in Analysis/Delinearization work under NPM.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D87741
2020-09-21 17:59:08 -07:00
Fangrui Song
8fdac7cb7a Revert D71539 "Recommit "[SCEV] Look through single value PHIs.""
This reverts commit 11dccf8d3aa5d55210f8b886fb21926c7a8353ca.

A bootstrapped clang crashes (due to ArrayRef::front called on an empty
ArrayRef) when compiling some files.  Very strangely, this only reproduces with
modules.

```
13 0x0000564d3349e968 llvm::ArrayRef<llvm::BasicBlock*>::front() const /proc/self/cwd/llvm/include/llvm/ADT/ArrayRef.h:160:7
14 0x0000564d3349e896 llvm::LoopBase<llvm::BasicBlock, llvm::Loop>::getHeader() const /proc/self/cwd/llvm/include/llvm/Analysis/LoopInfo.h:104:50
15 0x0000564d3349fd9d llvm::LoopBase<llvm::BasicBlock, llvm::Loop>::getLoopLatch() const /proc/self/cwd/llvm/include/llvm/Analysis/LoopInfoImpl.h:210:11
16 0x0000564d33593c8a llvm::ScalarEvolution::computeBackedgeTakenCount(llvm::Loop const*, bool) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:6933:15
17 0x0000564d33592ebc llvm::ScalarEvolution::getBackedgeTakenInfo(llvm::Loop const*) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:0:30
18 0x0000564d33593a54 llvm::ScalarEvolution::getBackedgeTakenCount(llvm::Loop const*, llvm::ScalarEvolution::ExitCountKind) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:6487:36
19 0x0000564d32be2402 llvm::ScalarEvolution::getConstantMaxBackedgeTakenCount(llvm::Loop const*) /proc/self/cwd/llvm/include/llvm/Analysis/ScalarEvolution.h:768:5
20 0x0000564d33590807 llvm::ScalarEvolution::getRangeRef(llvm::SCEV const*, llvm::ScalarEvolution::RangeSignHint) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:5495:19
21 0x0000564d320abab7 llvm::ScalarEvolution::getSignedRange(llvm::SCEV const*) /proc/self/cwd/llvm/include/llvm/Analysis/ScalarEvolution.h:840:12
22 0x0000564d335a03aa llvm::ScalarEvolution::isKnownPredicateViaConstantRanges(llvm::CmpInst::Predicate, llvm::SCEV const*, llvm::SCEV const*) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:9239:60
23 0x0000564d33586a80 llvm::ScalarEvolution::isKnownViaNonRecursiveReasoning(llvm::CmpInst::Predicate, llvm::SCEV const*, llvm::SCEV const*) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:10284:60
```
2020-09-21 17:21:43 -07:00
Roman Lebedev
0ab99bb314
[NFC][SCEV] Cleanup lowering of @llvm.uadd.sat, (-1 - V) is just ~V 2020-09-21 22:10:59 +03:00
Roman Lebedev
64e2cb7e96
[SCEV] Recognize @llvm.uadd.sat as %y + umin(%x, (-1 - %y))
----------------------------------------
define i32 @src(i32 %x, i32 %y) {
%0:
  %r = uadd_sat i32 %x, %y
  ret i32 %r
}
=>
define i32 @tgt(i32 %x, i32 %y) {
%0:
  %t0 = sub nsw nuw i32 4294967295, %y
  %t1 = umin i32 %x, %t0
  %r = add nuw i32 %t1, %y
  ret i32 %r
}
Transformation seems to be correct!

The alternative, naive, lowering could be the following,
although i don't think it's better,
thought it will likely be needed for sadd/ssub/*shl:

----------------------------------------
define i32 @src(i32 %x, i32 %y) {
%0:
  %r = uadd_sat i32 %x, %y
  ret i32 %r
}
=>
define i32 @tgt(i32 %x, i32 %y) {
%0:
  %t0 = zext i32 %x to i33
  %t1 = zext i32 %y to i33
  %t2 = add nuw i33 %t0, %t1
  %t3 = zext i32 4294967295 to i33
  %t4 = umin i33 %t2, %t3
  %r = trunc i33 %t4 to i32
  ret i32 %r
}
Transformation seems to be correct!
2020-09-21 20:25:54 +03:00
Roman Lebedev
fedc9549d5
[SCEV] Recognize @llvm.usub.sat as %x - (umin %x, %y)
----------------------------------------
define i32 @src(i32 %x, i32 %y) {
%0:
  %r = usub_sat i32 %x, %y
  ret i32 %r
}
=>
define i32 @tgt(i32 %x, i32 %y) {
%0:
  %t0 = umin i32 %x, %y
  %r = sub nuw i32 %x, %t0
  ret i32 %r
}
Transformation seems to be correct!
2020-09-21 20:25:54 +03:00
Roman Lebedev
1bb7ab8c4a
[SCEV] Recognize @llvm.abs as smax(x, -x)
As per alive2 (ignoring undef):

----------------------------------------
define i32 @src(i32 %x, i1 %y) {
%0:
  %r = abs i32 %x, 0
  ret i32 %r
}
=>
define i32 @tgt(i32 %x, i1 %y) {
%0:
  %neg_x = mul i32 %x, 4294967295
  %r = smax i32 %x, %neg_x
  ret i32 %r
}
Transformation seems to be correct!

----------------------------------------
define i32 @src(i32 %x, i1 %y) {
%0:
  %r = abs i32 %x, 1
  ret i32 %r
}
=>
define i32 @tgt(i32 %x, i1 %y) {
%0:
  %neg_x = mul nsw i32 %x, 4294967295
  %r = smax i32 %x, %neg_x
  ret i32 %r
}
Transformation seems to be correct!
2020-09-21 20:25:53 +03:00
Florian Hahn
11dccf8d3a Recommit "[SCEV] Look through single value PHIs."
This commit was originally because it was suspected to cause a crash,
but a reproducer did not surface.

A crash that was exposed by this change was fixed in 1d8f2e52925b.

This reverts the revert commit 0581c0b0eeba03da590d1176a4580cf9b9e8d1e3.
2020-09-21 11:59:50 +01:00
Nikita Popov
445db89b53 [LVI] Get value range from mask comparison
InstCombine likes to canonicalize comparisons of the form
X == C || X == C+1 into (X & -2) == C'. Make sure LVI can still
recover the value range from this. Can of course also be useful
for proper mask comparisons.

For the sake of clarity, the implementation goes through KnownBits
to compute the range.
2020-09-20 21:13:57 +02:00
Nikita Popov
f94bbe19b6 [LVI] Refactor getValueFromICmpCondition (NFC)
Rewrite this in a way where the core logic is in a separate
function, that is invoked with swapped operands. This makes it
easier to add handling for additional icmp patterns.
2020-09-20 21:13:57 +02:00
Dávid Bolvanský
2990518b03 [MemLoc] Support lllvm.memcpy.inline in MemoryLocation::getForArgument
Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D87971
2020-09-20 14:01:48 +02:00
Fangrui Song
6913812abc Fix some clang-tidy bugprone-argument-comment issues 2020-09-19 20:41:25 -07:00
Dávid Bolvanský
d716f1608c [MemLoc] Support bcmp in MemoryLocation::getForArgument
Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D87964
2020-09-19 17:12:43 +02:00
Sanjay Patel
f74a334fe3 [ConstantFolding] add undef handling for fmin/fmax intrinsics
The output here may not be optimal (yet), but it should be
consistent for commuted operands (it was not before) and
correct. We can do better by checking FMF and NaN if needed.

Code in InstSimplify generally assumes that we have already
folded code like this, so it was not handling 2 constant
inputs by commuting consistently.
2020-09-19 10:31:01 -04:00
Andrew Litteken
132aaec4f2 [IRSim] Adding ilist for IRInstructionData.
The IRInstructionData structs are a different representation of the
program.  This list treats the program as if it was "flattened" and
the only parent is this list.  This lets us easily create ranges of
instructions.

Differential Revision: https://reviews.llvm.org/D86969
2020-09-19 00:18:39 -05:00
Vitaly Buka
97bfac076a [NFC][StackSafety] Replace auto with type
Fixes static analyzer is warning.
2020-09-18 17:10:28 -07:00
Sanjay Patel
3f100e64b4 [InstSimplify] fix fmin/fmax miscompile for partial undef vectors (PR47567)
It would also be correct to return the variable operand in these cases,
but eliminating a variable use is probably better for optimization.
2020-09-18 10:05:44 -04:00
Florian Hahn
4635f6050b [SCEV] Generalize SCEVParameterRewriter to accept SCEV expression as target.
This patch extends SCEVParameterRewriter to support rewriting unknown
epxressions to arbitrary SCEV expressions. It will be used by further
patches.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D67176
2020-09-18 10:05:02 +01:00
Andrew Litteken
7e4c6fb854 [IRSim] Adding IR Instruction Mapper
This introduces the IRInstructionMapper, and the associated wrapper for
instructions, IRInstructionData, that maps IR level Instructions to
unsigned integers.

Mapping is done mainly by using the "isSameOperationAs" comparison
between two instructions.  If they return true, the opcode, result type,
and operand types of the instruction are used to hash the instruction
with an unsigned integer.  The mapper accepts instruction ranges, and
adds each resulting integer to a list, and each wrapped instruction to
a separate list.

At present, branches, phi nodes are not mapping and exception handling
is illegal.  Debug instructions are not considered.

The different mapping schemes are tested in
unittests/Analysis/IRSimilarityIdentifierTest.cpp

Recommit of: b04c1a9d3127730c05e8a22a0e931a12a39528df

Differential Revision: https://reviews.llvm.org/D86968
2020-09-17 14:06:16 -05:00
Mikael Holmen
bb037c2a76 [ConstraintSystem] Remove local variable that is set but not read [NFC]
gcc 7.4 warns about it.
2020-09-17 14:26:48 +02:00
Sjoerd Meijer
6637d72ddd [Lint] Add check for intrinsic get.active.lane.mask
As @efriedma pointed out in D86301, this "not equal to 0 check" of
get.active.lane.mask's second operand needs to live here in Lint and not the
Verifier.

Differential Revision: https://reviews.llvm.org/D87228
2020-09-17 09:22:03 +01:00
Stella Stamenova
a895040eb0 Revert "[IRSim] Adding IR Instruction Mapper"
This reverts commit b04c1a9d3127730c05e8a22a0e931a12a39528df.
2020-09-16 20:00:43 -07:00
Andrew Litteken
b04c1a9d31 [IRSim] Adding IR Instruction Mapper
This introduces the IRInstructionMapper, and the associated wrapper for
instructions, IRInstructionData, that maps IR level Instructions to
unsigned integers.

Mapping is done mainly by using the "isSameOperationAs" comparison
between two instructions.  If they return true, the opcode, result type,
and operand types of the instruction are used to hash the instruction
with an unsigned integer.  The mapper accepts instruction ranges, and
adds each resulting integer to a list, and each wrapped instruction to
a separate list.

At present, branches, phi nodes are not mapping and exception handling
is illegal.  Debug instructions are not considered.

The different mapping schemes are tested in
unittests/Analysis/IRSimilarityIdentifierTest.cpp

Differential Revision: https://reviews.llvm.org/D86968
2020-09-16 20:49:21 -05:00
Arthur Eubanks
f4ea0f9814 [NewPM] Port -print-alias-sets to NPM
Really it should be named print<alias-sets>, but for the sake of
changing fewer tests, added a TODO to rename after NPM switch and test
cleanup.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D87713
2020-09-16 18:34:56 -07:00
Alina Sbirlea
344a3d0bc0 [MemorySSA] Rename uses in blocks with Phis.
Renaming should include blocks with existing Phis.

Resolves PR45927.

Differential Revision: https://reviews.llvm.org/D87661
2020-09-16 17:24:17 -07:00
Nikita Popov
0bb06f297f [InstSimplify] Clarify SimplifyWithOpReplaced() return value
If SimplifyWithOpReplaced() cannot simplify the value, null should
be returned. Make sure this really does happen in all cases,
including those where SimplifyBinOp() returns the original value.

This does not matter for existing users, but does mattter for
D87480, which would go into an infinite loop otherwise.
2020-09-16 20:53:26 +02:00