Commit Graph

175 Commits

Author SHA1 Message Date
Tim Shen a0757d8ebd Patch by @wecing (Chenguang Wang).
The current getFoldedSizeOf() implementation uses naive recursion, which
could be really slow when the input structure type is too complex.

This issue was first brought up in
http://llvm.org/bugs/show_bug.cgi?id=8281; this change fixes it by
adding memoization.

Differential Revision: https://reviews.llvm.org/D6594
2021-02-19 12:44:17 -08:00
Juneyoung Lee 06829034ca Revert "[ConstantFold] Fold more operations to poison"
This reverts commit 53040a968d due to its
bad interaction with select i1 -> and/or i1 transformation.

This fixes:
https://bugs.llvm.org/show_bug.cgi?id=49005
https://bugs.llvm.org/show_bug.cgi?id=48435
2021-02-04 00:24:02 +09:00
Juneyoung Lee 29f8628d1f [Constant] Add containsPoisonElement
This patch

- Adds containsPoisonElement that checks existence of poison in constant vector elements,
- Renames containsUndefElement to containsUndefOrPoisonElement to clarify its behavior & updates its uses properly

With this patch, isGuaranteedNotToBeUndefOrPoison's tests w.r.t constant vectors are added because its analysis is improved.

Thanks!

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D94053
2021-01-06 12:10:33 +09:00
Luo, Yuanke 981a0bd858 [X86] Add x86_amx type for intel AMX.
The x86_amx is used for AMX intrisics. <256 x i32> is bitcast to x86_amx when
it is used by AMX intrinsics, and x86_amx is bitcast to <256 x i32> when it
is used by load/store instruction. So amx intrinsics only operate on type x86_amx.
It can help to separate amx intrinsics from llvm IR instructions (+-*/).
Thank Craig for the idea. This patch depend on https://reviews.llvm.org/D87981.

Differential Revision: https://reviews.llvm.org/D91927
2020-12-30 13:52:13 +08:00
Juneyoung Lee 9c49dcc356 [ConstantFold] Don't fold and/or i1 poison to poison (NFC)
.. because it causes miscompilation when combined with select i1 -> and/or.

It is the select fold which is incorrect; but it is costly to disable the fold, so hack this one.

D92270
2020-11-30 22:58:31 +09:00
Juneyoung Lee 53040a968d [ConstantFold] Fold more operations to poison
This patch folds more operations to poison.

Alive2 proof: https://alive2.llvm.org/ce/z/mxcb9G (it does not contain tests about div/rem because they fold to poison when raising UB)

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D92270
2020-11-29 21:19:48 +09:00
Juneyoung Lee c6b62efb91 [ConstantFold] Fold operations to poison if possible
This patch updates ConstantFold, so operations are folded into poison if possible.

<alive2 proofs>
casts: https://alive2.llvm.org/ce/z/WSj7rw
binary operations (arithmetic): https://alive2.llvm.org/ce/z/_7dEyJ
binary operations (bitwise): https://alive2.llvm.org/ce/z/cezjVN
vector/aggregate operations: https://alive2.llvm.org/ce/z/BQ7hWz
unary ops: https://alive2.llvm.org/ce/z/yBRs4q
other ops: https://alive2.llvm.org/ce/z/iXbcFD

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D92203
2020-11-29 02:28:40 +09:00
Christopher Tetreault 792f8e1114 [SVE] Take constant fold fast path for splatted vscale vectors
This should be a perfectly reasonable operation for scalable vectors.
Currently, it only works for zeroinitializer values of
ScalableVectorType, but the fundamental operation is sound and it should
be possible to make it work for other splats

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D77442
2020-11-17 12:45:31 -08:00
Shimin Cui 95bda510fb [ConstantFold] Fold the comparison of bitcasted global values
This is to simplify icmp instructions in the form like:

%cmp = icmp eq i32 (i8*, i8*)* bitcast (i32 (i32**, i32**)* @f32 to i32
%(i8*, i8*)), bitcast (i32 (i64**, i64**) @f64 to i32 (i8*, i8*)*)

Here @f32 and @f64 are two functions.

Differential Revision: https://reviews.llvm.org/D87850
2020-10-20 12:41:49 -07:00
Eli Friedman d751f86189 [ConstantFold] Make areGlobalsPotentiallyEqual less aggressive.
In particular, we shouldn't make assumptions about globals which are
unnamed_addr: we can fold them together with other globals.

Also while I'm here, use isInterposable() instead of trying to
explicitly name all the different kinds of weak linkage.

Fixes https://bugs.llvm.org/show_bug.cgi?id=47090

Differential Revision: https://reviews.llvm.org/D87123
2020-09-11 17:23:08 -07:00
Eli Friedman 37f2776d1a [ConstantFold] Fold binary arithmetic on scalable vector splats.
It's a nice simplification, and it confuses instcombine if we don't do
it.

Differential Revision: https://reviews.llvm.org/D87422
2020-09-11 16:41:58 -07:00
David Sherwood f4257c5832 [SVE] Make ElementCount members private
This patch changes ElementCount so that the Min and Scalable
members are now private and can only be accessed via the get
functions getKnownMinValue() and isScalable(). In addition I've
added some other member functions for more commonly used operations.
Hopefully this makes the class more useful and will reduce the
need for calling getKnownMinValue().

Differential Revision: https://reviews.llvm.org/D86065
2020-08-28 14:43:53 +01:00
Mehdi Amini a407ec9b6d Revert "Revert "[NFC][llvm] Make the contructors of `ElementCount` private.""
Was reverted because MLIR/Flang builds were broken, these APIs have been
fixed in the meantime.
2020-08-19 17:26:36 +00:00
Mehdi Amini 4fc56d70aa Revert "[NFC][llvm] Make the contructors of `ElementCount` private."
This reverts commit 264afb9e6a.
(and dependent 6b742cc48 and fc53bd610f)

MLIR/Flang are broken.
2020-08-19 17:21:37 +00:00
Francesco Petrogalli 264afb9e6a [NFC][llvm] Make the contructors of `ElementCount` private.
Differential Revision: https://reviews.llvm.org/D86120
2020-08-19 16:26:44 +00:00
Arthur Eubanks 41f49736a9 [ConstProp] Handle insertelement constants
Previously ConstantFoldExtractElementInstruction() would only work with
insertelement instructions, not contants. This properly handles
insertelement constants as well.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D85865
2020-08-13 15:59:17 -07:00
Craig Topper a7a06ded8b Recommit "[InstSimplify] Remove select ?, undef, X -> X and select ?, X, undef -> X transforms" and its follow up patches
This recommits the following patches now that D85684 has landed

1cf6f210a2 [IR] Disable select ? C : undef -> C fold in ConstantFoldSelectInstruction unless we know C isn't poison.
469da663f2 [InstSimplify] Re-enable select ?, undef, X -> X transform when X is provably not poison
122b0640fc [InstSimplify] Don't fold vectors of partial undef in SimplifySelectInst if the non-undef element value might produce poison
ac0af12ed2 [InstSimplify] Add test cases for opportunities to fold select ?, X, undef -> X when we can prove X isn't poison
9b1e95329a [InstSimplify] Remove select ?, undef, X -> X and select ?, X, undef -> X transforms
2020-08-12 10:45:27 -07:00
Craig Topper 00f3579aea Revert "[InstSimplify] Remove select ?, undef, X -> X and select ?, X, undef -> X transforms" and subsequent patches
This reverts most of the following patches due to reports of miscompiles.
I've left the added test cases with comments updated to be FIXMEs.

1cf6f210a2 [IR] Disable select ? C : undef -> C fold in ConstantFoldSelectInstruction unless we know C isn't poison.
469da663f2 [InstSimplify] Re-enable select ?, undef, X -> X transform when X is provably not poison
122b0640fc [InstSimplify] Don't fold vectors of partial undef in SimplifySelectInst if the non-undef element value might produce poison
ac0af12ed2 [InstSimplify] Add test cases for opportunities to fold select ?, X, undef -> X when we can prove X isn't poison
9b1e95329a [InstSimplify] Remove select ?, undef, X -> X and select ?, X, undef -> X transforms
2020-07-15 22:02:33 -07:00
Craig Topper 1cf6f210a2 [IR] Disable select ? C : undef -> C fold in ConstantFoldSelectInstruction unless we know C isn't poison.
This matches the recent change to InstSimplify from D83440.

Differential Revision: https://reviews.llvm.org/D83535
2020-07-10 10:42:25 -07:00
David Sherwood ee26a31e7b [SVE] Make ConstantFoldGetElementPtr work for scalable vectors of indices
This patch fixes a compiler crash that was hit when trying to simplify
the following code:

getelementptr [2 x i64], [2 x i64]* null, i64 0, <vscale x 2 x i64> zeroinitializer

For the case where we have a null pointer value like above, we just
need to ensure we don't assume the indices are always fixed width.

Differential Revision: https://reviews.llvm.org/D82183
2020-06-25 07:28:19 +01:00
Eli Friedman a2caa3b614 Remove GlobalValue::getAlignment().
This function is deceptive at best: it doesn't return what you'd expect.
If you have an arbitrary GlobalValue and you want to determine the
alignment of that pointer, Value::getPointerAlignment() returns the
correct value.  If you want the actual declared alignment of a function
or variable, GlobalObject::getAlignment() returns that.

This patch switches all the users of GlobalValue::getAlignment to an
appropriate alternative.

Differential Revision: https://reviews.llvm.org/D80368
2020-06-23 19:13:42 -07:00
Christopher Tetreault 8819202dfd [SVE] Eliminate bad VectorType::getNumElements() calls from ConstantFold
Summary:
Assume all usages of this function are explicitly fixed-width operations
and cast to FixedVectorType

Reviewers: efriedma, sdesmalen, c-rhodes, majnemer, dblaikie

Reviewed By: sdesmalen

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80262
2020-06-17 14:19:56 -07:00
Christopher Tetreault 900f78a714 [SVE] Eliminate calls to default-false VectorType::get() from IR
Reviewers: efriedma, kmclaughlin, sdesmalen, dexonsmith, dblaikie

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80261
2020-06-03 13:56:45 -07:00
Eli Friedman f26bdb539e Make Value::getPointerAlignment() return an Align, not a MaybeAlign.
If we don't know anything about the alignment of a pointer, Align(1) is
still correct: all pointers are at least 1-byte aligned.

Included in this patch is a bugfix for an issue discovered during this
cleanup: pointers with "dereferenceable" attributes/metadata were
assumed to be aligned according to the type of the pointer.  This
wasn't intentional, as far as I can tell, so Loads.cpp was fixed to
stop making this assumption. Frontends may need to be updated.  I
updated clang's handling of C++ references, and added a release note for
this.

Differential Revision: https://reviews.llvm.org/D80072
2020-05-20 16:37:20 -07:00
Christopher Tetreault 3ecced163f [SVE] Remove calls to isScalable from IR
Reviewers: efriedma, sdesmalen, dexonsmith, dblaikie

Reviewed By: sdesmalen

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77691
2020-04-23 11:51:22 -07:00
Christopher Tetreault 5f07dcd23c [SVE] Remove calls to getBitWidth from IR
Reviewers: efriedma, sdesmalen, RKSimon, majnemer

Reviewed By: majnemer

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77897
2020-04-14 13:44:10 -07:00
Christopher Tetreault 40ed21bb71 Clean up usages of asserting vector getters in Type
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.

Reviewers: dexonsmith, sdesmalen, efriedma

Reviewed By: efriedma

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77276
2020-04-10 14:18:47 -07:00
Eli Friedman 68b03aee1a Remove SequentialType from the type heirarchy.
Now that we have scalable vectors, there's a distinction that isn't
getting captured in the original SequentialType: some vectors don't have
a known element count, so counting the number of elements doesn't make
sense.

In some cases, there's a better way to express the commonality using
other methods. If we're dealing with GEPs, there's GEP methods; if we're
dealing with a ConstantDataSequential, we can query its element type
directly.

In the relatively few remaining cases, I just decided to write out
the type checks. We're talking about relatively few places, and I think
the abstraction doesn't really carry its weight. (See thread "[RFC]
Refactor class hierarchy of VectorType in the IR" on llvmdev.)

Differential Revision: https://reviews.llvm.org/D75661
2020-04-06 17:03:49 -07:00
Eli Friedman 1ee6ec2bf3 Remove "mask" operand from shufflevector.
Instead, represent the mask as out-of-line data in the instruction. This
should be more efficient in the places that currently use
getShuffleVector(), and paves the way for further changes to add new
shuffles for scalable vectors.

This doesn't change the syntax in textual IR. And I don't currently plan
to change the bitcode encoding in this patch, although we'll probably
need to do something once we extend shufflevector for scalable types.

I expect that once this is finished, we can then replace the raw "mask"
with something more appropriate for scalable vectors.  Not sure exactly
what this looks like at the moment, but there are a few different ways
we could handle it.  Maybe we could try to describe specific shuffles.
Or maybe we could define it in terms of a function to convert a fixed-length
array into an appropriate scalable vector, using a "step", or something
like that.

Differential Revision: https://reviews.llvm.org/D72467
2020-03-31 13:08:59 -07:00
Thomas Raoux 3ea0774b13 [ConstantFold][NFC] Compile time optimization for large vectors
Optimize the common case of splat vector constant. For large vector
going through all elements is expensive. For splatr/broadcast cases we
can skip going through all elements.

Differential Revision: https://reviews.llvm.org/D76664
2020-03-30 11:27:09 -07:00
Eli Friedman e24e95fe90 Remove CompositeType class.
The existence of the class is more confusing than helpful, I think; the
commonality is mostly just "GEP is legal", which can be queried using
APIs on GetElementPtrInst.

Differential Revision: https://reviews.llvm.org/D75660
2020-03-18 13:53:17 -07:00
Huihui Zhang f4f2706572 [ConstantFold][SVE] Fix constant folding for scalable vector compare instruction.
Summary:
Do not iterate on scalable vector. Also do not return constant scalable vector
from ConstantInt::get().
Fix result type by using getElementCount() instead of getNumElements().

Reviewers: sdesmalen, efriedma, apazos, huntergr, willlovett

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73753
2020-03-12 16:15:38 -07:00
Huihui Zhang 118abf2017 [SVE] Update API ConstantVector::getSplat() to use ElementCount.
Summary:
Support ConstantInt::get() and Constant::getAllOnesValue() for scalable
vector type, this requires ConstantVector::getSplat() to take in 'ElementCount',
instead of 'unsigned' number of element count.

This change is needed for D73753.

Reviewers: sdesmalen, efriedma, apazos, spatel, huntergr, willlovett

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, cfe-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74386
2020-03-12 13:22:41 -07:00
Sanjay Patel d799190851 [ConstantFold] fold fsub -0.0, undef to undef rather than NaN
A question about this behavior came up on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139003.html
...and as part of backend improvements in D73978, but this is an IR
change first because we already have fairly thorough tests in place
here.

We decided not to implement a more general change that would have
folded any FP binop with nearly arbitrary constant + undef operand
to undef because that is not theoretically correct (even if it is
practically correct).

Differential Revision: https://reviews.llvm.org/D74713
2020-02-21 08:03:19 -05:00
Huihui Zhang 801857c59e [ConstantFold][SVE] Fix constant folding for bitcast.
Do not iterate on scalable vector type in BitCastConstantVector.
Continuation work of D70985, D71147.

Support for folding bitcast into splat value is kept in D74095, as
it depends on D71637.

Differential Revision: https://reviews.llvm.org/D71389
2020-02-05 15:39:57 -08:00
Christopher Tetreault b03f3fbd6a Reapply: [SVE] Fix bug in simplification of scalable vector instructions
This reverts commit a05441038a, reapplying
commit 31574d38ac
2020-02-05 10:00:09 -08:00
Reid Kleckner a05441038a Revert "[SVE] Fix bug in simplification of scalable vector instructions"
This reverts commit 31574d38ac.

The newly added shufflevector test does not pass locally on either of my
workstations.
2020-02-03 11:12:09 -08:00
Christopher Tetreault 31574d38ac [SVE] Fix bug in simplification of scalable vector instructions
Summary:
* Most of the simplifications in SimplifyShuffleVectorInst depend on the
concrete value of, or the length of the mask vector. For scalable
vectors, this cannot be known at compile time.
** for these tests, detect if the vector is scalable before attempting
the transformation
* The functions ShuffleVectorInst::getMaskValue and
ShuffleVectorInst::getShuffleMask access the value of the constant mask.
However, since the length of the mask is unknown at compile time, these
function do not work for scalable vectors. Add asserts to ensure that
the input mask is not scalable

Reviewers: efriedma, sdesmalen, apazos, chrisj, huihuiz

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73555
2020-02-03 10:15:56 -08:00
Huihui Zhang 34e6552dcb [ConstantFold][SVE] Fix constant folding for scalable vector unary operations.
Summary:
Similar to issue D71445. Scalable vector should not be evaluated element by element.
Add support to handle scalable vector UndefValue.

Reviewers: sdesmalen, efriedma, apazos, huntergr, willlovett

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73678
2020-01-30 10:45:15 -08:00
Huihui Zhang d2e2fc450e [ConstantFold][SVE] Fix constant folding for scalable vector binary operations.
Summary:
Scalable vector should not be evaluated element by element.
Add support to handle scalable vector UndefValue.

Reviewers: sdesmalen, huntergr, spatel, lebedev.ri, apazos, efriedma, willlovett

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71445
2020-01-29 10:49:08 -08:00
Eli Friedman 7c69a03c56 [ConstantFold][SVE] Fix constant folding for shufflevector.
Don't try to fold away shuffles which can't be folded.  Fix creation of
shufflevector constant expressions.

Differential Revision: https://reviews.llvm.org/D71147
2019-12-09 15:31:50 -08:00
Huihui Zhang 381d3c5c45 [ConstantFold][SVE] Skip scalable vectors in ConstantFoldInsertElementInstruction.
Summary:
Should not constant fold insertelement instruction for scalable vector type.

Reviewers: huntergr, sdesmalen, spatel, levedev.ri, apazos, efriedma, willlovett

Reviewed By: efriedma, spatel

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70985
2019-12-05 19:43:19 -08:00
Florian Hahn 8eeabbaf5d [ConstantFold] Handle identity folds at top of ConstantFoldBinaryInst
Currently we miss folds with undef and identity values for binary ops
that do not fold to undef in general.

We can generalize the identity simplifications and do them before
checking for undef in particular.

Alive checks:
 * OR - https://rise4fun.com/Alive/8OsK
 * AND - https://rise4fun.com/Alive/e3tE

This will also allow us to remove some now redundant cases throughout
the function, but I would like to do this as follow-up. That should make
tracking down potential issues easier.

Reviewers: spatel, RKSimon, lebedev.ri

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D70169
2019-11-17 21:30:14 +00:00
aqjune e87d71668e [IR] Redefine Freeze instruction
Summary:
This patch redefines freeze instruction from being UnaryOperator to a subclass of UnaryInstruction.

ConstantExpr freeze is removed, as discussed in the previous review.
FreezeOperator is not added because there's no ConstantExpr freeze.
`freeze i8* null` test is added to `test/Bindings/llvm-c/freeze.ll` as well, because the null pointer-related bug in `tools/llvm-c/echo.cpp` is now fixed.
InstVisitor has visitFreeze now because freeze is not unaryop anymore.

Reviewers: whitequark, deadalnix, craig.topper, jdoerfert, lebedev.ri

Reviewed By: craig.topper, lebedev.ri

Subscribers: regehr, nlopes, mehdi_amini, hiraditya, steven_wu, dexonsmith, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69932
2019-11-12 10:49:00 +09:00
aqjune 92ef101da9 [IR] Remove switch's default block that causes clang 8 raise error 2019-11-05 16:31:51 +09:00
aqjune 58acbce3de [IR] Add Freeze instruction
Summary:
- Define Instruction::Freeze, let it be UnaryOperator
- Add support for freeze to LLLexer/LLParser/BitcodeReader/BitcodeWriter
  The format is `%x = freeze <ty> %v`
- Add support for freeze instruction to llvm-c interface.
- Add m_Freeze in PatternMatch.
- Erase freeze when lowering IR to SelDag.

Reviewers: deadalnix, hfinkel, efriedma, lebedev.ri, nlopes, jdoerfert, regehr, filcab, delcypher, whitequark

Reviewed By: lebedev.ri, jdoerfert

Subscribers: jfb, kristof.beyls, hiraditya, lebedev.ri, steven_wu, dexonsmith, xbolva00, delcypher, spatel, regehr, trentxintong, vsk, filcab, nlopes, mehdi_amini, deadalnix, llvm-commits

Differential Revision: https://reviews.llvm.org/D29011
2019-11-05 15:54:56 +09:00
Jay Foad dc63d6175a [ConstantFold] Push extractelement into getelementptr's operands
This fixes a minor oversight mentioned in the review of D69379:
we should push extractelement into the operands of getelementptr
regardless of whether that enables further folding.
2019-10-29 10:31:52 +00:00
Jay Foad 843c0adf0f [ConstantFold] Fold extractelement of getelementptr
Summary:
Getelementptr has vector type if any of its operands are vectors
(the scalar operands being implicitly broadcast to all vector elements).
Extractelement applied to a vector getelementptr can be folded by
applying the extractelement in turn to all of the vector operands.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69379
2019-10-28 18:32:39 +00:00
Guillaume Chatelet bae629b966 [Alignment][NFC] Value::getPointerAlignment returns MaybeAlign
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet, jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68398

llvm-svn: 374889
2019-10-15 13:58:22 +00:00
Sanjay Patel b32e4664a7 [ConstantFold] fix inconsistent handling of extractelement with undef index (PR42689)
Any constant other than zero was already folded to undef if the index is undef.
https://bugs.llvm.org/show_bug.cgi?id=42689

llvm-svn: 374729
2019-10-13 17:34:08 +00:00