When rewriting loop exit values, IndVars considers this transform not profitable if
the loop instruction has a loop user which it believes cannot be optimized away.
In current implementation only calls that immediately use the instruction are considered
as such.
This patch extends the definition of "hard" users to any side-effecting instructions
(which usually cannot be optimized away from the loop) and also allows handling
of not just immediate users, but use chains.
Differentlai Revision: https://reviews.llvm.org/D51584
Reviewed By: etherzhhb
llvm-svn: 345814
When we calculate a product of 2 AddRecs, we end up making quite massive
computations to deduce the operands of resulting AddRec. This process can
be optimized by computing all args of intermediate sum and then calling
`getAddExpr` once rather than calling `getAddExpr` with intermediate
result every time a new argument is computed.
Differential Revision: https://reviews.llvm.org/D53189
Reviewed By: rtereshin
llvm-svn: 345813
Correct costings of SK_ExtractSubvector requires the SubTy argument to indicate the type/size of the extracted subvector.
Unlike the rest of the shuffle kinds this means that the main Ty argument represents the source vector type not the destination!
I've done my best to fix a number of vectorizer uses:
SLP - the reduction epilogue costs should be using a SK_PermuteSingleSrc shuffle as these all occur at the hardware vector width - we're not extracting (illegal) subvector types. This is causing the cost model diffs as SK_ExtractSubvector costs are poorly handled and tend to just return 1 at the moment.
LV - I'm not clear on what the SK_ExtractSubvector should represents for recurrences - I've used a <1 x ?> subvector extraction as that seems to match the VF delta.
Differential Revision: https://reviews.llvm.org/D53573
llvm-svn: 345617
Sub, SDiv and UDiv are not commutative, so only the RHS operand can fold a
load. This patch adds a check for this.
Review: Ulrich Weigand
https://reviews.llvm.org/D53791
llvm-svn: 345596
The SystemZ backend can do arithmetic of memory by loading and then extending
one of the operands. Similarly, a load + truncate can be folded into an
operand.
This patch improves the SystemZ TTI cost function to recognize this.
Review: Ulrich Weigand
https://reviews.llvm.org/D52692
llvm-svn: 345327
Enable the DAG optimization that converts vector div/rem with constants into
multiply+shifts sequences by expanding them early. This is needed since
ISD::SMUL_LOHI is 'Custom' lowered on SystemZ, and will therefore not be
available to BuildSDIV after legalization.
Better cost values for these instructions based on how they will be
implemented (a constant divisor is cheaper).
Review: Ulrich Weigand
https://reviews.llvm.org/D53196
llvm-svn: 345321
Non-uniform division/remainder handling was added back at D49248/D50765 - so share the 'mul+sub' costs that already exist for uniform cases.
llvm-svn: 345164
Summary:
Teach vectorizer about vectorizing variant value stores to uniform
address. Similar to rL343028, we do not allow vectorization if we have
multiple stores to the same uniform address.
Cost model already has the change for considering the extract
instruction cost for a variant value store. See added test cases for how
vectorization is done.
The patch also contains changes to the ORE messages.
Reviewers: Ayal, mkuper, anemet, hsaito
Subscribers: rkruppe, llvm-commits
Differential Revision: https://reviews.llvm.org/D52656
llvm-svn: 344613
SCEV's transform that turns `{A1,+,A2,+,...,+,An}<L> * {B1,+,B2,+,...,+,Bn}<L>` into
a single AddRec of size `2n+1` with complex combinatorial coefficients can easily
trigger exponential growth of the SCEV (in case if nothing gets folded and simplified).
We tried to restrain this transform using the option `scalar-evolution-max-add-rec-size`,
but its default value seems to be insufficiently small: the test attached to this patch
with default value of this option `16` has a SCEV of >3M symbols (when printed out).
This patch reduces the simplification limit. It is not a cure to combinatorial
explosions, but at least it reduces this corner case to something more or less
reasonable.
Differential Revision: https://reviews.llvm.org/D53282
Reviewed By: sanjoy
llvm-svn: 344584
Until mischeduler is clever enough to avoid spilling in a vectorized loop
with many (scalar) DLRs it is better to avoid high vectorization factors (8
and above).
llvm-svn: 344129
A new function getNumVectorRegs() is better to use for the number of needed
vector registers instead of getNumberOfParts(). This is to make sure that the
number of vector registers (and typically operations) required for a vector
type is accurate.
getNumberOfParts() which was previously used works by splitting the vector
type until it is legal gives incorrect results for types with a non
power of two number of elements (rare).
A new static function getScalarSizeInBits() that also checks for a pointer
type and returns 64U for it since otherwise it gets a value of 0). Used in a
few places where Ty may be pointer.
Review: Ulrich Weigand
llvm-svn: 344115
This is the third patch in a series intended to make
https://reviews.llvm.org/D44748 more easily reviewable. Please see that
patch for more context. The second being r344013.
The intent is to make the output of printing a LocationSize more
precise. The main motivation for this is that we plan to add a bit to
distinguish whether a given LocationSize is an upper-bound or is
precise; making that information available in pretty-printing is nice.
llvm-svn: 344108
Summary:
We are overly conservative in loop vectorizer with respect to stores to loop
invariant addresses.
More details in https://bugs.llvm.org/show_bug.cgi?id=38546
This is the first part of the fix where we start with vectorizing loop invariant
values to loop invariant addresses.
This also includes changes to ORE for stores to invariant address.
Reviewers: anemet, Ayal, mkuper, mssimpso
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50665
llvm-svn: 343028
After recent improvements which makes better use of LOC instead of IPM, the
TTI cost functions also needs to be updated to reflect this.
This involves sext, zext and xor of i1.
The tests were updated so that for z13 the new costs are expected, while the
old costs are still checked for on zEC12.
Review: Ulrich Weigand
https://reviews.llvm.org/D51339
llvm-svn: 342207
This patch does the following things:
1. update SymbolicallyEvaluateGEP so that it bails out if it cannot preserve inrange arribute;
2. update llvm/test/Analysis/ConstantFolding/gep.ll to remove UB in it;
3. remove inaccurate comment above ConstantFoldInstOperandsImpl in llvm/lib/Analysis/ConstantFolding.cpp;
4. add a new regression test that makes sure that no optimizations change an inrange GEP in an unexpected way.
Patch by Zhaomo Yang!
Differential Revision: https://reviews.llvm.org/D51698
llvm-svn: 341888
The only point to this change is the test diffs. When I remove this code entirely (in favor of the recently added generic handling), I don't want there to be any confusion due to spurious test diffs.
As an aside, the fact out tests are AST construction order dependent is not great. I thought about fixing that, but the reasonable schemes I might want (e.g. sort by name) need the test diffs anyways.
Philip
llvm-svn: 341841
There were two combines not covered by the check before now, neither of which
actually differed from normal in the benefit analysis.
The most recent seems to be because it was just added at the top of the
function (naturally). The older is from way back in 2008 (r46687) when we just
didn't put those checks in so routinely, and has been diligently maintained
since.
llvm-svn: 341831
AliasSetTracker has special case handling for memset, memcpy and memmove which pre-existed argmemonly on functions and readonly and writeonly on arguments. This patch generalizes it using the AA infrastructure to any call correctly annotated.
The motivation here is to cut down on confusion, not performance per se. For most instructions, there is a direct mapping to alias set. However, this is not guaranteed by the interface and was not in fact true for these three intrinsics *and only these three intrinsics*. I kept getting myself confused about this invariant, so I figured it would be good to clearly distinguish between a instructions and alias sets. Calls happened to be an easy target.
The nice side effect is that custom implementations of memset/memcpy/memmove - including wrappers discovered by IPO - can now be optimized the same as builts by LICM.
Note: The actual removal of the memset/memtransfer specific handling will happen in a follow on NFC patch. It was originally part of this one, but separate for ease of review and rebase.
Differential Revision: https://reviews.llvm.org/D50730
llvm-svn: 341713
Summary:
This is patch 1 of the new DivergenceAnalysis (https://reviews.llvm.org/D50433).
The purpose of this patch is to free up the name DivergenceAnalysis for the new generic
implementation. The generic implementation class will be shared by specialized
divergence analysis classes.
Patch by: Simon Moll
Reviewed By: nhaehnle
Subscribers: jvesely, jholewinski, arsenm, nhaehnle, mgorny, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D50434
Change-Id: Ie8146b11be2c50d5312f30e11c7a3036a15b48cb
llvm-svn: 341071
This patch issues an error message if Darwin ABI is attempted with the PPC
backend. It also cleans up existing test cases, either converting the test to
use an alternative triple or removing the test if the coverage is no longer
needed.
Updated Tests
-------------
The majority of test cases were updated to use a different triple that does not
include the Darwin ABI. Many tests were also updated to use FileCheck, in place
of grep.
Deleted Tests
-------------
llvm/test/tools/dsymutil/PowerPC/sibling.test was originally added to test
specific functionality of dsymutil using an object file created with an old
version of llvm-gcc for a Powerbook G4. After a discussion with @JDevlieghere he
suggested removing the test.
llvm/test/CodeGen/PowerPC/combine_loads_from_build_pair.ll was converted from a
PPC test to a SystemZ test, as the behavior is also reproducible there.
All other tests that were deleted were specific to the darwin/ppc ABI and no
longer necessary.
Phabricator Review: https://reviews.llvm.org/D50988
llvm-svn: 340795
Summary: This was inheriting the cost from the AVX table, but should be legal under AVX512.
Reviewers: RKSimon
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51267
llvm-svn: 340708
The way that PhiValues is integrated with BasicAA it is possible for a pass
which uses BasicAA to pick up an instance of BasicAA that uses PhiValues without
intending to, and then delete values from a function in a way that causes
PhiValues to return dangling pointers to these deleted values. Fix this by
having a set of callback value handles to invalidate values when they're
deleted.
llvm-svn: 340613
These changes expand the FunctionAttr logic in order to mark functions as
WriteOnly when appropriate. This is done through an additional bool variable
and extended logic.
Reviewers: hfinkel, jdoerfert
Differential Revision: https://reviews.llvm.org/D48387
llvm-svn: 340537
In general we can't assume flat loads are uniform, and cases where we can prove
they are should be handled through infer-address-spaces.
Differential Revision: https://reviews.llvm.org/D50991
llvm-svn: 340343
Volatility is not an aliasing property. We used to model volatile as if it had extremely conservative aliasing implications, but that hasn't been true for several years now. So, it doesn't make sense to be in AliasSet.
It also turns out the code is entirely a noop. Outside of the AST code to update it, there was only one user: load store promotion in LICM. L/S promotion doesn't need the check since it walks all the users of the address anyway. It already checks each load or store via !isUnordered which causes us to bail for volatile accesses. (Look at the lines immediately following the two remove asserts.)
There is the possibility of some small compile time impact here, but the only case which will get noticeably slower is a loop with a large number of loads and stores to the same address where only the last one we inspect is volatile. This is sufficiently rare it's not worth optimizing for..
llvm-svn: 340312
This is another step towards being able to canonicalize to the funnel shift
intrinsics in IR (see D49242 for the initial patch).
We should not have any loss of simplification power in IR between these and
the equivalent IR constructs.
Differential Revision: https://reviews.llvm.org/D50848
llvm-svn: 340022
