This patch fixes a regression caused by the operand reordering refactoring patch https://reviews.llvm.org/D59973 .
The fix changes the strategy to Splat instead of Opcode, if broadcast opportunities are found.
Please see the lit test for some examples.
Committed on behalf of @vporpo (Vasileios Porpodas)
Differential Revision: https://reviews.llvm.org/D62427
llvm-svn: 362613
Instead of passing around fast-math-flags as a parameter, we can set those
using an IRBuilder guard object. This is no-functional-change-intended.
The motivation is to eventually fix the vectorizers to use and set the
correct fast-math-flags for reductions. Examples of that not behaving as
expected are:
https://bugs.llvm.org/show_bug.cgi?id=23116 (should be able to reduce with less than 'fast')
https://bugs.llvm.org/show_bug.cgi?id=35538 (possible miscompile for -0.0)
D61802 (should be able to reduce with IR-level FMF)
Differential Revision: https://reviews.llvm.org/D62272
llvm-svn: 362612
@jdoerfert Looks like these are placeholders for incoming abstract attributes patches so I've just commented the code out, even though this is usually frowned upon.
llvm-svn: 362592
This reverts commit 5b32f60ec31ce136edac6f693538aeb6039f4ad0.
The fix is in commit 4f9e68148bd0dada2d6997625432385918ac2e2c.
This patch fixes the CorrelatedValuePropagation pass to keep
prof branch_weights metadata of SwitchInst consistent.
It makes use of SwitchInstProfUpdateWrapper.
New tests are added.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D62126
llvm-svn: 362583
NOTE: Note that no attributes are derived yet. This patch will not go in
alone but only with others that derive attributes. The framework is
split for review purposes.
This commit introduces the Attributor pass infrastructure and fixpoint
iteration framework. Further patches will introduce abstract attributes
into this framework.
In a nutshell, the Attributor will update instances of abstract
arguments until a fixpoint, or a "timeout", is reached. Communication
between the Attributor and the abstract attributes that are derived is
restricted to the AbstractState and AbstractAttribute interfaces.
Please see the file comment in Attributor.h for detailed information
including design decisions and typical use case. Also consider the class
documentation for Attributor, AbstractState, and AbstractAttribute.
Reviewers: chandlerc, homerdin, hfinkel, fedor.sergeev, sanjoy, spatel, nlopes, nicholas, reames
Subscribers: mehdi_amini, mgorny, hiraditya, bollu, steven_wu, dexonsmith, dang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59918
llvm-svn: 362578
Summary:
Following the cleanup in D48202, method foldBlockIntoPredecessor has the
same behavior. Replace its uses with MergeBlockIntoPredecessor.
Remove foldBlockIntoPredecessor.
Reviewers: chandlerc, dmgreen
Subscribers: jlebar, javed.absar, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62751
llvm-svn: 362538
This patch fixes a problem that occurs in LowerSwitch when a switch statement has a PHI node as its condition, and the PHI node only has two incoming blocks, and one of those incoming blocks is through an unreachable default in the switch statement. When this condition occurs, LowerSwitch holds a pointer to the condition value, but removes the switch block as a predecessor of the PHI block, causing the PHI node to be replaced. LowerSwitch then tries to use its stale pointer to the original condition value, causing a crash.
Differential Revision: https://reviews.llvm.org/D62560
llvm-svn: 362427
Extract a willNotOverflow() helper function that is shared between
eliminateOverflowIntrinsic() and strengthenOverflowingOperation().
Use WithOverflowInst for the former.
We'll be able to reuse the same code for saturating intrinsics as
well.
llvm-svn: 362305
Fix for https://bugs.llvm.org/show_bug.cgi?id=31181 and partial fix
for LFTR poison handling issues in general.
When LFTR moves a condition from pre-inc to post-inc, it may now
depend on value that is poison due to nowrap flags. To avoid this,
we clear any nowrap flag that SCEV cannot prove for the post-inc
addrec.
Additionally, LFTR may switch to a different IV that is dynamically
dead and as such may be arbitrarily poison. This patch will correct
nowrap flags in some but not all cases where this happens. This is
related to the adoption of IR nowrap flags for the pre-inc addrec.
(See some of the switch_to_different_iv tests, where flags are not
dropped or insufficiently dropped.)
Finally, there are likely similar issues with the handling of GEP
inbounds, but we don't have a test case for this yet.
Differential Revision: https://reviews.llvm.org/D60935
llvm-svn: 362292
At the moment, LoopPredication completely bails out if it sees a latch of the form:
%cmp = icmp ne %iv, %N
br i1 %cmp, label %loop, label %exit
OR
%cmp = icmp ne %iv.next, %NPlus1
br i1 %cmp, label %loop, label %exit
This is unfortunate since this is exactly the form that LFTR likes to produce. So, go ahead and recognize simple cases where we can.
For pre-increment loops, we leverage the fact that LFTR likes canonical counters (i.e. those starting at zero) and a (presumed) range fact on RHS to discharge the check trivially.
For post-increment forms, the key insight is in remembering that LFTR had to insert a (N+1) for the RHS. CVP can hopefully prove that add nsw/nuw (if there's appropriate range on N to start with). This leaves us both with the post-inc IV and the RHS involving an nsw/nuw add, and SCEV can discharge that with no problem.
This does still need to be extended to handle non-one steps, or other harder patterns of variable (but range restricted) starting values. That'll come later.
Differential Revision: https://reviews.llvm.org/D62748
llvm-svn: 362282
When the object size argument is -1, no checking can be done, so calling the
_chk variant is unnecessary. We already did this for a bunch of these
functions.
rdar://50797197
Differential revision: https://reviews.llvm.org/D62358
llvm-svn: 362272
If we can determine that a saturating add/sub will not overflow based
on range analysis, convert it into a simple binary operation. This is
a sibling transform to the existing with.overflow handling.
Reapplying this with an additional check that the saturating intrinsic
has integer type, as LVI currently does not support vector types.
Differential Revision: https://reviews.llvm.org/D62703
llvm-svn: 362263
Noticed on D62703. LVI only handles plain integers, not vectors of
integers. This was previously not an issue, because vector support
for with.overflow is only a relatively recent addition.
llvm-svn: 362261
If we can determine that a saturating add/sub will not overflow
based on range analysis, convert it into a simple binary operation.
This is a sibling transform to the existing with.overflow handling.
Differential Revision: https://reviews.llvm.org/D62703
llvm-svn: 362242
It looks this fold was already partially happening, indirectly
via some other folds, but with one-use limitation.
No other fold here has that restriction.
https://rise4fun.com/Alive/ftR
llvm-svn: 362217
Previously, this used a statement like this:
Map[A] = Map[B];
This is equivalent to the following:
const auto &Src = Map[B];
auto &Dest = Map[A];
Dest = Src;
The second statement, "auto &Dest = Map[A];" can insert a new
element into the DenseMap, which can potentially grow and reallocate
the DenseMap's internal storage, which will invalidate the existing
reference to the source. When doing the actual assignment,
the Src reference is dereferenced, accessing memory that was
freed when the DenseMap grew.
This issue hasn't shown up when LLVM was built with Clang, because
the right hand side ended up dereferenced before evaulating the
left hand side. (If the value type is a larger data type, Clang doesn't
do this but behaves like GCC.)
With GCC, a cast to Value* isn't enough to make it dereference the
right hand side reference before invoking operator[] (while that is
enough to make Clang/LLVM do the right thing for larger types), but
storing it in an intermediate variable in a separate statement works.
This fixes PR42065.
Differential Revision: https://reviews.llvm.org/D62624
llvm-svn: 362150
When we switch to opaque pointer types we will need some way to describe
how many bytes a 'byval' parameter should occupy on the stack. This adds
a (for now) optional extra type parameter.
If present, the type must match the pointee type of the argument.
The original commit did not remap byval types when linking modules, which broke
LTO. This version fixes that.
Note to front-end maintainers: if this causes test failures, it's probably
because the "byval" attribute is printed after attributes without any parameter
after this change.
llvm-svn: 362128
VPlan.h already contains the declaration of VPlanPtr type alias:
using VPlanPtr = std::unique_ptr<VPlan>;
The LoopVectorizationPlanner class also contains the same declaration
of VPlanPtr and therefore LoopVectorize requires a long wording when
its methods return VPlanPtr:
LoopVectorizationPlanner::VPlanPtr
LoopVectorizationPlanner::buildVPlanWithVPRecipes(...)
but LoopVectorize.cpp includes VPlan.h (via LoopVectorizationPlanner.h)
and can use VPlanPtr from that header.
Patch by Pavel Samolysov.
Reviewers: hsaito, rengolin, fhahn
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D62576
llvm-svn: 362126
Summary:
I'm adding ORE to memset/memcpy formation, with tests,
but mainly this is split off from D61144.
Reviewers: reames, anemet, thegameg, craig.topper
Reviewed By: thegameg
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62631
llvm-svn: 362092
Currently, only the following information is provided by LoopVectorizer
in the case when the CF of the loop is not legal for vectorization:
LV: Can't vectorize the instructions or CFG
LV: Not vectorizing: Cannot prove legality.
But this information is not enough for the root cause analysis; what is
exactly wrong with the loop should also be printed:
LV: Not vectorizing: The exiting block is not the loop latch.
Patch by Pavel Samolysov.
Reviewers: mkuper, hsaito, rengolin, fhahn
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D62311
llvm-svn: 362056
Based on the overflow direction information added in D62463, we can
now fold always overflowing signed saturating add/sub to signed min/max.
Differential Revision: https://reviews.llvm.org/D62544
llvm-svn: 362006
Summary:
When we import an alias, we do so by making a clone of the aliasee. Just
as this clone uses the original alias name and linkage, it should also
use the same visibility (not the aliasee's visibility). Otherwise,
linker behavior is affected (e.g. if the aliasee was hidden, but the
alias is not, the resulting imported clone should not be hidden,
otherwise the linker will make the final symbol hidden which is
incorrect).
Reviewers: wmi
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62535
llvm-svn: 361989
Fix PR41279 where critical edges to EHPad are not split.
The fix is to not instrument those critical edges. We used to be able to know
the size of counters right after MST is computed. With this, we have to
pre-collect the instrument BBs to know the size, and then instrument them.
Differential Revision: https://reviews.llvm.org/D62439
llvm-svn: 361882
This reverts commit 53f2f3286572cb879b3861d7c15480e4d830dd3b.
As reported on D62126, this causes assertion failures if the switch
has incorrect branch_weights metadata, which may happen as a result
of other transforms not handling it correctly yet.
llvm-svn: 361881
In order to fold an always overflowing signed saturating add/sub,
we need to know in which direction the always overflow occurs.
This patch splits up AlwaysOverflows into AlwaysOverflowsLow and
AlwaysOverflowsHigh to pass through this information (but it is
not used yet).
Differential Revision: https://reviews.llvm.org/D62463
llvm-svn: 361858
This was reverted in r360086 as it was supected of causing mysterious test
failures internally. However, it was never concluded that this patch was the
root cause.
> The code was previously checking that candidates for sinking had exactly
> one use or were a store instruction (which can't have uses). This meant
> we could sink call instructions only if they had a use.
>
> That limitation seemed a bit arbitrary, so this patch changes it to
> "instruction has zero or one use" which seems more natural and removes
> the need to special-case stores.
>
> Differential revision: https://reviews.llvm.org/D59936
llvm-svn: 361811
This patch fixes the CorrelatedValuePropagation pass to keep
prof branch_weights metadata of SwitchInst consistent.
It makes use of SwitchInstProfUpdateWrapper.
New tests are added.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D62126
llvm-svn: 361808
The code to preserve LCSSA PHIs currently only properly supports
reduction PHIs and PHIs for values defined outside the latches.
This patch improves the LCSSA PHI handling to cover PHIs for values
defined in the latches.
Fixes PR41725.
Reviewers: efriedma, mcrosier, davide, jdoerfert
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D61576
llvm-svn: 361743
Rather than gating on "isSwitchDense" (resulting in necessesarily
sparse lookup tables even when they were generated), always run
this quite cheap transform.
This transform is useful not just for generating tables.
LowerSwitch also wants this: read LowerSwitch.cpp:257.
Be careful to not generate worse code, by introducing a
SubThreshold heuristic.
Instead of just sorting by signed, generalize the finding of the
best base.
And now that it is run unconditionally, do not replicate its
functionality in SwitchToLookupTable (which could use a Sub
when having a hole is smaller, hence the SubThreshold
heuristic located in a single place).
This simplifies SwitchToLookupTable, and fixes
some ugly corner cases due to the use of signed numbers,
such as a table containing i16 32768 and 32769, of which
32769 would be interpreted as -32768, and now the code thinks
the table is size 65536.
(We still use unconditional subtraction when building a single-register mask,
but I think this whole block should go when the more general sparse
map is added, which doesn't leave empty holes in the table.)
And the reason test4 and test5 did not trigger was documented wrong:
it was because they were not considered sufficiently "dense".
Also, fix generation of invalid LLVM-IR: shl by bit-width.
llvm-svn: 361727
