This renames Worklist.AddDeferred() to Worklist.add() and
Worklist.Add() to Worklist.push(). The intention here is that
Worklist.add() should be the go-to method for explicit worklist
management, while the raw Worklist.push() is mostly for
InstCombine internals. I will then migrate uses of Worklist.push()
to Worklist.add() in followup changes.
As suggested by spatel on D73411 I'm also changing the remaining
method names to lowercase first character, in line with current
coding standards.
Differential Revision: https://reviews.llvm.org/D73745
Summary:
A recent change to enable more importing of global variables with
references exposed some efficiency issues with export computation.
See D73724 for more information and detailed analysis.
The first was specific to variable importing. The code was marking every
copy of a referenced value (from possibly thousands of files in the case
of linkonce_odr) as exported, and we only need to mark the copy in the
module containing the variable def being imported as exported. The
reason is that this is tracking what values are newly exported as a
result of importing. Anything that was defined in another module and
simply used in the exporting module is already exported, and would have
been identified by the caller (e.g. the LTO API implementations).
The second issue is that the code was re-adding previously exported
values (along with all references). It is easy to identify when a
variable was already imported into the same module (via the
import list insert call return value), and we already did this for
function importing. However, what we weren't doing for either function
or variable importing was avoiding a re-insertion when it was previously
exported into a different importing module. The reason we couldn't do
this is there was no way of telling from the export list whether it was
previously inserted there because its definition was exported (in which
case we already marked all its references as exported) from when it was
inserted there because it was referenced by another exported value (in
which case we haven't yet inserted its own references).
To address this we can restructure the way the export list is
constructed. This patch only adds the actual imported definitions
(variable or function) to the export list for its module during the
import computation. After import computation is complete, where we were
already post-processing the export list we go ahead and add all
references made by those exported values to the export list.
These changes speed up the thin link not only with constant variable
importing enabled, but also without (due to the efficiency improvement
in function importing).
Some thin link user time measurements for one large application, average
of 5 runs:
With constant variable importing enabled:
- without this patch: 479.5s
- with this patch: 74.6s
Without constant variable importing enabled:
- without this patch: 80.6s
- with this patch: 70.3s
Note I have not re-enabled constant variable importing here, as I would
like to do additional compile time measurements with these fixes first.
Reviewers: evgeny777
Subscribers: mehdi_amini, inglorion, hiraditya, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73851
bo (splat X), (bo Y, OtherOp) --> bo (splat (bo X, Y)), OtherOp
This patch depends on the splat analysis enhancement in D73549.
See the test with comment:
; Negative test - mismatched splat elements
...as the motivation for that first patch.
The motivating case for reassociating splatted ops is shown in PR42174:
https://bugs.llvm.org/show_bug.cgi?id=42174
In that example, a slight change in order-of-associative math results
in a big difference in IR and codegen. This patch gets all of the
unnecessary shuffles out of the way, but doesn't address the potential
scalarization (see D50992 or D73480 for that).
Differential Revision: https://reviews.llvm.org/D73703
Duplicating instructions can lead to code size increases but using
a threshold of 3 is good for reducing code size.
Differential Revision: https://reviews.llvm.org/D72916
If all call sites are in `norecurse` functions we can derive `norecurse`
as the ReversePostOrderFunctionAttrsPass does. This should make
ReversePostOrderFunctionAttrsLegacyPass obsolete once the Attributor is
enabled.
Reviewed By: uenoku
Differential Revision: https://reviews.llvm.org/D72017
If we know that all call sites have been processed we can derive an
early fixpoint. The use in this patch is likely not to trigger right now
but a follow up patch will make use of it.
Reviewed By: uenoku, baziotis
Differential Revision: https://reviews.llvm.org/D72016
If we had `noalias` on an argument the inliner created alias scope
metadata already. However, the call site `noalias` annotation was not
considered. Since the Attributor can derive such call site `noalias`
annotation we should treat them the same as argument annotations.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D73528
Fix attempt
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Some code gen passes use MBFIWrapper to keep track of the frequency of new
blocks. This was not taken into account and could lead to incorrect frequencies
as MBFI silently returns zero frequency for unknown/new blocks.
Add a variant for MBFIWrapper in the PGSO query interface.
Depends on D73494.
We may calculate reassociable math ops in arbitrary order when creating a shuffle reduction,
so there's no guarantee that things like 'nsw' hold on those intermediate values. Drop all
poison-generating flags for safety.
This change is limited to shuffle reductions because I don't think we have a problem in the
general case (where we intersect flags of each scalar op that goes into a vector op), but if
there's evidence of other cases being wrong, we can extend this fix to cover those cases.
https://bugs.llvm.org/show_bug.cgi?id=44536
Differential Revision: https://reviews.llvm.org/D73727
In line with current conventions, create new instructions rather
than modify two operands in place and performing manual worklist
management.
This should be NFC apart from possible worklist order changes.
from FC0.ExitBlock to FC1.ExitBlock when proven safe.
Summary:
Currently LoopFusion give up when the second loop nest guard
block or the first loop nest exit block is not empty. For example:
if (0 < N) {
for (int i = 0; i < N; ++i) {}
x+=1;
}
y+=1;
if (0 < N) {
for (int i = 0; i < N; ++i) {}
}
The above example should be safe to fuse.
This PR moves instructions in FC1 guard block (e.g. y+=1;) to
FC0 guard block, or instructions in FC0 exit block (e.g. x+=1;) to
FC1 exit block, which then LoopFusion is able to fuse them.
Reviewer: kbarton, jdoerfert, Meinersbur, dmgreen, fhahn, hfinkel,
bmahjour, etiotto
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D73641
Summary:
When constant folding, constants that are wrapped in metadata were not
folded. This could lead to dbg.values being the only user of a constant
expression, due to the non-dbg uses having been rewritten, resulting in
the constant later on being removed by some other pass. This occurred
with the attached test case, in which the non-rewritten GEP in the
dbg.value intrinsic was later on removed by globalopt.
This patch makes the code look through metadata and fold such constants.
I guess that we in the future may want to allow dbg.values using GEPs and
other constant expressions to be emittable even if there are no non-dbg
uses, but for example SelectionDAG does not support that.
Reviewers: jmorse, aprantl, vsk, davide
Reviewed By: aprantl, vsk, davide
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D73630
Summary:
Add trimming of unused components of s_buffer_load.
For s_buffer_load and unformatted buffer_load also trim unused
components at the beginning of vector and update offset accordingly.
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71785
Summary:
In a release build this variable becomes unused and may break the build
with `-Werror,-Wunused-variable`.
Reviewers: gribozavr2, jdoerfert, sstefan1
Reviewed By: gribozavr2
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73683
InstCombine operates on the basic premise that the operands of the
currently processed instruction have already been simplified. It
achieves this by pushing instructions to the worklist in reverse
program order, so that instructions are popped off in program order.
The worklist management in the main combining loop also makes sure
to uphold this invariant.
However, the same is not true for all the code that is performing
manual worklist management. The largest problem (addressed in this
patch) are instructions inserted by InstCombine's IRBuilder. These
will be pushed onto the worklist in order of insertion (generally
matching program order), which means that a) the users of the
original instruction will be visited first, as they are pushed later
in the main loop and b) the newly inserted instructions will be
visited in reverse program order.
This causes a number of problems: First, folds operate on instructions
that have not had their operands simplified, which may result in
optimizations being missed (ran into this in
https://reviews.llvm.org/D72048#1800424, which was the original
motivation for this patch). Additionally, this increases the amount
of folds InstCombine has to perform, both within one iteration, and
by increasing the number of total iterations.
This patch addresses the issue by adding a Worklist.AddDeferred()
method, which is used for instructions inserted by IRBuilder. These
will only be added to the real worklist after the combine finished,
and in reverse order, so they will end up processed in program order.
I should note that the same should also be done to nearly all other
uses of Worklist.Add(), but I'm starting with just this occurrence,
which has by far the largest test fallout.
Most of the test changes are due to
https://bugs.llvm.org/show_bug.cgi?id=44521 or other cases where
we don't canonicalize something. These are neutral. One regression
has been addressed in D73575 and D73647. The remaining regression
in an shl+sdiv fold can't really be fixed without dropping another
transform, but does not seem particularly problematic in the first
place.
Differential Revision: https://reviews.llvm.org/D73411
Summary:
This patch makes sure that the field VFShape.VF is greater than zero
when demangling the vector function name of scalable vector functions
encoded in the "vector-function-abi-variant" attribute.
This change is required to be able to provide instances of VFShape
that can be used to query the VFDatabase for the vectorization passes,
as such passes always require a positive value for the Vectorization Factor (VF)
needed by the vectorization process.
It is not possible to extract the value of VFShape.VF from the mangled
name of scalable vector functions, because it is encoded as
`x`. Therefore, the VFABI demangling function has been modified to
extract such information from the IR declaration of the vector
function, under the assumption that _all_ vectors in the signature of
the vector function have the same number of lanes. Such assumption is
valid because it is also assumed by the Vector Function ABI
specifications supported by the demangling function (x86, AArch64, and
LLVM internal one).
The unit tests that demangle scalable names have been modified by
adding the IR module that carries the declaration of the vector
function name being demangled.
In particular, the demangling function fails in the following cases:
1. When the declaration of the scalable vector function is not
present in the module.
2. When the value of VFSHape.VF is not greater than 0.
Reviewers: jdoerfert, sdesmalen, andwar
Reviewed By: jdoerfert
Subscribers: mgorny, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73286
A pointer is privatizeable if it can be replaced by a new, private one.
Privatizing pointer reduces the use count, interaction between unrelated
code parts. This is a first step towards replacing argument promotion.
While we can already handle recursion (unlike argument promotion!) we
are restricted to stack allocations for now because we do not analyze
the uses in the callee.
Reviewed By: uenoku
Differential Revision: https://reviews.llvm.org/D68852
The helpers AAReturnedFromReturnedValues and
AACallSiteReturnedFromReturned are useful not only to avoid code
duplication but also to avoid recomputation of results. If we have N
call sites we should not recompute the function return information N
times but once. These are mostly straightforward usages with some minor
improvements on the helpers and addition of a new one
(IRPosition::getAssociatedType) that knows about function return types.
For the
icmp eq (add X, C1), C2 => icmp eq X, C2-C1
icmp eq (sub C1, X), C2 => icmp eq X, C1-C2
folds, this allows C1 to be non-splat and contain undefs.
C2 is still splat, due to the structure of the code.
This is to address the remaining part of the regression in D73411,
where demanded element analysis replaces some elements with undef.
Differential Revision: https://reviews.llvm.org/D73647
This commit fixes PR39321.
GlobalExtensions is not guaranteed to be destroyed when optimizer plugins are unloaded. If it is indeed destroyed after a plugin is dlclose-d, the destructor of the corresponding ExtensionFn is not mapped anymore, causing a call to unmapped memory during destruction.
This commit guarantees that extensions coming from external plugins are removed from GlobalExtensions when the plugin is unloaded if GlobalExtensions has not been destroyed yet.
Differential Revision: https://reviews.llvm.org/D71959
proven safe.
Summary:
Currently LoopFusion give up when the second loop nest preheader is
not empty. For example:
for (int i = 0; i < 100; ++i) {}
x+=1;
for (int i = 0; i < 100; ++i) {}
The above example should be safe to fuse.
This PR moves instructions in FC1 preheader (e.g. x+=1; ) to
FC0 preheader, which then LoopFusion is able to fuse them.
Reviewer: kbarton, Meinersbur, jdoerfert, dmgreen, fhahn, hfinkel,
bmahjour, etiotto
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D71821
cmp (splat V1, M), SplatC --> splat (cmp V1, SplatC'), M
As discussed in PR44588:
https://bugs.llvm.org/show_bug.cgi?id=44588
...we try harder to push shuffles after binops than after compares.
This patch handles the special (but presumably most common case) of
splat shuffles. If both operands are splats, then we can do the
comparison on the non-splat inputs followed by splat of the compare.
That should take care of the regression noted in D73411.
There's another potential fold requested in PR37463 to scalarize the
compare, but that's another patch (and it's not clear if we can do
that without the ability to undo it later):
https://bugs.llvm.org/show_bug.cgi?id=37463
Differential Revision: https://reviews.llvm.org/D73575
There was a TODO in AAValueConstantRangeArgument to reuse
AAArgumentFromCallSiteArguments. We now do this by allowing new States
to be build from the bestState.
If we invalidate an attribute we need to inform all dependent ones even
if the fixpoint state is not invalid. Before we only continued
invalidation if the fixpoint state was invalid, now we signal a change
in case the fixpoint state is valid.
The test case was already included in D71620 but the problem was hiding
because it only manifested with the old PM (for that input).
This patch modularizes the way we check for no-alias call site arguments
by putting the existing logic into helper functions. The reasoning was
not changed but special cases for readonly/readnone were added.
If `null` is not defined we cannot access it, hence the pointer is
`noalias`. While this is not helpful on it's own it simplifies later
deductions that can skip over already known `noalias` pointers in
certain situations.
During extraction, stale llvm.assume handles may be retained in the
original function. The setup is:
1) CodeExtractor unregisters assumptions in the blocks that are to be
extracted.
2) Extraction happens. There are now two functions: f1 and f1.extracted.
3) Leftover assumptions in f1 (/not/ removed as they were not in the set of
blocks to be extracted) now have affected-value llvm.assume handles in
f1.extracted.
When assumptions for a value used in f1 are looked up, ValueTracking can assert
as some of the handles are in the wrong function. To fix this, simply erase the
llvm.assume calls in the extracted function.
Alternatives include flushing the assumption cache in the original function, or
walking all values used in the original function to prune stale affected-value
handles. Both seem more expensive.
Testing: check-llvm, LNT run with -mllvm -hot-cold-split enabled
rdar://58460728
Nikita Popov