By default, the Attributor tracks potential dependences between abstract
attributes based on the issued Attributor::getAAFor queries. This
simplifies the development of new abstract attributes but it can also
lead to spurious dependences that might increase compile time and make
internalization harder (D63312). With this patch, abstract attributes
can opt-out of implicit dependence tracking and instead register
dependences explicitly. It is up to the implementation to make sure all
existing dependences are registered.
Differential Revision: https://reviews.llvm.org/D63314
llvm-svn: 369935
Summary:
We can now manifest alignment information in load/store instructions if
the pointer is known to have a better alignment.
Reviewers: uenoku, sstefan1, lebedev.ri
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66567
llvm-svn: 369804
Summary:
If the unique return value is a constant we now replace call uses with
that constant.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66551
llvm-svn: 369785
Summary:
If we have a loop in which the dereferenceability of a pointer decreases
we did slowly decrease it iteration by iteration, leading to a timeout.
With this patch we detect such circular reasoning and indicate a
fixpoint early.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66558
llvm-svn: 369784
Summary:
If we have a negative inbounds offset dereferenceabily "grows". However,
until we do not handle the overflow that can occur in the
dereferenceable bytes and the problem with loops, we simply do not grow
the state.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66557
llvm-svn: 369771
Summary:
When we have new attributes and we end the fixpoint iteration because
the iteration limit is reached, we need to treat the new ones as if they
changed in the last iteration, as they might have.
This adds a test for which we should not derive anything regardless of
the iteration limit, e.g., if we abort there should not be any
attributes manifested in the IR.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66549
llvm-svn: 369768
Locally the tight iterations bounds work fine but the bots seem unhappy.
Try to get green bots and some time to determine the underlying problem.
llvm-svn: 369592
Summary:
To be able to track how many iterations we need to manifest all
information we check for we now make the maximum iteration count
explicit. The count is set tightly now and should be kept that way.
Reviewers: uenoku, sstefan1
Subscribers: bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66554
llvm-svn: 369586
For an internal function, if all its call sites are dead, the body of the function is considered dead.
Reviewers: jdoerfert, uenoku
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D66155
llvm-svn: 369470
Before, we create the set of abstract attributes initially and then
dealt with the fact hat a lookup could fail, e.g., return a nullptr.
This patch will ensure we always return a valid object from a lookup,
allowing us not only to remove the nullptr checks but also to grow the
set of abstract attributes "in-flight" on-demand.
One can now start from those that have the best chance of improving
performance without the need to specify all they might depend on.
While this introduces some boilerplate, the usage of attributes is much
easier and cleaner now.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66276
llvm-svn: 369331
Summary:
This is analogous to D66128 but for AADereferenceable. We have the logic
concentrated in the floating value updateImpl and we use the combiner
helper classes for arguments and return values.
The regressions will go away with "on-demand" attribute creation.
Improvements are already visible in the existing tests.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66272
llvm-svn: 369329
Summary:
What D66126 did for AAAlign, this patch does for AANonNull. Agian, the
logic becomes more concise and localized. Again, returned poiners are
not annotated properly but that will not be an issue if this lands with
the "on-demand" generation of attributes. First improvements due to the
genericValueTraversal are already visible.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66128
llvm-svn: 369328
Summary:
Before we required the comparison against null to be "canonical", hence
null to be operand #1. This patch allows null to be in either operand,
similar to the handling of loaded globals that follows.
Reviewers: sanjoy, hfinkel, aykevl, sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66321
llvm-svn: 369158
Summary:
This is the first commit aiming to structure the attribute deduction.
The base idea is that we have default propagation patterns as listed
below on top of which we can add specific, e.g., context sensitive,
logic.
Deduction patterns used in this patch:
- argument states are determined from call site argument states,
see AAAlignArgument and AAArgumentFromCallSiteArguments.
- call site argument states are determined as if they were floating
values, see AAAlignCallSiteArgument and AAAlignFloating.
- floating value states are determined by traversing the def-use chain
and combining the states determined for the leaves, see
AAAlignFloating and genericValueTraversal.
- call site return states are determined from function return states,
see AAAlignCallSiteReturned and AACallSiteReturnedFromReturned.
- function return states are determined from returned value states,
see AAAlignReturned and AAReturnedFromReturnedValues.
Through this strategy all logic for alignment is concentrated in the
AAAlignFloating::updateImpl method.
Note: This commit works on its own but is part of a larger change that
involves "on-demand" creation of abstract attributes that will
participate in the fixpoint iteration. Without this part, we sometimes
do not have an AAAlign abstract attribute to query, loosing information
we determined before. All tests have appropriate FIXMEs and the
information will be recovered once we added all parts.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66126
llvm-svn: 369144
Summary:
As one of the first attributes, and one of the complex ones,
AAReturnedValues was not using liveness but we filtered the result after
the fact. This change adds liveness usage during the creation. The
algorithm is also improved and shorter.
The new algorithm will collect returned values over time using the
generic facilities that work with liveness already, e.g.,
genericValueTraversal which does not look at dead PHI node predecessors.
A test to show how this leads to better results is included.
Note: Unresolved calls and resolved calls are now tracked explicitly.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66120
llvm-svn: 368922
Summary:
So far, whenever one wants to look at returned values, one had to deal
with the AAReturnedValues and potentially with the AAIsDead attribute.
In the same spirit as other checkForAllXXX methods, we add this
functionality now to the Attributor. By adopting the use sites we got
better results when return instructions were dead.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65733
llvm-svn: 368222
A function is "no-return" if we never reach a return instruction, either
because there are none or the ones that exist are dead.
Test have been adjusted:
- either noreturn was added, or
- noreturn was avoided by modifying the code.
The new noreturn_{sync,async} test make sure we do handle invoke
instructions with a noreturn (and potentially nowunwind) callee
correctly, even in the presence of potential asynchronous exceptions.
llvm-svn: 367948
When we remove instructions cached references could still be live. This
patch avoids removing invoke instructions that are replaced by calls and
instead keeps them around but in a dead block.
llvm-svn: 367933
Summary:
This contains various fixes:
- Explicitly determine and return the next noreturn instruction.
- If an invoke calls a noreturn function which is not nounwind we
keep the unwind destination live. This also means we require an
invoke. Though we can still add the unreachable to the normal
destination block.
- Check if the return instructions are dead after we look for calls
to avoid triggering an optimistic fixpoint in the presence of
assumed liveness information.
- Make the interface work with "const" pointers.
- Some simplifications
While additional tests are included, full coverage is achieved only with
D59978.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65701
llvm-svn: 367791
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.
Also modifies the parser to accept IR in that form for obvious reasons.
llvm-svn: 367755
Modifying other AbstractAttributes to use Liveness AA and skip dead instructions.
Reviewers: jdoerfert, uenoku
Subscribers: hiraditya, llvm-commits
Differential revision: https://reviews.llvm.org/D65243
llvm-svn: 367725
Summary: As clarified in D53184, volatile load and store do not trap. Therefore, we should remove volatile checks for instructions in `isGuaranteedToTransferExecutionToSuccessor`.
Reviewers: jdoerfert, efriedma, nikic
Reviewed By: nikic
Subscribers: hiraditya, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65375
llvm-svn: 367226
Summary:
Deduce dereferenceable attribute in Attributor.
These will be added in a later patch.
* dereferenceable(_or_null)_globally (D61652)
* Deduction based on load instruction (similar to D64258)
Reviewers: jdoerfert, sstefan1
Reviewed By: jdoerfert
Subscribers: hiraditya, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64876
llvm-svn: 366788
[Attributor] Liveness analysis.
Liveness analysis abstract attribute used to indicate which BasicBlocks are dead and can therefore be ignored.
Right now we are only looking at noreturn calls.
Reviewers: jdoerfert, uenoku
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D64162
llvm-svn: 366769
[Attributor] Liveness analysis.
Liveness analysis abstract attribute used to indicate which BasicBlocks are dead and can therefore be ignored.
Right now we are only looking at noreturn calls.
Reviewers: jdoerfert, uenoku
Subscribers: hiraditya, llvm-commits
Differential revision: https://reviews.llvm.org/D64162
llvm-svn: 366753
Liveness analysis abstract attribute used to indicate which BasicBlocks are dead and can therefore be ignored.
Right now we are only looking at noreturn calls.
Reviewers: jdoerfert, uenoku
Subscribers: hiraditya, llvm-commits
Differential revision: https://reviews.llvm.org/D64162
llvm-svn: 366736
Porting function return value attribute noalias to attributor.
This will be followed with a patch for callsite and function argumets.
Reviewers: jdoerfert
Subscribers: lebedev.ri, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D63067
llvm-svn: 366728
Summary:
Deduce the "willreturn" attribute for functions.
For now, intrinsics are not willreturn. More annotation will be done in another patch.
Reviewers: jdoerfert
Subscribers: jvesely, nhaehnle, nicholas, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63046
llvm-svn: 366335
There are scenarios where mutually recursive functions may cause the SCC
to contain both read only and write only functions. This removes an
assertion when adding read attributes which caused a crash with a the
provided test case, and instead just doesn't add the attributes.
Patch by Luke Lau <luke.lau@intel.com>
Differential Revision: https://reviews.llvm.org/D60761
llvm-svn: 366090
Introduce and deduce "nosync" function attribute to indicate that a function
does not synchronize with another thread in a way that other thread might free memory.
Reviewers: jdoerfert, jfb, nhaehnle, arsenm
Subscribers: wdng, hfinkel, nhaenhle, mehdi_amini, steven_wu,
dexonsmith, arsenm, uenoku, hiraditya, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D62766
llvm-svn: 365830
Deduce the "returned" argument attribute by collecting all potentially
returned values.
Not only the unique return value, if any, can be used by subsequent
attributes but also the set of all potentially returned values as well
as the mapping from returned values to return instructions that they
originate from (see AAReturnedValues::checkForallReturnedValues).
Change in statistics (-stats) for LLVM-TS + Spec2006, totaling ~19% more "returned" arguments.
ADDED: attributor NumAttributesManifested n/a -> 637
ADDED: attributor NumAttributesValidFixpoint n/a -> 25545
ADDED: attributor NumFnArgumentReturned n/a -> 637
ADDED: attributor NumFnKnownReturns n/a -> 25545
ADDED: attributor NumFnUniqueReturned n/a -> 14118
CHANGED: deadargelim NumRetValsEliminated 470 -> 449 ( -4.468%)
REMOVED: functionattrs NumReturned 535 -> n/a
CHANGED: indvars NumElimIdentity 138 -> 164 ( +18.841%)
Reviewers: homerdin, hfinkel, fedor.sergeev, sanjoy, spatel, nlopes, nicholas, reames, efriedma, chandlerc
Subscribers: hiraditya, bollu, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D59919
llvm-svn: 365407
This patch adds a function attribute, nofree, to indicate that a function does
not, directly or indirectly, call a memory-deallocation function (e.g., free,
C++'s operator delete).
Reviewers: jdoerfert
Differential Revision: https://reviews.llvm.org/D49165
llvm-svn: 365336
This patch introduces a new function attribute, willreturn, to indicate
that a call of this function will either exhibit undefined behavior or
comes back and continues execution at a point in the existing call stack
that includes the current invocation.
This attribute guarantees that the function does not have any endless
loops, endless recursion, or terminating functions like abort or exit.
Patch by Hideto Ueno (@uenoku)
Reviewers: jdoerfert
Subscribers: mehdi_amini, hiraditya, steven_wu, dexonsmith, lebedev.ri, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62801
llvm-svn: 364555
Pointers that are in-bounds (either through dereferenceable_or_null or
thorough a getelementptr inbounds) cannot be captured with a comparison
against null. There is no way to construct a pointer that is still in
bounds but also NULL.
This helps safe languages that insert null checks before load/store
instructions. Without this patch, almost all pointers would be
considered captured even for simple loads. With this patch, an icmp with
null will not be seen as escaping as long as certain conditions are met.
There was a lot of discussion about this patch. See the Phabricator
thread for detals.
Differential Revision: https://reviews.llvm.org/D60047
llvm-svn: 362900
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
This commit is a preparation of upcoming patches on attribute deduction.
It will shorten the diffs and make it clear what we inferred before.
Reviewers: chandlerc, homerdin, hfinkel, fedor.sergeev, sanjoy, spatel, nlopes
Subscribers: bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59903
llvm-svn: 362577
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
The presence of readnone and an access range attribute (argmemonly,
inaccessiblememonly, inaccessiblemem_or_argmemonly) is considered an
error by the verifier. This seems strict but also not wrong. This
patch makes sure function attribute detection will remove all access
range attributes for readnone functions.
llvm-svn: 341927
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.
More details : https://lkml.org/lkml/2018/4/4/601
GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.
-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.
This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.
Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv
Reviewed By: efriedma, george.burgess.iv
Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits
Differential Revision: https://reviews.llvm.org/D47895
llvm-svn: 336613
Summary:
This patch introduce new intrinsic -
strip.invariant.group that was described in the
RFC: Devirtualization v2
Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar
Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits
Differential Revision: https://reviews.llvm.org/D47103
Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 336073
Summary:
launder.invariant.group has the same rules of capturing as
bitcast, gep, etc - the original value is not captured
if the returned pointer is not captured.
With this patch, we mark 40% more functions as noalias when compiling with -fstrict-vtable-pointers;
1078 vs 1778 (39.37%)
Reviewers: sanjoy, davide, nlewycky, majnemer, mehdi_amini
Subscribers: JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D32673
llvm-svn: 331587
Summary:
This was motivated by absence of PrunEH functionality in new PM.
It was decided that a proper way to do PruneEH is to add NoUnwind inference
into PostOrderFunctionAttrs and then perform normal SimplifyCFG on top.
This change generalizes attribute handling implemented for (a removal of)
Convergent attribute, by introducing a generic builder-like class
AttributeInferer
It registers all the attribute inference requests, storing per-attribute
predicates into a vector, and then goes through an SCC Node, scanning all
the instructions for not breaking attribute assumptions.
The main idea is that as soon all the instructions from all the functions
of SCC Node conform to attribute assumptions then we are free to infer
the attribute as set for all the functions of SCC Node.
It handles two distinct cases of attributes:
- those that might break due to derefinement of the function code
for these attributes we are allowed to apply inference only if all the
functions are "exact definitions". Example - NoUnwind.
- those that do not care about derefinement
for these attributes we are allowed to apply inference as soon as we see
any function definition. Example - removal of Convergent attribute.
Also in this commit:
* Converted all the FunctionAttrs tests to use FileCheck and added new-PM
invocations to them
* FunctionAttrs/convergent.ll test demonstrates a difference in behavior between
new and old PM implementations. Marked with FIXME.
* PruneEH tests were converted to new-PM as well, using function-attrs+simplify-cfg
combo as intended
* some of "other" tests were updated since function-attrs now infers 'nounwind'
even for old PM pipeline
* -disable-nounwind-inference hidden option added as a possible workaround for a supposedly
rare case when nounwind being inferred by default presents a problem
Reviewers: chandlerc, jlebar
Reviewed By: jlebar
Subscribers: eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D44415
llvm-svn: 328377
- Fix for bug 36078.
- Prevent the functionattrs, function-attrs, globalopt and argpromotion passes
from changing naked functions.
- These passes can perform some alterations to the functions that should not be
applied. An example is removing parameters that are seemingly not used because
they are only referenced in the inline assembly. Another example is marking
the function as fastcc.
llvm-svn: 325788
This patch implements Chandler's idea [0] for supporting languages that
require support for infinite loops with side effects, such as Rust, providing
part of a solution to bug 965 [1].
Specifically, it adds an `llvm.sideeffect()` intrinsic, which has no actual
effect, but which appears to optimization passes to have obscure side effects,
such that they don't optimize away loops containing it. It also teaches
several optimization passes to ignore this intrinsic, so that it doesn't
significantly impact optimization in most cases.
As discussed on llvm-dev [2], this patch is the first of two major parts.
The second part, to change LLVM's semantics to have defined behavior
on infinite loops by default, with a function attribute for opting into
potential-undefined-behavior, will be implemented and posted for review in
a separate patch.
[0] http://lists.llvm.org/pipermail/llvm-dev/2015-July/088103.html
[1] https://bugs.llvm.org/show_bug.cgi?id=965
[2] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118632.html
Differential Revision: https://reviews.llvm.org/D38336
llvm-svn: 317729
It now knows the tricks of both functions.
Also, fix a bug that considered allocas of non-zero address space to be always non null
Differential Revision: https://reviews.llvm.org/D37628
llvm-svn: 312869
Fixes PR31789 - When loop-vectorize tries to use these intrinsics for a
non-default address space pointer we fail with a "Calling a function with a
bad singature!" assertion. This patch solves this by adding the 'vector of
pointers' argument as an overloaded type which will determine the address
space.
Differential revision: https://reviews.llvm.org/D31490
llvm-svn: 302018
Summary:
Attaching !absolute_symbol to a global variable does two things:
1) Marks it as an absolute symbol reference.
2) Specifies the value range of that symbol's address.
Teach the X86 backend to allow absolute symbols to appear in place of
immediates by extending the relocImm and mov64imm32 matchers. Start using
relocImm in more places where it is legal.
As previously proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/105800.html
Differential Revision: https://reviews.llvm.org/D25878
llvm-svn: 289087
Trying to infer the 'returned' attribute if an argument is already
'returned' can lead to verification failure: inference might determine
that a different argument is passed through which would result in two
different arguments marked as 'returned'.
This fixes PR30350.
llvm-svn: 281221
We skipped over ReturnInsts which didn't return an argument which would
lead us to incorrectly conclude that an argument returned by another
ReturnInst was 'returned'.
This reverts commit r275756.
This fixes PR28610.
llvm-svn: 276008
This reverts also r275029, "Update Clang tests after adding inference for the returned argument attribute"
It broke LTO build. Seems miscompilation.
llvm-svn: 275756
This reverts commit r275042; the initial commit triggered self-hosting failures
on ARM/AArch64. James Molloy identified the problematic backend code, which has
been disabled in r275677. Trying again...
Original commit message:
Let FuncAttrs infer the 'returned' argument attribute
A function can have one argument with the 'returned' attribute, indicating that
the associated argument is always the return value of the function. Add
FuncAttrs inference logic.
llvm-svn: 275678
A function can have one argument with the 'returned' attribute, indicating that
the associated argument is always the return value of the function. Add
FuncAttrs inference logic.
Differential Revision: http://reviews.llvm.org/D22202
llvm-svn: 275027
This actually uncovered a surprisingly large chain of ultimately unused
TLI args.
From what I can gather, this argument is a remnant of when
isKnownNonNull would look at the TLI directly.
The current approach seems to be that InferFunctionAttrs runs early in
the pipeline and uses TLI to annotate the TLI-dependent non-null
information as return attributes.
This also removes the dependence of functionattrs on TLI altogether.
llvm-svn: 274455
There are two separate issues:
- LLVM doesn't consider infinite loops to be side effects: we happily
hoist/sink above/below loops whose bounds are unknown.
- The absence of the noreturn attribute is insufficient for us to know
if a function will definitely return. Relying on noreturn in the
middle-end for any property is an accident waiting to happen.
llvm-svn: 273762
Below are my super rough notes when porting. They can probably serve as
a basic guide for porting other passes to the new PM. As I port more
passes I'll expand and generalize this and make a proper
docs/HowToPortToNewPassManager.rst document. There is also missing
documentation for general concepts and API's in the new PM which will
require some documentation.
Once there is proper documentation in place we can put up a list of
passes that have to be ported and game-ify/crowdsource the rest of the
porting (at least of the middle end; the backend is still unclear).
I will however be taking personal responsibility for ensuring that the
LLD/ELF LTO pipeline is ported in a timely fashion. The remaining passes
to be ported are (do something like
`git grep "<the string in the bullet point below>"` to find the pass):
General Scalar:
[ ] Simplify the CFG
[ ] Jump Threading
[ ] MemCpy Optimization
[ ] Promote Memory to Register
[ ] MergedLoadStoreMotion
[ ] Lazy Value Information Analysis
General IPO:
[ ] Dead Argument Elimination
[ ] Deduce function attributes in RPO
Loop stuff / vectorization stuff:
[ ] Alignment from assumptions
[ ] Canonicalize natural loops
[ ] Delete dead loops
[ ] Loop Access Analysis
[ ] Loop Invariant Code Motion
[ ] Loop Vectorization
[ ] SLP Vectorizer
[ ] Unroll loops
Devirtualization / CFI:
[ ] Cross-DSO CFI
[ ] Whole program devirtualization
[ ] Lower bitset metadata
CGSCC passes:
[ ] Function Integration/Inlining
[ ] Remove unused exception handling info
[ ] Promote 'by reference' arguments to scalars
Please let me know if you are interested in working on any of the passes
in the above list (e.g. reply to the post-commit thread for this patch).
I'll probably be tackling "General Scalar" and "General IPO" first FWIW.
Steps as I port "Deduce function attributes in RPO"
---------------------------------------------------
(note: if you are doing any work based on these notes, please leave a
note in the post-commit review thread for this commit with any
improvements / suggestions / incompleteness you ran into!)
Note: "Deduce function attributes in RPO" is a module pass.
1. Do preparatory refactoring.
Do preparatory factoring. In this case all I had to do was to pull out a static helper (r272503).
(TODO: give more advice here e.g. if pass holds state or something)
2. Rename the old pass class.
llvm/lib/Transforms/IPO/FunctionAttrs.cpp
Rename class ReversePostOrderFunctionAttrs -> ReversePostOrderFunctionAttrsLegacyPass
in preparation for adding a class ReversePostOrderFunctionAttrs as the pass in the new PM.
(edit: actually wait what? The new class name will be
ReversePostOrderFunctionAttrsPass, so it doesn't conflict. So this step is
sort of useless churn).
llvm/include/llvm/InitializePasses.h
llvm/lib/LTO/LTOCodeGenerator.cpp
llvm/lib/Transforms/IPO/IPO.cpp
llvm/lib/Transforms/IPO/FunctionAttrs.cpp
Rename initializeReversePostOrderFunctionAttrsPass -> initializeReversePostOrderFunctionAttrsLegacyPassPass
(note that the "PassPass" thing falls out of `s/ReversePostOrderFunctionAttrs/ReversePostOrderFunctionAttrsLegacyPass/`)
Note that the INITIALIZE_PASS macro is what creates this identifier name, so renaming the class requires this renaming too.
Note that createReversePostOrderFunctionAttrsPass does not need to be
renamed since its name is not generated from the class name.
3. Add the new PM pass class.
In the new PM all passes need to have their
declaration in a header somewhere, so you will often need to add a header.
In this case
llvm/include/llvm/Transforms/IPO/FunctionAttrs.h is already there because
PostOrderFunctionAttrsPass was already ported.
The file-level comment from the .cpp file can be used as the file-level
comment for the new header. You may want to tweak the wording slightly
from "this file implements" to "this file provides" or similar.
Add declaration for the new PM pass in this header:
class ReversePostOrderFunctionAttrsPass
: public PassInfoMixin<ReversePostOrderFunctionAttrsPass> {
public:
PreservedAnalyses run(Module &M, AnalysisManager<Module> &AM);
};
Its name should end with `Pass` for consistency (note that this doesn't
collide with the names of most old PM passes). E.g. call it
`<name of the old PM pass>Pass`.
Also, move the doxygen comment from the old PM pass to the declaration of
this class in the header.
Also, include the declaration for the new PM class
`llvm/Transforms/IPO/FunctionAttrs.h` at the top of the file (in this case,
it was already done when the other pass in this file was ported).
Now define the `run` method for the new class.
The main things here are:
a) Use AM.getResult<...>(M) to get results instead of `getAnalysis<...>()`
b) If the old PM pass would have returned "false" (i.e. `Changed ==
false`), then you should return PreservedAnalyses::all();
c) In the old PM getAnalysisUsage method, observe the calls
`AU.addPreserved<...>();`.
In the case `Changed == true`, for each preserved analysis you should do
call `PA.preserve<...>()` on a PreservedAnalyses object and return it.
E.g.:
PreservedAnalyses PA;
PA.preserve<CallGraphAnalysis>();
return PA;
Note that calls to skipModule/skipFunction are not supported in the new PM
currently, so optnone and optimization bisect support do not work. You can
just drop those calls for now.
4. Add the pass to the new PM pass registry to make it available in opt.
In llvm/lib/Passes/PassBuilder.cpp add a #include for your header.
`#include "llvm/Transforms/IPO/FunctionAttrs.h"`
In this case there is already an include (from when
PostOrderFunctionAttrsPass was ported).
Add your pass to llvm/lib/Passes/PassRegistry.def
In this case, I added
`MODULE_PASS("rpo-functionattrs", ReversePostOrderFunctionAttrsPass())`
The string is from the `INITIALIZE_PASS*` macros used in the old pass
manager.
Then choose a test that uses the pass and use the new PM `-passes=...` to
run it.
E.g. in this case there is a test that does:
; RUN: opt < %s -basicaa -functionattrs -rpo-functionattrs -S | FileCheck %s
I have added the line:
; RUN: opt < %s -aa-pipeline=basic-aa -passes='require<targetlibinfo>,cgscc(function-attrs),rpo-functionattrs' -S | FileCheck %s
The `-aa-pipeline=basic-aa` and
`require<targetlibinfo>,cgscc(function-attrs)` are what is needed to run
functionattrs in the new PM (note that in the new PM "functionattrs"
becomes "function-attrs" for some reason). This is just pulled from
`readattrs.ll` which contains the change from when functionattrs was ported
to the new PM.
Adding rpo-functionattrs causes the pass that was just ported to run.
llvm-svn: 272505
The memory location that corresponds to a volatile operation is very
special. They are observed by the machine in ways which we cannot
reason about.
Differential Revision: http://reviews.llvm.org/D20555
llvm-svn: 270879
It turns out that too many passes are relying on alias analysis results
for control dependencies. Until we fix that by introducing a more accurate
modelling of control dependencies, special case assume in MemorySSA instead.
Also introduce tests to ensure we don't regress the FunctionAttrs or LICM
passes.
Differential Revision: http://reviews.llvm.org/D20658
llvm-svn: 270823
A volatile load has side effects beyond what callers expect readonly to
signify. For example, it is not safe to reorder two function calls
which each perform a volatile load to the same memory location.
llvm-svn: 270671
Summary:
Fixes PR26774.
If you're aware of the issue, feel free to skip the "Motivation"
section and jump directly to "This patch".
Motivation:
I define "refinement" as discarding behaviors from a program that the
optimizer has license to discard. So transforming:
```
void f(unsigned x) {
unsigned t = 5 / x;
(void)t;
}
```
to
```
void f(unsigned x) { }
```
is refinement, since the behavior went from "if x == 0 then undefined
else nothing" to "nothing" (the optimizer has license to discard
undefined behavior).
Refinement is a fundamental aspect of many mid-level optimizations done
by LLVM. For instance, transforming `x == (x + 1)` to `false` also
involves refinement since the expression's value went from "if x is
`undef` then { `true` or `false` } else { `false` }" to "`false`" (by
definition, the optimizer has license to fold `undef` to any non-`undef`
value).
Unfortunately, refinement implies that the optimizer cannot assume
that the implementation of a function it can see has all of the
behavior an unoptimized or a differently optimized version of the same
function can have. This is a problem for functions with comdat
linkage, where a function can be replaced by an unoptimized or a
differently optimized version of the same source level function.
For instance, FunctionAttrs cannot assume a comdat function is
actually `readnone` even if it does not have any loads or stores in
it; since there may have been loads and stores in the "original
function" that were refined out in the currently visible variant, and
at the link step the linker may in fact choose an implementation with
a load or a store. As an example, consider a function that does two
atomic loads from the same memory location, and writes to memory only
if the two values are not equal. The optimizer is allowed to refine
this function by first CSE'ing the two loads, and the folding the
comparision to always report that the two values are equal. Such a
refined variant will look like it is `readonly`. However, the
unoptimized version of the function can still write to memory (since
the two loads //can// result in different values), and selecting the
unoptimized version at link time will retroactively invalidate
transforms we may have done under the assumption that the function
does not write to memory.
Note: this is not just a problem with atomics or with linking
differently optimized object files. See PR26774 for more realistic
examples that involved neither.
This patch:
This change introduces a new set of linkage types, predicated as
`GlobalValue::mayBeDerefined` that returns true if the linkage type
allows a function to be replaced by a differently optimized variant at
link time. It then changes a set of IPO passes to bail out if they see
such a function.
Reviewers: chandlerc, hfinkel, dexonsmith, joker.eph, rnk
Subscribers: mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D18634
llvm-svn: 265762
Summary:
Previously we had a notion of convergent functions but not of convergent
calls. This is insufficient to correctly analyze calls where the target
is unknown, e.g. indirect calls.
Now a call is convergent if it targets a known-convergent function, or
if it's explicitly marked as convergent. As usual, we can remove
convergent where we can prove that no convergent operations are
performed in the call.
Originally landed as r261544, then reverted in r261544 for (incidental)
build breakage. Re-landed here with no changes.
Reviewers: chandlerc, jingyue
Subscribers: llvm-commits, tra, jhen, hfinkel
Differential Revision: http://reviews.llvm.org/D17739
llvm-svn: 263481
Summary:
Previously we had a notion of convergent functions but not of convergent
calls. This is insufficient to correctly analyze calls where the target
is unknown, e.g. indirect calls.
Now a call is convergent if it targets a known-convergent function, or
if it's explicitly marked as convergent. As usual, we can remove
convergent where we can prove that no convergent operations are
performed in the call.
Reviewers: chandlerc, jingyue
Subscribers: hfinkel, jhen, tra, llvm-commits
Differential Revision: http://reviews.llvm.org/D17317
llvm-svn: 261544
This test builds on 261250 (IR support for cmpxchg of pointers) and 261245 (capture tracking support for cmpxchg) to show that correctly analyze the capturing of pointers in a cmpxchg of pointer type.
llvm-svn: 261284
These atomic operations are conceptually both a load and store from the same location. As such, we can treat them as the most conservative of those two components which in practice, means we can treat them like stores. An cmpxchg or atomicrmw captures the values, but not the locations accessed.
Note: We can probably be more aggressive about the comparison value in an cmpxhg since to have it be in memory, it must already be captured, but I figured it was better to avoid that for the moment.
Note 2: It turns out that since we don't actually support cmpxchg of pointer type, writing a negative test is impossible.
Differential Revision: http://reviews.llvm.org/D17400
llvm-svn: 261245
convert one test to use this.
This is a particularly significant milestone because it required
a working per-function AA framework which can be queried over each
function from within a CGSCC transform pass (and additionally a module
analysis to be accessible). This is essentially *the* point of the
entire pass manager rewrite. A CGSCC transform is able to query for
multiple different function's analysis results. It works. The whole
thing appears to actually work and accomplish the original goal. While
we were able to hack function attrs and basic-aa to "work" in the old
pass manager, this port doesn't use any of that, it directly leverages
the new fundamental functionality.
For this to work, the CGSCC framework also has to support SCC-based
behavior analysis, etc. The only part of the CGSCC pass infrastructure
not sorted out at this point are the updates in the face of inlining and
running function passes that mutate the call graph.
The changes are pretty boring and boiler-plate. Most of the work was
factored into more focused preperatory patches. But this is what wires
it all together.
llvm-svn: 261203
than the SCC object, and have it scan the instruction stream directly
rather than relying on call records.
This makes the behavior of this routine consistent between libc routines
and LLVM intrinsics for libc routines. We can go and start teaching it
about those being norecurse, but we should behave the same for the
intrinsic and the libc routine rather than differently. I chatted with
James Molloy and the inconsistency doesn't seem intentional and likely
is due to intrinsic calls not being modelled in the call graph analyses.
This also fixes a bug where we would deduce norecurse on optnone
functions, when generally we try to handle optnone functions as-if they
were replaceable and thus unanalyzable.
llvm-svn: 260813
Summary:
Remove the convergent attribute on any functions which provably do not
contain or invoke any convergent functions.
After this change, we'll be able to modify clang to conservatively add
'convergent' to all functions when compiling CUDA.
Reviewers: jingyue, joker.eph
Subscribers: llvm-commits, tra, jhen, hfinkel, resistor, chandlerc, arsenm
Differential Revision: http://reviews.llvm.org/D17013
llvm-svn: 260319
FunctionAttrs does an "optimistic" analysis of SCCs as a unit, which
means normally it is able to disregard calls from an SCC into itself.
However, calls and invokes with operand bundles are allowed to have
memory effects not fully described by the memory effects on the call
target, so we can't be optimistic around operand-bundled calls from an
SCC into itself.
llvm-svn: 260244
a top-down manner into a true top-down or RPO pass over the call graph.
There are specific patterns of function attributes, notably the
norecurse attribute, which are most effectively propagated top-down
because all they us caller information.
Walk in RPO over the call graph SCCs takes the form of a module pass run
immediately after the CGSCC pass managers postorder walk of the SCCs,
trying again to deduce norerucrse for each singular SCC in the call
graph.
This removes a very legacy pass manager specific trick of using a lazy
revisit list traversed during finalization of the CGSCC pass. There is
no analogous finalization step in the new pass manager, and a lazy
revisit list is just trying to produce an RPO iteration of the call
graph. We can do that more directly if more expensively. It seems
unlikely that this will be the expensive part of any compilation though
as we never examine the function bodies here. Even in an LTO run over
a very large module, this should be a reasonable fast set of operations
over a reasonably small working set -- the function call graph itself.
In the future, if this really is a compile time performance issue, we
can look at building support for both post order and RPO traversals
directly into a pass manager that builds and maintains the PO list of
SCCs.
Differential Revision: http://reviews.llvm.org/D15785
llvm-svn: 257163
a standalone pass.
There is no call graph or even interesting analysis for this part of
function attributes -- it is literally inferring attributes based on the
target library identification. As such, we can do it using a much
simpler module pass that just walks the declarations. This can also
happen much earlier in the pass pipeline which has benefits for any
number of other passes.
In the process, I've cleaned up one particular aspect of the logic which
was necessary in order to separate the two passes cleanly. It now counts
inferred attributes independently rather than just counting all the
inferred attributes as one, and the counts are more clearly explained.
The two test cases we had for this code path are both ... woefully
inadequate and copies of each other. I've kept the superset test and
updated it. We need more testing here, but I had to pick somewhere to
stop fixing everything broken I saw here.
Differential Revision: http://reviews.llvm.org/D15676
llvm-svn: 256466
is (by default) run much earlier than FuncitonAttrs proper.
This allows forcing optnone or other widely impactful attributes. It is
also a bit simpler as the force attribute behavior needs no specific
iteration order.
I've added the pass into the default module pass pipeline and LTO pass
pipeline which mirrors where function attrs itself was being run.
Differential Revision: http://reviews.llvm.org/D15668
llvm-svn: 256465
This provides a way to force a function to have certain attributes from the command line. This can be useful when debugging or doing workload exploration, where manually editing IR is tedious or not possible (due to build systems etc).
The syntax is -force-attribute=function_name:attribute_name
All function attributes are parsed except alignstack as it requires an argument.
llvm-svn: 253550
While setting function attributes we check all instructions that may access memory. For a call instruction we check all arguments. The special check is required for pointers.
I added vector-of-pointers to the call arguments types that should be checked.
Differential Revision: http://reviews.llvm.org/D14693
llvm-svn: 253363
A function can be marked as norecurse if:
* The SCC to which it belongs has cardinality 1; and either
a) It does not call any non-norecurse function. This includes self-recursion; or
b) It only has one callsite and the function that callsite is within is marked norecurse.
a) is best propagated bottom-up and b) is best propagated top-down.
We build up the norecurse attributes bottom-up using the existing SCC pass, and mark functions with no obvious recursion (but not provably norecurse) to sweep later, top-down.
llvm-svn: 252862
Summary:
This change fixes an iterator wraparound bug in
`determinePointerReadAttrs`.
Ideally, ++'ing off the `end()` of an iplist should result in a failed
assert, but currently iplist seems to silently wrap to the head of the
list on `end()++`. This is why the bad behavior is difficult to
demonstrate.
Reviewers: chandlerc, reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14350
llvm-svn: 252386
Teach FunctionAttr to infer the nonnull attribute on return values of functions which never return a potentially null value. This is done both via a conservative local analysis for the function itself and a optimistic per-SCC analysis. If no function in the SCC returns anything which could be null (other than values from other functions in the SCC), we can conclude no function returned a null pointer. Even if some function within the SCC returns a null pointer, we may be able to locally conclude that some don't.
Differential Revision: http://reviews.llvm.org/D9688
llvm-svn: 246476
The personality routine currently lives in the LandingPadInst.
This isn't desirable because:
- All LandingPadInsts in the same function must have the same
personality routine. This means that each LandingPadInst beyond the
first has an operand which produces no additional information.
- There is ongoing work to introduce EH IR constructs other than
LandingPadInst. Moving the personality routine off of any one
particular Instruction and onto the parent function seems a lot better
than have N different places a personality function can sneak onto an
exceptional function.
Differential Revision: http://reviews.llvm.org/D10429
llvm-svn: 239940
Summary:
In case of functions that have a pointer argument and only pass it to
each other, the function attributes pass deduces that the pointer should
get the readnone attribute, but fails to remove a readonly attribute
that may already have been present.
Reviewers: nlewycky
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9995
llvm-svn: 238152
See r230786 and r230794 for similar changes to gep and load
respectively.
Call is a bit different because it often doesn't have a single explicit
type - usually the type is deduced from the arguments, and just the
return type is explicit. In those cases there's no need to change the
IR.
When that's not the case, the IR usually contains the pointer type of
the first operand - but since typed pointers are going away, that
representation is insufficient so I'm just stripping the "pointerness"
of the explicit type away.
This does make the IR a bit weird - it /sort of/ reads like the type of
the first operand: "call void () %x(" but %x is actually of type "void
()*" and will eventually be just of type "ptr". But this seems not too
bad and I don't think it would benefit from repeating the type
("void (), void () * %x(" and then eventually "void (), ptr %x(") as has
been done with gep and load.
This also has a side benefit: since the explicit type is no longer a
pointer, there's no ambiguity between an explicit type and a function
that returns a function pointer. Previously this case needed an explicit
type (eg: a function returning a void() function was written as
"call void () () * @x(" rather than "call void () * @x(" because of the
ambiguity between a function returning a pointer to a void() function
and a function returning void).
No ambiguity means even function pointer return types can just be
written alone, without writing the whole function's type.
This leaves /only/ the varargs case where the explicit type is required.
Given the special type syntax in call instructions, the regex-fu used
for migration was a bit more involved in its own unique way (as every
one of these is) so here it is. Use it in conjunction with the apply.sh
script and associated find/xargs commands I've provided in rr230786 to
migrate your out of tree tests. Do let me know if any of this doesn't
cover your cases & we can iterate on a more general script/regexes to
help others with out of tree tests.
About 9 test cases couldn't be automatically migrated - half of those
were functions returning function pointers, where I just had to manually
delete the function argument types now that we didn't need an explicit
function type there. The other half were typedefs of function types used
in calls - just had to manually drop the * from those.
import fileinput
import sys
import re
pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)')
addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$")
func_end = re.compile("(?:void.*|\)\s*)\*$")
def conv(match, line):
if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)):
return line
return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():]
for line in sys.stdin:
sys.stdout.write(conv(re.search(pat, line), line))
llvm-svn: 235145
Essentially the same as the GEP change in r230786.
A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)
import fileinput
import sys
import re
pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")
for line in sys.stdin:
sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))
Reviewers: rafael, dexonsmith, grosser
Differential Revision: http://reviews.llvm.org/D7649
llvm-svn: 230794
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.
This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.
* This doesn't modify gep operators, only instructions (operators will be
handled separately)
* Textual IR changes only. Bitcode (including upgrade) and changing the
in-memory representation will be in separate changes.
* geps of vectors are transformed as:
getelementptr <4 x float*> %x, ...
->getelementptr float, <4 x float*> %x, ...
Then, once the opaque pointer type is introduced, this will ultimately look
like:
getelementptr float, <4 x ptr> %x
with the unambiguous interpretation that it is a vector of pointers to float.
* address spaces remain on the pointer, not the type:
getelementptr float addrspace(1)* %x
->getelementptr float, float addrspace(1)* %x
Then, eventually:
getelementptr float, ptr addrspace(1) %x
Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.
update.py:
import fileinput
import sys
import re
ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile( r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
def conv(match, line):
if not match:
return line
line = match.groups()[0]
if len(match.groups()[5]) == 0:
line += match.groups()[2]
line += match.groups()[3]
line += ", "
line += match.groups()[1]
line += "\n"
return line
for line in sys.stdin:
if line.find("getelementptr ") == line.find("getelementptr inbounds"):
if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
line = conv(re.match(ibrep, line), line)
elif line.find("getelementptr ") != line.find("getelementptr ("):
line = conv(re.match(normrep, line), line)
sys.stdout.write(line)
apply.sh:
for name in "$@"
do
python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
rm -f "$name.tmp"
done
The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh
After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).
The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.
Reviewers: rafael, dexonsmith, grosser
Differential Revision: http://reviews.llvm.org/D7636
llvm-svn: 230786
call DAGCombiner. But we ran into a case (on Windows) where the
calling convention causes argument lowering to bail out of fast-isel,
and we end up in CodeGenAndEmitDAG() which does run DAGCombiner.
So, we need to make DAGCombiner check for 'optnone' after all.
Commit includes the test that found this, plus another one that got
missed in the original optnone work.
llvm-svn: 221168
attribute and function argument attribute synthesizing and propagating.
As with the other uses of this attribute, the goal remains a best-effort
(no guarantees) attempt to not optimize the function or assume things
about the function when optimizing. This is particularly useful for
compiler testing, bisecting miscompiles, triaging things, etc. I was
hitting specific issues using optnone to isolate test code from a test
driver for my fuzz testing, and this is one step of fixing that.
llvm-svn: 215538
Summary:
I searched Transforms/ and Analysis/ for 'ByVal' and updated those call
sites to check for inalloca if appropriate.
I added tests for any change that would allow an optimization to fire on
inalloca.
Reviewers: nlewycky
Differential Revision: http://llvm-reviews.chandlerc.com/D2449
llvm-svn: 200281
- Instead of setting the suffixes in a bunch of places, just set one master
list in the top-level config. We now only modify the suffix list in a few
suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).
- Aside from removing the need for a bunch of lit.local.cfg files, this enables
4 tests that were inadvertently being skipped (one in
Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
XFAILED).
- This commit also fixes a bunch of config files to use config.root instead of
older copy-pasted code.
llvm-svn: 188513
Various tests had sprung up over the years which had --check-prefix=ABC on the
RUN line, but "CHECK-ABC:" later on. This happened to work before, but was
strictly incorrect. FileCheck is getting stricter soon though.
Patch by Ron Ofir.
llvm-svn: 188173
This update was done with the following bash script:
find test/Transforms -name "*.ll" | \
while read NAME; do
echo "$NAME"
if ! grep -q "^; *RUN: *llc" $NAME; then
TEMP=`mktemp -t temp`
cp $NAME $TEMP
sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
while read FUNC; do
sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
done
mv $TEMP $NAME
fi
done
llvm-svn: 186268
This implies annotating it as nounwind and its arguments as nocapture. To be
conservative, we do not annotate the arguments with noalias since some platforms
do not have restrict on the declaration for gettimeofday.
llvm-svn: 185502
The simplify-libcalls pass implemented a doInitialization hook to infer
function prototype attributes for well-known functions. Given that the
simplify-libcalls pass is going away *and* that the functionattrs pass
is already in place to deduce function attributes, I am moving this logic
to the functionattrs pass. This approach was discussed during patch
review:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20121126/157465.html.
llvm-svn: 177619
The AttributeSetNode contains all of the attributes. This removes one (hopefully
last) use of the Attribute class as a container of multiple attributes.
llvm-svn: 173761
This was done through the aid of a terrible Perl creation. I will not
paste any of the horrors here. Suffice to say, it require multiple
staged rounds of replacements, state carried between, and a few
nested-construct-parsing hacks that I'm not proud of. It happens, by
luck, to be able to deal with all the TCL-quoting patterns in evidence
in the LLVM test suite.
If anyone is maintaining large out-of-tree test trees, feel free to poke
me and I'll send you the steps I used to convert things, as well as
answer any painful questions etc. IRC works best for this type of thing
I find.
Once converted, switch the LLVM lit config to use ShTests the same as
Clang. In addition to being able to delete large amounts of Python code
from 'lit', this will also simplify the entire test suite and some of
lit's architecture.
Finally, the test suite runs 33% faster on Linux now. ;]
For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s
llvm-svn: 159525
captured. This allows the tracker to look at the specific use, which may be
especially interesting for function calls.
Use this to fix 'nocapture' deduction in FunctionAttrs. The existing one does
not iterate until a fixpoint and does not guarantee that it produces the same
result regardless of iteration order. The new implementation builds up a graph
of how arguments are passed from function to function, and uses a bottom-up walk
on the argument-SCCs to assign nocapture. This gets us nocapture more often, and
does so rather efficiently and independent of iteration order.
llvm-svn: 147327
for pre-2.9 bitcode files. We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.
As usual, updating the testsuite is a PITA.
llvm-svn: 133337
to optionally look for constant or local (alloca) memory.
Teach BasicAliasAnalysis::pointsToConstantMemory to look through Select
and Phi nodes, and to support looking for local memory.
Remove FunctionAttrs' PointsToLocalOrConstantMemory function, now that
AliasAnalysis knows all the tricks that it knew.
llvm-svn: 118412
consider it to be readonly. In fact, don't even consider it to be
readonly if it does a volatile load from an AllocaInst either (it
is debatable as to whether readonly would be correct or not in this
case; play safe for the moment). This fixes PR8279.
llvm-svn: 117783
phi nodes when deciding which pointers point to local memory.
I actually checked long ago how useful this is, and it isn't
very: it hardly ever fires in the testsuite, but since Chris
wants it here it is!
llvm-svn: 92836
memcpy, memset and other intrinsics that only access their arguments
to be readnone if the intrinsic's arguments all point to local memory.
This improves the testcase in the README to readonly, but it could in
theory be made readnone, however this would involve more sophisticated
analysis that looks through the memcpy.
llvm-svn: 92829
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.
llvm-svn: 81537
bits captured, but the pointer marked nocapture. In fact
I now recall that this problem is why only readnone functions
returning void were considered before! However keep a small
fix that was also in r70876: a readnone function returning
void can result in bits being captured if it unwinds, so
test for this.
llvm-svn: 71168
the readnone. Since MallocInst is scheduled for deletion
it doesn't seem worth doing anything more subtle, such as
having mayWriteToMemory return true for MallocInst.
llvm-svn: 71077
only capture their arguments by returning them or
throwing an exception or not based on the argument
value. Patch essentially by Frits van Bommel.
llvm-svn: 70876
was it not very helpful, it was also wrong! The problem
is shown in the testcase: the alloca might be passed to
a nocapture callee which dereferences it and returns the
original pointer. But because it was a nocapture call we
think we don't need to track its uses, but we do.
llvm-svn: 61876
the argument to be stored to an alloca by tracking uses
of the alloca. This occurs 4 times (out of 7121, 0.05%)
in MultiSource/Applications, so may not be worth it. On
the other hand, it is easy to do and fairly cheap. The
functions it helps are: W_addcom and W_addlit in spiff;
process_args (argv) in d (make_dparser); ercPixConcealIMB
in JM/ldecod.
llvm-svn: 61570
functions that don't write can't leak a pointer except through
the return value, so a void readonly function is implicitly nocapture.
Test these, and add a test that verifies that f1 calling f2 with an
otherwise dead pointer gets both of them marked nocapture.
llvm-svn: 61552
to work out (in a very simplistic way) which function
arguments (pointer arguments only) are only dereferenced
and so do not escape. Mark such arguments 'nocapture'.
llvm-svn: 61525
Johannes Doerfert