Causes unexpected memory issue with New PM this time.
The new PM invalidates BPI but not BFI, leaving the
reference to BPI from BFI invalid.
Abandon this patch. There is a more general solution
which also handles runtime infinite loop (but not statically).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320180 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Make enum ModRefInfo an enum class. Changes to ModRefInfo values should
be done using inline wrappers.
This should prevent future bit-wise opearations from being added, which can be more error-prone.
Reviewers: sanjoy, dberlin, hfinkel, george.burgess.iv
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40933
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320107 91177308-0d34-0410-b5e6-96231b3b80d8
This caused PR35519.
> [memcpyopt] Teach memcpyopt to optimize across basic blocks
>
> This teaches memcpyopt to make a non-local memdep query when a local query
> indicates that the dependency is non-local. This notably allows it to
> eliminate many more llvm.memcpy calls in common Rust code, often by 20-30%.
>
> Fixes PR28958.
>
> Differential Revision: https://reviews.llvm.org/D38374
>
> [memcpyopt] Commit file missed in r319482.
>
> This change was meant to be included with r319482 but was accidentally
> omitted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319873 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The aim is to make ModRefInfo checks and changes more intuitive
and less error prone using inline methods that abstract the bit operations.
Ideally ModRefInfo would become an enum class, but that change will require
a wider set of changes into FunctionModRefBehavior.
Reviewers: sanjoy, george.burgess.iv, dberlin, hfinkel
Subscribers: nlopes, llvm-commits
Differential Revision: https://reviews.llvm.org/D40749
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319821 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
I don't think rL309080 is the right fix for PR33494 -- caching ExitLimit only
hides the problem[0]. The real issue is that because of how we forget SCEV
expressions ScalarEvolution::getBackedgeTakenInfo, in the test case for PR33494
computing the backedge for any loop invalidates the trip count for every other
loop. This effectively makes the SCEV cache useless.
I've instead made the SCEV expression invalidation in
ScalarEvolution::getBackedgeTakenInfo less aggressive to fix this issue.
[0]: One way to think about this is that rL309080 essentially augmented the
backedge-taken-count cache with another equivalent exit-limit cache. The bug
went away because we were explicitly not clearing the exit-limit cache in
getBackedgeTakenInfo. But instead of doing all of that, we can just avoid
clearing the backedge-taken-count cache.
Reviewers: mkazantsev, mzolotukhin
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D39361
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319678 91177308-0d34-0410-b5e6-96231b3b80d8
Support for outlining multiple regions of each function is added, as well as some basic heuristics to determine which regions are good to outline. Outline candidates limited to regions that are single-entry & single-exit. We also avoid outlining regions that produce live-exit variables, which may inhibit some forms of code motion (like commoning).
Fallback to the regular partial inlining scheme is retained when either i) no regions are identified for outlining in the function, or ii) the outlined function could not be inlined in any of its callers.
Differential Revision: https://reviews.llvm.org/D38190
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319398 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
First step in adding MemorySSA as dependency for loop pass manager.
Adding the dependency under a flag.
New pass manager: MSSA pointer in LoopStandardAnalysisResults can be null.
Legacy and new pass manager: Use cl::opt EnableMSSALoopDependency. Disabled by default.
Reviewers: sanjoy, davide, gberry
Subscribers: mehdi_amini, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D40274
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318772 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Add the following heuristics for irreducible loop metadata:
- When an irreducible loop header is missing the loop header weight metadata,
give it the minimum weight seen among other headers.
- Annotate indirectbr targets with the loop header weight metadata (as they are
likely to become irreducible loop headers after indirectbr tail duplication.)
These greatly improve the accuracy of the block frequency info of the Python
interpreter loop (eg. from ~3-16x off down to ~40-55% off) and the Python
performance (eg. unpack_sequence from ~50% slower to ~8% faster than GCC) due to
better register allocation under PGO.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39980
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318693 91177308-0d34-0410-b5e6-96231b3b80d8
making it no longer even remotely simple.
The pass will now be more of a "full loop unswitching" pass rather than
anything substantively simpler than any other approach. I plan to rename
it accordingly once the dust settles.
The key ideas of the new loop unswitcher are carried over for
non-trivial unswitching:
1) Fully unswitch a branch or switch instruction from inside of a loop to
outside of it.
2) Update the CFG and IR. This avoids needing to "remember" the
unswitched branches as well as avoiding excessively cloning and
reliance on complex parts of simplify-cfg to cleanup the cfg.
3) Update the analyses (where we can) rather than just blowing them away
or relying on something else updating them.
Sadly, #3 is somewhat compromised here as the dominator tree updates
were too complex for me to want to reason about. I will need to make
another attempt to do this now that we have a nice dynamic update API
for dominators. However, we do adhere to #3 w.r.t. LoopInfo.
This approach also adds an important principls specific to non-trivial
unswitching: not *all* of the loop will be duplicated when unswitching.
This fact allows us to compute the cost in terms of how much *duplicate*
code is inserted rather than just on raw size. Unswitching conditions
which essentialy partition loops will work regardless of the total loop
size.
Some remaining issues that I will be addressing in subsequent commits:
- Handling unstructured control flow.
- Unswitching 'switch' cases instead of just branches.
- Moving to the dynamic update API for dominators.
Some high-level, interesting limitationsV that folks might want to push
on as follow-ups but that I don't have any immediate plans around:
- We could be much more clever about not cloning things that will be
deleted. In fact, we should be able to delete *nothing* and do
a minimal number of clones.
- There are many more interesting selection criteria for which branch to
unswitch that we might want to look at. One that I'm interested in
particularly are a set of conditions which all exit the loop and which
can be merged into a single unswitched test of them.
Differential revision: https://reviews.llvm.org/D34200
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318549 91177308-0d34-0410-b5e6-96231b3b80d8
This function checks that:
1) It is safe to expand a SCEV;
2) It is OK to materialize it at the specified location.
For example, attempt to expand a loop's AddRec to the same loop's preheader should fail.
Differential Revision: https://reviews.llvm.org/D39236
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318377 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317729 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently the block frequency analysis is an approximation for irreducible
loops.
The new irreducible loop metadata is used to annotate the irreducible loop
headers with their header weights based on the PGO profile (currently this is
approximated to be evenly weighted) and to help improve the accuracy of the
block frequency analysis for irreducible loops.
This patch is a basic support for this.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: mehdi_amini, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D39028
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317278 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Compute the strongly connected components of the CFG and fall back to
use these for blocks that are in loops that are not detected by
LoopInfo when computing loop back-edge and exit branch probabilities.
Reviewers: dexonsmith, davidxl
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D39385
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317094 91177308-0d34-0410-b5e6-96231b3b80d8
- Targets that want to support memcmp expansions now return the list of
supported load sizes.
- Expansion codegen does not assume that all power-of-two load sizes
smaller than the max load size are valid. For examples, this is not the
case for x86(32bit)+sse2.
Fixes PR34887.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316905 91177308-0d34-0410-b5e6-96231b3b80d8
If particular target supports volatile memory access operations, we can
avoid AS casting to generic AS. Currently it's only enabled in NVPTX for
loads and stores that access global & shared AS.
Differential Revision: https://reviews.llvm.org/D39026
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316495 91177308-0d34-0410-b5e6-96231b3b80d8
This creates ODR violations if the function is called from another inline function in a header and also creates binary bloat from duplicate definitions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316476 91177308-0d34-0410-b5e6-96231b3b80d8
This creates ODR violations if the function is called from another inline function in a header and also creates binary bloat from duplicate definitions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316475 91177308-0d34-0410-b5e6-96231b3b80d8
This creates ODR violations if the function is called from another inline function in a header and also creates binary bloat from duplicate definitions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316474 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If a compare instruction is same or inverse of the compare in the
branch of the loop latch, then return a constant evolution node.
Currently scope of evaluation is limited to SCEV computation for
PHI nodes.
This shall facilitate computations of loop exit counts in cases
where compare appears in the evolution chain of induction variables.
Will fix PR 34538
Reviewers: sanjoy, hfinkel, junryoungju
Reviewed By: junryoungju
Subscribers: javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D38494
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316054 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r315713. It causes PR34968.
I think I know what the problem is, but I don't think I'll have time to fix it
this week.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315962 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds the ability to perform IPSCCP-like interprocedural analysis to
the generic sparse propagation solver. The patch gives clients the ability to
define their own custom LatticeKey types that the generic solver maps to custom
LatticeVal types. The custom lattice keys can be used, for example, to
distinguish among mappings for regular values, values returned from functions,
and values stored in global variables. Clients are responsible for defining how
to convert between LatticeKeys and LLVM Values by providing a specialization of
the LatticeKeyInfo template.
The added unit tests demonstrate how the generic solver can be used to perform
a simplified version of interprocedural constant propagation.
Differential Revision: https://reviews.llvm.org/D37353
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315919 91177308-0d34-0410-b5e6-96231b3b80d8
This patch moves some common utility functions out of IPSCCP and makes them
available globally. The functions determine if interprocedural data-flow
analyses can propagate information through function returns, arguments, and
global variables.
Differential Revision: https://reviews.llvm.org/D37638
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315719 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change uses the loop use list added in the previous change to remember the
loops that appear in the trip count expressions of other loops; and uses it in
forgetLoop. This lets us not scan every loop in the function on a forgetLoop
call.
With this change we no longer invalidate clear out backedge taken counts on
forgetValue. I think this is fine -- the contract is that SCEV users must call
forgetLoop(L) if their change to the IR could have changed the trip count of L;
solely calling forgetValue on a value feeding into the backedge condition of L
is not enough. Moreover, I don't think we can strengthen forgetValue to be
sufficient for invalidating trip counts without significantly re-architecting
SCEV. For instance, if we have the loop:
I = *Ptr;
E = I + 10;
do {
// ...
} while (++I != E);
then the backedge taken count of the loop is 9, and it has no reference to
either I or E, i.e. there is no way in SCEV today to re-discover the dependency
of the loop's trip count on E or I. So a SCEV client cannot change E to (say)
"I + 20", call forgetValue(E) and expect the loop's trip count to be updated.
Reviewers: atrick, sunfish, mkazantsev
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D38435
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315713 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch teaches SCEV to calculate the maxBECount when the end bound
of the loop can vary. Note that we cannot calculate the exactBECount.
This will only be done when both conditions are satisfied:
1. the loop termination condition is strictly LT.
2. the IV is proven to not overflow.
This provides more information to users of SCEV and can be used to
improve identification of finite loops.
Reviewers: sanjoy, mkazantsev, silviu.baranga, atrick
Reviewed by: mkazantsev
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38825
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315683 91177308-0d34-0410-b5e6-96231b3b80d8
Significantly reduces performancei (~30%) of gipfeli
(https://github.com/google/gipfeli)
I have not yet managed to reproduce this regression with the open-source
version of the benchmark on github, but will work with others to get a
reproducer to you later today.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315680 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently we do not correctly invalidate memoized results for add recurrences
that were created directly (i.e. they were not created from a `Value`). This
change fixes this by keeping loop use lists and using the loop use lists to
determine which SCEV expressions to invalidate.
Here are some statistics on the number of uses of in the use lists of all loops
on a clang bootstrap (config: release, no asserts):
Count: 731310
Min: 1
Mean: 8.555150
50th %time: 4
95th %tile: 25
99th %tile: 53
Max: 433
Reviewers: atrick, sunfish, mkazantsev
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D38434
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315672 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Add LLVM_FORCE_ENABLE_DUMP cmake option, and use it along with
LLVM_ENABLE_ASSERTIONS to set LLVM_ENABLE_DUMP.
Remove NDEBUG and only use LLVM_ENABLE_DUMP to enable dump methods.
Move definition of LLVM_ENABLE_DUMP from config.h to llvm-config.h so
it'll be picked up by public headers.
Differential Revision: https://reviews.llvm.org/D38406
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315590 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fixes the bug introduced in https://reviews.llvm.org/D35907; the bug is reported by http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20171002/491452.html.
Before D35907, when GetUnderlyingObjects fails to find an identifiable object, allMMOsOkay lambda in getUnderlyingObjectsForInstr returns false and Objects vector is cleared. This behavior is unintentionally changed by D35907.
This patch makes the behavior for such case same as the previous behavior.
Since D35907 introduced a wrapper function getUnderlyingObjectsForCodeGen around GetUnderlyingObjects, getUnderlyingObjectsForCodeGen is modified to return a boolean value to ask the caller to clear the Objects vector.
Differential Revision: https://reviews.llvm.org/D38735
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315565 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes the work lists from std::vector to SmallVector, which
matches the SCCP implementation. This patch also updates some related comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315373 91177308-0d34-0410-b5e6-96231b3b80d8
The new name clarifies the function's relation to getValueState. That is,
unlike getValueState, the state of a given value will not be initialized if
it's not already in the map.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315356 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If the pointer width is 32 bits and the calculated GEP offset is
negative, we call APInt::getLimitedValue(), which does a
*zero*-extension of the offset. That's wrong -- we should do an sext.
Fixes a bug introduced in rL314362 and found by Evgeny Astigeevich.
Reviewers: efriedma
Subscribers: sanjoy, javed.absar, llvm-commits, eastig
Differential Revision: https://reviews.llvm.org/D38557
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314935 91177308-0d34-0410-b5e6-96231b3b80d8
Function isLoweredToCall can only accept non-null function pointer, but a function pointer can be null for indirect function call. So check it before calling isLoweredToCall from getInstructionLatency.
Differential Revision: https://reviews.llvm.org/D38204
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314927 91177308-0d34-0410-b5e6-96231b3b80d8
Recommitting r314517 with the fix for handling ConstantExpr.
Original commit message:
Currently, getGEPCost() returns TCC_FREE whenever a GEP is a legal addressing
mode in the target. However, since it doesn't check its actual users, it will
return FREE even in cases where the GEP cannot be folded away as a part of
actual addressing mode. For example, if an user of the GEP is a call
instruction taking the GEP as a parameter, then the GEP may not be folded in
isel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314923 91177308-0d34-0410-b5e6-96231b3b80d8
Before the patch this was in Analysis. Moving it to IR and making it implicit
part of LLVMContext::diagnose allows the full opt-remark facility to be used
outside passes e.g. the pass manager. Jessica is planning to use this to
report function size after each pass. The same could be used for time
reports.
Tested with BUILD_SHARED_LIBS=On.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314909 91177308-0d34-0410-b5e6-96231b3b80d8
All the buildbots are red, e.g.
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-lld/builds/2436/
> Summary:
> This patch tries to vectorize loads of consecutive memory accesses, accessed
> in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
> which was reverted back due to some basic issue with representing the 'use mask' of
> jumbled accesses.
>
> This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
>
> Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
>
> Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh
>
> Reviewed By: Ayal
>
> Subscribers: hans, mzolotukhin
>
> Differential Revision: https://reviews.llvm.org/D36130
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314824 91177308-0d34-0410-b5e6-96231b3b80d8
