Summary:
It is sometimes important to check that some newly-computed value
is non-negative and only `n` bits wide (where `n` is a variable.)
There are **many** ways to check that:
https://godbolt.org/z/o4RB8D
The last variant seems best?
(I'm sure there are some other variations i haven't thought of..)
Let's handle the second variant first, since it is much simpler.
https://rise4fun.com/Alive/LYjYhttps://bugs.llvm.org/show_bug.cgi?id=38708
Reviewers: spatel, craig.topper, RKSimon
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51985
llvm-svn: 342067
Fix for https://bugs.llvm.org/show_bug.cgi?id=38912.
In GVNHoist::computeInsertionPoints() we iterate over the Value
Numbers and calculate the Iterated Dominance Frontiers without
clearing the IDFBlocks vector first. IDFBlocks ends up accumulating
an insane number of basic blocks, which bloats the compilation time
of SemaChecking.cpp with ubsan enabled.
Differential Revision: https://reviews.llvm.org/D51980
llvm-svn: 342055
Previously the alignment on the newly created switch table data was not set,
meaning that DataLayout::getPreferredAlignment was free to overalign it to 16
bytes. This causes unnecessary code bloat.
Differential Revision: https://reviews.llvm.org/D51800
llvm-svn: 342039
Move the 2 classes out of LoopVectorize.cpp to make it easier to re-use
them for VPlan outside LoopVectorize.cpp
Reviewers: Ayal, mssimpso, rengolin, dcaballe, mkuper, hsaito, hfinkel, xbolva00
Reviewed By: rengolin, xbolva00
Differential Revision: https://reviews.llvm.org/D49488
llvm-svn: 342027
Summary:
The InductionDescriptor and RecurrenceDescriptor classes basically analyze the IR to identify the respective IVs. So, it is better to have them in the "Analysis" directory instead of the "Transforms" directory.
The rationale for this is to make the Induction and Recurrence descriptor classes available for analysis passes. Currently including them in an analysis pass produces link error (http://lists.llvm.org/pipermail/llvm-dev/2018-July/124456.html).
Induction and Recurrence descriptors are moved from Transforms/Utils/LoopUtils.h|cpp to Analysis/IVDescriptors.h|cpp.
Reviewers: dmgreen, llvm-commits, hfinkel
Reviewed By: dmgreen
Subscribers: mgorny
Differential Revision: https://reviews.llvm.org/D51153
llvm-svn: 342016
Name: op_ugt_sum
%a = add i8 %x, %y
%r = icmp ugt i8 %x, %a
=>
%notx = xor i8 %x, -1
%r = icmp ugt i8 %y, %notx
Name: sum_ult_op
%a = add i8 %x, %y
%r = icmp ult i8 %a, %x
=>
%notx = xor i8 %x, -1
%r = icmp ugt i8 %y, %notx
https://rise4fun.com/Alive/ZRxI
AFAICT, this doesn't interfere with any add-saturation patterns
because those have >1 use for the 'add'. But this should be
better for IR analysis and codegen in the basic cases.
This is another fold inspired by PR14613:
https://bugs.llvm.org/show_bug.cgi?id=14613
llvm-svn: 342004
This reverts rL341954.
The builder `sanitizer-x86_64-linux-bootstrap-ubsan` has been
failing with timeouts at stage2 clang/ubsan:
[3065/3073] Linking CXX executable bin/lld
command timed out: 1200 seconds without output running python
../sanitizer_buildbot/sanitizers/buildbot_selector.py,
attempting to kill
llvm-svn: 342001
These are the folds in Alive;
Name: xor_ult
Pre: isPowerOf2(-C1)
%xor = xor i8 %x, C1
%r = icmp ult i8 %xor, C1
=>
%r = icmp ugt i8 %x, ~C1
Name: xor_ugt
Pre: isPowerOf2(C1+1)
%xor = xor i8 %x, C1
%r = icmp ugt i8 %xor, C1
=>
%r = icmp ugt i8 %x, C1
https://rise4fun.com/Alive/Vty
The ugt case in its simplest form was already handled by DemandedBits,
but that's not ideal as shown in the multi-use test.
I'm not sure if these are all of the symmetrical folds, but I adjusted
the existing code for one of the folds to try to show the similarities.
There's no obvious connection, but this is another preliminary step
for PR14613...
https://bugs.llvm.org/show_bug.cgi?id=14613
llvm-svn: 341997
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D51902
llvm-svn: 341987
Summary:
Update MemorySSA in old LoopUnswitch pass.
Actual dependency and update is disabled by default.
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D45301
llvm-svn: 341984
I noticed that we were not back-propagating undef lanes to shuffle masks when we have a
shuffle that reduces the vector width. This is part of investigating/solving PR38691:
https://bugs.llvm.org/show_bug.cgi?id=38691
The DAG equivalent was proposed with:
D51696
Differential Revision: https://reviews.llvm.org/D51433
llvm-svn: 341981
Right now, the counters are added in regards of the number of successors
for a given BasicBlock: it's good when we've only 1 or 2 successors (at
least with BranchInstr). But in the case of a switch statement, the
BasicBlock after switch has several predecessors and we need know from
which BB we're coming from.
So the idea is to revert what we're doing: add a PHINode in each block
which will select the counter according to the incoming BB. They're
several pros for doing that:
- we fix the "switch" bug
- we remove the function call to "__llvm_gcov_indirect_counter_increment"
and the lookup table stuff
- we replace by PHINodes, so the optimizer will probably makes a better
job.
Patch by calixte!
Differential Revision: https://reviews.llvm.org/D51619
llvm-svn: 341977
For vectors, getPrimitiveSizeInBits returns the full vector width. This code should using the element size for vectors. This could be fixed by calling getScalarSizeInBits, but its even easier to just get it from the APInt we're checking.
Differential Revision: https://reviews.llvm.org/D51938
llvm-svn: 341971
There are 2 cases when we create PHI nodes:
* For the result of the call that was duplicated in the split blocks.
Those PHI nodes should have the debug location of the call.
* For values produced before the call. Those instructions need to be
duplicated in the split blocks and the PHI nodes should have the
debug locations of those instructions.
Fixes PR37962.
Reviewers: junbuml, gbedwell, vsk
Reviewed By: junbuml
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D51919
llvm-svn: 341970
Summary:
Place global arrays in comdat sections with their associated functions.
This makes sure they are stripped along with the functions they
reference, even on the BFD linker.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D51902
llvm-svn: 341951
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
Currently we re-use cached info from sub loops or traverse them
to populate AliasSetTracker. But after that we traverse all basic blocks
from the current loop. This is redundant work.
All what we need is traversing the all basic blocks from the loop except
those which are used to get the data from the cache.
This should improve compile time only.
Reviewers: mkazantsev, reames, kariddi, anna
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51715
llvm-svn: 341896
IndVarSimplify's design is somewhat odd in the way how it reports that
some transform has made a change. It has a `Changed` field which can
be set from within any function, which makes it hard to track whether or
not it was set properly after a transform was made. It leads to oversights
in setting this flag where needed, see example in PR38855.
This patch removes the `Changed` field, turns it into a local and unifies
the signatures of all relevant transform functions to return boolean value
which designates whether or not this transform has made a change.
Differential Revision: https://reviews.llvm.org/D51850
Reviewed By: skatkov
llvm-svn: 341893
I'd made exactly this same change before, but it appears to have been accidentally reverted in another change. (I'm assuming accidental since it was without comment or test case, and in an unrelated change.)
llvm-svn: 341892
Summary:
Revert min/max changes in rL341674 dues to high compile times causing timeouts (PR38897).
Checking in to unblock failing builds. Patch available for post-commit review and re-revert once resolved.
Working on a smaller reproducer for PR38897.
Reviewers: craig.topper, spatel
Subscribers: sanjoy, jlebar, llvm-commits
Differential Revision: https://reviews.llvm.org/D51897
llvm-svn: 341883
Before tagging a function with coldcc make sure the target supports cold calling
convention. Without this patch HotColdSplitting pass fails on aarch64 with:
fatal error: error in backend: Unsupported calling convention.
llvm-svn: 341838
There were two combines not covered by the check before now, neither of which
actually differed from normal in the benefit analysis.
The most recent seems to be because it was just added at the top of the
function (naturally). The older is from way back in 2008 (r46687) when we just
didn't put those checks in so routinely, and has been diligently maintained
since.
llvm-svn: 341831
When GVN propagates an equality by replacing one value with another it also
needs to invalidate the cached information for the value being replaced.
Differential Revision: https://reviews.llvm.org/D51218
llvm-svn: 341820
Currently, `rewriteFirstIterationLoopExitValues` does not set Changed flag even if it makes
changes in the IR. There is no clear evidence that it can cause a crash, but it
looks highly suspicious and likely invalid.
Differential Revision: https://reviews.llvm.org/D51779
Reviewed By: skatkov
llvm-svn: 341779
Currently, `sinkUnusedInvariants` does not set Changed flag even if it makes
changes in the IR. There is no clear evidence that it can cause a crash, but it
looks highly suspicious and likely invalid.
Differential Revision: https://reviews.llvm.org/D51777
Reviewed By: skatkov
llvm-svn: 341777
Summary:
Move InductionDescriptor::transform() routine from LoopUtils to its only uses in LoopVectorize.cpp.
Specifically, the function is renamed as InnerLoopVectorizer::emitTransformedIndex().
This is a child to D51153.
Reviewers: dmgreen, llvm-commits
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D51837
llvm-svn: 341776
Summary:
Block splitting is done with either identical edges being merged, or not.
Only critical edges can be split without merging identical edges based on an option.
Teach the memoryssa updater to take this into account: for the same edge between two blocks only move one entry from the Phi in Old to the new Phi in New.
Reviewers: george.burgess.iv
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D51563
llvm-svn: 341709
shuf (sel (shuf NarrowCond, undef, WideMask), X, Y), undef, NarrowMask) -->
sel NarrowCond, (shuf X, undef, NarrowMask), (shuf Y, undef, NarrowMask)
The motivating case from:
https://bugs.llvm.org/show_bug.cgi?id=38691
...is the last regression test. In that case, we're just left with the narrow select.
Note that if we do create new shuffles, they use the existing extraction identity mask,
so there's no danger that this transform creates arbitrary shuffles.
Differential Revision: https://reviews.llvm.org/D51496
llvm-svn: 341708
Summary:
Do away with demangling. It wasn't really necessary.
Declared some local functions to be static.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51740
llvm-svn: 341681
If the ~X wasn't able to simplify above the max/min, we might be able to simplify it by moving it below the max/min.
I had to modify the ~(min/max ~X, Y) transform to prevent getting stuck in a loop when we saw the new ~(max/min X, ~Y) before the ~Y had been folded away to remove the new not.
Differential Revision: https://reviews.llvm.org/D51398
llvm-svn: 341674
Fix a latent bug in loop vectorizer which generates incorrect code for
memory accesses that are executed conditionally. As pointed in review,
this bug definitely affects uniform loads and may affect conditional
stores that should have turned into scatters as well).
The code gen for conditionally executed uniform loads on architectures
that support masked gather instructions is broken.
Without this patch, we were unconditionally executing the *conditional*
load in the vectorized version.
This patch does the following:
1. Uniform conditional loads on architectures with gather support will
have correct code generated. In particular, the cost model
(setCostBasedWideningDecision) is fixed.
2. For the recipes which are handled after the widening decision is set,
we use the isScalarWithPredication(I, VF) form which is added in the
patch.
3. Fix the vectorization cost model for scalarization
(getMemInstScalarizationCost): implement and use isPredicatedInst to
identify *all* predicated instructions, not just scalar+predicated. So,
now the cost for scalarization will be increased for maskedloads/stores
and gather/scatter operations. In short, we should be choosing the
gather/scatter in place of scalarization on archs where it is
profitable.
4. We needed to weaken the assert in useEmulatedMaskMemRefHack.
Reviewers: Ayal, hsaito, mkuper
Differential Revision: https://reviews.llvm.org/D51313
llvm-svn: 341673
Find cold blocks based on profile information (or optionally with static analysis).
Forward propagate profile information to all cold-blocks.
Outline a cold region.
Set calling conv and prof hint for the callsite of the outlined function.
Worked in collaboration with: Sebastian Pop <s.pop@samsung.com>
Differential Revision: https://reviews.llvm.org/D50658
llvm-svn: 341669
If OtherOpT or OtherOpF have scalar types and the condition is a vector,
we would create an invalid select.
Reviewers: spatel, john.brawn, mssimpso, craig.topper
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D51781
llvm-svn: 341666
Currently eliminateInstructions only returns true if any instruction got
replaced. In the test case for this patch, we eliminate the trivially
dead calls, for which eliminateInstructions not do a replacement and the
function is not marked as changed, which is why the inliner crashes
while traversing the call graph.
Alternatively we could also change eliminateInstructions to return true
in case we mark instructions for deletion, but that's slightly more code
and doing it at the place where the replacement happens seems safer.
Fixes PR37517.
Reviewers: davide, mcrosier, efriedma, bjope
Reviewed By: bjope
Differential Revision: https://reviews.llvm.org/D51169
llvm-svn: 341651
Introduce the -msan-kernel flag, which enables the kernel instrumentation.
The main differences between KMSAN and MSan instrumentations are:
- KMSAN implies msan-track-origins=2, msan-keep-going=true;
- there're no explicit accesses to shadow and origin memory.
Shadow and origin values for a particular X-byte memory location are
read and written via pointers returned by
__msan_metadata_ptr_for_load_X(u8 *addr) and
__msan_store_shadow_origin_X(u8 *addr, uptr shadow, uptr origin);
- TLS variables are stored in a single struct in per-task storage. A call
to a function returning that struct is inserted into every instrumented
function before the entry block;
- __msan_warning() takes a 32-bit origin parameter;
- local variables are poisoned with __msan_poison_alloca() upon function
entry and unpoisoned with __msan_unpoison_alloca() before leaving the
function;
- the pass doesn't declare any global variables or add global constructors
to the translation unit.
llvm-svn: 341637
Roman Lebedev