MergeICmps will currently sort (by offset) all comparisons in a chain,
including those that do not get merged. This is problematic in two ways:
* We may end up moving the original first block into the middle of
the chain, in which case the "extra work" instructions will also
be in the middle of the chain, resulting in invalid IR
(reported in https://reviews.llvm.org/D108782#3005583).
* Reordering branches is generally not legal, because it may
introduce branch on poison, which is UB (PR51845). The merging
done by MergeICmps is legal as long as we assume that memcmp()
works on frozen memory, but the reordering of unmerged comparisons
is definitely incorrect (without inserting freeze instructions),
so we should avoid it.
There are easier ways to fix the first issue, but I figured it was
worthwhile to do this properly to also fix the second one. What we
now do is to restore the original relative order of (potentially
merged) comparisons.
I took the liberty of dropping the MERGEICMPS_DOT_ON functionality,
because it would be more awkward to implement now (as the before and
after representation is different) and it doesn't seem terribly
useful nowadays.
Differential Revision: https://reviews.llvm.org/D110024
This patch fixes the crash found by PR51614:
whenever doing tail folding, interleave groups must be considered under mask.
Another fix D108900 follows for targets that support masked loads and stores:
when *deciding* to vectorize with masked interleave groups, check if the access
is reverse - which is currently not supported; rather than (only) asserting when
computing cost and generating code.
Differential Revision: https://reviews.llvm.org/D108891
We already have pow(x, y) * pow(x, z) -> pow(x, y + z) transformation, but we are missing same transformation for powi (power is integer).
Requires reassoc.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D109954
isValidAssumeForContext can provide better results with access to the
dominator tree in some cases. This patch adjusts computeConstantRange to
allow passing through a dominator tree.
The use VectorCombine is updated to pass through the DT to enable
additional scalarization.
Note that similar APIs like computeKnownBits already accept optional dominator
tree arguments.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D110175
This patch allows sinking an instruction which can have multiple uses in a
single user. We were previously over-restrictive by looking for exactly one use,
rather than one user.
Also added an API for retrieving a unique undroppable user.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D109700
This fixes PR51730, a heap-use-after-free bug in
replaceConditionalBranchesOnConstant().
With the attached reproducer we were left with a function looking
something like this after replaceAndRecursivelySimplify():
[...]
cont2.i:
br i1 %.not1.i, label %handler.type_mismatch3.i, label %cont4.i
handler.type_mismatch3.i:
%3 = phi i1 [ %2, %cont2.thread.i ], [ false, %cont2.i ]
unreachable
cont4.i:
unreachable
[...]
with both the branch instruction and PHI node being in the worklist. As
a result of replacing the branch instruction with an unconditional
branch, the PHI node in %handler.type_mismatch3.i would be removed. This
then resulted in a heap-use-after-free bug due to accessing that removed
PHI node in the next worklist iteration.
This is solved by using a value handle worklist. I am a unsure if this
is the most idiomatic solution. Another solution could have been to
produce a worklist just containing the interesting branch instructions,
but I thought that it perhaps was a bit cleaner to keep all worklist
filtering in the loop that does the rewrites.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D109221
First (and biggest) change is to use "Killing/Dead" in place of "Later/Earlier" base for names in DSE. For example, [Maybe]DeadLoc - is a location killed by KillingI instruction. I believe such names are more descriptive and easy to understand than current ones.
Second, there are inconsistencies in naming where different names are used for the same thing. Fixed that too.
Third, reordered parameters of isPartialOverwrite, tryToMergePartialOverlappingStores, isOverwrite to make them consistent between each other. This greatly reduces potential mistakes.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D106947
When following a case of a switch instruction is guaranteed to lead to
UB, we can safely break these edges and redirect those cases into a newly
created unreachable block. As result, CFG will become simpler and we can
remove some of Phi inputs to make further analyzes easier.
Patch by Dmitry Bakunevich!
Differential Revision: https://reviews.llvm.org/D109428
Reviewed By: lebedev.ri
We implement logic to convert a byte offset into a sequence of GEP
indices for that offset in a number of places. This patch adds a
DataLayout::getGEPIndicesForOffset() method, which implements the
core logic. I've updated SROA, ConstantFolding and InstCombine to
use it, and there's a few more places where it looks relevant.
Differential Revision: https://reviews.llvm.org/D110043
Reworked reordering algorithm. Originally, the compiler just tried to
detect the most common order in the reordarable nodes (loads, stores,
extractelements,extractvalues) and then fully rebuilding the graph in
the best order. This was not effecient, since it required an extra
memory and time for building/rebuilding tree, double the use of the
scheduling budget, which could lead to missing vectorization due to
exausted scheduling resources.
Patch provide 2-way approach for graph reodering problem. At first, all
reordering is done in-place, it doe not required tree
deleting/rebuilding, it just rotates the scalars/orders/reuses masks in
the graph node.
The first step (top-to bottom) rotates the whole graph, similarly to the previous
implementation. Compiler counts the number of the most used orders of
the graph nodes with the same vectorization factor and then rotates the
subgraph with the given vectorization factor to the most used order, if
it is not empty. Then repeats the same procedure for the subgraphs with
the smaller vectorization factor. We can do this because we still need
to reshuffle smaller subgraph when buildiong operands for the graph
nodes with lasrger vectorization factor, we can rotate just subgraph,
not the whole graph.
The second step (bottom-to-top) scans through the leaves and tries to
detect the users of the leaves which can be reordered. If the leaves can
be reorder in the best fashion, they are reordered and their user too.
It allows to remove double shuffles to the same ordering of the operands in
many cases and just reorder the user operations instead. Plus, it moves
the final shuffles closer to the top of the graph and in many cases
allows to remove extra shuffle because the same procedure is repeated
again and we can again merge some reordering masks and reorder user nodes
instead of the operands.
Also, patch improves cost model for gathering of loads, which improves
x264 benchmark in some cases.
Gives about +2% on AVX512 + LTO (more expected for AVX/AVX2) for {625,525}x264,
+3% for 508.namd, improves most of other benchmarks.
The compile and link time are almost the same, though in some cases it
should be better (we're not doing an extra instruction scheduling
anymore) + we may vectorize more code for the large basic blocks again
because of saving scheduling budget.
Differential Revision: https://reviews.llvm.org/D105020
In default pipelines the ModuleInlinerWrapperPass is adding the
InlinerPass to the pipeline twice, once due to MandatoryFirst (passing
true in the ctor) and then a second time with false as argument.
To make it possible to bisect and reduce opt test cases for this
part of the pipeline we need to be able to choose between the two
different variants of the InlinerPass when running opt. This patch is
changing 'inline' to a CGSCC_PASS_WITH_PARAMS in the PassRegistry,
making it possible run opt with both -passes=cgscc(inline) and
-passes=cgscc(inline<only-mandatory>).
Reviewed By: aeubanks, mtrofin
Differential Revision: https://reviews.llvm.org/D109877
All transforms of IndVars have prerequisite requirement of LCSSA and LoopSimplify
form and rely on it. Added test that shows that this actually stands.
This reverts commit 6fec6552f54885ae06bf76b35f9f1173a0561a4c.
The patch was reverted on incorrect claim that this patch may break LCSSA form
when the loop is not in a simplify form. All IndVars' transform insure that
the loop is in simplify and LCSSA form, so if it wasn't broken before this
transform, it will also not be broken after it.
The scev-based salvaging for LSR can sometimes produce unnecessarily
verbose expressions. This patch adds logic to detect when the value to
be recovered and the induction variable differ by only a constant
offset. Then, the expression to derive the current iteration count can
be omitted from the dbg.value in favour of the offset.
Reviewed by: aprantl
Differential Revision: https://reviews.llvm.org/D109044
The AAExecutionDomain instance checks if a BB is executed by the main
thread only. Currently, this only checks the `__kmpc_kernel_init` call
for generic regions to indicate the path taken by the main thread. In
the new runtime, we want to be able to detect basic blocks even in SPMD
mode. For this we enable it to check thread-ID intrinsics being compared
to zero as well.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D109849
Nobody has complained about this, and the documentation for
LLVMContext::yield() states that LLVM is allowed to never call it.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D110008
This introduces an option to allow specialising on the address of global
values. This option is off by default because it is likely not that profitable
to do so and needs more investigation. Before, we were specialising on addresses
and thus this changes the default behaviour.
Differential Revision: https://reviews.llvm.org/D109775
Do not call `TryToShrinkGlobalToBoolean` for address spaces
that don't allow initializers. It inserts an initializer value
while shrinking to bool. Used the target hook introduced with
D109337 to skip this call for the restricted address spaces.
Reviewed By: tra
Differential Revision: https://reviews.llvm.org/D109823
To make the IR easier to analyze, this pass makes some minor transformations.
After that, even if it doesn't decide to optimize anything, it can't report that
it changed nothing and preserved all the analyses.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D109855
Skip stack accesses unless requested, as the memory profiler runtime
does not currently look at or report accesses for these addresses.
Differential Revision: https://reviews.llvm.org/D109868
getMetadata() currently uses a weird API where it populates a
structure passed to it, and optionally merges into it. Instead,
we can return the AAMDNodes and provide a separate merge() API.
This makes usages more compact.
Differential Revision: https://reviews.llvm.org/D109852
This makes some tests in vector-reductions-logical.ll more stable when
applying D108837.
The cost of branching is higher when vector ops are involved due to
potential SLP transformations.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D108935
Change the asan-module pass into a MODULE_PASS_WITH_PARAMS in the
pass registry, and add a single parameter called 'kernel' that
can be set instead of having a special pass name 'kasan-module'
to trigger that special pass config.
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Split ThreadSanitizerPass into ThreadSanitizerPass (as a function
pass) and ModuleThreadSanitizerPass (as a module pass).
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Split MemorySanitizerPass into MemorySanitizerPass (as a function
pass) and ModuleMemorySanitizerPass (as a module pass).
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Alive2 for `{insert/extract}element`: https://alive2.llvm.org/ce/z/hwy_E-
Actually, no one file of test suite is touched by this change,
which means that is rare pattern not generated by frontend. But
it's worth being in place.
Differential Revision: https://reviews.llvm.org/D109236
In particular, it couldn't handle cases where lookup table constant
expressions involved bitcasts. This does not seem to come up
frequently in C++, but comes up reasonably often in Rust via
`#[derive(Debug)]`.
Originally reported by pcwalton.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D109565
This reverts commit 4ac4e52189aa6d80c3d59dc2c8f7dcc0cb7f9d58.
There are couple of test failures, which needs update of the test cases.
Doing a clean revert and will recommit the change along with fixed
testcases.
Fix build bot failure in rG4ac4e521 caused due to assumeBundleBuilder
using new API (getUniqueUndroppableUser).
We now continue using the existing API for AssumeBundleBuilder
(getSingleUndroppableUser).
Sorry for the noise here.
Tests-Run: failing testcase passes.
This patch allows sinking an instruction which can have multiple uses in a
single user. We were previously over-restrictive by looking for exactly one use,
rather than one user.
Also, the API for retrieving undroppable user has been updated accordingly since
in both usecases (Attributor and InstCombine), we seem to care about the user,
rather than the use.
Reviewed-By: nikic
Differential Revision: https://reviews.llvm.org/D109700
I was wondering how instcombine does on the examples in D109236,
and we're missing a basic transform:
inselt (ext X), (ext Y), Index --> ext (inselt X, Y, Index)
https://alive2.llvm.org/ce/z/z2aBu9
Note that there are several possible extensions of this fold
(see TODO comments).
Differential Revision: https://reviews.llvm.org/D109537
