Handle the fact that not only constant expressions, but also
constant aggregates containing expressions can trap.
This still doesn't fix the original C reproducer, probably due to
more issues remaining in other passes.
Per the documentation in Support/InstructionCost.h, the purpose of an invalid cost is so that clients can change behavior on impossible to cost inputs. CodeMetrics was instead asserting that invalid costs never occurred.
On a target with an incomplete cost model - e.g. RISCV - this means that transformations would crash on (falsely) invalid constructs - e.g. scalable vectors. While we certainly should improve the cost model - and I plan to do so in the near future - we also shouldn't be crashing. This violates the explicitly stated purpose of an invalid InstructionCost.
I updated all of the "easy" consumers where bailouts were locally obvious. I plan to follow up with loop unroll in a following change.
Differential Revision: https://reviews.llvm.org/D127131
Clang-format InstructionSimplify and convert all "FunctionName"s to
"functionName". This patch does touch a lot of files but gets done with
the cleanup of InstructionSimplify in one commit.
This is the alternative to the less invasive clang-format only patch: D126783
Reviewed By: spatel, rengolin
Differential Revision: https://reviews.llvm.org/D126889
The IV widening code currently asserts that terminators aren't SCEVable
-- however, this is not the case for invokes with a returned attribute.
As far as I can tell, this assertions is not necessary -- even if we
have a critical edge (the second test case), the trunc gets inserted
in a legal position.
Fixes https://github.com/llvm/llvm-project/issues/55925.
Differential Revision: https://reviews.llvm.org/D127288
Enhance memchr libcall folder to handle constant arrays consisting
of one or two sequences of cosecutive equal characters.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D126515
Now that transforms introducing branch on poison have been removed,
we can stop marking ranges that have been derived from branch
conditions as containing undef. The existing comment explains why
this is legal. I've checked that alive2 is happy with SCCP tests
after this change.
Differential Revision: https://reviews.llvm.org/D126647
Some cl::ZeroOrMore were added to avoid the `may only occur zero or one times!`
error. More were added due to cargo cult. Since the error has been removed,
cl::ZeroOrMore is unneeded.
Also remove cl::init(false) while touching the lines.
I chose to encode the allockind information in a string constant because
otherwise we would get a bit of an explosion of keywords to deal with
the possible permutations of allocation function types.
I'm not sure that CodeGen.h is the correct place for this enum, but it
seemed to kind of match the UWTableKind enum so I put it in the same
place. Constructive suggestions on a better location most certainly
encouraged.
Differential Revision: https://reviews.llvm.org/D123088
Need to use all ReductionOps when propagating flags for the reduction
ops, otherwise transformation is not correct. Plus, need to drop nuw/nsw
flags.
Differential Revision: https://reviews.llvm.org/D126371
This is a followup to D125754. We introduce two branches, one
before the unrolled loop and one before the epilogue (and similar
for the prologue case). The previous patch only froze the
condition on the first branch.
Rather than independently freezing the second condition, this patch
instead freezes TripCount and bases BECount on it. These are the
two quantities involved in the conditions, and this ensures that
both work on a consistent, non-poisonous trip count.
Differential Revision: https://reviews.llvm.org/D125896
Fixes a bug preventing moving the loop's metadata to an outer loop's header,
which happens if the loop's exit is also the header of an outer loop.
Adjusts test for above.
Fixes#55416.
Differential Revision: https://reviews.llvm.org/D125574
Evaluation odering in function call arguments is implementation-dependent.
In fact, gcc evaluates bottom-top and clang does top-bottom.
Fixes#55283 partially.
Part of https://reviews.llvm.org/D125627
The modified function was incorrectly (not unnecessarily) ignoring grandchild
loops, and this change fixes the bug. In particular, this fixes the handling of
the loop { inner, body }. The TODO in the same function is talking about the b1
self loop, which may be "unnecessarily" lost, but that is a different issue.
%x umin_seq %y is currently expanded to %x == 0 ? 0 : umin(%x, %y).
This patch changes the expansion to umin(%x, freeze %y) instead
(https://alive2.llvm.org/ce/z/wujUhp).
The motivation for this change are the test cases affected by
D124910, where the freeze expansion ultimately produces better
optimization results. This is largely because
`(%x umin_seq %y) == %x` is a common expansion pattern, which
reliably optimizes in freeze representation, but only sometimes
with the zero comparison (in particular, if %x == 0 can fold to
something else, we generally won't be able to cover reasonable
code from this.)
Differential Revision: https://reviews.llvm.org/D125372
When performing runtime unrolling with multiple exits, one of the
earlier (non-latch) exits may exit the loop on the first iteration,
such that we never branch on the latch exit condition. As such, we
need to freeze the condition of the new branch that is introduced
before the loop, as it now executes unconditionally.
Differential Revision: https://reviews.llvm.org/D125754
This patch adds initial support for a pointer diff based runtime check
scheme for vectorization. This scheme requires fewer computations and
checks than the existing full overlap checking, if it is applicable.
The main idea is to only check if source and sink of a dependency are
far enough apart so the accesses won't overlap in the vector loop. To do
so, it is sufficient to compute the difference and compare it to the
`VF * UF * AccessSize`. It is sufficient to check
`(Sink - Src) <u VF * UF * AccessSize` to rule out a backwards
dependence in the vector loop with the given VF and UF. If Src >=u Sink,
there is not dependence preventing vectorization, hence the overflow
should not matter and using the ULT should be sufficient.
Note that the initial version is restricted in multiple ways:
1. Pointers must only either be read or written, by a single
instruction (this allows re-constructing source/sink for
dependences with the available information)
2. Source and sink pointers must be add-recs, with matching steps
3. The step must be a constant.
3. abs(step) == AccessSize.
Most of those restrictions can be relaxed in the future.
See https://github.com/llvm/llvm-project/issues/53590.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D119078
We're having a hard time booting the ARCH=i386 Linux kernel with clang
after removing -ffreestanding because instcombine was dropping inreg
from callers during libcall simplification, but not the callees defined
in different translation units. This led the callers and callees to have
wildly different calling conventions, which (predictably) blew up at
runtime.
Infer the inreg param attrs on function declarations from the module
metadata "NumRegisterParameters." This allows us to boot the ARCH=i386
Linux kernel (w/ -ffreestanding removed).
Fixes: https://github.com/llvm/llvm-project/issues/53645
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D125285
When a callee function is inlined via an invoke instruction, every function call inside the callee, if not an invoke, will be converted to an invoke after cloned to the caller body. I found that during the conversion the !prof metadata was dropped. This in turned caused a cloned indirect call not properly promoted in subsequent passes.
The particular scenario I was investigating was with AutoFDO and thinLTO. In prelink, no ICP was triggered (neither by the sample loader nor PGO ICP), no indirect call was promoted. This is because 1) the particular indirect call did not have inlined samples; and 2) PGO ICP was intentionally disabled. After inlining, the prof metadata was dropped. Then in postlink, PGO ICP jumped in but didn't do anything. Thus the opportunity was missed.
I'm making a simple fix to preserve !prof metadata when converting call to invoke.
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D125249
Per feedback on D123086 after submit.
Also added a test for vec_malloc et al attribute inference to show it's
doing the right thing.
The new tests exposed a defect, corrected by adding vec_free to the list of
free functions in MemoryBuiltins.cpp, which had been overlooked all the
way back in D94710, over a year ago.
Differential Revision: https://reviews.llvm.org/D124859
libcalls." (was 0f8c626). This reverts commit 14d9390.
The patch previously failed to recognize cases where user had defined a
function alias with an identical name as that of the library
function. Module::getFunction() would then return nullptr which is what the
sanitizer discovered.
In this updated version a new function isLibFuncEmittable() has as well been
introduced which is now used instead of TLI->has() anytime a library function
is to be emitted . It additionally also makes sure there is e.g. no function
alias with the same name in the module.
Reviewed By: Eli Friedman
Differential Revision: https://reviews.llvm.org/D123198
Per the guidance in
https://llvm.org/docs/Atomics.html#atomics-and-ir-optimization,
an atomic load from a constant global can be dropped, as there can
be no stores to synchronize with. Any write to the constant global
would be UB.
IPSCCP will already drop such loads, but the main helper in Local
doesn't recognize this currently. This is motivated by D118387.
Differential Revision: https://reviews.llvm.org/D124241
TI->getBitWidth can be > 64 and in those cases the shift will be UB due
to the exponent being too large.
To fix this, cap the shift at 63. I think this should work out fine,
because TableSize is itself a 64 bit type and the maximum table size
must fit in the type. Also, if we would underestimate the size here, at
most we get an extra ZExt.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D124608
Replace the condition value with the known constant value on the
threaded edge. This happens implicitly with phi threading because
we replace with the incoming value, but not for non-phi threading.
SimplifyCFG implements basic jump threading, if a branch is
performed on a phi node with constant operands. However,
InstCombine canonicalizes such phis to the condition value of a
previous branch, if possible. SimplifyCFG does support this as
well, but only in the very limited case where the same condition
is used in a direct predecessor -- notably, this does not include
the common diamond pattern (i.e. two consecutive if/elses on the
same condition).
This patch extends the code to look back a limited number of
blocks to find a branch on the same value, rather than only
looking at the direct predecessor.
Fixes https://github.com/llvm/llvm-project/issues/54980.
Differential Revision: https://reviews.llvm.org/D124159
Previously all entries in global_ctors had to have the void()* type and
we'd skip evaluating bitcasted functions. With opaque pointers we may
see the function directly.
Fixes#55147.
Reviewed By: #opaque-pointers, nikic
Differential Revision: https://reviews.llvm.org/D124553
I found this bug when performing a two-stage build of clang with
Function Specialization enabled and tuned aggressively. The crash
appears only on release builds.
Fixes https://github.com/llvm/llvm-project/issues/55000.
Before accessing the contents of the ArgInfo iterator inside
SCCPInstVisitor::markArgInFuncSpecialization, we should be
checking that the iterator is valid.
Differential Revision: https://reviews.llvm.org/D124114
This continues the push away from hard-coded knowledge about functions
towards attributes. We'll use this to annotate free(), realloc() and
cousins and obviate the hard-coded list of free functions.
Differential Revision: https://reviews.llvm.org/D123083
This reorganizes the code as a preparation for D123865:
* Use more descriptive names for variables
* Simplify a condition by use an already calculated value
for `MaxPeelCount`
* Remove a duplicate log entry
* Report basic values for loop costs
Differential Revision: https://reviews.llvm.org/D124388
MisExpect diagnostics should not prevent compilation from succeeding, and the
assertion is insufficient to prevent division by zero in release builds.
This patch addresses that by replacing the assert with an early return.
Additionally, it disables MisExpect diagnostics when using sample profiling,
since this is the only known case where this error has manifested.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D124302
Reapplying without changes, after a fix to a dependent patch.
-----
Rather than creating a PHI node and then using the PHI threading
code, directly handle this case in
FoldCondBranchOnValueKnownInPredecessor().
This change is supposed to be NFC-ish, but may cause changes due
to different transform order.
Reapply with SmallMapVector instead of SmallDenseMap, which should
address the non-determinism issue.
-----
This general threading transform can be performed whenever we know
a constant value for the condition in a predecessor, which would
currently just be the case of a phi node with constant arguments.
This reverts commit 3df86e799e.
This reverts commit 8988254667.
`[SimplifyCFG] Handle branch on same condition in pred more directly`
caused non-determinism when compiling opt with a bootstrapped clang.
I have to revert the dependent commit as well.
Debugify in OriginalDebugInfo mode, does (DebugInfo) collect-before-pass & check-after-pass
for each instruction, which is pretty expensive. When used to analyze DebugInfo losses
in large projects (like LLVM), this raises the build time unacceptably.
This patch introduces a limit for the number of processed functions per compile unit.
By default, the limit is set to UINT_MAX (practically unlimited), and by using the introduced
option -debugify-func-limit the limit could be set to any positive integer number.
Differential revision: https://reviews.llvm.org/D115714
Rather than creating a PHI node and then using the PHI threading
code, directly handle this case in
FoldCondBranchOnValueKnownInPredecessor().
This change is supposed to be NFC-ish, but may cause changes due
to different transform order.
This general threading transform can be performed whenever we know
a constant value for the condition in a predecessor, which would
currently just be the case of a phi node with constant arguments.
BlockIsSimpleEnoughToThreadThrough() already checks that the phi
(and all other instructions) are not used outside the block, so
this one-use check is not necessary for legality. I also don't
see any reason why it would be necessary for profitability (in
fact, those extra uses will be replaced with constants, which
should be generally profitable).
test/Transforms/InstCombine/pr39177.ll failed in a -DLLVM_USE_SANITIZER=Undefined build.
```
lib/Transforms/Utils/BuildLibCalls.cpp:1217:17: runtime error: reference binding to null pointer of type 'llvm::Function'
```
`Function &F = *M->getFunction(Name);`
This reverts commit 0f8c626723.
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
A new set of overloaded functions named getOrInsertLibFunc() are now supposed
to be used instead of getOrInsertFunction() when building a libcall from
within an LLVM optimizer(). The idea is that this new function also makes
sure that any mandatory argument attributes are added to the function
prototype (after calling getOrInsertFunction()).
inferLibFuncAttributes() is renamed to inferNonMandatoryLibFuncAttrs() as it
only adds attributes that are not necessary for correctness but merely
helping with later optimizations.
Generally, the front end is responsible for building a correct function
prototype with the needed argument attributes. If the middle end however is
the one creating the call, e.g. when replacing one libcall with another, it
then must take this responsibility.
This continues the work of properly handling argument extension if required
by the target ABI when building a lib call. getOrInsertLibFunc() now does
this for all libcalls currently built by any LLVM optimizer. It is expected
that when in the future a new optimization builds a new libcall with an
integer argument it is to be added to getOrInsertLibFunc() with the proper
handling. Note that not all targets have it in their ABI to sign/zero extend
integer arguments to the full register width, but this will be done
selectively as determined by getExtAttrForI32Param().
Review: Eli Friedman, Nikita Popov, Dávid Bolvanský
Differential Revision: https://reviews.llvm.org/D123198
The previous patch introduced the offloading binary format so we can
store some metada along with the binary image. This patch introduces
using this inside the linker wrapper and Clang instead of the previous
method that embedded the metadata in the section name.
Differential Revision: https://reviews.llvm.org/D122683
The NewDefault was used to simplify the updating of PHI nodes, but it
causes some inefficiency for target that will run structurizer later. For
example, for a simple two-case switch, the extra NewDefault is causing
unstructured CFG like:
O
/ \
O O
/ \ / \
C1 ND C2
\ | /
\ | /
D
The change is to avoid the ND(NewDefault) block, that is we will get a
structured CFG for above example like:
O
/ \
/ \
O O
/ \ / \
C1 \ / C2
\-> D <-/
The IR change introduced by this patch should be trivial to other targets,
so I am doing this unconditionally.
Fall-through among the cases will also cause unstructured CFG, but it need
more work and will be addressed in a separate change.
Reviewed by: arsenm
Differential Revision: https://reviews.llvm.org/D123607
This reverts commit e810d55809.
The commit was not taken into account the fact that strduped string could be
modified. Checking if such modification happens would make the function very
costly, without a test case in mind it's not worth the effort.
C11 specifies memchr() as follows:
> The memchr function locates the first occurrence of c (converted
> to an unsigned char) in the initial n characters (each interpreted
> as unsigned char) of the object pointed to by s. The implementation
> shall behave as if it reads the characters sequentially and stops
> as soon as a matching character is found.
In particular, it is well-defined to specify a memchr size larger
than the underlying object, as long as the character is found before
the end of the object.
Differential Revision: https://reviews.llvm.org/D123665
This should be "NFC" as written, but it will make D122485 smaller
and give us more flexibility to experiment with optimization level
vs. compile-time.
Differential Revision: https://reviews.llvm.org/D123625
This renames functions for more general usage (and current capitalization style)
before a proposed logic change in D122485.
Differential Revision: https://reviews.llvm.org/D123614
Currently, the utility supports lowering of non atomic memory transfer routines only. This patch adds support for atomic version of memcopy. This may be useful for targets not supporting atomic memcopy.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D118443
This is part of being able to get rid of two more columns in
MemoryBuiltins.cpp's large table. We'll have two more changes before
we can finish the job.
Differential Revision: https://reviews.llvm.org/D119582
Add void casts to mark the variables used, next to the places where
they are used in assert or `LLVM_DEBUG()` expressions.
Differential Revision: https://reviews.llvm.org/D123117
By specification, source and destination of llvm.memcpy.* must either be equal or non-overlapping. This semantics is hard or impossible to figure out once lowered. This patch explicitly marks loads from source and stores to destination as not aliasing if source and destination is known to be not equal.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D118441
getExtAttrForI32Param() is the method to be used for determining the type of
extension attribute (if any) that is to be added for a signed/unsigned
argument.
Previously, the SExt attribute was always added to the i32 ldexp* argument as
it was expected to be ignored by targets not needing it. This patch now
changes this so that it is only added for the targets that need it in the
first place.
Putchar() argument is now also extended as required by the target (SystemZ in
the test), to fix the issue below. Many more libcalls will be handled
similarly in a following patch.
Fixes https://github.com/llvm/llvm-project/issues/54532.
Differential Revision: https://reviews.llvm.org/D123030
Review: Eli Friedman
If both the character and string are known, but the length
potentially isn't, we can optimize the memchr() call to a select
of either the known position of the character or null.
Split off from https://reviews.llvm.org/D122836.
Handle the simple constant char case before the bitmask optimization.
This will allow extending the code to handle a non-constant size
argument in a followup change.
Split out from https://reviews.llvm.org/D122836.
If the memchr() size is 1, then we can convert the call into a
single-byte comparison. This works even if both the string and the
character are unknown.
Split off from https://reviews.llvm.org/D122836.
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
According to the current design, if a floating point operation is
represented by a constrained intrinsic somewhere in a function, all
floating point operations in the function must be represented by
constrained intrinsics. It imposes additional requirements to inlining
mechanism. If non-strictfp function is inlined into strictfp function,
all ordinary FP operations must be replaced with their constrained
counterparts.
Inlining strictfp function into non-strictfp is not implemented as it
would require replacement of all FP operations in the host function,
which now is undesirable due to expected performance loss.
Differential Revision: https://reviews.llvm.org/D69798
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
The current implementation of Function Specialization does not allow
specializing more than one arguments per function call, which is a
limitation I am lifting with this patch.
My main challenge was to choose the most suitable ADT for storing the
specializations. We need an associative container for binding all the
actual arguments of a specialization to the function call. We also
need a consistent iteration order across executions. Lastly we want
to be able to sort the entries by Gain and reject the least profitable
ones.
MapVector fits the bill but not quite; erasing elements is expensive
and using stable_sort messes up the indices to the underlying vector.
I am therefore using the underlying vector directly after calculating
the Gain.
Differential Revision: https://reviews.llvm.org/D119880
For MachO, lower `@llvm.global_dtors` into `@llvm_global_ctors` with
`__cxa_atexit` calls to avoid emitting the deprecated `__mod_term_func`.
Reuse the existing `WebAssemblyLowerGlobalDtors.cpp` to accomplish this.
Enable fallback to the old behavior via Clang driver flag
(`-fregister-global-dtors-with-atexit`) or llc / code generation flag
(`-lower-global-dtors-via-cxa-atexit`). This escape hatch will be
removed in the future.
Differential Revision: https://reviews.llvm.org/D121736
Before this patch the DebugifyLevel option was used for
the synthetic mode, so after this, it will be used in
the original mode as well.
Differential Revision: https://reviews.llvm.org/D115623
Before we start addressing the issue with having
a lot of false positives when using debugify in
the original mode, we have made a few patches that
should speed up the execution of the testing
utility Passes.
For example, when testing a large project
(let's say LLVM project itself), we can face
a lot of potential DI issues. Usually, we use
-verify-each-debuginfo-preserve (that is very
similar to -debugify-each) -- it collects
DI metadata before each Pass, and after the Pass
it checks if the Pass preserved the DI metadata.
However, we can speed up this process, since we
don't need to collect DI metadata before each
Pass -- we could use the DI metadata that are
collected after the previous Pass from
the pipeline as an input for the next Pass.
This patch speeds up the utility for ~2x.
Differential Revision: https://reviews.llvm.org/D115622
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Differential Revision: https://reviews.llvm.org/D115907
For MachO, lower `@llvm.global_dtors` into `@llvm_global_ctors` with
`__cxa_atexit` calls to avoid emitting the deprecated `__mod_term_func`.
Reuse the existing `WebAssemblyLowerGlobalDtors.cpp` to accomplish this.
Enable fallback to the old behavior via Clang driver flag
(`-fregister-global-dtors-with-atexit`) or llc / code generation flag
(`-lower-global-dtors-via-cxa-atexit`). This escape hatch will be
removed in the future.
Differential Revision: https://reviews.llvm.org/D121736
This code queries TTI on a single function, which is considered to
be representative. This is a bit odd, but probably fine in practice.
However, I think we should at least avoid querying declarations,
which e.g. will generally lack target attributes, and for which
we don't seem to ever query TTI in other places.
For MachO, lower `@llvm.global_dtors` into `@llvm_global_ctors` with
`__cxa_atexit` calls to avoid emitting the deprecated `__mod_term_func`.
Reuse the existing `WebAssemblyLowerGlobalDtors.cpp` to accomplish this.
Enable fallback to the old behavior via Clang driver flag
(`-fregister-global-dtors-with-atexit`) or llc / code generation flag
(`-lower-global-dtors-via-cxa-atexit`). This escape hatch will be
removed in the future.
Differential Revision: https://reviews.llvm.org/D121327
Extend -wholeprogramdevirt-check to support both the existing
trapping mode on an incorrect devirtualization, as well as a new
mode to fallback to an indirect call on a mismatch. The new mode is
The new mode is useful in cases where we want to enable
devirtualization but cannot fully guarantee whole program visibility
(e.g in the case where LTO has been disabled for a small set of objects
that could potentially override virtual methods without having a symbol
reference to anything in the base class including the vtable).
Remove !prof and !callees metadata (which are used by indirect call
promotion) from both the new direct call and the fallback indirect call
(so that we don't perform another round of promotion on the latter).
Also remove it from the direct call in the non-fallback cases, which
was an oversight, although it didn't seem to cause any issues. Add tests
for the metadata removal covering the various cases.
Differential Revision: https://reviews.llvm.org/D121419
If there are no ctors, then this can have an arbirary zero-sized
value. The current code checks for null, but it could also be
undef or poison.
Replacing the specific null check with a check for
non-ConstantArray.
MinBaseDistance may be odr-used by std::max, leading to an undefined symbol linker error:
```
ld.lld: error: undefined symbol: (anonymous namespace)::MinCostMaxFlow::MinBaseDistance
>>> referenced by SampleProfileInference.cpp:744 (/home/ray/llvm-project/llvm/lib/Transforms/Utils/SampleProfileInference.cpp:744)
>>> lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SampleProfileInference.cpp.o:((anonymous namespace)::FlowAdjuster::jumpDistance(llvm::FlowJump*) const)
```
Since llvm-project is still using C++ 14, workaround it with a cast.
The OpenMPIRBuilder has a bug. Specifically, suppose you have two nested openmp parallel regions (writing with MLIR for ease)
```
omp.parallel {
%a = ...
omp.parallel {
use(%a)
}
}
```
As OpenMP only permits pointer-like inputs, the builder will wrap all of the inputs into a stack allocation, and then pass this
allocation to the inner parallel. For example, we would want to get something like the following:
```
omp.parallel {
%a = ...
%tmp = alloc
store %tmp[] = %a
kmpc_fork(outlined, %tmp)
}
```
However, in practice, this is not what currently occurs in the context of nested parallel regions. Specifically to the OpenMPIRBuilder,
the entirety of the function (at the LLVM level) is currently inlined with blocks marking the corresponding start and end of each
region.
```
entry:
...
parallel1:
%a = ...
...
parallel2:
use(%a)
...
endparallel2:
...
endparallel1:
...
```
When the allocation is inserted, it presently inserted into the parent of the entire function (e.g. entry) rather than the parent
allocation scope to the function being outlined. If we were outlining parallel2, the corresponding alloca location would be parallel1.
This causes a variety of bugs, including https://github.com/llvm/llvm-project/issues/54165 as one example.
This PR allows the stack allocation to be created at the correct allocation block, and thus remedies such issues.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D121061
This will let us start moving away from hard-coded attributes in
MemoryBuiltins.cpp and put the knowledge about various attribute
functions in the compilers that emit those calls where it probably
belongs.
Differential Revision: https://reviews.llvm.org/D117921
`ArgInfo` is reduced to only contain a pair of {formal,actual} values.
The specialized function `Fn` and the `Partial` flag are redundant in
this structure. The `Gain` is moved to a new struct `SpecializationInfo`.
The value mappings created by cloneCandidateFunction() are being used
by rewriteCallSites() for matching the formal arguments of recursive
functions.
The list of specializations is passed by reference to calculateGains()
instead of being returned by value.
The `IsPartial` flag is removed from isArgumentInteresting() and
getPossibleConstants() as it's no longer used anywhere in the code.
Differential Revision: https://reviews.llvm.org/D120753
The verify call was taking 50% of the compile time in our internal LLVM
fork when trying to unroll many loops.
Differential Revision: https://reviews.llvm.org/D113028
Currently adding attribute no_sanitize("bounds") isn't disabling
-fsanitize=local-bounds (also enabled in -fsanitize=bounds). The Clang
frontend handles fsanitize=array-bounds which can already be disabled by
no_sanitize("bounds"). However, instrumentation added by the
BoundsChecking pass in the middle-end cannot be disabled by the
attribute.
The fix is very similar to D102772 that added the ability to selectively
disable sanitizer pass on certain functions.
In this patch, if no_sanitize("bounds") is provided, an additional
function attribute (NoSanitizeBounds) is attached to IR to let the
BoundsChecking pass know we want to disable local-bounds checking. In
order to support this feature, the IR is extended (similar to D102772)
to make Clang able to preserve the information and let BoundsChecking
pass know bounds checking is disabled for certain function.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D119816
SCEVs ExprValueMap currently tracks not only which IR Values
correspond to a given SCEV expression, but additionally stores that
it may be expanded in the form X+Offset. In theory, this allows
reusing existing IR Values in more cases.
In practice, this doesn't seem to be particularly useful (the test
changes are rather underwhelming) and adds a good bit of complexity.
Per https://github.com/llvm/llvm-project/issues/53905, we have an
invalidation issue with these offseted expressions.
Differential Revision: https://reviews.llvm.org/D120311
Summary:
We use a section to embed offloading code into the host for later
linking. This is normally unique to the translation unit as it is thrown
away during linking. However, if the user performs a relocatable link
the sections will be merged and we won't be able to access the files
stored inside. This patch changes the section variables to have external
linkage and a name defined by the section name, so if two sections are
combined during linking we get an error.
The `SplitIndirectBrCriticalEdges` function was originally designed for
`CodeGenPrepare` and skipped splitting of edges when the destination
block didn't contain any `PHI` instructions. This only makes sense when
reducing COPYs like `CodeGenPrepare`. In the case of
`PGOInstrumentation` or `GCOVProfiling` it would result in missed
counters and wrong result in functions with computed goto.
Differential Revision: https://reviews.llvm.org/D120096
Constants cannot be cyclic, but they can be tree-like. Keep a
visited set to ensure we do not degenerate to exponential run-time.
This fixes the problem reported in https://reviews.llvm.org/D117223#3335482,
though I haven't been able to construct a concise test case for
the issue. This requires a combination of dead constants and the
kind of constant expression tree that textual IR cannot represent
(because the textual representation, unlike the in-memory
representation, is also exponential in size).
This code could be generalized to be type-independent, but for now
just ensure that the same type constraints are enforced with opaque
pointers as with typed pointers.
By convention, memcpy/memmove intrinsics are always used with i8
pointers (though this is not enforced), so in practice this code
was always using an i8 type. Make that explicit.
Of course, i8 is not a very profitable choice, and this code could
be more performant by picking an appropriate larger type. But that
would require additional test coverage and correctness review, and
certainly shouldn't be a decision based on the pointer element type.
Chuanqi Xu