We previously used the `noinline` attributes to specify some defintions
which should be kept alive in the runtime. These were then stripped
immediately in the OpenMPOpt module pass. However, Since the changes in
D130298, we not explicitly state which functions will have external
visiblity in the bitcode library. Additionally the OpenMPOpt module pass
should run before the inliner pass, so this shouldn't make a difference
in whether or not the functions will be alive for the initial pass of
OpenMPOpt. This should simplify the interface, and additionally save
time spend on scanning funciton names for noinline.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D130368
In D129523, it was noted that there is are some questionable naked casts
from Instruction to BinaryOperator, which could be addressed by doing a
dyn_cast directly to BinaryOperator, avoiding the need for the later cast.
This cleans up that casting.
Reviewed By: nikic, spatel, RKSimon
Differential Revision: https://reviews.llvm.org/D130448
In D129523, it was noted that the approach to check whether a value can
have FastMathFlags was done in different ways, and they should be made
consistent. This patch makes minor changes to fix that.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D130408
If we look at a write, we should not enact the "has been written to"
logic introduced to avoid spurious write -> read dependences. Doing so
lead to elimination of stores we needed, which is obviously bad.
The name `getEntrySamples` was misleading for 2 reasons. One, it's
close in name to `Function::getEntryCount`, but the equivalent here is
`getHeadSamples`; second, as opposed to the other get* APIs in
`FunctionSamples`, it performs an estimate/heuristic rather than just
retrieving raw data (or a non-heuristic derivate off that data, like
`getMaxCountInside`)
The new name should more clearly communicate its intent; and, being
close (in name) to `getHeadSamples`, it should allow the reader discover
the relation between them.
Also updated the doc comments for both `getHeadSamples[Estimate]` so a
reader may better understand the relation between them.
Differential Revision: https://reviews.llvm.org/D130281
Reorganize the code to make it clear what is and isn't handle, and why.
Restructure bailout to remove (false and confusing) dependence on
CM_Scalarize; just return invalid cost and propagate, that's what it
is for.
The internalize pass supports an option to provide a list of symbols
that should not be internalized. THis is useful retaining certain
defintions that should be kept alive. However, this interface is
somewhat difficult to use as it requires knowing every single symbol's
name and specifying it. Many APIs provide common prefixes for the
symbols exported by the library, so it would make sense to be able to
match these using a simple glob pattern. This patch changes the handling
from a simple string comparison to a glob pattern match.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D130319
If a function is non-recursive we only performed intra-procedural
reasoning for reachability (via AA::isPotentiallyReachable). However,
if it is re-entrant that doesn't mean we can't reach. Instead of this
problematic logic in the reachability reasoning we utilize logic in
AAPointerInfo. If a location is for sure written by a function it can
be re-entrant or recursive we know only intra-procedural reasoning is
sufficient.
The existing code doesn't expect dummy values (undef, poison, null-derived
constants etc) as arguments of these intrinsics. However, they can be there
in unreached code. Currently we fail trying to find base for them.
Handle these cases separately. Return null as base for them to be consistent
with the handling in the main algorithm in findBaseDefiningValue.
Differential Revision: https://reviews.llvm.org/D129561
Reviewed By: apilipenko
If we have a dominating must-write access we do not need to know the
initial value of some object to perform reasoning about the potential
values. The dominating must-write has overwritten the initial value.
This code confuses LV's "Uniform" and LVL/LAI's "Uniform". Despite the
common name, these are different.
* LVs notion means that only the first lane *of each unrolled part* is
required. That is, lanes within a single unroll factor are considered
uniform. This allows e.g. widenable memory ops to be considered
uses of uniform computations.
* LVL and LAI's notion refers to all lanes across all unrollings.
IsUniformMem is in turn defined in terms of LAI's notion. Thus a
UniformMemOpmeans is a memory operation with a loop invariant address.
This means the same address is accessed in every iteration.
The tweaked piece of code was trying to match a uniform mem op (i.e.
fully loop invariant address), but instead checked for LV's notion of
uniformity. In theory, this meant with UF > 1, we could speculate
a load which wasn't safe to execute.
This ends up being mostly silent in current code as it is nearly
impossible to create the case where this difference is visible. The
closest I've come in the test case from 54cb87, but even then, the
incorrect result is only visible in the vplan debug output; before this
change we sink the unsafely speculated load back into the user's predicate
blocks before emitting IR. Both before and after IR are correct so the
differences aren't "interesting".
The other test changes are uninteresting. They're cases where LV's uniform
analysis is slightly weaker than SCEV isLoopInvariant.
This probably should have been part of D123089, but the effects of it
don't show up until we start removing functions from the table in
D130107. Oops.
Differential Revision: https://reviews.llvm.org/D130184
The InstCombine test is reduced from issue #56601. Without the more
liberal match for ConstantExpr, we try to rearrange constants in
Negator forever.
Alternatively, we could adjust the definition of m_ImmConstant to be
more conservative, but that's probably a larger patch, and I don't
see any downside to changing m_ConstantExpr. We never capture and
modify a ConstantExpr; transforms just want to avoid it.
Differential Revision: https://reviews.llvm.org/D130286
This patch adds the AArch64 hook for preferPredicateOverEpilogue,
which currently returns true if SVE is enabled and one of the
following conditions (non-exhaustive) is met:
1. The "sve-tail-folding" option is set to "all", or
2. The "sve-tail-folding" option is set to "all+noreductions"
and the loop does not contain reductions,
3. The "sve-tail-folding" option is set to "all+norecurrences"
and the loop has no first-order recurrences.
Currently the default option is "disabled", but this will be
changed in a later patch.
I've added new tests to show the options behave as expected here:
Transforms/LoopVectorize/AArch64/sve-tail-folding-option.ll
Differential Revision: https://reviews.llvm.org/D129560
Replace the value-accepting isReallocLikeFn() overload with a
getReallocatedOperand() function, which returns which operand is
the one being reallocated. Currently, this is always the first one,
but once allockind(realloc) is respected, the reallocated operand
will be determined by the allocptr parameter attribute.
Remove isFreeCall() in favor of getFreedOperand(). Replace the
two remaining uses with a getFreedOperand() != nullptr check, as
they only care that something is getting freed. (The usage in DSE
is correct as such. The allocator-related checks in CFLGraph look
rather questionable in general.)
Use getFreedOperand() instead of isFreeCall() to remove the
implicit assumption that any pointer operand to a free function
is the operand being freed. This won't actually matter until we
handle allockind(free).
We currently assume in a number of places that free-like functions
free their first argument. This is true for all hardcoded free-like
functions, but with the new attribute-based design, the freed
argument is supposed to be indicated by the allocptr attribute.
To make sure we handle this correctly once allockind(free) is
respected, add a getFreedOperand() helper which returns the freed
argument, rather than just indicating whether the call frees *some*
argument.
This migrates most but not all users of isFreeCall() to the new
API. The remaining users are a bit more tricky.
Reapply the patch with getObjectSize() replaced by getAllocSize().
The former will also look through calls that return their argument,
and we'll end up placing dereferenceable attributes on intrinsics
like llvm.launder.invariant.group. While this isn't wrong, it also
doesn't seem to be particularly useful. For now, use getAllocSize()
instead, which sticks closer to the original behavior of this code.
-----
This code is just interested in the allocsize, not any other
allocator properties.
We were quite conservative when it came to PHI node handling to avoid
recursive reasoning. Now we check more direct if we have seen a PHI
already or not. This allows non-recursive PHI chains to be handled.
This also exposed a bug as we did only model the effect of one loop
traversal. `phi_no_store_3` has been adapted to show how we would have
used `undef` instead of `1` before. With this patch we don't replace
it at all, which is expected as we do not argue about loop iterations
(or alignments).
If we only have exact accesses we should never require the bit-pattern
to be uniform (in this case 0). Only a non-exact access should force us
to require only 0 values.
If we are right shifting a multiply by a negated power of 2 where
the power of 2 is the same as the shift amount, we can replace with
a negate followed by an And.
New tests have not been committed yet but the patch shows the diffs.
Let me know if you want any changes or additional tests.
Differential Revision: https://reviews.llvm.org/D130103
Put AllocationFn check before I->willReturn can allow CodeGenPrepare to remove useless malloc instruction
Differential Revision: https://reviews.llvm.org/D130126
An srem or sdiv has two cases which can cause undefined behavior, not just one. The existing code did not account for this, and as a result, we miscompiled when we encountered e.g. a srem i64 %v, -1 in a conditional block.
Instead of hand rolling the logic, just use the utility function which exists exactly for this purpose.
Differential Revision: https://reviews.llvm.org/D130106
When F calls G calls H, G is nounwind, and G is inlined into F, then the
inlined call-site to H should be effectively nounwind so as not to lose
information during inlining.
If H itself is nounwind (which often happens when H is an intrinsic), we
no longer mark the callsite explicitly as nounwind. Previously, there
were cases where the inlined call-site of H differs from a pre-existing
call-site of H in F *only* in the explicitly added nounwind attribute,
thus preventing common subexpression elimination.
v2:
- just check CI->doesNotThrow
v3 (resubmit after revert at 3443788087):
- update Clang tests
Differential Revision: https://reviews.llvm.org/D129860
Kazu Hirata