This PR removes the old `nocapture` attribute, replacing it with the new
`captures` attribute introduced in #116990. This change is
intended to be essentially NFC, replacing existing uses of `nocapture`
with `captures(none)` without adding any new analysis capabilities.
Making use of non-`none` values is left for a followup.
Some notes:
* `nocapture` will be upgraded to `captures(none)` by the bitcode
reader.
* `nocapture` will also be upgraded by the textual IR reader. This is to
make it easier to use old IR files and somewhat reduce the test churn in
this PR.
* Helper APIs like `doesNotCapture()` will check for `captures(none)`.
* MLIR import will convert `captures(none)` into an `llvm.nocapture`
attribute. The representation in the LLVM IR dialect should be updated
separately.
There are a lot of tests that do not depend upon the IR output
for validation, relying instead on the debug output. For these
tests we can add the -disable-output command line argument.
Change `getScaledReduction` to take an existing vector, rather than
creating and returning a new one each call.
Rename `getScaledReduction` to `getScaledReductions` to more accurately
reflect what it's now doing.
---------
Co-authored-by: Karlo Basioli <68535415+basioli-k@users.noreply.github.com>
Live-ins don't need to be handled, other than adding to the exit phi
recipe. Do that early and assert that otherwise the exit value is
defined in the vector loop region.
This should enable simply skipping other exit values that do not need
further fixing, e.g. if handling the exit value from the early exit
directly in handleUncountableEarlyExit.
PR: https://github.com/llvm/llvm-project/pull/123819
The last attempt failed a sanitiser build because we were
creating a reference to a null Predicates pointer in
isDereferenceableAndAlignedInLoop. This was exposed by
the unit test IsDerefReadOnlyLoop in
unittests/Analysis/LoadsTest.cpp. I fixed this by falling
back on getConstantMaxBackedgeTakenCount if Predicates is
null - see line 316 in llvm/lib/Analysis/Loads.cpp. There
are no other changes.
Update HCFG builder to preserve the original latch block of the initial
VPlan, ensuring there is always a latch.
It also skips creating the BranchOnCond for the latch of the top-level
loop, instead of removing it later. Exiting via the latch is controlled
by later recipes.
This further unifies HCFG construction and prepares for use to also
build an initial VPlan (VPlan0) for inner loops.
This remove some erroneous debug info from tests that should address the
test failures that showed up when the this was previously committed.
This reverts commit 6716ce8b641f0e42e2343e1694ee578b027be0c4.
Introduced stack buffer overflow, see #120272.
`getScaledReduction` can return empty vector, and there is not check for
that.
This reverts commit c9b7303b9b18129c4ee6b56aaa2a0a9f59be2d09.
This reverts commit caf0540b91b0fee31353dc7049ae836e0f814cff.
Chaining partial reductions, where multiple partial reductions share an
accumulator, allow for more values to be combined together as part of
the reduction without discarding the semantics of the partial reduction
itself.
For similar reasons for fixed-width being prefered to scalable for
Neoverse V2, this patch enables the UseFixedOverScalableIfEqualCost
feature when using -mcpu=cortex-x2, x3, x4 and x925 that are similar to
Neoverse V2.
This reverts the revert commit 58326f1d5b5b379590af92dd129b2f3b3e96af46.
The build failure in sanitizer stage2 builds has been fixed with
0d39fe6f5bb3edf0bddec09a8c6417377390aeac.
Original commit message:
Model updating IV users directly in VPlan, replace fixupIVUsers.
Now simple extracts are created for all phis in the exit block during
initial VPlan construction. A later VPlan transform
(optimizeInductionExitUsers) replaces extracts of inductions with
their pre-computed values if possible.
This completes the transition towards modeling all live-outs directly in
VPlan.
There are a few follow-ups:
* emit extracts initially also for resume phis, and optimize them
tougher with IV exit users
* support for VPlans with multiple exits in optimizeInductionExitUsers.
Depends on https://github.com/llvm/llvm-project/pull/110004,
https://github.com/llvm/llvm-project/pull/109975 and
https://github.com/llvm/llvm-project/pull/112145.
Model updating IV users directly in VPlan, replace fixupIVUsers.
Now simple extracts are created for all phis in the exit block during
initial VPlan construction. A later VPlan transform
(optimizeInductionExitUsers) replaces extracts of inductions with
their pre-computed values if possible.
This completes the transition towards modeling all live-outs directly in
VPlan.
There are a few follow-ups:
* emit extracts initially also for resume phis, and optimize them
tougher with IV exit users
* support for VPlans with multiple exits in optimizeInductionExitUsers.
Depends on https://github.com/llvm/llvm-project/pull/110004,
https://github.com/llvm/llvm-project/pull/109975 and
https://github.com/llvm/llvm-project/pull/112145.
If a pointer gets freed, it may not be dereferenceable any longer, even
though there is a dominating dereferenceable assumption. As first step,
only consider assumptions if the pointer value cannot be freed if
UseDerefAtPointSemantics is used.
PR: https://github.com/llvm/llvm-project/pull/123196
This commit relands the changes from "[LV]: Teach LV to recursively
(de)interleave. #89018"
Reason for revert:
- The patch exposed a bug in the IA pass, the bug is now fixed and landed by commit: #122643
Update the test to use use-dereferenceable-at-point-semantics=1.
Existing tests are updated with the nofree attribute and a new one has
been added showing that the dereferenceable assumption is used after the
pointer may be freed.
Currently when we encounter a negative step in the induction
variable isDereferenceableAndAlignedInLoop bails out because
the element size is signed greater than the step. This patch
adds support for negative steps in cases where we detect the
start address for the load is of the form base + offset. In
this case the address decrements in each iteration so we need
to calculate the access size differently. I have done this by
caling getStartAndEndForAccess from LoopAccessAnalysis.cpp.
The motivation for this patch comes from PR #88385 where a
reviewer requested reusing isDereferenceableAndAlignedInLoop,
but that PR itself does support reverse loops.
The changed test in LoopVectorize/X86/load-deref-pred.ll now
passes because previously we were calculating the total access
size incorrectly, whereas now it is 412 bytes and fits
perfectly into the alloca.
Change the inheritance of class VPWidenSelectRecipe to class
VPRecipeWithIRFlags, which allows recipe of the select to pass the
fastmath flags.The patch of #119847 will add the fastmath flag to for
recipe
Currently we fail to detect the case where BTC + 1 wraps, i.e. the
vector trip count is 0, In those cases, the minimum iteration count
check will fail, and the vector code will never be executed.
Explicitly check for this condition in computeMaxVF and avoid trying to
vectorize alltogether.
Note that a number of tests needed to be updated, because the vector
loop would never be executed given the input IR.
Fixes https://github.com/llvm/llvm-project/issues/122558.
This fixes a miscompilation extracted from 525.x264_r, where we were
failing to update the runtime VF of a VPReverseVectorPointerRecipe.
We were removing a use of VF whilst iterating over the users() iterator,
which messed up the iterator in-flight and caused us to miss some
recipes. This fixes it by copying the users into a SmallVector first.
Fixes#122681Fixes#122682
Following 0e528ac404e13ed2d952a2d83aaf8383293c851e, this patch adjusts
the resume value of VPReductionPHIRecipe for FindLastIV reductions.
Replacing the resume value with:
ResumeValue = ResumeValue == StartValue ? SentinelValue : ResumeValue;
This addressed the correctness issue when the start value might not be
less than the minimum value of a monotonically increasing induction
variable.
Thanks Florian Hahn for the help.
---------
Co-authored-by: Florian Hahn <flo@fhahn.com>
This relands the reverted #120721 with a fix for cases where neither
reduction operand are the reduction phi. Only
63114239cc8d26225a0ef9920baacfc7cc00fc58 and
63114239cc8d26225a0ef9920baacfc7cc00fc58 are new on top of the reverted
PR.
---------
Co-authored-by: Nicholas Guy <nicholas.guy@arm.com>
Use the existing VPlan-based analysis to identify recipes that only have
their first lane demanded and transform them to uniform recpliate
recipes. This simplifies the generated code in some places and prepares
for fixing https://github.com/llvm/llvm-project/issues/122496.
Also use getPointerAlignment when trying to use alignment and
dereferenceable assumptions. This catches cases where dereferencable is
known via the assumption but alignment is known via getPointerAlignment
(e.g. via argument attribute or align of 1)
PR: https://github.com/llvm/llvm-project/pull/120916
Currently we emit early-exit related debug messages/remarks even when
there is a single exit. Update to only check isVectorizableEarlyExitLoop
if there isn't a single exit block.
PR: https://github.com/llvm/llvm-project/pull/121994
This is a split-off from #109833 and only adds code relating to checking
if a struct-returning call can be vectorized.
This initial patch only allows the case where all users of the struct
return are `extractvalue` operations that can be widened.
```
%call = tail call { float, float } @foo(float %in_val)
%extract_a = extractvalue { float, float } %call, 0
%extract_b = extractvalue { float, float } %call, 1
```
Note: The tests require the VFABI changes from #119000 to pass.
This just copies the same conservative definition from mayWriteToMemory,
and enables more VPInstructions to be hoisted out in LICM.
I think this should give more accurate costs, and I was able to build
llvm-test-suite without the legacy-vplan cost model assertion going off.
VPExpandSCEVRecipes must be placed in the entry and are alway uniform.
This fixes a crash by always identifying them as uniform, even if the
main vector loop region has been removed.
Fixes https://github.com/llvm/llvm-project/issues/121897.
