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.
Legalize extract-from-ends using uniform VPReplicateRecipe of wide
inductions to use regular VPReplicateRecipe, so the correct end value
is available.
Fixes https://github.com/llvm/llvm-project/issues/121745.
Update optimizeForVFAndUF to completely remove the vector loop region
when possible. At the moment, we cannot remove the region if it contains
* widened IVs: the recipe is needed to generate the step vector
* reductions: ComputeReductionResults requires the reduction phi recipe
for codegen.
Both cases can be addressed by more explicit modeling.
The patch also includes a number of updates to allow executing VPlans
without a vector loop region.
Depends on https://github.com/llvm/llvm-project/pull/110004
Check the VPlan directly to determine if a VPValue is an optimiziable IV
or IV use instead of checking the underlying IR instructions.
Split off from https://github.com/llvm/llvm-project/pull/112147. This
refactoring enables moving IV end value creation from the legacy
fixupIVUsers to a VPlan-based transform.
There is one case we now won't optimize, that is IVs with subtracts and
non-constant steps. But as this is a minor optimization and doesn't
impact correctness, the benefits of performing the check in VPlan should
outweigh the missed case.
This fixes a crash when building SPEC CPU 2017 with EVL tail folding
when widening @llvm.log10 intrinsics.
@llvm.log10 and some other intrinsics don't have a corresponding VP
intrinsic, so this fixes the crash by removing the assert and bailing
instead.
Update wide induction increments to use the same step as the corresponding
wide induction. This enables detecting induction increments directly in
VPlan and removes redundant splats.
LoopVectorizationCostModel::needsExtract should recognise instructions
that have been widened by scalarizing as scalar instructions, and thus
not needing an extract when used by later scalarized instructions.
This fixes an incorrect cost calculation in computePredInstDiscount,
where we are adding a scalarization overhead cost when we shouldn't,
though I haven't come up with a test case where it makes a difference.
It will make a difference when the cost model switches to using the cost
kind TCK_CodeSize for optsize, as not doing this causes the test
LoopVectorize/X86/small-size.ll to get worse.
Add missing test coverage of loops where the vector loop region can be
removed that include replicate recipes as well as nested loops.
Extra test coverage for https://github.com/llvm/llvm-project/pull/108378.
Currently available intrinsics are only ld2/st2, which don't support interleaving factor > 2.
This patch teaches the LV to use ld2/st2 recursively to support high
interleaving factors.
This re-lands the reverted #92418
When the VF is small enough so that dividing the VF by the scaling
factor results in 1, the reduction phi execution thinks the VF is scalar
and sets the reduction's output as a scalar value, tripping assertions
expecting a vector value. The latest commit in this PR fixes that by
using `State.VF` in the scalar check, rather than the divided VF.
---------
Co-authored-by: Nicholas Guy <nicholas.guy@arm.com>
I've only fixed up the tests where I was able to use a simple sed script
to replace the text. Even after this patch lands, there are still over
50 tests that need updating in X86/CostModel!
Following on from https://github.com/llvm/llvm-project/pull/94499, this
patch adds support to the Loop Vectorizer to emit the partial reduction
intrinsics where they may be beneficial for the target.
---------
Co-authored-by: Samuel Tebbs <samuel.tebbs@arm.com>
Currently the addUsersInExitBlocks incorrectly assumes exit phis only
have a single operand, which may not be the case for loops with early
exits when they share a common exit block.
Also further relax the assertion in fixupIVUsers to allow exit values if
they come from theloop latch/middle.block.
PR: https://github.com/llvm/llvm-project/pull/120260
