20 Commits

Author SHA1 Message Date
Nikita Popov
9cf67f6ea0 [LoopVectorize] Convert most tests to opaque pointers (NFC)
The unsized-pointee-crash.ll and zero-sized-pointee-crash.ll tests
have been removed, because these issues are not relevant for opaque
pointers.
2023-06-12 13:10:22 +02:00
Nikita Popov
9ed2f14c87 [AsmParser] Remove typed pointer auto-detection
IR is now always parsed in opaque pointer mode, unless
-opaque-pointers=0 is explicitly given. There is no automatic
detection of typed pointers anymore.

The -opaque-pointers=0 option is added to any remaining IR tests
that haven't been migrated yet.

Differential Revision: https://reviews.llvm.org/D141912
2023-01-18 09:58:32 +01:00
Paul Walker
eae26b6640 [IRBuilder] Use canonical i64 type for insertelement index used by vector splats.
Instcombine prefers this canonical form (see getPreferredVectorIndex),
as does IRBuilder when passing the index as an integer so we may as
well use the prefered form from creation.

NOTE: All test changes are mechanical with nothing else expected
beyond a change of index type from i32 to i64.

Differential Revision: https://reviews.llvm.org/D140983
2023-01-11 14:08:06 +00:00
Roman Lebedev
be51fa4580
[NFC] Port all runlines for LoopVectorize pass tests to -passes syntax 2022-12-05 22:17:30 +03:00
Florian Hahn
1ed555a62b
[LV] Fix test cases where vector loop never executed.
It looks like the vector loops in the modified test cases
unintentionally never get executed. Update the exit condition to ensure
it does to avoid them getting optimized away in upcoming changes.
2022-08-31 13:24:49 +01:00
Martin Sebor
0dcfe7aa35 [InstCombine] Tighten up known library function signature tests (PR #56463)
Replace a switch statement used to validate arguments to known library
functions with a more consistent table-driven approach and tighten it
up.
2022-08-10 14:15:46 -06:00
Sander de Smalen
3e47f009ff [LV] Consider ExtractValue as uniform.
Since all operands to ExtractValue must be loop-invariant when we deem
the loop vectorizable, we can consider ExtractValue to be uniform.

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D107286
2021-08-05 16:20:50 +01:00
Florian Hahn
23c2f2e6b2
[LV] Mark increment of main vector loop induction variable as NUW.
This patch marks the induction increment of the main induction variable
of the vector loop as NUW when not folding the tail.

If the tail is not folded, we know that End - Start >= Step (either
statically or through the minimum iteration checks). We also know that both
Start % Step == 0 and End % Step == 0. We exit the vector loop if %IV +
%Step == %End. Hence we must exit the loop before %IV + %Step unsigned
overflows and we can mark the induction increment as NUW.

This should make SCEV return more precise bounds for the created vector
loops, used by later optimizations, like late unrolling.

At the moment quite a few tests still need to be updated, but before
doing so I'd like to get initial feedback to make sure I am not missing
anything.

Note that this could probably be further improved by using information
from the original IV.

Attempt of modeling of the assumption in Alive2:
https://alive2.llvm.org/ce/z/H_DL_g

Part of a set of fixes required for PR50412.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D103255
2021-06-07 10:47:52 +01:00
Juneyoung Lee
4a8e6ed2f7 [SLP,LV] Use poison constant vector for shufflevector/initial insertelement
This patch makes SLP and LV emit operations with initial vectors set to poison constant instead of undef.
This is a part of efforts for using poison vector instead of undef to represent "doesn't care" vector.
The goal is to make nice shufflevector optimizations valid that is currently incorrect due to the tricky interaction between undef and poison (see https://bugs.llvm.org/show_bug.cgi?id=44185 ).

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D94061
2021-01-06 11:22:50 +09:00
Sjoerd Meijer
f44ba25135 ExtractValue instruction costs
Instruction ExtractValue wasn't handled in
LoopVectorizationCostModel::getInstructionCost(). As a result, it was modeled
as a mul which is not really accurate. Since it is free (most of the times),
this now gets a cost of 0 using getInstructionCost.

This is a follow-up of D92208, that required changing this regression test.
In a follow up I will look at InsertValue which also isn't handled yet.

Differential Revision: https://reviews.llvm.org/D92317
2020-12-01 10:42:23 +00:00
Sjoerd Meijer
5110ff0817 [AArch64][CostModel] Fix cost for mul <2 x i64>
This was modeled to have a cost of 1, but since we do not have a MUL.2d this is
scalarized into vector inserts/extracts and scalar muls.

Motivating precommitted test is test/Transforms/SLPVectorizer/AArch64/mul.ll,
which we don't want to SLP vectorize.

Test Transforms/LoopVectorize/AArch64/extractvalue-no-scalarization-required.ll
unfortunately needed changing, but the reason is documented in
LoopVectorize.cpp:6855:

  // The cost of executing VF copies of the scalar instruction. This opcode
  // is unknown. Assume that it is the same as 'mul'.

which I will address next as a follow up of this.

Differential Revision: https://reviews.llvm.org/D92208
2020-11-30 11:36:55 +00:00
Florian Hahn
1ccc49924a [AArch64] Add getCFInstrCost, treat branches as free for throughput.
D79164/2596da31740f changed getCFInstrCost to return 1 per default.
AArch64 did not have its own implementation, hence the throughput cost
of CFI instructions is overestimated. On most cores, most branches should
be predicated and essentially free throughput wise.

This restores a 9% performance regression on a SPEC2006 benchmark on
AArch64 with -O3 LTO & PGO.

This patch effectively restores pre 2596da31740f behavior for AArch64
and undoes the AArch64 test changes of the patch.

Reviewers: samparker, dmgreen, anemet

Reviewed By: samparker

Differential Revision: https://reviews.llvm.org/D82755
2020-06-30 20:34:04 +01:00
Sam Parker
2596da3174 [CostModel] getCFInstrCost in getUserCost.
Have BasicTTI call the base implementation so that both agree on the
default behaviour, which the default being a cost of '1'. This has
required an X86 specific implementation as it seems to be very
reliant on those instructions being free. Changes are also made to
AMDGPU so that their implementations distinguish between cost kinds,
so that the unrolling isn't affected. PowerPC also has its own
implementation to prevent changes to the reg-usage vectorizer test.

The cost model test changes now reflect that ret instructions are not
generally free.

Differential Revision: https://reviews.llvm.org/D79164
2020-06-15 09:28:46 +01:00
Sjoerd Meijer
9529597cf4 Recommit #2: "[LV] Induction Variable does not remain scalar under tail-folding."
This was reverted because of a miscompilation. At closer inspection, the
problem was actually visible in a changed llvm regression test too. This
one-line follow up fix/recommit will splat the IV, which is what we are trying
to avoid if unnecessary in general, if tail-folding is requested even if all
users are scalar instructions after vectorisation. Because with tail-folding,
the splat IV will be used by the predicate of the masked loads/stores
instructions. The previous version omitted this, which caused the
miscompilation. The original commit message was:

If tail-folding of the scalar remainder loop is applied, the primary induction
variable is splat to a vector and used by the masked load/store vector
instructions, thus the IV does not remain scalar. Because we now mark
that the IV does not remain scalar for these cases, we don't emit the vector IV
if it is not used. Thus, the vectoriser produces less dead code.

Thanks to Ayal Zaks for the direction how to fix this.
2020-05-13 13:50:09 +01:00
Benjamin Kramer
f936457f80 Revert "Recommit "[LV] Induction Variable does not remain scalar under tail-folding.""
This reverts commit ae45b4dbe73ffde5fe3119835aa947d5a49635ed. It
causes miscompilations, test case on the mailing list.
2020-05-08 14:49:10 +02:00
Sjoerd Meijer
ae45b4dbe7 Recommit "[LV] Induction Variable does not remain scalar under tail-folding."
With 3 llvm regr tests fixed/updated that I had missed.
2020-05-07 11:52:20 +01:00
Sjoerd Meijer
20d67ffeae Revert "[LV] Induction Variable does not remain scalar under tail-folding."
This reverts commit 617aa64c84146468b384453375d1d34f97eb57db.

while I investigate buildbot failures.
2020-05-07 09:29:56 +01:00
Sjoerd Meijer
617aa64c84 [LV] Induction Variable does not remain scalar under tail-folding.
If tail-folding of the scalar remainder loop is applied, the primary induction
variable is splat to a vector and used by the masked load/store vector
instructions, thus the IV does not remain scalar. Because we now mark
that the IV does not remain scalar for these cases, we don't emit the vector IV
if it is not used. Thus, the vectoriser produces less dead code.

Thanks to Ayal Zaks for the direction how to fix this.

Differential Revision: https://reviews.llvm.org/D78911
2020-05-07 09:15:23 +01:00
Francesco Petrogalli
66c120f025 [VectorUtils] Rework the Vector Function Database (VFDatabase).
Summary:
This commits is a rework of the patch in
https://reviews.llvm.org/D67572.

The rework was requested to prevent out-of-tree performance regression
when vectorizing out-of-tree IR intrinsics. The vectorization of such
intrinsics is enquired via the static function `isTLIScalarize`. For
detail see the discussion in https://reviews.llvm.org/D67572.

Reviewers: uabelho, fhahn, sdesmalen

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72734
2020-01-16 15:08:26 +00:00
Florian Hahn
9428d95ce7 [LV] Exclude loop-invariant inputs from scalar cost computation.
Loop invariant operands do not need to be scalarized, as we are using
the values outside the loop. We should ignore them when computing the
scalarization overhead.

Fixes PR41294

Reviewers: hsaito, rengolin, dcaballe, Ayal

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D59995

llvm-svn: 366030
2019-07-14 20:12:36 +00:00