32 Commits

Author SHA1 Message Date
Ramkumar Ramachandra
2d4a8dadba
[VPlan] Use DL index type consistently for GEPs (#169396)
In preparation to strip VPUnrollPartAccessor and unroll recipes
directly, strip unnecessary complication in getGEPIndexTy, as the unroll
part will no longer be available in follow-ups (see #168886 for
instance). The patch also helps by doing a mass test update up-front.
Narrowing the GEP index type conditionally does not yield any benefit,
and the change is non-functional in terms of emitted assembly. While at
it, avoid hard-coding address-space 0, and use the pointer operand's
address space to get the GEP index type.
2025-11-26 12:25:55 +00:00
Ramkumar Ramachandra
c25e0d3e29
[VPlan] Simplify x + 0 -> x (#169394) 2025-11-25 05:58:41 +00:00
Ramkumar Ramachandra
299ea95747
[VPlan] Drop poison-generating flags on induction trunc (#168922)
After truncating an integer-induction, neither nuw nor nsw hold.

Fixes #168902.

Co-authored-by: Florian Hahn <flo@fhahn.com>
2025-11-21 08:14:46 +00:00
Ramkumar Ramachandra
ef023cae38
Reland [VPlan] Expand WidenInt inductions with nuw/nsw (#168354)
Changes: The previous patch had to be reverted to a mismatching-OpType
assert in cse. The reduced-test has now been added corresponding to a
RVV pointer-induction, and the pointer-induction case has been updated
to use createOverflowingBinaryOp.

While at it, record VPIRFlags in VPWidenInductionRecipe.
2025-11-17 13:44:25 +00:00
Alex Bradbury
f2336d4c7e
Revert "[VPlan] Expand WidenInt inductions with nuw/nsw" (#168080)
Reverts llvm/llvm-project#163538

This is causing build failures on the two-stage RVV buildbots. e.g.
https://lab.llvm.org/buildbot/#/builders/214/builds/1363. I've shared a
reproducer and more information at
https://github.com/llvm/llvm-project/pull/163538#issuecomment-3533482822

This reverts commit 355e0f94af5adabe90ac57110ce1b47596afd4cd.
2025-11-14 16:11:48 +00:00
Ramkumar Ramachandra
355e0f94af
[VPlan] Expand WidenInt inductions with nuw/nsw (#163538)
While at it, record VPIRFlags in VPWidenInductionRecipe.
2025-11-14 12:10:55 +00:00
Florian Hahn
8460dbb450
[VPlan] Mark VPInstruction::Broadcast as not reading/writing memory.
This enables additional DCE/CSE opportunities and ensures that we don't
end up with multiple redundant users of a VPInstruction using EVL. It
fixes a verifier error in the added test_3_inductions test.
2025-09-27 20:48:42 +01:00
Florian Hahn
2016af5652
[VPlan] Create epilogue minimum iteration check in VPlan. (#157545)
Move creation of the minimum iteration check for the epilogue vector
loop to VPlan. This is a first step towards breaking up and moving
skeleton creation for epilogue vectorization to VPlan.

It moves most logic out of EpilogueVectorizerEpilogueLoop: the minimum
iteration check is created directly in VPlan, connecting the check
blocks from the main vector loop is done as post-processing. Next steps
are to move connecting and updating the branches from the check blocks
to VPlan, as well as updating the incoming values for phis.

Test changes are improvements due to folding of live-ins.

PR: https://github.com/llvm/llvm-project/pull/157545
2025-09-25 07:13:38 +00:00
Florian Hahn
eee9755881
[LV] Refine check to find epilogue IV resume value.
Make sure to check that the vector trip count is containedin the list of
incoming values to serve as tie-breaker with phis with all-zero incoming
values.

Fixes https://github.com/llvm/llvm-project/issues/151686.
2025-08-01 20:54:39 +01:00
Florian Hahn
89ae085859
[VPlan] Remove VPVectorPointer for part 0 after unrolling. (#149735)
VPVectorPointer for part 0 is just the pointer operand. Simplify it
after unrolling. This removes a large number of redundant GEPs with
index 0.

PR: https://github.com/llvm/llvm-project/pull/149735
2025-07-27 13:53:26 +01:00
Florian Hahn
2c7d40b2f0
[VPlan] Generalize SCALAR-STEPS removal to any unroll factor.
Follow-up to dfca6c0d3bf9d1a056 to extend isUnrolled handle any unrolled
VPlan, which means there's a single UF, but it will be > 1 if unrolling
took place.
2025-03-26 21:03:50 +00:00
Florian Hahn
dfca6c0d3b
[VPlan] Remove no-op SCALAR-STEPS after unrolling. (#123655)
After unrolling, there may be additional simplifications that can be
applied. One example is removing SCALAR-STEPS for the first part where
only the first lane is demanded.

This removes redundant adds of 0 from a large number of tests (~200),
many which I am still working on updating.

In preparation for removing redundant WideIV steps added in
https://github.com/llvm/llvm-project/pull/119284.

PR: https://github.com/llvm/llvm-project/pull/123655
2025-03-25 12:57:24 +00:00
Florian Hahn
62994c3291
[VPlan] Also introduce explicit broadcasts for values from entry VPBB.
Update and generalize materializeBroadcasts to also introduce explicit
broadcasts for VPValues defined in the Plans Entry block.

This fixes a crash when trying to insert the broadcasts generated by
VPTransformState::get after the generating instruction, which isn't
possible after invoke instructions.

Fixes https://github.com/llvm/llvm-project/issues/128838.
2025-03-12 22:03:19 +00:00
Florian Hahn
4277c21059
[VPlan] Introduce explicit broadcasts for live-ins. (#124644)
Add a new VPInstruction::Broadcast opcode and use it to materialize
explicit broadcasts of live-ins. The initial patch only materlizes the
broadcasts if the vector preheader dominates all uses that need it.
Later patches will pick the best valid insert point, thus retiring
implicit hoisting of broadcasts from VPTransformsState::get().

PR: https://github.com/llvm/llvm-project/pull/124644
2025-02-26 13:57:51 +00:00
Florian Hahn
32c4493d5f
[VPlan] Add incoming values for all predecessor to ResumePHI (NFCI).
Follow-up as discussed when using VPInstruction::ResumePhi for all resume
values (#112147). This patch explicitly adds incoming values for each
predecessor in VPlan. This simplifies codegen and allows transformations
adjusting the predecessors of blocks with

NFC modulo incoming block order in phis.
2025-02-09 11:20:20 +00:00
Florian Hahn
7f3428d3ed
[VPlan] Compute induction end values in VPlan. (#112145)
Use createDerivedIV to compute IV end values directly in VPlan, instead
of creating them up-front.

This allows updating IV users outside the loop as follow-up.

Depends on https://github.com/llvm/llvm-project/pull/110004 and
https://github.com/llvm/llvm-project/pull/109975.

PR: https://github.com/llvm/llvm-project/pull/112145
2024-12-29 19:05:08 +00:00
Florian Hahn
4ad0fdd163
[VPlan] Remove reverse() of predecessors from VPInstruction::generate.
This was originally done to reduce the diff for the change. Remove it
and update the remaining tests. NFC modulo reordering of incoming
values.

Clean up after https://github.com/llvm/llvm-project/pull/114292.
2024-12-17 20:44:32 +00:00
Florian Hahn
7f7f540a48
Reapply "[VPlan] Update scalar induction resume values in VPlan. (#110577)"
This reverts commit f09b16e2671cbcdf7cb7dc7ed705db092a9deda1.

The crash when building llvm-test-suite with stage2 should have been
fixed by 1091fad31a83d5ab87eb6fa11fe3bdb3f0d152ea.
2024-12-06 19:41:51 +00:00
Nikita Popov
f09b16e267 Revert "[VPlan] Update scalar induction resume values in VPlan. (#110577)"
This reverts commit 0678e2058364ec10b94560d27ec7138dfa003287.
This reverts commit 1091fad31a83d5ab87eb6fa11fe3bdb3f0d152ea.

Causes crashes in llvm-test-suite when using stage 2 clang.
2024-12-06 18:01:42 +01:00
Florian Hahn
0678e20583
[VPlan] Update scalar induction resume values in VPlan. (#110577)
Updated ILV.createInductionResumeValues (now createInductionResumeVPValue)
to directly update the VPIRInstructions wrapping the original phis with the 
created resume values.

This is the first step towards modeling them completely in VPlan.
Subsequent patches will move creation of the resume values completely
into VPlan.

Depends on https://github.com/llvm/llvm-project/pull/109975.

PR: https://github.com/llvm/llvm-project/pull/110577
2024-12-06 12:26:19 +00:00
Julian Nagele
a8538b9138
[LV] Vectorize Epilogues for loops with small VF but high IC (#108190)
- Consider MainLoopVF * IC when determining whether Epilogue
Vectorization is profitable
- Allow the same VF for the Epilogue as for the main loop
- Use an upper bound for the trip count of the Epilogue when choosing
the Epilogue VF

PR: https://github.com/llvm/llvm-project/pull/108190
---------

Co-authored-by: Florian Hahn <flo@fhahn.com>
2024-11-17 19:35:32 +00:00
Paul Walker
38fffa630e
[LLVM][IR] Use splat syntax when printing Constant[Data]Vector. (#112548) 2024-11-06 11:53:33 +00:00
Florian Hahn
53266f73f0
[VPlan] Run DCE after unrolling.
This cleans up a number of dead recipes after unrolling if only their
first or last parts are used. This simplifies a number of tests.

Fixes https://github.com/llvm/llvm-project/issues/109581.
2024-09-22 22:08:46 +01:00
Florian Hahn
8ec406757c
[VPlan] Implement unrolling as VPlan-to-VPlan transform. (#95842)
This patch implements explicit unrolling by UF  as VPlan transform. In
follow up patches this will allow simplifying VPTransform state (no need
to store unrolled parts) as well as recipe execution (no need to
generate code for multiple parts in an each recipe). It also allows for
more general optimziations (e.g. avoid generating code for recipes that
are uniform-across parts).

It also unifies the logic dealing with unrolled parts in a single place,
rather than spreading it out across multiple places (e.g. VPlan post
processing for header-phi recipes previously.)

In the initial implementation, a number of recipes still take the
unrolled part as additional, optional argument, if their execution
depends on the unrolled part.

The computation for start/step values for scalable inductions changed
slightly. Previously the step would be computed as scalar and then
splatted, now vscale gets splatted and multiplied by the step in a
vector mul.

This has been split off https://github.com/llvm/llvm-project/pull/94339
which also includes changes to simplify VPTransfomState and recipes'
::execute.

The current version mostly leaves existing ::execute untouched and
instead sets VPTransfomState::UF to 1.

A follow-up patch will clean up all references to VPTransformState::UF.

Another follow-up patch will simplify VPTransformState to only store a
single vector value per VPValue.

PR: https://github.com/llvm/llvm-project/pull/95842
2024-09-21 19:47:37 +01:00
Florian Hahn
f18536d642
[VPlan] Model address separately. (#72164)
Move vector pointer generation to a separate VPVectorPointerRecipe.
This untangles address computation from the memory recipes future
and is also needed to enable explicit unrolling in VPlan.

https://github.com/llvm/llvm-project/pull/72164
2024-01-01 19:51:15 +00:00
Florian Hahn
707359ecf5
Recommit "[LV] Re-use existing broadcast value for live-ins."
This reverts commit 245ec675a4e41f7ec24dfc998720bffdc46a6c53.

Recommits eea9258648ce with a fix to only erase the instruction from the
first part if it is defined outside the loop. This fixes a
use-after-free error reported.
2023-08-01 15:54:02 +01:00
Martin Storsjö
245ec675a4 Revert "[LV] Re-use existing broadcast value for live-ins."
This reverts commit eea9258648ce73507f6f85c395de978af659d498.

That commit triggered crashes in the following testcase:

$ cat reduced.c
typedef struct {
  int a[8]
} b;
typedef struct {
  b *c;
  short d
} e;
void f() {
  int g;
  char *h;
  e *i = f;
  short j = i->d;
  int a = i->c->a[0];
  for (;;)
    for (; g < a; g++) {
      *h = j * i->d >> 8;
      h++;
    }
}
$ clang -target aarch64-linux-gnu -w -c -O2 reduced.c
2023-07-25 10:35:41 +03:00
Florian Hahn
eea9258648
[LV] Re-use existing broadcast value for live-ins.
When requesting a vector value for a live-in, we can re-use the
broadcast of the live-in of part 0 for parts > 0.
2023-07-24 11:50:47 +01:00
Florian Hahn
3d4eed0133
[LV] Reuse SCEV expansion results for epilogue vectorization.
When generating code for the epilogue vector loop, we need to re-use the
expansion results for induction steps generated for the main vector
loop, as the pre-header of the epilogue vector loop may not dominate the
vector preheader of the epilogue.

This fixes a reported crash. Note that this is a workaround which should
be removed soon once induction resume value creation is handled in VPlan
directly.
2023-05-11 22:00:07 +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
Florian Hahn
f69ac9a22d
[LV] Support widened induction variables in epilogue vectorization.
Code generation now uses the start VPValue of induction recipes.

This makes it possible to adjust the start value of the epilogue
vector loop to use the 'resume' value of the main vector loop.

Fixes #59459.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D92132
2022-12-21 13:58:50 +00:00
Florian Hahn
d58f670788
[LV] Add test for #59459. 2022-12-21 13:23:25 +00:00