[PATCH] D76674: [Attributor] Derive better alignment for accessed pointers

[Johannes Doerfert via Phabricator via llvm-commits]

jdoerfert created this revision.
jdoerfert added reviewers: lebedev.ri, uenoku, sstefan1, baziotis.
Herald added subscribers: arphaman, bollu, hiraditya.
Herald added a project: LLVM.
lebedev.ri added a comment.
jdoerfert updated this revision to Diff 252239.
jdoerfert updated this revision to Diff 252240.

That's the patch i showed, yes :)
I'm not sure this is sound.
Given underaligned load, we can't just take max(align of load, abi alignment)


jdoerfert added a comment.

In D76674#1938540 <https://reviews.llvm.org/D76674#1938540>, @lebedev.ri wrote:

> That's the patch i showed, yes :)
>  I'm not sure this is sound.
>  Given underaligned load, we can't just take max(align of load, abi alignment)


Hm, so we can only look at the abi if the load alignment is unspecified?


jdoerfert added a comment.

Repsect underaligned accesses, already tested in `Transforms/Attributor/ArgumentPromotion/alignment.ll`


jdoerfert added a comment.

Simplify helper code


Use DL & ABI information for better alignment deduction, e.g., if a type
is accessed and the ABI specifies an alignment requirement for such an
access we can use it. This is based on a patch by @lebedev.ri and
inspired by getBaseAlign in Loads.cpp.

Depends on D76673 <https://reviews.llvm.org/D76673>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D76674

Files:
  llvm/lib/Transforms/IPO/Attributor.cpp
  llvm/test/Transforms/Attributor/ArgumentPromotion/2008-07-02-array-indexing.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/X86/min-legal-vector-width.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/attrs.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/byval-2.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/chained.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/musttail.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/sret.ll
  llvm/test/Transforms/Attributor/callbacks.ll
  llvm/test/Transforms/Attributor/dereferenceable-1.ll
  llvm/test/Transforms/Attributor/dereferenceable-2.ll
  llvm/test/Transforms/Attributor/heap_to_stack.ll
  llvm/test/Transforms/Attributor/misc.ll
  llvm/test/Transforms/Attributor/range.ll
  llvm/test/Transforms/Attributor/readattrs.ll
  llvm/test/Transforms/Attributor/value-simplify.ll

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