[PATCH] D73428: [Attributor] Improve `noalias` deduction based on memory information

[Johannes Doerfert via Phabricator via llvm-commits]

jdoerfert created this revision.
jdoerfert added reviewers: uenoku, sstefan1, baziotis.
Herald added subscribers: jfb, bollu, hiraditya.
Herald added a project: LLVM.

We now use memory behavior and memory location information to deduce
`noalias` for (call site) arguments. The key idea is that `noalias`
does not prevent aliases but accesses that would cause a race if
executed concurrently. The main benefit from using `argmemonly` to
deduce `noalias` on arguments is that the parameter values doe not
have to be `noalias` themselves. Later improvements can even allow
accesses to non-arguments if they do not alias with the arguments.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73428

Files:
  llvm/lib/Transforms/IPO/Attributor.cpp
  llvm/test/Transforms/Attributor/ArgumentPromotion/2008-02-01-ReturnAttrs.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/X86/attributes.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/X86/min-legal-vector-width.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/attrs.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/basictest.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/byval-2.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/byval.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/control-flow.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/control-flow2.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/dbg.ll
  llvm/test/Transforms/Attributor/ArgumentPromotion/variadic.ll
  llvm/test/Transforms/Attributor/IPConstantProp/PR16052.ll
  llvm/test/Transforms/Attributor/IPConstantProp/pthreads.ll
  llvm/test/Transforms/Attributor/align.ll
  llvm/test/Transforms/Attributor/internal-noalias.ll
  llvm/test/Transforms/Attributor/misc.ll
  llvm/test/Transforms/Attributor/noalias.ll
  llvm/test/Transforms/Attributor/nofree.ll
  llvm/test/Transforms/Attributor/nonnull.ll
  llvm/test/Transforms/Attributor/range.ll
  llvm/test/Transforms/Attributor/value-simplify.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D73428.240424.patch
Type: text/x-patch
Size: 45898 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200126/00987c25/attachment.bin>