[PATCH] D153624: [SCEV] Make use of non-null pointers for range calculation

[Nikita Popov via Phabricator via llvm-commits]

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We know that certain pointers (e.g. non-extern-weak globals or allocas in default address space) are not null, in which case the lowest address they can be allocated at is their alignment.

This allows us to calculate better exit counts for loops that have an additional null check in the guarding condition (see `@alloca_icmp_null_exit_count`).


https://reviews.llvm.org/D153624

Files:
  llvm/lib/Analysis/ScalarEvolution.cpp
  llvm/test/Analysis/ScalarEvolution/alloca.ll
  llvm/test/Analysis/ScalarEvolution/incorrect-exit-count.ll
  llvm/test/Analysis/ScalarEvolution/load.ll
  llvm/test/Analysis/ScalarEvolution/nsw.ll
  llvm/test/Analysis/ScalarEvolution/ptrtoint-global.ll
  llvm/test/Analysis/ScalarEvolution/sdiv.ll
  llvm/test/Analysis/ScalarEvolution/srem.ll

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