[PATCH] D109883: [Analysis] Add support for vscale in computeKnownBitsFromOperator

[David Sherwood via Phabricator via llvm-commits]

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In ValueTracking.cpp we use a function called
computeKnownBitsFromOperator to determine the known bits of a value.
For the vscale intrinsic if the function contains the vscale_range
attribute we can use the maximum value of vscale to determine some
known zero bits. This should help to improve code quality by
allowing certain optimisations to take place.

Tests added here:

  Transforms/InstCombine/icmp-vscale.ll


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D109883

Files:
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/test/Transforms/InstCombine/icmp-vscale.ll
  llvm/test/Transforms/LoopVectorize/AArch64/sve-widen-phi.ll

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