[all-commits] [llvm/llvm-project] afc2b7: [AArch64][CostModel] Make sext/zext free if folded...

[david-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: afc2b7db026a9d6c71d1f0d1ec9dd1ca56d1601f
      https://github.com/llvm/llvm-project/commit/afc2b7db026a9d6c71d1f0d1ec9dd1ca56d1601f
  Author: David Sherwood <david.sherwood at arm.com>
  Date:   2023-04-20 (Thu, 20 Apr 2023)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
    M llvm/test/Analysis/CostModel/AArch64/masked_ldst.ll

  Log Message:
  -----------
  [AArch64][CostModel] Make sext/zext free if folded into a masked load

The BasicTTIImpl implementation of getCastInstrCost ensures
that the cost of zext/sext is 0 when following a load if we
know the combined extending load is legal. For SVE we can do
the same for masked loads too, since they use exactly the
same underlying instruction.

Differential Revision: https://reviews.llvm.org/D148123