[PATCH] D103799: [CostModel] Express cost(urem) as cost(div+mul+sub) when set to Expand.

[Sander de Smalen via Phabricator via llvm-commits]

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The Legalizer expands the operations of urem/srem into a div+mul+sub or divrem
when those are legal/custom. This patch changes the cost-model to reflect that
cost.

Since there is no 'divrem' Instruction in LLVM IR, the cost of divrem
is assumed to be the same as div+mul+sub since the three operations will
need to be executed at runtime regardless.

Patch co-authored by David Sherwood (@david-arm)


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D103799

Files:
  llvm/include/llvm/CodeGen/BasicTTIImpl.h
  llvm/test/Analysis/CostModel/AArch64/sve-remainder.ll
  llvm/test/Analysis/CostModel/ARM/divrem.ll
  llvm/test/Analysis/CostModel/X86/rem.ll

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