[PATCH] D76434: [SCEV] Query for immediate cost in Expander

[Sam Parker via Phabricator via llvm-commits]

samparker created this revision.
samparker added reviewers: lebedev.ri, reames, echristo, mkazantsev, hfinkel, craig.topper, arsenm.
Herald added subscribers: danielkiss, zzheng, hiraditya, kristof.beyls, wdng, nemanjai.

Change isHighCostExpansion to query the backend for the use of an constant. This also sinks the idea of a free constant into the default TTI implementation as it is reasonable enough to assume that a constant is likely to be free, rather than the same cost as a 'basic' - which is the cost of most instructions. It seems that the biggest causes of change are due by loop unrolling, which has affected PPC, X86 and ARM.


https://reviews.llvm.org/D76434

Files:
  llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
  llvm/lib/Analysis/ScalarEvolutionExpander.cpp
  llvm/test/CodeGen/ARM/indvar-cost.ll
  llvm/test/CodeGen/ARM/indvar-unroll-imm-cost.ll
  llvm/test/Transforms/IndVarSimplify/eliminate-trunc.ll
  llvm/test/Transforms/IndVarSimplify/iv-widen.ll
  llvm/test/Transforms/IndVarSimplify/loop-invariant-conditions.ll
  llvm/test/Transforms/IndVarSimplify/widen-loop-comp.ll
  llvm/test/Transforms/LoopUnroll/PowerPC/p8-unrolling-legalize-vectors.ll
  llvm/test/Transforms/LoopVectorize/X86/float-induction-x86.ll
  llvm/test/Transforms/SpeculateAroundPHIs/convergent.ll

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