[PATCH] D90070: [CostModel] Add optional VecPred argument to getCmpSelInstrCost.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: samparker, dmgreen, spatel, RKSimon.
Herald added subscribers: kbarton, hiraditya, kristof.beyls, nemanjai.
Herald added a project: LLVM.
fhahn requested review of this revision.

On some targets, like AArch64, vector selects can be efficiently lowered
if the vector condition is a compare with a supported predicate.

This patch adds a new argument to getCmpSelInstrCost, to indicate the
predicate of the feeding select condition. Note that it is not
sufficient to use the context instruction when querying the cost of a
vector select starting from a scalar one, because the condition of the
vector select could be composed of compares with different predicates.

This change greatly improves modeling the costs of certain
compare/select patterns on AArch64.

I am also planning on putting up patches to make use of the new argument in
SLPVectorizer & LV.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D90070

Files:
  llvm/include/llvm/Analysis/TargetTransformInfo.h
  llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
  llvm/include/llvm/CodeGen/BasicTTIImpl.h
  llvm/lib/Analysis/TargetTransformInfo.cpp
  llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
  llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
  llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
  llvm/lib/Target/ARM/ARMTargetTransformInfo.h
  llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
  llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.h
  llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
  llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h
  llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
  llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
  llvm/lib/Target/X86/X86TargetTransformInfo.cpp
  llvm/lib/Target/X86/X86TargetTransformInfo.h
  llvm/test/Analysis/CostModel/AArch64/vector-select.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D90070.300385.patch
Type: text/x-patch
Size: 24919 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20201023/c5b1464d/attachment.bin>