[PATCH] D68544: [X86][AVX] Access a scalar float/double as a free extract from a broadcast load (PR43217)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon created this revision.
RKSimon added reviewers: craig.topper, spatel, lebedev.ri.
Herald added a subscriber: hiraditya.
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If a fp scalar is loaded and then used as both a scalar and a vector broadcast, perform the load as a broadcast and then extract the scalar for 'free' from the 0th element.

This involved switching the order of the X86ISD::BROADCAST combines so we only convert to X86ISD::BROADCAST_LOAD once all other canonicalizations have been attempted.

Fixed PR43217


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D68544

Files:
  llvm/lib/Target/X86/X86ISelLowering.cpp
  llvm/test/CodeGen/X86/avx-vbroadcast.ll

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