[all-commits] [llvm/llvm-project] b0045f: [ARM] Fix a bug in finding a pair of extracts to c...

[pzhengqc via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b0045f559549e993629a7d541b3b1df3f8144814
      https://github.com/llvm/llvm-project/commit/b0045f559549e993629a7d541b3b1df3f8144814
  Author: Pengxuan Zheng <pzheng at quicinc.com>
  Date:   2021-10-06 (Wed, 06 Oct 2021)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    A llvm/test/CodeGen/ARM/vector-extract.ll

  Log Message:
  -----------
  [ARM] Fix a bug in finding a pair of extracts to create VMOVRRD

D100244 missed a check on the ResNo of the extract's operand 0 when finding a
pair of extracts to combine into a VMOVRRD (extract(x, n); extract(x, n+1) ->
VMOVRRD(extract x, n/2)). As a result, it can incorrectly pair an extract(x, n)
with another extract(x:3, n+1) for example. This patch fixes the bug by adding
the proper check on ResNo.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D111188