[PATCH] D91207: [AArch64][GlobalISel] Select arith extended add/sub in manual selection code

[Jessica Paquette via Phabricator via llvm-commits]

paquette created this revision.
paquette added a reviewer: aemerson.
Herald added subscribers: danielkiss, hiraditya, kristof.beyls, rovka.
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paquette requested review of this revision.

The manual selection code for add/sub was not checking if it was possible to fold in shifts + extends (the *rx opcode variants).

As a result, we could never select things like

  cmp x1, w0, uxtw #2

Because we don't import any patterns for compares.

This adds support for the arithmetic shifted register forms and updates tests for instructions selected using `emitADD`, `emitADDS`, and `emitSUBS`.

This is a 0.1% geomean code size improvement on SPECINT2000 at -Os.


https://reviews.llvm.org/D91207

Files:
  llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
  llvm/test/CodeGen/AArch64/GlobalISel/opt-fold-compare.mir
  llvm/test/CodeGen/AArch64/GlobalISel/select-cmp.mir
  llvm/test/CodeGen/AArch64/GlobalISel/select-ptr-add.mir
  llvm/test/CodeGen/AArch64/GlobalISel/select-uaddo.mir

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