[PATCH] D32687: [DAGCombine] (uaddo X, (addcarry Y, 0, Carry)) -> (addcarry X, Y, Carry)

[Amaury SECHET via Phabricator via llvm-commits]

deadalnix created this revision.

This is a common pattern that arise when legalizing large integers operations. Only do it when Y + 1 cannot overflow as this would change the carry behavior of uaddo .


https://reviews.llvm.org/D32687

Files:
  lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  test/CodeGen/X86/adde-carry.ll
  test/CodeGen/X86/mul-i1024.ll
  test/CodeGen/X86/mul-i256.ll
  test/CodeGen/X86/mul-i512.ll

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