[PATCH] D27044: Compilation crash after node replacement

[Elena Demikhovsky via llvm-commits]

delena created this revision.
delena added reviewers: zvi, craig.topper, RKSimon, spatel.
delena added a subscriber: llvm-commits.
delena set the repository for this revision to rL LLVM.

The bug is here: https://llvm.org/bugs/show_bug.cgi?id=31045

The problem occurs when we take a node N and analyze its predecessors (operands of operands). We start from N and recursively go up N = N->getOperand(0).
On some stage of the climbing, we decide to replace one of predecessors with ReplaceAllUsesWith(N, NewNode). The ReplaceAllUsesWith works recursively and at some stage kills parent node.
I added ReplaceOneUseWith() to prevent recursive deletion.
Please let me know if this solution looks reasonable. (I attached the original reproducer, I'll minimize it if the solution itself makes sense.)


Repository:
  rL LLVM

https://reviews.llvm.org/D27044

Files:
  ../include/llvm/CodeGen/SelectionDAG.h
  ../lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  ../lib/Target/X86/X86ISelDAGToDAG.cpp
  ../test/CodeGen/X86/addr-calc-crash.ll

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