[LLVMdev] RAUW in shift-and reassociation during X86 ISel

[Adam Nemet]

Hi Dan,

I am trying to understand the change you made in http://llvm.org/viewvc/llvm-project?view=revision&revision=57465

In order to understand the details, I tried to revert the change but the test case still passes which is not very surprising after 6 years :(.

I am seeing a related new bug that causes a load that was stashed on the NodeStack and in RecordedNodes during iSel to get deleted because the RAUW during MatchAddress CSE’s the load.

I am hoping that you’d still remember some of the details of why we need to modify the DAG like this.  Thanks.

Adam