From ba955397ac44e5df6135469d76c645fdcac256da Mon Sep 17 00:00:00 2001
From: Chen Zheng <czhengsz@cn.ibm.com>
Date: Mon, 3 Aug 2020 08:37:52 -0400
Subject: [PATCH] [SCEVExpander][PowerPC]clear scev rewriter before deleting
 instructions.

Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D85130
---
 llvm/lib/Target/PowerPC/PPCLoopInstrFormPrep.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/llvm/lib/Target/PowerPC/PPCLoopInstrFormPrep.cpp b/llvm/lib/Target/PowerPC/PPCLoopInstrFormPrep.cpp
index a7546d2be5d8..0068ad7174ee 100644
--- a/llvm/lib/Target/PowerPC/PPCLoopInstrFormPrep.cpp
+++ b/llvm/lib/Target/PowerPC/PPCLoopInstrFormPrep.cpp
@@ -606,6 +606,10 @@ bool PPCLoopInstrFormPrep::rewriteLoadStores(Loop *L, Bucket &BucketChain,
       NewBasePtr = NewPHI;
   }
 
+  // Clear the rewriter cache, because values that are in the rewriter's cache
+  // can be deleted below, causing the AssertingVH in the cache to trigger.
+  SCEVE.clear();
+
   if (Instruction *IDel = dyn_cast<Instruction>(BasePtr))
     BBChanged.insert(IDel->getParent());
   BasePtr->replaceAllUsesWith(NewBasePtr);