[CodeGen] Fix getArrayAccessFor crashes as in bug 32534 with -polly-vectorizer=polly.

Root cause is VectorBlockGenerator::copyStmt iterates all instructions
in basic block, however some load instructions may be not unnecessary
thus removed by simplification. As a result, these load instructions
don't have a corresponding array.

Looking at BlockGenerator::copyBB, it only iterates instructions list
of ScopStmt. Given it must be a block type scop in case of
vectorization, I think we should do the same in
VectorBlockGenerator::copyStmt.

Patch by bin.narwal <bin.narwal@gmail.com>

Differential Revision: https://reviews.llvm.org/D70076

diff --git a/polly/lib/CodeGen/BlockGenerators.cpp b/polly/lib/CodeGen/BlockGenerators.cpp
index 599ae6c..ca8d80f 100644 (file)
--- a/polly/lib/CodeGen/BlockGenerators.cpp
+++ b/polly/lib/CodeGen/BlockGenerators.cpp
@@ -1391,8 +1391,8 @@ void VectorBlockGenerator::copyStmt(
 
   generateScalarVectorLoads(Stmt, VectorBlockMap);
 
-  for (Instruction &Inst : *BB)
-    copyInstruction(Stmt, &Inst, VectorBlockMap, ScalarBlockMap, NewAccesses);
+  for (Instruction *Inst : Stmt.getInstructions())
+    copyInstruction(Stmt, Inst, VectorBlockMap, ScalarBlockMap, NewAccesses);
 
   verifyNoScalarStores(Stmt);
 }