[PATCH] D134229: [RISCV] Make computeIncomingVLVTYPE more conservative when merging predecessor state.

[Craig Topper via Phabricator via llvm-commits]

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If we have already calculated the incoming state before, use that
as our starting point to ensure we are conservative.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D134229

Files:
  llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp


Index: llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
+++ llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
@@ -1088,7 +1088,9 @@
 
   BBInfo.InQueue = false;
 
-  VSETVLIInfo InInfo;
+  // Start with the previous entry so that we keep the most conservative state
+  // we have ever found.
+  VSETVLIInfo InInfo = BBInfo.Pred;
   if (MBB.pred_empty()) {
     // There are no predecessors, so use the default starting status.
     InInfo.setUnknown();


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