[llvm] [RISCV] Move RISCVInsertVSETVLI to after phi elimination (PR #91440)

[Piyou Chen via llvm-commits]

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@@ -519,28 +527,31 @@ class VSETVLIInfo {
   bool getTailAgnostic() const { return TailAgnostic; }
   bool getMaskAgnostic() const { return MaskAgnostic; }
 
-  bool hasNonZeroAVL() const {
+  bool hasNonZeroAVL(const LiveIntervals *LIS) const {
     if (hasAVLImm())
       return getAVLImm() > 0;
-    if (hasAVLReg())
-      return isNonZeroLoadImmediate(getAVLDefMI());
+    if (hasAVLReg()) {
+      if (auto *DefMI = LIS->getInstructionFromIndex(getAVLVNInfo()->def))
+        return isNonZeroLoadImmediate(*DefMI);
+    }
     if (hasAVLVLMAX())
       return true;
     if (hasAVLIgnored())
       return false;
     return false;
   }
 
-  bool hasEquallyZeroAVL(const VSETVLIInfo &Other) const {
+  bool hasEquallyZeroAVL(const VSETVLIInfo &Other,
+                         const LiveIntervals *LIS) const {
     if (hasSameAVL(Other))
       return true;
-    return (hasNonZeroAVL() && Other.hasNonZeroAVL());
+    return (hasNonZeroAVL(LIS) && Other.hasNonZeroAVL(LIS));
   }
 
   bool hasSameAVL(const VSETVLIInfo &Other) const {
     if (hasAVLReg() && Other.hasAVLReg())
-      return AVLRegDef.DefMI == Other.AVLRegDef.DefMI &&
-             AVLRegDef.DefReg == Other.AVLRegDef.DefReg;
+      return getAVLVNInfo()->id == Other.getAVLVNInfo()->id &&
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BeMg wrote:

Maybe `getAVLVNInfo()->def == Other.getAVLVNInfo()->def` is better than id? 

https://github.com/llvm/llvm-project/pull/91440