[PATCH] D82632: [NFCI][SCEV] getPointerBase(): de-recursify

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri updated this revision to Diff 273853.
lebedev.ri added a comment.

In D82632#2118113 <https://reviews.llvm.org/D82632#2118113>, @efriedma wrote:

> I'd prefer not to add the cutoff until we have a real use for it.


I see, droped it.

LG?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82632/new/

https://reviews.llvm.org/D82632

Files:
  llvm/lib/Analysis/ScalarEvolution.cpp


Index: llvm/lib/Analysis/ScalarEvolution.cpp
===================================================================
--- llvm/lib/Analysis/ScalarEvolution.cpp
+++ llvm/lib/Analysis/ScalarEvolution.cpp
@@ -3953,23 +3953,25 @@
   if (!V->getType()->isPointerTy())
     return V;
 
-  if (const SCEVCastExpr *Cast = dyn_cast<SCEVCastExpr>(V)) {
-    return getPointerBase(Cast->getOperand());
-  } else if (const SCEVNAryExpr *NAry = dyn_cast<SCEVNAryExpr>(V)) {
-    const SCEV *PtrOp = nullptr;
-    for (const SCEV *NAryOp : NAry->operands()) {
-      if (NAryOp->getType()->isPointerTy()) {
-        // Cannot find the base of an expression with multiple pointer operands.
-        if (PtrOp)
-          return V;
-        PtrOp = NAryOp;
+  while (true) {
+    if (const SCEVCastExpr *Cast = dyn_cast<SCEVCastExpr>(V)) {
+      V = Cast->getOperand();
+    } else if (const SCEVNAryExpr *NAry = dyn_cast<SCEVNAryExpr>(V)) {
+      const SCEV *PtrOp = nullptr;
+      for (const SCEV *NAryOp : NAry->operands()) {
+        if (NAryOp->getType()->isPointerTy()) {
+          // Cannot find the base of an expression with multiple pointer ops.
+          if (PtrOp)
+            return V;
+          PtrOp = NAryOp;
+        }
       }
-    }
-    if (!PtrOp)
+      if (!PtrOp) // All operands were non-pointer.
+        return V;
+      V = PtrOp;
+    } else // Not something we can look further into.
       return V;
-    return getPointerBase(PtrOp);
   }
-  return V;
 }
 
 /// Push users of the given Instruction onto the given Worklist.


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