[llvm] 3f162e8 - [SCEVExpander] Assert single pointer op in add (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2021-08-29T20:30:56+02:00
New Revision: 3f162e8e6da14726c7666f5c935c503fcb784a41

URL: https://github.com/llvm/llvm-project/commit/3f162e8e6da14726c7666f5c935c503fcb784a41
DIFF: https://github.com/llvm/llvm-project/commit/3f162e8e6da14726c7666f5c935c503fcb784a41.diff

LOG: [SCEVExpander] Assert single pointer op in add (NFC)

There can only be one pointer operand in an add expression, and
we have sorted operands to guarantee that it is the first. As
such, the pointer check for other operands is dead code.

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
index ca1545b82e039..e0205c1fd582f 100644
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -765,7 +765,11 @@ Value *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) {
       // This is the first operand. Just expand it.
       Sum = expand(Op);
       ++I;
-    } else if (PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) {
+      continue;
+    }
+
+    assert(!Op->getType()->isPointerTy() && "Only first op can be pointer");
+    if (PointerType *PTy = dyn_cast<PointerType>(Sum->getType())) {
       // The running sum expression is a pointer. Try to form a getelementptr
       // at this level with that as the base.
       SmallVector<const SCEV *, 4> NewOps;
@@ -779,16 +783,6 @@ Value *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) {
         NewOps.push_back(X);
       }
       Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum);
-    } else if (PointerType *PTy = dyn_cast<PointerType>(Op->getType())) {
-      // The running sum is an integer, and there's a pointer at this level.
-      // Try to form a getelementptr. If the running sum is instructions,
-      // use a SCEVUnknown to avoid re-analyzing them.
-      SmallVector<const SCEV *, 4> NewOps;
-      NewOps.push_back(isa<Instruction>(Sum) ? SE.getUnknown(Sum) :
-                                               SE.getSCEV(Sum));
-      for (++I; I != E && I->first == CurLoop; ++I)
-        NewOps.push_back(I->second);
-      Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, expand(Op));
     } else if (Op->isNonConstantNegative()) {
       // Instead of doing a negate and add, just do a subtract.
       Value *W = expandCodeForImpl(SE.getNegativeSCEV(Op), Ty, false);