[llvm-commits] CVS: llvm/lib/Analysis/BasicAliasAnalysis.cpp

[Chris Lattner]

Changes in directory llvm/lib/Analysis:

BasicAliasAnalysis.cpp updated: 1.4 -> 1.5

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Log message:

Fix bug: BasicAA/2003-03-04-GEPCrash.ll


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Diffs of the changes:

Index: llvm/lib/Analysis/BasicAliasAnalysis.cpp
diff -u llvm/lib/Analysis/BasicAliasAnalysis.cpp:1.4 llvm/lib/Analysis/BasicAliasAnalysis.cpp:1.5
--- llvm/lib/Analysis/BasicAliasAnalysis.cpp:1.4	Sun Mar  2 17:43:34 2003
+++ llvm/lib/Analysis/BasicAliasAnalysis.cpp	Tue Mar  4 10:40:17 2003
@@ -274,24 +274,18 @@
         Indices1.push_back((Value*)Op1);
       else {
         // GEP1 is known to produce a value less than GEP2.  To be
-        // conservatively correct, we must assume the largest
-        // possible constant is used in this position.  This cannot
-        // be the initial index to the GEP instructions (because we
-        // know we have at least one element before this one with
-        // the different constant arguments), so we know that the
-        // current index must be into either a struct or array.
-        // Because of this, we can calculate the maximum value
-        // possible.
+        // conservatively correct, we must assume the largest possible constant
+        // is used in this position.  This cannot be the initial index to the
+        // GEP instructions (because we know we have at least one element before
+        // this one with the different constant arguments), so we know that the
+        // current index must be into either a struct or array.  Because we know
+        // it's not constant, this cannot be a structure index.  Because of
+        // this, we can calculate the maximum value possible.
         //
-        const Type *ElTy = GEP1->getIndexedType(GEPPointerTy,
-                                                Indices1, true);
-        if (const StructType *STy = dyn_cast<StructType>(ElTy)) {
-          Indices1.push_back(ConstantUInt::get(Type::UByteTy,
-                                               STy->getNumContainedTypes()));
-        } else {
-          Indices1.push_back(ConstantSInt::get(Type::LongTy,
-                                               cast<ArrayType>(ElTy)->getNumElements()));
-        }
+        const ArrayType *ElTy =
+          cast<ArrayType>(GEP1->getIndexedType(GEPPointerTy, Indices1, true));
+        Indices1.push_back(ConstantSInt::get(Type::LongTy,
+                                             ElTy->getNumElements()-1));
       }
       
       if (isa<Constant>(Op2))