commit 57ab82784ddb8d21eb0041d52f8490d8fd404e29
Author: Michael Kuperstein <mkuper@google.com>
Date:   Wed Dec 21 17:34:21 2016 +0000

    [ConstantFolding] Fix vector GEPs harder
    
    For vector GEPs, CastGEPIndices can end up in an infinite recursion, because
    we compare the vector type to the scalar pointer type, find them different,
    and then try to cast a type to itself.
    
    Differential Revision: https://reviews.llvm.org/D28009
    
    
    git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290260 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index cf0d5e4..9e521e1 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -742,13 +742,16 @@ Constant *CastGEPIndices(Type *SrcElemTy, ArrayRef<Constant *> Ops,
     if ((i == 1 ||
          !isa<StructType>(GetElementPtrInst::getIndexedType(
              SrcElemTy, Ops.slice(1, i - 1)))) &&
-        Ops[i]->getType() != (i == 1 ? IntPtrTy : IntPtrScalarTy)) {
+        Ops[i]->getType()->getScalarType() != IntPtrScalarTy) {
       Any = true;
+      Type *NewType = Ops[i]->getType()->isVectorTy()
+                          ? IntPtrTy
+                          : IntPtrTy->getScalarType();
       NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i],
                                                                       true,
-                                                                      IntPtrTy,
+                                                                      NewType,
                                                                       true),
-                                              Ops[i], IntPtrTy));
+                                              Ops[i], NewType));
     } else
       NewIdxs.push_back(Ops[i]);
   }
diff --git a/test/Analysis/ConstantFolding/vectorgep-crash.ll b/test/Analysis/ConstantFolding/vectorgep-crash.ll
index bcc96b2..e7a5117 100644
--- a/test/Analysis/ConstantFolding/vectorgep-crash.ll
+++ b/test/Analysis/ConstantFolding/vectorgep-crash.ll
@@ -17,3 +17,24 @@ top:
   %0 = bitcast <8 x double*> %VectorGep14 to <8 x i64*>
   ret <8 x i64*> %0
 }
+
+%struct.A = type { i32, %struct.B* }
+%struct.B = type { i64, %struct.C* }
+%struct.C = type { i64 }
+
+@G = internal global [65 x %struct.A] zeroinitializer, align 16
+; CHECK-LABEL: @test
+; CHECK: ret <16 x i32*> getelementptr ([65 x %struct.A], [65 x %struct.A]* @G, <16 x i64> zeroinitializer, <16 x i64> <i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 8, i64 9, i64 10, i64 11, i64 12, i64 13, i64 14, i64 15, i64 16>, <16 x i32> zeroinitializer)
+define <16 x i32*> @test() {
+vector.body:
+  %VectorGep = getelementptr [65 x %struct.A], [65 x %struct.A]* @G, <16 x i64> zeroinitializer, <16 x i64> <i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 8, i64 9, i64 10, i64 11, i64 12, i64 13, i64 14, i64 15, i64 16>, <16 x i32> zeroinitializer
+  ret <16 x i32*> %VectorGep
+}
+
+; CHECK-LABEL: @test2
+; CHECK: ret <16 x i32*> getelementptr ([65 x %struct.A], [65 x %struct.A]* @G, <16 x i64> zeroinitializer, <16 x i64> <i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 8, i64 9, 
+define <16 x i32*> @test2() {
+vector.body:
+  %VectorGep = getelementptr [65 x %struct.A], [65 x %struct.A]* @G, <16 x i32> zeroinitializer, <16 x i64> <i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 8, i64 9, i64 10, i64 11, i64 12, i64 13, i64 14, i64 15, i64 16>, <16 x i32> zeroinitializer
+  ret <16 x i32*> %VectorGep
+}