To create a copy of a SmallVector with an element removed from the
middle, copy the elements in two groups, rather than copying all the
elements and then doing an erase on the middle of the result. These
are SmallVectors, so we shouldn't expect to hit dynamic allocation
in the common case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111151 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 7140652..6eb0793 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1530,8 +1530,9 @@
           if (Mul->getNumOperands() != 2) {
             // If the multiply has more than two operands, we must get the
             // Y*Z term.
-            SmallVector<const SCEV *, 4> MulOps(Mul->op_begin(), Mul->op_end());
-            MulOps.erase(MulOps.begin()+MulOp);
+            SmallVector<const SCEV *, 4> MulOps(Mul->op_begin(),
+                                                Mul->op_begin()+MulOp);
+            MulOps.append(Mul->op_begin()+MulOp+1, Mul->op_end());
             InnerMul = getMulExpr(MulOps);
           }
           const SCEV *One = getConstant(Ty, 1);
@@ -1564,15 +1565,15 @@
             const SCEV *InnerMul1 = Mul->getOperand(MulOp == 0);
             if (Mul->getNumOperands() != 2) {
               SmallVector<const SCEV *, 4> MulOps(Mul->op_begin(),
-                                                  Mul->op_end());
-              MulOps.erase(MulOps.begin()+MulOp);
+                                                  Mul->op_begin()+MulOp);
+              MulOps.append(Mul->op_begin()+MulOp+1, Mul->op_end());
               InnerMul1 = getMulExpr(MulOps);
             }
             const SCEV *InnerMul2 = OtherMul->getOperand(OMulOp == 0);
             if (OtherMul->getNumOperands() != 2) {
               SmallVector<const SCEV *, 4> MulOps(OtherMul->op_begin(),
-                                                  OtherMul->op_end());
-              MulOps.erase(MulOps.begin()+OMulOp);
+                                                  OtherMul->op_begin()+OMulOp);
+              MulOps.append(OtherMul->op_begin()+OMulOp+1, OtherMul->op_end());
               InnerMul2 = getMulExpr(MulOps);
             }
             const SCEV *InnerMulSum = getAddExpr(InnerMul1,InnerMul2);