Index: lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- lib/Transforms/Vectorize/LoopVectorize.cpp
+++ lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -1577,6 +1577,28 @@
     return II.getConsecutiveDirection();
   }
 
+  const SCEV *PtrScev = SE->getSCEV(Ptr);
+  const SCEVAddRecExpr *PtrAddRec = nullptr;
+  const DataLayout &DL = Gep->getModule()->getDataLayout();
+  // If this Ptr value is SCEVAddRecExpr, has constant stride and the stride
+  // equals to the size of pointer element type, we know it is consecutive.
+  if (PtrScev && (PtrAddRec = dyn_cast<SCEVAddRecExpr>(PtrScev))) {
+    const SCEV *Step = PtrAddRec->getStepRecurrence(*SE);
+    const SCEVConstant *C = dyn_cast<SCEVConstant>(Step);
+    if (!C)
+      return 0;
+    const APInt &APStepVal = C->getValue()->getValue();
+    int64_t StepVal = APStepVal.getSExtValue();
+    int64_t ElemSize =
+        DL.getTypeAllocSize(Ptr->getType()->getPointerElementType());
+    if (StepVal == ElemSize)
+      return 1;
+    else if (StepVal == -ElemSize)
+      return -1;
+    else
+      return 0;
+  }
+
   unsigned InductionOperand = getGEPInductionOperand(Gep);
 
   // Check that all of the gep indices are uniform except for our induction
@@ -1696,8 +1718,13 @@
   VectorParts &Entry = WidenMap.get(Instr);
 
   // Handle consecutive loads/stores.
+  Instruction *GepPtrInst = nullptr;
   GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr);
-  if (Gep && Legal->isInductionVariable(Gep->getPointerOperand())) {
+  if (Gep &&
+      (GepPtrInst = dyn_cast_or_null<Instruction>(Gep->getPointerOperand())) &&
+      !SE->isLoopInvariant(SE->getSCEV(GepPtrInst), OrigLoop)) {
+    // The case Gep->getPointerOperand() is an induction variable
+    // or a SCEVAddRecExpr.
     setDebugLocFromInst(Builder, Gep);
     Value *PtrOperand = Gep->getPointerOperand();
     Value *FirstBasePtr = getVectorValue(PtrOperand)[0];
Index: test/Transforms/LoopVectorize/pr23580.ll
===================================================================
--- test/Transforms/LoopVectorize/pr23580.ll
+++ test/Transforms/LoopVectorize/pr23580.ll
@@ -0,0 +1,58 @@
+; PR23580
+; RUN: opt < %s -loop-vectorize -instcombine -S | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.B = type { i16 }
+%class.G = type <{ %struct.F, [2 x i32], i8, [7 x i8] }>
+%struct.F = type { i8, i8, i8, i16, i32* }
+
+@a = global i32 0, align 4
+
+declare %struct.B* @_ZN1C5m_fn1Ev()
+
+; Check geps inside for.body are merged so loop vectorizer can recognize loads
+; inside for.body to be inter-iterations consecutive, and generate %wide.loads.
+;
+; CHECK-LABEL: @fn2(
+; CHECK: %wide.load{{[0-9]*}} =
+; CHECK: %wide.load{{[0-9]*}} =
+
+define void @fn2(%class.G* nocapture readonly %this) align 2 {
+entry:
+  br label %for.preheader
+
+for.preheader:                                    ; preds = %entry
+  %call = call %struct.B* @_ZN1C5m_fn1Ev()
+  %tmp4 = load i32, i32* @a, align 4
+  %idx.ext = sext i32 %tmp4 to i64
+  %add.ptr = getelementptr inbounds %struct.B, %struct.B* %call, i64 %idx.ext
+  %cmp14.1 = icmp slt i32 1, %tmp4
+  br i1 %cmp14.1, label %for.body.lr.ph, label %for.end, !llvm.loop !0
+
+for.body.lr.ph:                                   ; preds = %for.preheader
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %k.02 = phi i32 [ 1, %for.body.lr.ph ], [ %add, %for.body ]
+  %idxprom15 = sext i32 %k.02 to i64
+  %arrayidx16 = getelementptr inbounds %struct.B, %struct.B* %add.ptr, i64 %idxprom15
+  %ival = getelementptr inbounds %struct.B, %struct.B* %arrayidx16, i32 0, i32 0
+  %tmp9 = load i16, i16* %ival, align 2
+  %add = add nsw i32 %k.02, 1
+  %arrayidx25 = getelementptr inbounds %struct.B, %struct.B* %call, i64 %idxprom15
+  %ival26 = getelementptr inbounds %struct.B, %struct.B* %arrayidx25, i32 0, i32 0
+  store i16 %tmp9, i16* %ival26, align 2
+  %cmp14 = icmp slt i32 %add, %tmp4
+  br i1 %cmp14, label %for.body, label %for.cond.for.end_crit_edge, !llvm.loop !0
+
+for.cond.for.end_crit_edge:                       ; preds = %for.body
+  br label %for.end
+
+for.end:                                          ; preds = %for.cond.for.end_crit_edge, %for.preheader
+  ret void
+}
+
+!0 = distinct !{!0, !1}
+!1 = !{!"llvm.loop.vectorize.width", i32 4}