Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5614,7 +5614,8 @@
         continue;
 
       Value *Ptr = getPointerOperand(&I);
-      int64_t Stride = getPtrStride(PSE, Ptr, TheLoop, Strides);
+      int64_t Stride = getPtrStride(PSE, Ptr, TheLoop, Strides, /*Assume=*/true, 
+                                    /*ShouldCheckWrap=*/false);
 
       const SCEV *Scev = replaceSymbolicStrideSCEV(PSE, Strides, Ptr);
       PointerType *PtrTy = dyn_cast<PointerType>(Ptr->getType());
Index: llvm/test/Transforms/LoopVectorize/AArch64/gather-cost.ll
===================================================================
--- llvm/test/Transforms/LoopVectorize/AArch64/gather-cost.ll
+++ llvm/test/Transforms/LoopVectorize/AArch64/gather-cost.ll
@@ -1,4 +1,4 @@
-; RUN: opt -loop-vectorize -mtriple=arm64-apple-ios -S -mcpu=cyclone < %s | FileCheck %s
+; RUN: opt -loop-vectorize -mtriple=arm64-apple-ios -S -mcpu=cyclone -enable-interleaved-mem-accesses=false < %s | FileCheck %s
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n32:64-S128"
 
 @kernel = global [512 x float] zeroinitializer, align 16
Index: llvm/test/Transforms/LoopVectorize/ARM/gather-cost.ll
===================================================================
--- llvm/test/Transforms/LoopVectorize/ARM/gather-cost.ll
+++ llvm/test/Transforms/LoopVectorize/ARM/gather-cost.ll
@@ -1,4 +1,4 @@
-; RUN: opt -loop-vectorize -mtriple=thumbv7s-apple-ios6.0.0 -S < %s | FileCheck %s
+; RUN: opt -loop-vectorize -mtriple=thumbv7s-apple-ios6.0.0 -enable-interleaved-mem-accesses=false -S < %s | FileCheck %s
 
 target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32"
 
Index: llvm/test/Transforms/LoopVectorize/interleaved-accesses-1.ll
===================================================================
--- llvm/test/Transforms/LoopVectorize/interleaved-accesses-1.ll
+++ llvm/test/Transforms/LoopVectorize/interleaved-accesses-1.ll
@@ -0,0 +1,84 @@
+; RUN: opt -S -loop-vectorize -instcombine -force-vector-width=4 -force-vector-interleave=1 -enable-interleaved-mem-accesses=true < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; Check that the interleaved-mem-access analysis identifies the access
+; to array 'in' as interleaved, despite the possibly wrapping unsigned
+; 'out_ix' index.
+;
+; If getPtrStride is called with Assume=false and ShouldCheckWrap=true it 
+; cannot resolve the stride because the SCEV could wrap and Stride!=1.
+; It getPtrStride is called with Assume=true or ShouldCheckWrap=false it
+; is able to return a stride of 2, and in turn the interleaved-mem-accesses
+; analysis is able to form an interleaving group. 
+
+;
+; #include <stdlib.h>
+; class Complex {
+; private:
+;  float real_;
+;  float imaginary_;
+;
+;public:
+; Complex() : real_(0), imaginary_(0) { }
+; Complex(float real, float imaginary) : real_(real), imaginary_(imaginary) { }
+; Complex(const Complex &rhs) : real_(rhs.real()), imaginary_(rhs.imaginary()) { }
+;
+; inline float real() const { return real_; }
+; inline float imaginary() const { return imaginary_; }
+;};
+;
+;Complex * w_factors_;
+;void test(Complex * __restrict__ out, Complex * __restrict__ in, size_t out_start, size_t size)
+;{
+;   for (size_t out_offset = 0; out_offset < size; ++out_offset)
+;     {
+;       size_t out_ix = out_start + out_offset;
+;       Complex t0 = in[out_ix];
+;       out[out_ix] = t0;
+;     }
+;}
+
+; CHECK: vector.body:
+; CHECK: %wide.vec = load <8 x i32>, <8 x i32>* {{.*}}, align 4
+; CHECK: shufflevector <8 x i32> %wide.vec, <8 x i32> undef, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
+; CHECK: shufflevector <8 x i32> %wide.vec, <8 x i32> undef, <4 x i32> <i32 1, i32 3, i32 5, i32 7>
+
+%class.Complex = type { float, float }
+
+@w_factors_ = local_unnamed_addr global %class.Complex* null, align 8
+
+define void @_Z4testP7ComplexS0_mm(%class.Complex* noalias nocapture %out, %class.Complex* noalias nocapture readonly %in, i64 %out_start, i64 %size) local_unnamed_addr {
+entry:
+  %cmp9 = icmp eq i64 %size, 0
+  br i1 %cmp9, label %for.cond.cleanup, label %for.body.preheader
+
+for.body.preheader:
+  br label %for.body
+
+for.cond.cleanup.loopexit:
+  br label %for.cond.cleanup
+
+for.cond.cleanup:
+  ret void
+
+for.body:
+  %out_offset.010 = phi i64 [ %inc, %for.body ], [ 0, %for.body.preheader ]
+  %add = add i64 %out_offset.010, %out_start
+  %arrayidx = getelementptr inbounds %class.Complex, %class.Complex* %in, i64 %add
+  %0 = bitcast %class.Complex* %arrayidx to i32*
+  %1 = load i32, i32* %0, align 4
+  %imaginary_.i.i = getelementptr inbounds %class.Complex, %class.Complex* %in, i64 %add, i32 1
+  %2 = bitcast float* %imaginary_.i.i to i32*
+  %3 = load i32, i32* %2, align 4
+  %arrayidx1 = getelementptr inbounds %class.Complex, %class.Complex* %out, i64 %add
+  %4 = bitcast %class.Complex* %arrayidx1 to i64*
+  %t0.sroa.4.0.insert.ext = zext i32 %3 to i64
+  %t0.sroa.4.0.insert.shift = shl nuw i64 %t0.sroa.4.0.insert.ext, 32
+  %t0.sroa.0.0.insert.ext = zext i32 %1 to i64
+  %t0.sroa.0.0.insert.insert = or i64 %t0.sroa.4.0.insert.shift, %t0.sroa.0.0.insert.ext
+  store i64 %t0.sroa.0.0.insert.insert, i64* %4, align 4
+  %inc = add nuw i64 %out_offset.010, 1
+  %exitcond = icmp eq i64 %inc, %size
+  br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body
+}