Index: lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
===================================================================
--- lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
+++ lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
@@ -692,6 +692,7 @@
       MachineInstr *MI = SwapVector[EntryIdx].VSEMI;
       unsigned UseReg = MI->getOperand(0).getReg();
       MachineInstr *DefMI = MRI->getVRegDef(UseReg);
+      unsigned DefReg = DefMI->getOperand(0).getReg();
       int DefIdx = SwapMap[DefMI];
 
       if (!SwapVector[DefIdx].IsSwap || SwapVector[DefIdx].IsLoad ||
@@ -707,6 +708,25 @@
         DEBUG(MI->dump());
         DEBUG(dbgs() << "\n");
       }
+
+      // Ensure all uses of the register defined by DefMI feed store
+      // instructions
+      for (MachineInstr &UseMI : MRI->use_nodbg_instructions(DefReg)) {
+        int UseIdx = SwapMap[&UseMI];
+
+        if (SwapVector[UseIdx].VSEMI->getOpcode() != MI->getOpcode()) {
+          SwapVector[Repr].WebRejected = 1;
+
+          DEBUG(dbgs() <<
+                format("Web %d rejected for swap not feeding only stores\n",
+                       Repr));
+          DEBUG(dbgs() << "  def " << " : ");
+          DEBUG(DefMI->dump());
+          DEBUG(dbgs() << "  use " << UseIdx << ": ");
+          DEBUG(SwapVector[UseIdx].VSEMI->dump());
+          DEBUG(dbgs() << "\n");
+        }
+      }
     }
   }
 
Index: test/CodeGen/PowerPC/swaps-le-7.ll
===================================================================
--- /dev/null
+++ test/CodeGen/PowerPC/swaps-le-7.ll
@@ -0,0 +1,55 @@
+; RUN: llc -mcpu=pwr8 -mtriple=powerpc64le-unknown-linux-gnu -O3 < %s | FileCheck %s
+;
+; This is a regression test based on https://llvm.org/bugs/show_bug.cgi?id=27735
+;
+
+@G1 = global <2 x double> <double 2.0, double -10.0>
+@G2 = global <2 x double> <double 3.0, double 4.0>
+@G3 = global <2 x double> <double 5.0, double 6.0>
+@G4 = global <2 x double> <double 7.0, double 8.0>
+
+; CHECK-LABEL: @zg
+; CHECK: xxspltd
+; CHECK-NEXT: xxspltd
+; CHECK-NEXT: xxswapd
+; CHECK-NEXT: xvmuldp
+; CHECK-NEXT: xvmuldp
+; CHECK-NEXT: xvsubdp
+; CHECK-NEXT: xvadddp
+; CHECK-NEXT: xxpermdi
+; CHECK-NEXT: xvsubdp
+; CHECK-NEXT: xxswapd
+; CHECK-NEXT: stxvd2x
+; CHECK-NEXT: blr
+
+; Function Attrs: noinline
+define void @zg(i8* %.G0011_640.0, i8* %.G0012_642.0, <2 x double>* %JJ, <2 x double>* %.ka0000_391, double %.unpack, double %.unpack66) #0 {
+L.JA291:
+  %Z.L.JA291.2 = load <2 x double>, <2 x double>* %.ka0000_391, align 16
+  store <2 x double> %Z.L.JA291.2, <2 x double>* %JJ, align 8
+  %Z.L.JA291.3 = bitcast i8* %.G0012_642.0 to <2 x double>*
+  %Z.L.JA291.4 = load <2 x double>, <2 x double>* %Z.L.JA291.3, align 1
+  %.elt136 = bitcast i8* %.G0011_640.0 to double*
+  %.unpack137 = load double, double* %.elt136, align 1
+  %.elt138 = getelementptr inbounds i8, i8* %.G0011_640.0, i64 8
+  %Z.L.JA291.5 = bitcast i8* %.elt138 to double*
+  %.unpack139 = load double, double* %Z.L.JA291.5, align 1
+  %Z.L.JA291.6 = insertelement <2 x double> undef, double %.unpack137, i32 0
+  %Z.L.JA291.7 = insertelement <2 x double> %Z.L.JA291.6, double %.unpack137, i32 1
+  %Z.L.JA291.8 = fmul <2 x double> %Z.L.JA291.2, %Z.L.JA291.7
+  %Z.L.JA291.9 = shufflevector <2 x double> %Z.L.JA291.2, <2 x double> undef, <2 x i32> <i32 1, i32 0>
+  %Z.L.JA291.10 = insertelement <2 x double> undef, double %.unpack139, i32 0
+  %Z.L.JA291.11 = insertelement <2 x double> %Z.L.JA291.10, double %.unpack139, i32 1
+  %Z.L.JA291.12 = fmul <2 x double> %Z.L.JA291.9, %Z.L.JA291.11
+  %Z.L.JA291.13 = fsub <2 x double> %Z.L.JA291.8, %Z.L.JA291.12
+  %Z.L.JA291.14 = fadd <2 x double> %Z.L.JA291.8, %Z.L.JA291.12
+  %Z.L.JA291.15 = shufflevector <2 x double> %Z.L.JA291.13, <2 x double> %Z.L.JA291.14, <2 x i32> <i32 0, i32 3>
+  %Z.L.JA291.16 = fsub <2 x double> %Z.L.JA291.4, %Z.L.JA291.15
+  %Z.L.JA291.17 = bitcast i8* %.G0012_642.0 to <2 x double>*
+  store <2 x double> %Z.L.JA291.16, <2 x double>* %Z.L.JA291.17, align 8
+  %.. = bitcast <2 x double>* %JJ to i32*
+  %.pre = load i32, i32* %.., align 32
+  ret void
+}
+
+attributes #0 = { noinline }
\ No newline at end of file