diff --git a/llvm/lib/Target/PowerPC/PPCInstr64Bit.td b/llvm/lib/Target/PowerPC/PPCInstr64Bit.td
--- a/llvm/lib/Target/PowerPC/PPCInstr64Bit.td
+++ b/llvm/lib/Target/PowerPC/PPCInstr64Bit.td
@@ -943,7 +943,7 @@
                         [(set i64:$rD, (sextloadi32 xaddrX4:$src))]>, isPPC64,
                         PPC970_DGroup_Cracked;
 // For fast-isel:
-let isCodeGenOnly = 1, mayLoad = 1 in {
+let isCodeGenOnly = 1, mayLoad = 1, hasSideEffects = 0 in {
 def LWA_32  : DSForm_1<58, 2, (outs gprc:$rD), (ins memrix:$src),
                       "lwa $rD, $src", IIC_LdStLWA, []>, isPPC64,
                       PPC970_DGroup_Cracked;
diff --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.td b/llvm/lib/Target/PowerPC/PPCInstrInfo.td
--- a/llvm/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.td
@@ -2039,6 +2039,7 @@
 }
 
 // Load Multiple
+let mayLoad = 1, mayStore = 0, hasSideEffects = 0 in 
 def LMW : DForm_1<46, (outs gprc:$rD), (ins memri:$src),
                   "lmw $rD, $src", IIC_LdStLMW, []>;
 
@@ -2193,6 +2194,7 @@
 }
 
 // Store Multiple
+let mayStore = 1, mayLoad = 0, hasSideEffects = 0 in
 def STMW : DForm_1<47, (outs), (ins gprc:$rS, memri:$dst),
                    "stmw $rS, $dst", IIC_LdStLMW, []>;
 
diff --git a/llvm/lib/Target/PowerPC/PPCInstrVSX.td b/llvm/lib/Target/PowerPC/PPCInstrVSX.td
--- a/llvm/lib/Target/PowerPC/PPCInstrVSX.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrVSX.td
@@ -1379,7 +1379,7 @@
                        [(set v4i32:$XT, (or v4i32:$XA, (vnot_ppc v4i32:$XB)))]>;
 
   // VSX scalar loads introduced in ISA 2.07
-  let mayLoad = 1, mayStore = 0 in {
+  let mayLoad = 1, mayStore = 0, hasSideEffects = 0 in {
     let CodeSize = 3 in
     def LXSSPX : XX1Form_memOp<31, 524, (outs vssrc:$XT), (ins memrr:$src),
                          "lxsspx $XT, $src", IIC_LdStLFD, []>;
@@ -1404,7 +1404,7 @@
   } // mayLoad
 
   // VSX scalar stores introduced in ISA 2.07
-  let mayStore = 1, mayLoad = 0 in {
+  let mayStore = 1, mayLoad = 0, hasSideEffects = 0 in {
     let CodeSize = 3 in
     def STXSSPX : XX1Form_memOp<31, 652, (outs), (ins vssrc:$XT, memrr:$dst),
                           "stxsspx $XT, $dst", IIC_LdStSTFD, []>;
@@ -2977,7 +2977,7 @@
 
   // When adding new D-Form loads/stores, be sure to update the ImmToIdxMap in
   // PPCRegisterInfo::PPCRegisterInfo and maybe save yourself some debugging.
-  let mayLoad = 1, mayStore = 0 in {
+  let mayLoad = 1, mayStore = 0, hasSideEffects = 0 in {
   // Load Vector
   def LXV : DQ_RD6_RS5_DQ12<61, 1, (outs vsrc:$XT), (ins memrix16:$src),
                             "lxv $XT, $src", IIC_LdStLFD, []>;
@@ -3022,7 +3022,7 @@
 
   // When adding new D-Form loads/stores, be sure to update the ImmToIdxMap in
   // PPCRegisterInfo::PPCRegisterInfo and maybe save yourself some debugging.
-  let mayStore = 1, mayLoad = 0 in {
+  let mayStore = 1, mayLoad = 0, hasSideEffects = 0 in {
   // Store Vector
   def STXV : DQ_RD6_RS5_DQ12<61, 5, (outs), (ins vsrc:$XT, memrix16:$dst),
                              "stxv $XT, $dst", IIC_LdStSTFD, []>;
@@ -3769,7 +3769,7 @@
   }
 }
 
-let Predicates = [HasP9Vector] in {
+let Predicates = [HasP9Vector], hasSideEffects = 0 in {
   let mayStore = 1 in {
     def SPILLTOVSR_STX : PseudoXFormMemOp<(outs),
                                           (ins spilltovsrrc:$XT, memrr:$dst),
diff --git a/llvm/test/CodeGen/PowerPC/extract-and-store.ll b/llvm/test/CodeGen/PowerPC/extract-and-store.ll
--- a/llvm/test/CodeGen/PowerPC/extract-and-store.ll
+++ b/llvm/test/CodeGen/PowerPC/extract-and-store.ll
@@ -794,8 +794,6 @@
 ;
 ; CHECK-P9-LABEL: test_13_consecutive_stores_of_bytes:
 ; CHECK-P9:       # %bb.0: # %entry
-; CHECK-P9-NEXT:    vsldoi v3, v2, v2, 4
-; CHECK-P9-NEXT:    stxsibx vs35, 0, r5
 ; CHECK-P9-NEXT:    vsldoi v3, v2, v2, 12
 ; CHECK-P9-NEXT:    li r3, 1
 ; CHECK-P9-NEXT:    stxsibx vs35, r5, r3
@@ -808,6 +806,8 @@
 ; CHECK-P9-NEXT:    vsldoi v3, v2, v2, 2
 ; CHECK-P9-NEXT:    li r3, 4
 ; CHECK-P9-NEXT:    stxsibx vs35, r5, r3
+; CHECK-P9-NEXT:    vsldoi v3, v2, v2, 4
+; CHECK-P9-NEXT:    stxsibx vs35, 0, r5
 ; CHECK-P9-NEXT:    vsldoi v3, v2, v2, 8
 ; CHECK-P9-NEXT:    li r3, 5
 ; CHECK-P9-NEXT:    stxsibx vs35, r5, r3
@@ -836,19 +836,19 @@
 ;
 ; CHECK-P9-BE-LABEL: test_13_consecutive_stores_of_bytes:
 ; CHECK-P9-BE:       # %bb.0: # %entry
-; CHECK-P9-BE-NEXT:    vsldoi v3, v2, v2, 13
-; CHECK-P9-BE-NEXT:    stxsibx vs35, 0, r5
+; CHECK-P9-BE-NEXT:    li r3, 3
 ; CHECK-P9-BE-NEXT:    vsldoi v3, v2, v2, 5
+; CHECK-P9-BE-NEXT:    stxsibx vs34, r5, r3
 ; CHECK-P9-BE-NEXT:    li r3, 1
 ; CHECK-P9-BE-NEXT:    stxsibx vs35, r5, r3
 ; CHECK-P9-BE-NEXT:    vsldoi v3, v2, v2, 2
 ; CHECK-P9-BE-NEXT:    li r3, 2
 ; CHECK-P9-BE-NEXT:    stxsibx vs35, r5, r3
-; CHECK-P9-BE-NEXT:    li r3, 3
 ; CHECK-P9-BE-NEXT:    vsldoi v3, v2, v2, 15
-; CHECK-P9-BE-NEXT:    stxsibx vs34, r5, r3
 ; CHECK-P9-BE-NEXT:    li r3, 4
 ; CHECK-P9-BE-NEXT:    stxsibx vs35, r5, r3
+; CHECK-P9-BE-NEXT:    vsldoi v3, v2, v2, 13
+; CHECK-P9-BE-NEXT:    stxsibx vs35, 0, r5
 ; CHECK-P9-BE-NEXT:    vsldoi v3, v2, v2, 9
 ; CHECK-P9-BE-NEXT:    li r3, 5
 ; CHECK-P9-BE-NEXT:    stxsibx vs35, r5, r3
diff --git a/llvm/test/CodeGen/PowerPC/scheduling-mem-dependency.ll b/llvm/test/CodeGen/PowerPC/scheduling-mem-dependency.ll
--- a/llvm/test/CodeGen/PowerPC/scheduling-mem-dependency.ll
+++ b/llvm/test/CodeGen/PowerPC/scheduling-mem-dependency.ll
@@ -1,19 +1,58 @@
 ; REQUIRES: asserts
 ; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -verify-misched -debug-only=machine-scheduler -o - 2>&1 > /dev/null | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 -verify-misched -debug-only=machine-scheduler -o - 2>&1 > /dev/null | FileCheck %s --check-prefix=CHECK-P9
 
 define i64 @store_disjoint_memory(i64* nocapture %P, i64 %v) {
 entry:
 ; CHECK: ********** MI Scheduling **********
 ; CHECK-LABEL: store_disjoint_memory:%bb.0
-; CHECK:SU(2):   STD renamable $x4, 24, renamable $x5 :: (store 8 into %ir.arrayidx)
+; CHECK:SU([[REG2:[0-9]+]]):   STD renamable $x{{[0-9]+}}, 24, renamable $x[[REG5:[0-9]+]]
 ; CHECK-NOT: Successors:
-; CHECK-NOT:    SU(3): Ord  Latency=0 Memory
-; CHECK:SU(3):   STD renamable $x4, 16, renamable $x5 :: (store 8 into %ir.arrayidx1)
+; CHECK-NOT:    SU([[REG3]]): Ord  Latency=0 Memory
+; CHECK:SU([[REG3:[0-9]+]]):   STD renamable $x{{[0-9]+}}, 16, renamable $x[[REG5]]
 ; CHECK: Predecessors:
-; CHECK-NOT:    SU(2): Ord  Latency=0 Memory
+; CHECK-NOT:    SU([[REG2]]): Ord  Latency=0 Memory
   %arrayidx = getelementptr inbounds i64, i64* %P, i64 3
   store i64 %v, i64* %arrayidx
   %arrayidx1 = getelementptr inbounds i64, i64* %P, i64 2
   store i64 %v, i64* %arrayidx1
   ret i64 %v
 }
+
+; LXSD is an instruction that can be modeled.
+@gd = external local_unnamed_addr global [500 x double], align 8
+@gf = external local_unnamed_addr global [500 x float], align 4
+
+define double @test_lxsd_no_barrier(double %a, double %b, double %c, double %d, double %e, double %f, double %g, double %h, double %i, double %j, double %k, double %l, double %m) {
+entry:
+  %0 = load double, double* getelementptr inbounds ([500 x double], [500 x double]* @gd, i64 0, i64 10), align 8
+  %1 = load double, double* getelementptr inbounds ([500 x double], [500 x double]* @gd, i64 0, i64 17), align 8
+  %2 = load double, double* getelementptr inbounds ([500 x double], [500 x double]* @gd, i64 0, i64 87), align 8
+  %3 = load double, double* getelementptr inbounds ([500 x double], [500 x double]* @gd, i64 0, i64 97), align 8
+  %4 = load double, double* getelementptr inbounds ([500 x double], [500 x double]* @gd, i64 0, i64 77), align 8
+  %add = fadd double %a, %b
+  %add1 = fadd double %add, %c
+  %add2 = fadd double %add1, %d
+  %add3 = fadd double %add2, %e
+  %add4 = fadd double %add3, %f
+  %add5 = fadd double %add4, %g
+  %add6 = fadd double %add5, %h
+  %add7 = fadd double %add6, %i
+  %add8 = fadd double %add7, %j
+  %add9 = fadd double %add8, %k
+  %add10 = fadd double %add9, %l
+  %add11 = fadd double %add10, %m
+  %add12 = fadd double %add11, %0
+  %add13 = fadd double %add12, %1
+  %add14 = fadd double %add13, %2
+  %add15 = fadd double %add14, %3
+  %add16 = fadd double %add15, %4
+  ret double %add16
+; CHECK-P9: ********** MI Scheduling **********
+; CHECK-P9-LABEL: test_lxsd_no_barrier:%bb.0 entry
+; CHECK-P9-NOT:Global memory object and new barrier chain: SU({{[0-9]+}}).
+; CHECK-P9:SU({{[0-9]+}}):   renamable $vf{{[0-9]+}} = LXSD 136
+; CHECK-P9:SU({{[0-9]+}}):   renamable $vf{{[0-9]+}} = LXSD 696
+; CHECK-P9:SU({{[0-9]+}}):   renamable $vf{{[0-9]+}} = LXSD 776
+; CHECK-P9:SU({{[0-9]+}}):   renamable $vf{{[0-9]+}} = LXSD 616
+}