Index: lib/Target/Mips/MipsInstructionSelector.cpp
===================================================================
--- lib/Target/Mips/MipsInstructionSelector.cpp
+++ lib/Target/Mips/MipsInstructionSelector.cpp
@@ -752,6 +752,10 @@
     I.eraseFromParent();
     return true;
   }
+  case G_FENCE: {
+    MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::SYNC)).addImm(0);
+    break;
+  }
   default:
     return false;
   }
Index: test/CodeGen/Mips/GlobalISel/instruction-select/fence.mir
===================================================================
--- /dev/null
+++ test/CodeGen/Mips/GlobalISel/instruction-select/fence.mir
@@ -0,0 +1,31 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -O0 -mtriple=mipsel-linux-gnu -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
+--- |
+
+  define void @atomic_load_i32(i32* %ptr) { ret void }
+
+...
+---
+name:            atomic_load_i32
+alignment:       2
+legalized:       true
+regBankSelected: true
+tracksRegLiveness: true
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: $a0
+
+    ; MIPS32-LABEL: name: atomic_load_i32
+    ; MIPS32: liveins: $a0
+    ; MIPS32: [[COPY:%[0-9]+]]:gpr32 = COPY $a0
+    ; MIPS32: [[LW:%[0-9]+]]:gpr32 = LW [[COPY]], 0 :: (load monotonic 4 from %ir.ptr)
+    ; MIPS32: SYNC 0
+    ; MIPS32: $v0 = COPY [[LW]]
+    ; MIPS32: RetRA implicit $v0
+    %0:gprb(p0) = COPY $a0
+    %1:gprb(s32) = G_LOAD %0(p0) :: (load monotonic 4 from %ir.ptr)
+    G_FENCE 4, 1
+    $v0 = COPY %1(s32)
+    RetRA implicit $v0
+
+...
Index: test/CodeGen/Mips/GlobalISel/legalizer/fence.mir
===================================================================
--- /dev/null
+++ test/CodeGen/Mips/GlobalISel/legalizer/fence.mir
@@ -0,0 +1,29 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -O0 -mtriple=mipsel-linux-gnu -run-pass=legalizer -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
+--- |
+
+  define void @atomic_load_i32(i32* %ptr) { ret void }
+
+...
+---
+name:            atomic_load_i32
+alignment:       2
+tracksRegLiveness: true
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: $a0
+
+    ; MIPS32-LABEL: name: atomic_load_i32
+    ; MIPS32: liveins: $a0
+    ; MIPS32: [[COPY:%[0-9]+]]:_(p0) = COPY $a0
+    ; MIPS32: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[COPY]](p0) :: (load monotonic 4 from %ir.ptr)
+    ; MIPS32: G_FENCE 4, 1
+    ; MIPS32: $v0 = COPY [[LOAD]](s32)
+    ; MIPS32: RetRA implicit $v0
+    %0:_(p0) = COPY $a0
+    %1:_(s32) = G_LOAD %0(p0) :: (load monotonic 4 from %ir.ptr)
+    G_FENCE 4, 1
+    $v0 = COPY %1(s32)
+    RetRA implicit $v0
+
+...
Index: test/CodeGen/Mips/GlobalISel/llvm-ir/fence.ll
===================================================================
--- /dev/null
+++ test/CodeGen/Mips/GlobalISel/llvm-ir/fence.ll
@@ -0,0 +1,13 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc  -O0 -mtriple=mipsel-linux-gnu -global-isel  -verify-machineinstrs %s -o -| FileCheck %s -check-prefixes=MIPS32
+
+define i32 @atomic_load_i32(i32* %ptr) {
+; MIPS32-LABEL: atomic_load_i32:
+; MIPS32:       # %bb.0:
+; MIPS32-NEXT:    lw $2, 0($4)
+; MIPS32-NEXT:    sync
+; MIPS32-NEXT:    jr $ra
+; MIPS32-NEXT:    nop
+  %val = load atomic i32, i32* %ptr acquire, align 4
+  ret i32 %val
+}
Index: test/CodeGen/Mips/GlobalISel/regbankselect/fence.mir
===================================================================
--- /dev/null
+++ test/CodeGen/Mips/GlobalISel/regbankselect/fence.mir
@@ -0,0 +1,30 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -O0 -mtriple=mipsel-linux-gnu -run-pass=regbankselect -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
+--- |
+
+  define void @atomic_load_i32(i32* %ptr) { ret void }
+
+...
+---
+name:            atomic_load_i32
+alignment:       2
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: $a0
+
+    ; MIPS32-LABEL: name: atomic_load_i32
+    ; MIPS32: liveins: $a0
+    ; MIPS32: [[COPY:%[0-9]+]]:gprb(p0) = COPY $a0
+    ; MIPS32: [[LOAD:%[0-9]+]]:gprb(s32) = G_LOAD [[COPY]](p0) :: (load monotonic 4 from %ir.ptr)
+    ; MIPS32: G_FENCE 4, 1
+    ; MIPS32: $v0 = COPY [[LOAD]](s32)
+    ; MIPS32: RetRA implicit $v0
+    %0:_(p0) = COPY $a0
+    %1:_(s32) = G_LOAD %0(p0) :: (load monotonic 4 from %ir.ptr)
+    G_FENCE 4, 1
+    $v0 = COPY %1(s32)
+    RetRA implicit $v0
+
+...