diff --git a/lib/Target/Mips/MipsInstrInfo.td b/lib/Target/Mips/MipsInstrInfo.td
index eb8b16b..e5d76c8 100644
--- a/lib/Target/Mips/MipsInstrInfo.td
+++ b/lib/Target/Mips/MipsInstrInfo.td
@@ -1022,10 +1022,14 @@
 }
 
 // peepholes
-def : Pat<(store (i32 0), addr:$dst), (SW ZERO, addr:$dst)>,
-      Requires<[NotN64]>;
-def : Pat<(store (i32 0), addr:$dst), (SW_P8 ZERO, addr:$dst)>,
-      Requires<[IsN64]>;
+let Predicates = [NotN64] in {
+  def : Pat<(store_a (i32 0), addr:$dst), (SW ZERO, addr:$dst)>;
+  def : Pat<(store_u (i32 0), addr:$dst), (USW ZERO, addr:$dst)>;
+}
+let Predicates = [IsN64] in {
+  def : Pat<(store_a (i32 0), addr:$dst), (SW_P8 ZERO, addr:$dst)>;
+  def : Pat<(store_u (i32 0), addr:$dst), (USW_P8 ZERO, addr:$dst)>;
+}
 
 // brcond patterns
 multiclass BrcondPats<RegisterClass RC, Instruction BEQOp, Instruction BNEOp,
diff --git a/test/CodeGen/Mips/swzero.ll b/test/CodeGen/Mips/swzero.ll
new file mode 100644
index 0000000..da1e036
--- /dev/null
+++ b/test/CodeGen/Mips/swzero.ll
@@ -0,0 +1,19 @@
+; RUN: llc -march=mipsel < %s | FileCheck %s
+
+%struct.unaligned = type <{ i32 }>
+
+define void @zero_u(%struct.unaligned* nocapture %p) nounwind {
+entry:
+; CHECK: usw $zero
+  %x = getelementptr inbounds %struct.unaligned* %p, i32 0, i32 0
+  store i32 0, i32* %x, align 1
+  ret void
+}
+
+define void @zero_a(i32* nocapture %p) nounwind {
+entry:
+; CHECK: sw $zero
+  store i32 0, i32* %p, align 4
+  ret void
+}
+