diff --git a/lib/Target/MSP430/MSP430InstrInfo.td b/lib/Target/MSP430/MSP430InstrInfo.td
index b5f9491b453..ced612e8631 100644
--- a/lib/Target/MSP430/MSP430InstrInfo.td
+++ b/lib/Target/MSP430/MSP430InstrInfo.td
@@ -671,30 +671,26 @@ def OR16rm : Pseudo<(outs GR16:$dst), (ins GR16:$src1, memsrc:$src2),
 let isTwoAddress = 0 in {
 def OR8mr  : Pseudo<(outs), (ins memdst:$dst, GR8:$src),
                 "bis.b\t{$src, $dst}",
-                [(store (or (load addr:$dst), GR8:$src), addr:$dst),
-                 (implicit SRW)]>;
+                [(store (or (load addr:$dst), GR8:$src), addr:$dst)]>;
 def OR16mr : Pseudo<(outs), (ins memdst:$dst, GR16:$src),
                 "bis.w\t{$src, $dst}",
-                [(store (or (load addr:$dst), GR16:$src), addr:$dst),
-                 (implicit SRW)]>;
+                [(store (or (load addr:$dst), GR16:$src), addr:$dst)]>;
 
 def OR8mi  : Pseudo<(outs), (ins memdst:$dst, i8imm:$src),
                 "bis.b\t{$src, $dst}",
-                [(store (or (load addr:$dst), (i8 imm:$src)), addr:$dst),
-                 (implicit SRW)]>;
+                [(store (or (load addr:$dst), (i8 imm:$src)), addr:$dst)]>;
 def OR16mi : Pseudo<(outs), (ins memdst:$dst, i16imm:$src),
                 "bis.w\t{$src, $dst}",
-                [(store (or (load addr:$dst), (i16 imm:$src)), addr:$dst),
-                 (implicit SRW)]>;
+                [(store (or (load addr:$dst), (i16 imm:$src)), addr:$dst)]>;
 
 def OR8mm  : Pseudo<(outs), (ins memdst:$dst, memsrc:$src),
                 "bis.b\t{$src, $dst}",
-                [(store (or (load addr:$dst), (i8 (load addr:$src))), addr:$dst),
-                 (implicit SRW)]>;
+                [(store (or (i8 (load addr:$dst)),
+                            (i8 (load addr:$src))), addr:$dst)]>;
 def OR16mm : Pseudo<(outs), (ins memdst:$dst, memsrc:$src),
                 "bis.w\t{$src, $dst}",
-                [(store (or (load addr:$dst), (i16 (load addr:$src))), addr:$dst),
-                 (implicit SRW)]>;
+                 [(store (or (i16 (load addr:$dst)),
+                             (i16 (load addr:$src))), addr:$dst)]>;
 }
 
 } // isTwoAddress = 1
diff --git a/test/CodeGen/MSP430/2009-10-10-OrImpDef.ll b/test/CodeGen/MSP430/2009-10-10-OrImpDef.ll
new file mode 100644
index 00000000000..856eb9db3f6
--- /dev/null
+++ b/test/CodeGen/MSP430/2009-10-10-OrImpDef.ll
@@ -0,0 +1,14 @@
+; RUN: llc -march=msp430 < %s
+; PR4779 
+define void @foo() nounwind {
+entry:
+	%r = alloca i8		; <i8*> [#uses=2]
+	%"alloca point" = bitcast i32 0 to i32		; <i32> [#uses=0]
+	volatile load i8* %r, align 1		; <i8>:0 [#uses=1]
+	or i8 %0, 1		; <i8>:1 [#uses=1]
+	volatile store i8 %1, i8* %r, align 1
+	br label %return
+
+return:		; preds = %entry
+	ret void
+}