diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 0025766..7900e97 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -178,6 +178,9 @@
     // These operations default to expand.
     setOperationAction(ISD::FGETSIGN, (MVT::ValueType)VT, Expand);
   }
+
+  // Most targets ignore the @llvm.prefetch intrinsic.
+  setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
   
   // ConstantFP nodes default to expand.  Targets can either change this to 
   // Legal, in which case all fp constants are legal, or use addLegalFPImmediate
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 67aeebf..0326ecf 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -211,7 +211,6 @@
   setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);
   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32  , Expand);
   setOperationAction(ISD::MEMBARRIER        , MVT::Other, Expand);
-  setOperationAction(ISD::PREFETCH          , MVT::Other, Expand);
 
   if (!Subtarget->hasV6Ops()) {
     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
diff --git a/lib/Target/Alpha/AlphaISelLowering.cpp b/lib/Target/Alpha/AlphaISelLowering.cpp
index 87f1eec..d208f59 100644
--- a/lib/Target/Alpha/AlphaISelLowering.cpp
+++ b/lib/Target/Alpha/AlphaISelLowering.cpp
@@ -116,7 +116,6 @@
   setOperationAction(ISD::STACKSAVE, MVT::Other, Expand); 
   setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64, Expand);
-  setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
 
   // We want to legalize GlobalAddress and ConstantPool and
   // ExternalSymbols nodes into the appropriate instructions to
diff --git a/lib/Target/CellSPU/SPUISelLowering.cpp b/lib/Target/CellSPU/SPUISelLowering.cpp
index e04722f..a6c0b87 100644
--- a/lib/Target/CellSPU/SPUISelLowering.cpp
+++ b/lib/Target/CellSPU/SPUISelLowering.cpp
@@ -321,7 +321,6 @@
   setOperationAction(ISD::STACKRESTORE      , MVT::Other, Expand);
   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32  , Expand);
   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64  , Expand);
-  setOperationAction(ISD::PREFETCH          , MVT::Other, Expand);
 
   // Cell SPU has instructions for converting between i64 and fp.
   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
diff --git a/lib/Target/IA64/IA64ISelLowering.cpp b/lib/Target/IA64/IA64ISelLowering.cpp
index dd330db..2ec08b6 100644
--- a/lib/Target/IA64/IA64ISelLowering.cpp
+++ b/lib/Target/IA64/IA64ISelLowering.cpp
@@ -109,7 +109,6 @@
       setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
       setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
       setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64, Expand);
-      setOperationAction(ISD::PREFETCH          , MVT::Other, Expand);
 
       // Thread Local Storage
       setOperationAction(ISD::GlobalTLSAddress, MVT::i64, Custom);
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 6e2a4f7..4865969 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -84,7 +84,6 @@
   setOperationAction(ISD::MEMSET, MVT::Other, Expand);
   setOperationAction(ISD::MEMCPY, MVT::Other, Expand);
   setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
-  setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
 
   setOperationAction(ISD::CTPOP, MVT::i32, Expand);
   setOperationAction(ISD::CTTZ , MVT::i32, Expand);
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 56837b9..32787bc 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -82,7 +82,6 @@
   setOperationAction(ISD::MEMSET, MVT::Other, Expand);
   setOperationAction(ISD::MEMCPY, MVT::Other, Expand);
   setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
-  setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
 
   // PowerPC has no SREM/UREM instructions
   setOperationAction(ISD::SREM, MVT::i32, Expand);
diff --git a/lib/Target/Sparc/SparcISelDAGToDAG.cpp b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
index 08af607..95f4e08 100644
--- a/lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -197,7 +197,6 @@
   setOperationAction(ISD::MEMSET, MVT::Other, Expand);
   setOperationAction(ISD::MEMCPY, MVT::Other, Expand);
   setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
-  setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
 
   setOperationAction(ISD::FSIN , MVT::f64, Expand);
   setOperationAction(ISD::FCOS , MVT::f64, Expand);
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 7b3b98f..e2dc29c 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -286,8 +286,8 @@
   setOperationAction(ISD::MEMSET          , MVT::Other, Custom);
   setOperationAction(ISD::MEMCPY          , MVT::Other, Custom);
 
-  if (!Subtarget->hasSSE1())
-    setOperationAction(ISD::PREFETCH      , MVT::Other, Expand);
+  if (Subtarget->hasSSE1())
+    setOperationAction(ISD::PREFETCH      , MVT::Other, Legal);
 
   if (!Subtarget->hasSSE2())
     setOperationAction(ISD::MEMBARRIER    , MVT::Other, Expand);