diff -r 11211f7cb5a0 -r 1af104d6cf99 src/cpu/x86/vm/assembler_x86.cpp
--- a/src/cpu/x86/vm/assembler_x86.cpp	Tue Aug 16 11:53:57 2011 -0700
+++ b/src/cpu/x86/vm/assembler_x86.cpp	Tue Aug 16 16:59:46 2011 -0700
@@ -2315,7 +2315,7 @@
 }
 
 void Assembler::prefetchr(Address src) {
-  NOT_LP64(assert(VM_Version::supports_3dnow_prefetch(), "must support"));
+  assert(VM_Version::supports_3dnow_prefetch(), "must support");
   InstructionMark im(this);
   prefetch_prefix(src);
   emit_byte(0x0D);
@@ -2347,7 +2347,7 @@
 }
 
 void Assembler::prefetchw(Address src) {
-  NOT_LP64(assert(VM_Version::supports_3dnow_prefetch(), "must support"));
+  assert(VM_Version::supports_3dnow_prefetch(), "must support");
   InstructionMark im(this);
   prefetch_prefix(src);
   emit_byte(0x0D);