more mumbling


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25826 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index fbe7e9d..b0b17da 100644
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -310,3 +310,7 @@
    before prolog-epilog rewriting.
 2) We shouldn't load into XMM regs only to store it back.
 
+//===---------------------------------------------------------------------===//
+
+Think about doing i64 math in SSE regs.
+