Tweak x86 -mcpu defaults.
 - Default to yonah on Darwin (to get SSE3).

 - Default to Pentium4 (32-bit) and x86-64 (64-bit) on
   non-Darwin. Welcome to the 21st century.

llvm-svn: 71069
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index bb568b1..d9ae003 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -565,6 +565,9 @@
   if (CPU == "core2")
     Features["ssse3"] = Features["sse3"] = Features["sse2"] = Features["sse"] =
       Features["mmx"] = true;
+  else if (CPU == "yonah")
+    Features["sse3"] = Features["sse2"] = Features["sse"] = 
+      Features["mmx"] = true;
   else if (CPU == "pentium4")
     Features["sse2"] = Features["sse"] = Features["mmx"] = true;
 }