Index: lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp
===================================================================
--- lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp
+++ lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp
@@ -54,4 +54,8 @@
   if (TheTriple.getArch() == Triple::mips ||
       TheTriple.getArch() == Triple::mipsel)
     UseIntegratedAssembler = true;
+
+  // Enable IAS by default for Debian mips64/mips64el.
+  if (TheTriple.getEnvironment() == Triple::GNUABI64)
+    UseIntegratedAssembler = true;
 }