[mips][microMIPSr6] Implement mips32 to microMIPSr6 mapping support
Differential Revision: http://reviews.llvm.org/D8661

llvm-svn: 235505
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
index 9c2508f..0cb8d55 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
@@ -179,13 +179,20 @@
       (Opcode != Mips::SLL_MM) && !Binary)
     llvm_unreachable("unimplemented opcode in EncodeInstruction()");
 
+  int NewOpcode = -1;
   if (isMicroMips(STI)) {
-    int NewOpcode = isMips32r6(STI) ?
-                    Mips::MipsR62MicroMipsR6(Opcode, Mips::Arch_micromipsr6) :
-                    Mips::Std2MicroMips(Opcode, Mips::Arch_micromips);
+    if (isMips32r6(STI)) {
+      NewOpcode = Mips::MipsR62MicroMipsR6(Opcode, Mips::Arch_micromipsr6);
+      if (NewOpcode == -1)
+        NewOpcode = Mips::Std2MicroMipsR6(Opcode, Mips::Arch_micromipsr6);
+    }
+    else
+      NewOpcode = Mips::Std2MicroMips(Opcode, Mips::Arch_micromips);
+
     if (NewOpcode != -1) {
       if (Fixups.size() > N)
         Fixups.pop_back();
+
       Opcode = NewOpcode;
       TmpInst.setOpcode (NewOpcode);
       Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI);