[mips] Implement %hi(sym1 - sym2) and %lo(sym1 - sym2) expressions

Patch implements %hi(sym1 - sym2) and %lo(sym1 - sym2) expressions for MIPS
by creating target expression class MipsMCExpr.

Patch by Sasa Stankovic.

Differential Revision: http://llvm-reviews.chandlerc.com/D2592

llvm-svn: 200783

1 files changed, 5 insertions, 2 deletions

diff --git a/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp b/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
index 82deec1a1e5..de724d33cff 100644
--- a/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
+++ b/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
@@ -14,6 +14,7 @@
 #define DEBUG_TYPE "asm-printer"
 #include "MipsInstPrinter.h"
 #include "MipsInstrInfo.h"
+#include "MCTargetDesc/MipsMCExpr.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
@@ -129,8 +130,10 @@ static void printExpr(const MCExpr *Expr, raw_ostream &OS) {
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(BE->getRHS());
     assert(SRE && CE && "Binary expression must be sym+const.");
     Offset = CE->getValue();
-  }
-  else if (!(SRE = dyn_cast<MCSymbolRefExpr>(Expr)))
+  } else if (const MipsMCExpr *ME = dyn_cast<MipsMCExpr>(Expr)) {
+    ME->print(OS);
+    return;
+  } else if (!(SRE = dyn_cast<MCSymbolRefExpr>(Expr)))
     assert(false && "Unexpected MCExpr type.");
 
   MCSymbolRefExpr::VariantKind Kind = SRE->getKind();