1 files changed, 25 insertions, 3 deletions
diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index b642c1cfe383..8213e512f45e 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -1042,8 +1042,8 @@ private:
       }
       PrevState = CurrState;
     }
-    void onRParen() {
-      PrevState = State;
+    bool onRParen(StringRef &ErrMsg) {
+      IntelExprState CurrState = State;
       switch (State) {
       default:
         State = IES_ERROR;
@@ -1054,9 +1054,27 @@ private:
       case IES_RBRAC:
       case IES_RPAREN:
         State = IES_RPAREN;
+        // In the case of a multiply, onRegister has already set IndexReg
+        // directly, with appropriate scale.
+        // Otherwise if we just saw a register it has only been stored in
+        // TmpReg, so we need to store it into the state machine.
+        if (CurrState == IES_REGISTER && PrevState != IES_MULTIPLY) {
+          // If we already have a BaseReg, then assume this is the IndexReg with
+          // no explicit scale.
+          if (!BaseReg) {
+            BaseReg = TmpReg;
+          } else {
+            if (IndexReg)
+              return regsUseUpError(ErrMsg);
+            IndexReg = TmpReg;
+            Scale = 0;
+          }
+        }
         IC.pushOperator(IC_RPAREN);
         break;
       }
+      PrevState = CurrState;
+      return false;
     }
     bool onOffset(const MCExpr *Val, SMLoc OffsetLoc, StringRef ID,
                   const InlineAsmIdentifierInfo &IDInfo,
@@ -2172,7 +2190,11 @@ bool X86AsmParser::ParseIntelExpression(IntelExprStateMachine &SM, SMLoc &End) {
       }
       break;
     case AsmToken::LParen:  SM.onLParen(); break;
-    case AsmToken::RParen:  SM.onRParen(); break;
+    case AsmToken::RParen:
+      if (SM.onRParen(ErrMsg)) {
+        return Error(Tok.getLoc(), ErrMsg);
+      }
+      break;
     }
     if (SM.hadError())
       return Error(Tok.getLoc(), "unknown token in expression");