MC/X86: Add custom hack for recognizing "imul $12, %eax" and friends.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111947 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 204ccf7..3f10b8e 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -826,6 +826,14 @@
     Operands.erase(Operands.begin() + 2);
   }
 
+  // FIXME: Hack to handle "imul A, B" which is an alias for "imul A, B, B".
+  if (Name.startswith("imul") && Operands.size() == 3 &&
+      static_cast<X86Operand*>(Operands.back())->isReg()) {
+    X86Operand *Op = static_cast<X86Operand*>(Operands.back());
+    Operands.push_back(X86Operand::CreateReg(Op->getReg(), Op->getStartLoc(),
+                                             Op->getEndLoc()));
+  }
+
   return false;
 }
 
diff --git a/test/MC/AsmParser/X86/x86_instructions.s b/test/MC/AsmParser/X86/x86_instructions.s
index 8adcc9e..eed69e0 100644
--- a/test/MC/AsmParser/X86/x86_instructions.s
+++ b/test/MC/AsmParser/X86/x86_instructions.s
@@ -158,3 +158,6 @@
 // CHECK: movaps	%xmm3, (%esi)
 // CHECK-STDERR: warning: scale factor without index register is ignored
 movaps %xmm3, (%esi, 2)
+
+// CHECK: imull $12, %eax, %eax
+imul $12, %eax