implement aliases for shld/shrd, part of rdar://8418316

llvm-svn: 113937

llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -834,6 +834,15 @@ ParseInstruction(StringRef Name, SMLoc NameLoc,
     std::swap(Operands[1], Operands[2]);
   }
   
+  // FIXME: Hack to handle recognize "sh[lr]d op,op" -> "shld $1, op,op".
+  if ((Name.startswith("shld") || Name.startswith("shrd")) &&
+      Operands.size() == 3) {
+    const MCExpr *One = MCConstantExpr::Create(1, getParser().getContext());
+    Operands.insert(Operands.begin()+1,
+                    X86Operand::CreateImm(One, NameLoc, NameLoc));
+  }
+  
+
   // FIXME: Hack to handle recognize "in[bwl] <op>".  Canonicalize it to
   // "inb <op>, %al".
   if ((Name == "inb" || Name == "inw" || Name == "inl") &&

llvm/test/MC/AsmParser/X86/x86_instructions.s

@@ -268,3 +268,14 @@ rcl	%bl
 rcll	0xdeadbeef(%ebx,%ecx,8)
 rcr	%ecx
 rcrl	0x12345678
+
+// rdar://8418316
+// CHECK: shldw	$1, %bx, %bx
+// CHECK: shldw	$1, %bx, %bx
+// CHECK: shrdw	$1, %bx, %bx
+// CHECK: shrdw	$1, %bx, %bx
+
+shld	%bx,%bx
+shld	$1, %bx,%bx
+shrd	%bx,%bx
+shrd	$1, %bx,%bx