ARM assembly parsing and encoding for SSAT16 instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136006 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 02ed547..f6f8adc 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -433,6 +433,14 @@
     int64_t Value = CE->getValue();
     return Value >= 0 && Value < 32;
   }
+  bool isImm1_16() const {
+    if (Kind != Immediate)
+      return false;
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
+    if (!CE) return false;
+    int64_t Value = CE->getValue();
+    return Value > 0 && Value < 17;
+  }
   bool isImm1_32() const {
     if (Kind != Immediate)
       return false;
@@ -704,6 +712,14 @@
     addExpr(Inst, getImm());
   }
 
+  void addImm1_16Operands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    // The constant encodes as the immediate-1, and we store in the instruction
+    // the bits as encoded, so subtract off one here.
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
+    Inst.addOperand(MCOperand::CreateImm(CE->getValue() - 1));
+  }
+
   void addImm1_32Operands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     // The constant encodes as the immediate-1, and we store in the instruction