ARM Assembly support for Thumb mov-immediate.

Correctly parse the forms of the Thumb mov-immediate instruction:
  1. 8-bit immediate 0-255.
  2. 12-bit shifted-immediate.

The 16-bit immediate "movw" form is also legal with just a "mov" mnemonic,
but is not yet supported. More parser logic necessary there due to fixups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133966 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 8fe504fb2b..178fe5229d 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -350,6 +350,22 @@ public:
   bool isCondCode() const { return Kind == CondCode; }
   bool isCCOut() const { return Kind == CCOut; }
   bool isImm() const { return Kind == Immediate; }
+  bool isImm0_255() 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 < 256;
+  }
+  bool isT2SOImm() const {
+    if (Kind != Immediate)
+      return false;
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
+    if (!CE) return false;
+    int64_t Value = CE->getValue();
+    return ARM_AM::getT2SOImmVal(Value) != -1;
+  }
   bool isReg() const { return Kind == Register; }
   bool isRegList() const { return Kind == RegisterList; }
   bool isDPRRegList() const { return Kind == DPRRegisterList; }
@@ -515,6 +531,16 @@ public:
     addExpr(Inst, getImm());
   }
 
+  void addImm0_255Operands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    addExpr(Inst, getImm());
+  }
+
+  void addT2SOImmOperands(MCInst &Inst, unsigned N) const {
+    assert(N == 1 && "Invalid number of operands!");
+    addExpr(Inst, getImm());
+  }
+
   void addMemBarrierOptOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     Inst.addOperand(MCOperand::CreateImm(unsigned(getMemBarrierOpt())));