Thumb assembly parsing and encoding for LDRH.

llvm-svn: 138060

2 files changed, 18 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrThumb.td b/llvm/lib/Target/ARM/ARMInstrThumb.td
index 35a745aa78a..edc4660034f 100644
--- a/llvm/lib/Target/ARM/ARMInstrThumb.td
+++ b/llvm/lib/Target/ARM/ARMInstrThumb.td
@@ -169,11 +169,13 @@ def t_addrmode_is4 : Operand<i32>,
 
 // t_addrmode_is2 := reg + imm5 * 2
 //
+def t_addrmode_is2_asm_operand : AsmOperandClass { let Name = "MemThumbRIs2"; }
 def t_addrmode_is2 : Operand<i32>,
                      ComplexPattern<i32, 2, "SelectThumbAddrModeImm5S2", []> {
   let EncoderMethod = "getAddrModeISOpValue";
   let DecoderMethod = "DecodeThumbAddrModeIS";
   let PrintMethod = "printThumbAddrModeImm5S2Operand";
+  let ParserMatchClass = t_addrmode_is2_asm_operand;
   let MIOperandInfo = (ops tGPR:$base, i32imm:$offsimm);
 }
 
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index d04b9b73cc4..60f16f83625 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -628,6 +628,15 @@ public:
     int64_t Val = Mem.OffsetImm->getValue();
     return Val >= 0 && Val <= 124 && (Val % 4) == 0;
   }
+  bool isMemThumbRIs2() const {
+    if (Kind != Memory || Mem.OffsetRegNum != 0 ||
+        !isARMLowRegister(Mem.BaseRegNum))
+      return false;
+    // Immediate offset, multiple of 4 in range [0, 62].
+    if (!Mem.OffsetImm) return true;
+    int64_t Val = Mem.OffsetImm->getValue();
+    return Val >= 0 && Val <= 62 && (Val % 2) == 0;
+  }
   bool isMemThumbRIs1() const {
     if (Kind != Memory || Mem.OffsetRegNum != 0 ||
         !isARMLowRegister(Mem.BaseRegNum))
@@ -1009,6 +1018,13 @@ public:
     Inst.addOperand(MCOperand::CreateImm(Val));
   }
 
+  void addMemThumbRIs2Operands(MCInst &Inst, unsigned N) const {
+    assert(N == 2 && "Invalid number of operands!");
+    int64_t Val = Mem.OffsetImm ? (Mem.OffsetImm->getValue() / 2) : 0;
+    Inst.addOperand(MCOperand::CreateReg(Mem.BaseRegNum));
+    Inst.addOperand(MCOperand::CreateImm(Val));
+  }
+
   void addMemThumbRIs1Operands(MCInst &Inst, unsigned N) const {
     assert(N == 2 && "Invalid number of operands!");
     int64_t Val = Mem.OffsetImm ? (Mem.OffsetImm->getValue()) : 0;