Thumb2 assembly parsing and encoding for LDRD(immediate).
Refactor operand handling for STRD as well. Tests for that forthcoming.
llvm-svn: 139322
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
index 69ec197..34b4e3d 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
@@ -144,6 +144,10 @@
/// operand.
uint32_t getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
+ /// getT2Imm8s4OpValue - Return encoding info for '+/- imm8<<2'
+ /// operand.
+ uint32_t getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
+ SmallVectorImpl<MCFixup> &Fixups) const;
/// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
@@ -720,6 +724,37 @@
return Binary;
}
+/// getT2Imm8s4OpValue - Return encoding info for
+/// '+/- imm8<<2' operand.
+uint32_t ARMMCCodeEmitter::
+getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
+ SmallVectorImpl<MCFixup> &Fixups) const {
+ // FIXME: The immediate operand should have already been encoded like this
+ // before ever getting here. The encoder method should just need to combine
+ // the MI operands for the register and the offset into a single
+ // representation for the complex operand in the .td file. This isn't just
+ // style, unfortunately. As-is, we can't represent the distinct encoding
+ // for #-0.
+
+ // {8} = (U)nsigned (add == '1', sub == '0')
+ // {7-0} = imm8
+ int32_t Imm8 = MI.getOperand(OpIdx).getImm();
+ bool isAdd = Imm8 >= 0;
+
+ // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
+ if (Imm8 < 0)
+ Imm8 = -Imm8;
+
+ // Scaled by 4.
+ Imm8 /= 4;
+
+ uint32_t Binary = Imm8 & 0xff;
+ // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
+ if (isAdd)
+ Binary |= (1 << 8);
+ return Binary;
+}
+
/// getT2AddrModeImm8s4OpValue - Return encoding info for
/// 'reg +/- imm8<<2' operand.
uint32_t ARMMCCodeEmitter::
@@ -746,6 +781,12 @@
} else
isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
+ // FIXME: The immediate operand should have already been encoded like this
+ // before ever getting here. The encoder method should just need to combine
+ // the MI operands for the register and the offset into a single
+ // representation for the complex operand in the .td file. This isn't just
+ // style, unfortunately. As-is, we can't represent the distinct encoding
+ // for #-0.
uint32_t Binary = (Imm8 >> 2) & 0xff;
// Immediate is always encoded as positive. The 'U' bit controls add vs sub.
if (isAdd)