[AVR] Add the assembly instruction printer
Summary:
This change adds the AVR assembly instruction printer.
No tests are included in this patch. I have left them downstream so we can
add them once `llc` successfully runs (there's very few components left
to upstream until this).
Reviewers: arsenm, kparzysz
Subscribers: wdng, beanz, mgorny
Differential Revision: https://reviews.llvm.org/D25028
llvm-svn: 282854
diff --git a/llvm/lib/Target/AVR/InstPrinter/AVRInstPrinter.cpp b/llvm/lib/Target/AVR/InstPrinter/AVRInstPrinter.cpp
new file mode 100644
index 0000000..58cc9b9
--- /dev/null
+++ b/llvm/lib/Target/AVR/InstPrinter/AVRInstPrinter.cpp
@@ -0,0 +1,172 @@
+//===-- AVRInstPrinter.cpp - Convert AVR MCInst to assembly syntax --------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class prints an AVR MCInst to a .s file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AVRInstPrinter.h"
+
+#include "MCTargetDesc/AVRMCTargetDesc.h"
+
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstrDesc.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FormattedStream.h"
+
+#include <cstring>
+
+#define DEBUG_TYPE "asm-printer"
+
+namespace llvm {
+
+// Include the auto-generated portion of the assembly writer.
+#define PRINT_ALIAS_INSTR
+#include "AVRGenAsmWriter.inc"
+
+void AVRInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
+ StringRef Annot, const MCSubtargetInfo &STI) {
+ unsigned Opcode = MI->getOpcode();
+
+ // First handle load and store instructions with postinc or predec
+ // of the form "ld reg, X+".
+ // TODO: We should be able to rewrite this using TableGen data.
+ switch (Opcode) {
+ case AVR::LDRdPtr:
+ case AVR::LDRdPtrPi:
+ case AVR::LDRdPtrPd:
+ O << "\tld\t";
+ printOperand(MI, 0, O);
+ O << ", ";
+
+ if (Opcode == AVR::LDRdPtrPd)
+ O << '-';
+
+ printOperand(MI, 1, O);
+
+ if (Opcode == AVR::LDRdPtrPi)
+ O << '+';
+ break;
+ case AVR::STPtrRr:
+ O << "\tst\t";
+ printOperand(MI, 0, O);
+ O << ", ";
+ printOperand(MI, 1, O);
+ break;
+ case AVR::STPtrPiRr:
+ case AVR::STPtrPdRr:
+ O << "\tst\t";
+
+ if (Opcode == AVR::STPtrPdRr)
+ O << '-';
+
+ printOperand(MI, 1, O);
+
+ if (Opcode == AVR::STPtrPiRr)
+ O << '+';
+
+ O << ", ";
+ printOperand(MI, 2, O);
+ break;
+ default:
+ if (!printAliasInstr(MI, O))
+ printInstruction(MI, O);
+
+ printAnnotation(O, Annot);
+ break;
+ }
+}
+
+const char *AVRInstPrinter::getPrettyRegisterName(unsigned RegNum,
+ MCRegisterInfo const &MRI) {
+ // GCC prints register pairs by just printing the lower register
+ // If the register contains a subregister, print it instead
+ if (MRI.getNumSubRegIndices() > 0) {
+ unsigned RegLoNum = MRI.getSubReg(RegNum, AVR::sub_lo);
+ RegNum = (RegLoNum != AVR::NoRegister) ? RegLoNum : RegNum;
+ }
+
+ return getRegisterName(RegNum);
+}
+
+void AVRInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
+ raw_ostream &O) {
+ const MCOperand &Op = MI->getOperand(OpNo);
+ const MCOperandInfo &MOI = this->MII.get(MI->getOpcode()).OpInfo[OpNo];
+
+ if (Op.isReg()) {
+ bool isPtrReg = (MOI.RegClass == AVR::PTRREGSRegClassID) ||
+ (MOI.RegClass == AVR::PTRDISPREGSRegClassID) ||
+ (MOI.RegClass == AVR::ZREGSRegClassID);
+
+ if (isPtrReg) {
+ O << getRegisterName(Op.getReg(), AVR::ptr);
+ } else {
+ O << getPrettyRegisterName(Op.getReg(), MRI);
+ }
+ } else if (Op.isImm()) {
+ O << Op.getImm();
+ } else {
+ assert(Op.isExpr() && "Unknown operand kind in printOperand");
+ O << *Op.getExpr();
+ }
+}
+
+/// This is used to print an immediate value that ends up
+/// being encoded as a pc-relative value.
+void AVRInstPrinter::printPCRelImm(const MCInst *MI, unsigned OpNo,
+ raw_ostream &O) {
+ const MCOperand &Op = MI->getOperand(OpNo);
+
+ if (Op.isImm()) {
+ int64_t Imm = Op.getImm();
+ O << '.';
+
+ // Print a position sign if needed.
+ // Negative values have their sign printed automatically.
+ if (Imm >= 0)
+ O << '+';
+
+ O << Imm;
+ } else {
+ assert(Op.isExpr() && "Unknown pcrel immediate operand");
+ O << *Op.getExpr();
+ }
+}
+
+void AVRInstPrinter::printMemri(const MCInst *MI, unsigned OpNo,
+ raw_ostream &O) {
+ const MCOperand &RegOp = MI->getOperand(OpNo);
+ const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);
+
+ assert(RegOp.isReg() && "Expected a register");
+
+ // Print the register.
+ printOperand(MI, OpNo, O);
+
+ // Print the {+,-}offset.
+ if (OffsetOp.isImm()) {
+ int64_t Offset = OffsetOp.getImm();
+
+ if (Offset >= 0)
+ O << '+';
+
+ O << Offset;
+ } else if (OffsetOp.isExpr()) {
+ O << *OffsetOp.getExpr();
+ } else {
+ llvm_unreachable("unknown type for offset");
+ }
+}
+
+} // end of namespace llvm
+