Enable the instruction printer in HexagonMCTargetDesc

[sidneym]

Summary

This adds the MCInstPrinter to the LLVMHexagonDesc library and removes the dependency LLVMHexagonAsmPrinter had on LLVMHexagonDesc. This is a prerequisite needed by the disassembler.

[• rafael]

lib/Target/Hexagon/InstPrinter/HexagonInstPrinter.cpp

159

Are this changes intended? The description doesn't mention them.

[shankarke]

lib/Target/Hexagon/InstPrinter/HexagonInstPrinter.cpp

42–43

remove else.

56–57

same as above comment.

[sidneym]

lib/Target/Hexagon/InstPrinter/HexagonInstPrinter.cpp

56–57

OK, will remove both.

159

While troublesome, the assert is intended to keep this routine from being attached to an incorrect insn.

The code below is the fix for the actual dependency. isConstExtended is in LLVMHexagonDesc, when the inst printer is registered in that library a circular dependency is formed.

[mcrosier]

Committed in r219826. Please close these after the change has been committed.

lib/Target/Hexagon/InstPrinter/HexagonInstPrinter.cpp

 #include "HexagonGenAsmWriter.inc"
 
 const char HexagonInstPrinter::PacketPadding = '\t';
+// Return the minimum value that a constant extendable operand can have
+// without being extended.
+static int getMinValue(uint64_t TSFlags) {
+  unsigned isSigned =
+      (TSFlags >> HexagonII::ExtentSignedPos) & HexagonII::ExtentSignedMask;
+  unsigned bits =
+      (TSFlags >> HexagonII::ExtentBitsPos) & HexagonII::ExtentBitsMask;
+
+  if (isSigned)
+    return -1U << (bits - 1);
+  else
+    return 0;
+}
+
+// Return the maximum value that a constant extendable operand can have
+// without being extended.
+static int getMaxValue(uint64_t TSFlags) {
+  unsigned isSigned =
+      (TSFlags >> HexagonII::ExtentSignedPos) & HexagonII::ExtentSignedMask;
+  unsigned bits =
+      (TSFlags >> HexagonII::ExtentBitsPos) & HexagonII::ExtentBitsMask;
+
+  if (isSigned)
+    return ~(-1U << (bits - 1));
+  else
+    return ~(-1U << bits);
+}
+
+// Return true if the instruction must be extended.
+static bool isExtended(uint64_t TSFlags) {
+  return (TSFlags >> HexagonII::ExtendedPos) & HexagonII::ExtendedMask;
+}
+
+// Return true if the instruction may be extended based on the operand value.
+static bool isExtendable(uint64_t TSFlags) {
+  return (TSFlags >> HexagonII::ExtendablePos) & HexagonII::ExtendableMask;
+}
 
 StringRef HexagonInstPrinter::getOpcodeName(unsigned Opcode) const {
   return MII.getName(Opcode);

 
 void HexagonInstPrinter::printExtOperand(const MCInst *MI, unsigned OpNo,
                                          raw_ostream &O) const {
-  const HexagonMCInst *HMCI = static_cast<const HexagonMCInst*>(MI);
-  if (HMCI->isConstExtended())
+  const MCOperand &MO = MI->getOperand(OpNo);
+  const MCInstrDesc &MII = getMII().get(MI->getOpcode());
+
+  assert((isExtendable(MII.TSFlags) || isExtended(MII.TSFlags)) &&
+         "Expecting an extendable operand");
+
+  if (MO.isExpr() || isExtended(MII.TSFlags)) {
     O << "#";
+  } else if (MO.isImm()) {
+    int ImmValue = MO.getImm();
+    if (ImmValue < getMinValue(MII.TSFlags) ||
+        ImmValue > getMaxValue(MII.TSFlags))
+      O << "#";
+  }
   printOperand(MI, OpNo, O);
 }
 

lib/Target/Hexagon/InstPrinter/LLVMBuild.txt

 type = Library
 name = HexagonAsmPrinter
 parent = Hexagon
-required_libraries = HexagonDesc MC Support
+required_libraries = MC Support
 add_to_library_groups = Hexagon

lib/Target/Hexagon/MCTargetDesc/HexagonMCTargetDesc.cpp

   X->InitMCCodeGenInfo(Reloc::Static, CM, OL);
   return X;
 }
+static MCInstPrinter *createHexagonMCInstPrinter(const Target &T,
+                                                 unsigned SyntaxVariant,
+                                                 const MCAsmInfo &MAI,
+                                                 const MCInstrInfo &MII,
+                                                 const MCRegisterInfo &MRI,
+                                                 const MCSubtargetInfo &STI) {
+    return new HexagonInstPrinter(MAI, MII, MRI);
+}
 
 // Force static initialization.
 extern "C" void LLVMInitializeHexagonTargetMC() {

   // Register the MC Code Emitter
   TargetRegistry::RegisterMCCodeEmitter(TheHexagonTarget,
                                         createHexagonMCCodeEmitter);
+
+  // Register the MC Inst Printer
+  TargetRegistry::RegisterMCInstPrinter(TheHexagonTarget,
+                                        createHexagonMCInstPrinter);
 }

lib/Target/Hexagon/MCTargetDesc/LLVMBuild.txt

 type = Library
 name = HexagonDesc
 parent = Hexagon
-required_libraries = HexagonInfo MC Support
+required_libraries = HexagonAsmPrinter HexagonInfo MC Support
 add_to_library_groups = Hexagon