[Xtensa] Move XtensaUtils to MCTargetDesc

PR #121118 attempted to introduce `checkRegister` used by
XtensaDisassembler. Since `checkRegister` and other functions in
XtensaUtils.cpp cannot link against XtensaCodeGen, move them to
XtensaDesc, which can be used by XtensaDisassembler.

Pull Request: #123969

Author: MaskRay

llvm/lib/Target/Xtensa/CMakeLists.txt

@@ -24,7 +24,6 @@ add_llvm_target(XtensaCodeGen
   XtensaRegisterInfo.cpp
   XtensaSubtarget.cpp
   XtensaTargetMachine.cpp
-  XtensaUtils.cpp
 
   LINK_COMPONENTS
   AsmPrinter

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaMCTargetDesc.cpp

@@ -32,6 +32,48 @@
 
 using namespace llvm;
 
+bool Xtensa::isValidAddrOffset(int Scale, int64_t OffsetVal) {
+  bool Valid = false;
+
+  switch (Scale) {
+  case 1:
+    Valid = (OffsetVal >= 0 && OffsetVal <= 255);
+    break;
+  case 2:
+    Valid = (OffsetVal >= 0 && OffsetVal <= 510) && ((OffsetVal & 0x1) == 0);
+    break;
+  case 4:
+    Valid = (OffsetVal >= 0 && OffsetVal <= 1020) && ((OffsetVal & 0x3) == 0);
+    break;
+  default:
+    break;
+  }
+  return Valid;
+}
+
+bool Xtensa::isValidAddrOffsetForOpcode(unsigned Opcode, int64_t Offset) {
+  int Scale = 0;
+
+  switch (Opcode) {
+  case Xtensa::L8UI:
+  case Xtensa::S8I:
+    Scale = 1;
+    break;
+  case Xtensa::L16SI:
+  case Xtensa::L16UI:
+  case Xtensa::S16I:
+    Scale = 2;
+    break;
+  case Xtensa::LEA_ADD:
+    return (Offset >= -128 && Offset <= 127);
+  default:
+    // assume that MI is 32-bit load/store operation
+    Scale = 4;
+    break;
+  }
+  return isValidAddrOffset(Scale, Offset);
+}
+
 static MCAsmInfo *createXtensaMCAsmInfo(const MCRegisterInfo &MRI,
                                         const Triple &TT,
                                         const MCTargetOptions &Options) {

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaMCTargetDesc.h

@@ -28,6 +28,7 @@ class MCObjectWriter;
 class MCRegisterInfo;
 class MCSubtargetInfo;
 class MCTargetOptions;
+class MachineInstr;
 class StringRef;
 class Target;
 class raw_ostream;
@@ -43,6 +44,15 @@ MCAsmBackend *createXtensaMCAsmBackend(const Target &T,
                                        const MCTargetOptions &Options);
 std::unique_ptr<MCObjectTargetWriter>
 createXtensaObjectWriter(uint8_t OSABI, bool IsLittleEndian);
+
+namespace Xtensa {
+// Check address offset for load/store instructions.
+// The offset should be multiple of scale.
+bool isValidAddrOffset(int Scale, int64_t OffsetVal);
+
+// Check address offset for load/store instructions.
+bool isValidAddrOffsetForOpcode(unsigned Opcode, int64_t Offset);
+} // namespace Xtensa
 } // end namespace llvm
 
 // Defines symbolic names for Xtensa registers.

llvm/lib/Target/Xtensa/XtensaISelDAGToDAG.cpp

@@ -10,9 +10,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "MCTargetDesc/XtensaMCTargetDesc.h"
 #include "Xtensa.h"
 #include "XtensaTargetMachine.h"
-#include "XtensaUtils.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/SelectionDAGISel.h"
@@ -75,7 +75,7 @@ class XtensaDAGToDAGISel : public SelectionDAGISel {
       ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1));
       int64_t OffsetVal = CN->getSExtValue();
 
-      Valid = isValidAddrOffset(Scale, OffsetVal);
+      Valid = Xtensa::isValidAddrOffset(Scale, OffsetVal);
 
       if (Valid) {
         // If the first operand is a FI, get the TargetFI Node.

llvm/lib/Target/Xtensa/XtensaRegisterInfo.cpp

@@ -11,9 +11,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "XtensaRegisterInfo.h"
+#include "MCTargetDesc/XtensaMCTargetDesc.h"
 #include "XtensaInstrInfo.h"
 #include "XtensaSubtarget.h"
-#include "XtensaUtils.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
@@ -99,7 +99,7 @@ bool XtensaRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   int64_t Offset =
       SPOffset + (int64_t)StackSize + MI.getOperand(FIOperandNum + 1).getImm();
 
-  bool Valid = isValidAddrOffset(MI, Offset);
+  bool Valid = Xtensa::isValidAddrOffsetForOpcode(MI.getOpcode(), Offset);
 
   // If MI is not a debug value, make sure Offset fits in the 16-bit immediate
   // field.