[NFC][MC][Decoder] Extract fixed pieces of decoder code into new header file

llvm/include/llvm/MC/MCDecoder.h

@@ -0,0 +1,67 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// Disassembler decoder helper functions.
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_MC_MCDECODER_H
+#define LLVM_MC_MCDECODER_H
+
+#include "llvm/MC/MCDisassembler/MCDisassembler.h"
+#include "llvm/Support/MathExtras.h"
+#include <cassert>
+
+namespace llvm::MCD {
+
+// Helper to propagate SoftFail status. Returns false if the status is Fail;
+// callers are expected to early-exit in that condition. (Note, the '&' operator
+// is correct to propagate the values of this enum; see comment on 'enum
+// DecodeStatus'.)
+inline bool Check(MCDisassembler::DecodeStatus &Out,
+                  MCDisassembler::DecodeStatus In) {
+  Out = static_cast<MCDisassembler::DecodeStatus>(Out & In);
+  return Out != MCDisassembler::Fail;
+}
+
+// fieldFromInstruction - Extracts a given span of bits from the instruction
+// bits and return it as an integer.
+template <typename IntType>
+#if defined(_MSC_VER) && !defined(__clang__)
+__declspec(noinline)
+#endif
+inline std::enable_if_t<std::is_integral_v<IntType>, IntType>
+fieldFromInstruction(const IntType &Insn, unsigned StartBit, unsigned NumBits) {
+  assert(StartBit + NumBits <= 64 && "Cannot support >64-bit extractions!");
+  assert(StartBit + NumBits <= (sizeof(IntType) * 8) &&
+         "Instruction field out of bounds!");
+  const IntType Mask = maskTrailingOnes<IntType>(NumBits);
+  return (Insn >> StartBit) & Mask;
+}
+
+template <typename InsnType>
+inline std::enable_if_t<!std::is_integral_v<InsnType>, uint64_t>
+fieldFromInstruction(const InsnType &Insn, unsigned StartBit,
+                     unsigned NumBits) {
+  return Insn.extractBitsAsZExtValue(NumBits, StartBit);
+}
+
+// Helper function for inserting bits extracted from an encoded instruction into
+// an integer-typed field.
+template <typename IntType>
+static std::enable_if_t<std::is_integral_v<IntType>, void>
+insertBits(IntType &field, IntType bits, unsigned startBit, unsigned numBits) {
+  // Check that no bit beyond numBits is set, so that a simple bitwise |
+  // is sufficient.
+  assert((~(((IntType)1 << numBits) - 1) & bits) == 0 &&
+         "bits has more than numBits bits set");
+  assert(startBit + numBits <= sizeof(IntType) * 8);
+  (void)numBits;
+  field |= bits << startBit;
+}
+
+} // namespace llvm::MCD
+
+#endif // LLVM_MC_MCDECODER_H

llvm/include/llvm/MC/MCDecoderOps.h

@@ -1,11 +1,11 @@
-//===------------ llvm/MC/MCDecoderOps.h - Decoder driver -------*- C++ -*-===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-// Disassembler decoder state machine driver.
+// Disassembler decoder state machine ops.
 //===----------------------------------------------------------------------===//
 #ifndef LLVM_MC_MCDECODEROPS_H
 #define LLVM_MC_MCDECODEROPS_H

llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp

@@ -15,6 +15,7 @@
 #include "MCTargetDesc/AArch64MCTargetDesc.h"
 #include "TargetInfo/AArch64TargetInfo.h"
 #include "Utils/AArch64BaseInfo.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCRelocationInfo.h"
 #include "llvm/MC/MCInst.h"
@@ -27,6 +28,7 @@
 #include <memory>
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "aarch64-disassembler"
 

llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp

@@ -27,6 +27,7 @@
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInstrDesc.h"
@@ -605,7 +606,7 @@ DecodeStatus AMDGPUDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
       Bytes = Bytes_.slice(0, MaxInstBytesNum);
     }
 
-    if (isGFX11Plus() && Bytes.size() >= 12 ) {
+    if (isGFX11Plus() && Bytes.size() >= 12) {
       DecoderUInt128 DecW = eat12Bytes(Bytes);
 
       if (isGFX11() &&

llvm/lib/Target/ARC/Disassembler/ARCDisassembler.cpp

@@ -16,6 +16,7 @@
 #include "MCTargetDesc/ARCMCTargetDesc.h"
 #include "TargetInfo/ARCTargetInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -24,6 +25,7 @@
 #include "llvm/MC/TargetRegistry.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "arc-disassembler"
 

llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp

@@ -13,6 +13,7 @@
 #include "TargetInfo/ARMTargetInfo.h"
 #include "Utils/ARMBaseInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -31,6 +32,7 @@
 #include <vector>
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "arm-disassembler"
 

llvm/lib/Target/AVR/Disassembler/AVRDisassembler.cpp

@@ -18,6 +18,7 @@
 
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -26,6 +27,7 @@
 #include "llvm/Support/Compiler.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "avr-disassembler"
 

llvm/lib/Target/BPF/Disassembler/BPFDisassembler.cpp

@@ -15,6 +15,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"

llvm/lib/Target/CSKY/Disassembler/CSKYDisassembler.cpp

@@ -15,6 +15,7 @@
 #include "TargetInfo/CSKYTargetInfo.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"

llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp

@@ -13,6 +13,7 @@
 #include "TargetInfo/HexagonTargetInfo.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCExpr.h"

llvm/lib/Target/Lanai/Disassembler/LanaiDisassembler.cpp

@@ -16,6 +16,7 @@
 #include "LanaiCondCode.h"
 #include "LanaiInstrInfo.h"
 #include "TargetInfo/LanaiTargetInfo.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCSubtargetInfo.h"
@@ -247,4 +248,4 @@ static DecodeStatus decodePredicateOperand(MCInst &Inst, unsigned Val,
     return MCDisassembler::Fail;
   Inst.addOperand(MCOperand::createImm(Val));
   return MCDisassembler::Success;
-}
+}

llvm/lib/Target/LoongArch/Disassembler/LoongArchDisassembler.cpp

@@ -13,6 +13,7 @@
 #include "MCTargetDesc/LoongArchMCTargetDesc.h"
 #include "TargetInfo/LoongArchTargetInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"

llvm/lib/Target/M68k/Disassembler/M68kDisassembler.cpp

@@ -19,6 +19,7 @@
 
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -27,6 +28,7 @@
 #include "llvm/Support/ErrorHandling.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "m68k-disassembler"
 

llvm/lib/Target/MSP430/Disassembler/MSP430Disassembler.cpp

@@ -14,6 +14,7 @@
 #include "MSP430.h"
 #include "TargetInfo/MSP430TargetInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -23,6 +24,7 @@
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "msp430-disassembler"
 

llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp

@@ -14,6 +14,7 @@
 #include "TargetInfo/MipsTargetInfo.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -29,6 +30,7 @@
 #include <cstdint>
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "mips-disassembler"
 

llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp

@@ -8,6 +8,7 @@
 
 #include "MCTargetDesc/PPCMCTargetDesc.h"
 #include "TargetInfo/PowerPCTargetInfo.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"

llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp

@@ -14,6 +14,7 @@
 #include "MCTargetDesc/RISCVMCTargetDesc.h"
 #include "TargetInfo/RISCVTargetInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -25,6 +26,7 @@
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "riscv-disassembler"
 

llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp

@@ -14,13 +14,15 @@
 #include "TargetInfo/SparcTargetInfo.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Support/Compiler.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "sparc-disassembler"
 

llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp

@@ -8,6 +8,7 @@
 
 #include "MCTargetDesc/SystemZMCTargetDesc.h"
 #include "TargetInfo/SystemZTargetInfo.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"

llvm/lib/Target/VE/Disassembler/VEDisassembler.cpp

@@ -15,13 +15,15 @@
 #include "VE.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Support/Compiler.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "ve-disassembler"
 

llvm/lib/Target/XCore/Disassembler/XCoreDisassembler.cpp

@@ -15,6 +15,7 @@
 #include "XCore.h"
 #include "XCoreRegisterInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"
@@ -23,6 +24,7 @@
 #include "llvm/Support/Compiler.h"
 
 using namespace llvm;
+using namespace llvm::MCD;
 
 #define DEBUG_TYPE "xcore-disassembler"
 

llvm/lib/Target/Xtensa/Disassembler/XtensaDisassembler.cpp

@@ -15,6 +15,7 @@
 #include "MCTargetDesc/XtensaMCTargetDesc.h"
 #include "TargetInfo/XtensaTargetInfo.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDecoder.h"
 #include "llvm/MC/MCDecoderOps.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCInst.h"