diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FaddRegisterHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FaddpStiStHandler.cs
similarity index 51%
rename from X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FaddRegisterHandler.cs
rename to X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FaddpStiStHandler.cs
index dcdea09..dd9a4ab 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FaddRegisterHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FaddpStiStHandler.cs
@@ -3,15 +3,15 @@ namespace X86Disassembler.X86.Handlers.FloatingPoint.Arithmetic;
using X86Disassembler.X86.Operands;
///
-/// Handler for FADD ST(i), ST(0) instruction (DC C0-C7)
+/// Handler for FADDP ST(i), ST instruction (DE C0-C7)
///
-public class FaddRegisterHandler : InstructionHandler
+public class FaddpStiStHandler : InstructionHandler
{
///
- /// Initializes a new instance of the FaddRegisterHandler class
+ /// Initializes a new instance of the FaddpStiStHandler class
///
/// The instruction decoder that owns this handler
- public FaddRegisterHandler(InstructionDecoder decoder)
+ public FaddpStiStHandler(InstructionDecoder decoder)
: base(decoder)
{
}
@@ -23,25 +23,23 @@ public class FaddRegisterHandler : InstructionHandler
/// True if this handler can decode the opcode
public override bool CanHandle(byte opcode)
{
- // FADD ST(i), ST(0) is DC C0-C7
- if (opcode != 0xDC) return false;
+ // FADDP ST(i), ST is DE C0-C7
+ if (opcode != 0xDE) return false;
if (!Decoder.CanReadByte())
{
return false;
}
- // Check if the ModR/M byte has reg field = 0 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 0
- return reg == 0 && mod == 3;
+ // Only handle C0-C7
+ return secondOpcode is >= 0xC0 and <= 0xC7;
}
///
- /// Decodes a FADD ST(i), ST(0) instruction
+ /// Decodes a FADDP ST(i), ST instruction
///
/// The opcode of the instruction
/// The instruction object to populate
@@ -53,25 +51,11 @@ public class FaddRegisterHandler : InstructionHandler
return false;
}
- // Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xC0);
// Set the instruction type
- instruction.Type = InstructionType.Fadd;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
+ instruction.Type = InstructionType.Faddp;
// Create the FPU register operands
var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivRegisterHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivRegisterHandler.cs
index 01cb4d8..295c875 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivRegisterHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivRegisterHandler.cs
@@ -31,13 +31,11 @@ public class FdivRegisterHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 6 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 6
- return reg == 6 && mod == 3;
+ // Only handle F0-F7
+ return secondOpcode is >= 0xF0 and <= 0xF7;
}
///
@@ -53,25 +51,11 @@ public class FdivRegisterHandler : InstructionHandler
return false;
}
- // Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xF0);
// Set the instruction type
instruction.Type = InstructionType.Fdiv;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivpStiStHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivpStiStHandler.cs
new file mode 100644
index 0000000..e3e2ce5
--- /dev/null
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivpStiStHandler.cs
@@ -0,0 +1,73 @@
+namespace X86Disassembler.X86.Handlers.FloatingPoint.Arithmetic;
+
+using X86Disassembler.X86.Operands;
+
+///
+/// Handler for FDIVP ST(i), ST instruction (DE F0-F7)
+///
+public class FdivpStiStHandler : InstructionHandler
+{
+ ///
+ /// Initializes a new instance of the FdivpStiStHandler class
+ ///
+ /// The instruction decoder that owns this handler
+ public FdivpStiStHandler(InstructionDecoder decoder)
+ : base(decoder)
+ {
+ }
+
+ ///
+ /// Checks if this handler can decode the given opcode
+ ///
+ /// The opcode to check
+ /// True if this handler can decode the opcode
+ public override bool CanHandle(byte opcode)
+ {
+ // FDIVP ST(i), ST is DE F0-F7
+ if (opcode != 0xDE) return false;
+
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
+
+ // Only handle F0-F7
+ return secondOpcode is >= 0xF0 and <= 0xF7;
+ }
+
+ ///
+ /// Decodes a FDIVP ST(i), ST instruction
+ ///
+ /// The opcode of the instruction
+ /// The instruction object to populate
+ /// True if the instruction was successfully decoded
+ public override bool Decode(byte opcode, Instruction instruction)
+ {
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xF0);
+
+ // Set the instruction type
+ instruction.Type = InstructionType.Fdivp;
+
+ // Create the FPU register operands
+ var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var st0Operand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
+
+ // Set the structured operands
+ instruction.StructuredOperands =
+ [
+ stiOperand,
+ st0Operand
+ ];
+
+ return true;
+ }
+}
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivrRegisterHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivrRegisterHandler.cs
index 12459c1..510cd13 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivrRegisterHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivrRegisterHandler.cs
@@ -31,13 +31,11 @@ public class FdivrRegisterHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 7 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 7
- return reg == 7 && mod == 3;
+ // Only handle F8-FF
+ return secondOpcode is >= 0xF8 and <= 0xFF;
}
///
@@ -53,25 +51,11 @@ public class FdivrRegisterHandler : InstructionHandler
return false;
}
- // Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xF8);
// Set the instruction type
instruction.Type = InstructionType.Fdivr;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivrpStiStHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivrpStiStHandler.cs
new file mode 100644
index 0000000..a2b3f9d
--- /dev/null
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FdivrpStiStHandler.cs
@@ -0,0 +1,73 @@
+namespace X86Disassembler.X86.Handlers.FloatingPoint.Arithmetic;
+
+using X86Disassembler.X86.Operands;
+
+///
+/// Handler for FDIVRP ST(i), ST instruction (DE F8-FF)
+///
+public class FdivrpStiStHandler : InstructionHandler
+{
+ ///
+ /// Initializes a new instance of the FdivrpStiStHandler class
+ ///
+ /// The instruction decoder that owns this handler
+ public FdivrpStiStHandler(InstructionDecoder decoder)
+ : base(decoder)
+ {
+ }
+
+ ///
+ /// Checks if this handler can decode the given opcode
+ ///
+ /// The opcode to check
+ /// True if this handler can decode the opcode
+ public override bool CanHandle(byte opcode)
+ {
+ // FDIVRP ST(i), ST is DE F8-FF
+ if (opcode != 0xDE) return false;
+
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
+
+ // Only handle F8-FF
+ return secondOpcode is >= 0xF8 and <= 0xFF;
+ }
+
+ ///
+ /// Decodes a FDIVRP ST(i), ST instruction
+ ///
+ /// The opcode of the instruction
+ /// The instruction object to populate
+ /// True if the instruction was successfully decoded
+ public override bool Decode(byte opcode, Instruction instruction)
+ {
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xF8);
+
+ // Set the instruction type
+ instruction.Type = InstructionType.Fdivrp;
+
+ // Create the FPU register operands
+ var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var st0Operand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
+
+ // Set the structured operands
+ instruction.StructuredOperands =
+ [
+ stiOperand,
+ st0Operand
+ ];
+
+ return true;
+ }
+}
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FmulRegisterHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FmulRegisterHandler.cs
index ccc8f12..fae6aa4 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FmulRegisterHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FmulRegisterHandler.cs
@@ -31,13 +31,11 @@ public class FmulRegisterHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 1 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 1
- return reg == 1 && mod == 3;
+ // Only handle C8-CF
+ return secondOpcode is >= 0xC8 and <= 0xCF;
}
///
@@ -53,25 +51,11 @@ public class FmulRegisterHandler : InstructionHandler
return false;
}
- // Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xC8);
// Set the instruction type
instruction.Type = InstructionType.Fmul;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FmulpStiStHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FmulpStiStHandler.cs
new file mode 100644
index 0000000..12222ce
--- /dev/null
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FmulpStiStHandler.cs
@@ -0,0 +1,73 @@
+namespace X86Disassembler.X86.Handlers.FloatingPoint.Arithmetic;
+
+using X86Disassembler.X86.Operands;
+
+///
+/// Handler for FMULP ST(i), ST instruction (DE C8-CF)
+///
+public class FmulpStiStHandler : InstructionHandler
+{
+ ///
+ /// Initializes a new instance of the FmulpStiStHandler class
+ ///
+ /// The instruction decoder that owns this handler
+ public FmulpStiStHandler(InstructionDecoder decoder)
+ : base(decoder)
+ {
+ }
+
+ ///
+ /// Checks if this handler can decode the given opcode
+ ///
+ /// The opcode to check
+ /// True if this handler can decode the opcode
+ public override bool CanHandle(byte opcode)
+ {
+ // FMULP ST(i), ST is DE C8-CF
+ if (opcode != 0xDE) return false;
+
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
+
+ // Only handle C8-CF
+ return secondOpcode is >= 0xC8 and <= 0xCF;
+ }
+
+ ///
+ /// Decodes a FMULP ST(i), ST instruction
+ ///
+ /// The opcode of the instruction
+ /// The instruction object to populate
+ /// True if the instruction was successfully decoded
+ public override bool Decode(byte opcode, Instruction instruction)
+ {
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xC8);
+
+ // Set the instruction type
+ instruction.Type = InstructionType.Fmulp;
+
+ // Create the FPU register operands
+ var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var st0Operand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
+
+ // Set the structured operands
+ instruction.StructuredOperands =
+ [
+ stiOperand,
+ st0Operand
+ ];
+
+ return true;
+ }
+}
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubRegisterHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubRegisterHandler.cs
index 2b6385c..0d42f92 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubRegisterHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubRegisterHandler.cs
@@ -31,13 +31,11 @@ public class FsubRegisterHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 4 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 4
- return reg == 4 && mod == 3;
+ // Only handle E0-E7
+ return secondOpcode is >= 0xE0 and <= 0xE7;
}
///
@@ -53,25 +51,11 @@ public class FsubRegisterHandler : InstructionHandler
return false;
}
- // Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xE0);
// Set the instruction type
instruction.Type = InstructionType.Fsub;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubpStiStHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubpStiStHandler.cs
new file mode 100644
index 0000000..57b1891
--- /dev/null
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubpStiStHandler.cs
@@ -0,0 +1,73 @@
+namespace X86Disassembler.X86.Handlers.FloatingPoint.Arithmetic;
+
+using X86Disassembler.X86.Operands;
+
+///
+/// Handler for FSUBP ST(i), ST instruction (DE E0-E7)
+///
+public class FsubpStiStHandler : InstructionHandler
+{
+ ///
+ /// Initializes a new instance of the FsubpStiStHandler class
+ ///
+ /// The instruction decoder that owns this handler
+ public FsubpStiStHandler(InstructionDecoder decoder)
+ : base(decoder)
+ {
+ }
+
+ ///
+ /// Checks if this handler can decode the given opcode
+ ///
+ /// The opcode to check
+ /// True if this handler can decode the opcode
+ public override bool CanHandle(byte opcode)
+ {
+ // FSUBP ST(i), ST is DE E0-E7
+ if (opcode != 0xDE) return false;
+
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
+
+ // Only handle E0-E7
+ return secondOpcode is >= 0xE0 and <= 0xE7;
+ }
+
+ ///
+ /// Decodes a FSUBP ST(i), ST instruction
+ ///
+ /// The opcode of the instruction
+ /// The instruction object to populate
+ /// True if the instruction was successfully decoded
+ public override bool Decode(byte opcode, Instruction instruction)
+ {
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xE0);
+
+ // Set the instruction type
+ instruction.Type = InstructionType.Fsubp;
+
+ // Create the FPU register operands
+ var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var st0Operand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
+
+ // Set the structured operands
+ instruction.StructuredOperands =
+ [
+ stiOperand,
+ st0Operand
+ ];
+
+ return true;
+ }
+}
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubrRegisterHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubrRegisterHandler.cs
index 36fd43e..94c3580 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubrRegisterHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubrRegisterHandler.cs
@@ -31,13 +31,11 @@ public class FsubrRegisterHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 5 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 5
- return reg == 5 && mod == 3;
+ // Only handle E8-EF
+ return secondOpcode is >= 0xE8 and <= 0xEF;
}
///
@@ -53,25 +51,11 @@ public class FsubrRegisterHandler : InstructionHandler
return false;
}
- // Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xE8);
// Set the instruction type
instruction.Type = InstructionType.Fsubr;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubrpStiStHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubrpStiStHandler.cs
new file mode 100644
index 0000000..00e54b8
--- /dev/null
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Arithmetic/FsubrpStiStHandler.cs
@@ -0,0 +1,73 @@
+namespace X86Disassembler.X86.Handlers.FloatingPoint.Arithmetic;
+
+using X86Disassembler.X86.Operands;
+
+///
+/// Handler for FSUBRP ST(i), ST instruction (DE E8-EF)
+///
+public class FsubrpStiStHandler : InstructionHandler
+{
+ ///
+ /// Initializes a new instance of the FsubrpStiStHandler class
+ ///
+ /// The instruction decoder that owns this handler
+ public FsubrpStiStHandler(InstructionDecoder decoder)
+ : base(decoder)
+ {
+ }
+
+ ///
+ /// Checks if this handler can decode the given opcode
+ ///
+ /// The opcode to check
+ /// True if this handler can decode the opcode
+ public override bool CanHandle(byte opcode)
+ {
+ // FSUBRP ST(i), ST is DE E8-EF
+ if (opcode != 0xDE) return false;
+
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
+
+ // Only handle E8-EF
+ return secondOpcode is >= 0xE8 and <= 0xEF;
+ }
+
+ ///
+ /// Decodes a FSUBRP ST(i), ST instruction
+ ///
+ /// The opcode of the instruction
+ /// The instruction object to populate
+ /// True if the instruction was successfully decoded
+ public override bool Decode(byte opcode, Instruction instruction)
+ {
+ if (!Decoder.CanReadByte())
+ {
+ return false;
+ }
+
+ // Read the ModR/M byte and calculate ST(i) index
+ var stIndex = (FpuRegisterIndex)(Decoder.ReadByte() - 0xE8);
+
+ // Set the instruction type
+ instruction.Type = InstructionType.Fsubrp;
+
+ // Create the FPU register operands
+ var stiOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var st0Operand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
+
+ // Set the structured operands
+ instruction.StructuredOperands =
+ [
+ stiOperand,
+ st0Operand
+ ];
+
+ return true;
+ }
+}
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomiHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomiHandler.cs
index 9b17a6c..af4f71b 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomiHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomiHandler.cs
@@ -31,13 +31,11 @@ public class FcomiHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 7 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 7
- return reg == 7 && mod == 3;
+ // Only handle F0-F7
+ return secondOpcode is >= 0xF0 and <= 0xF7;
}
///
@@ -54,33 +52,17 @@ public class FcomiHandler : InstructionHandler
}
// Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ var (mod, reg, rm, _) = ModRMDecoder.ReadModRMFpu();
// Set the instruction type
instruction.Type = InstructionType.Fcomi;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
- var destOperand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
- var srcOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var srcOperand = OperandFactory.CreateFPURegisterOperand(rm);
// Set the structured operands
instruction.StructuredOperands =
[
- destOperand,
srcOperand
];
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomipHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomipHandler.cs
index c6cbe3a..816fdaa 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomipHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcomipHandler.cs
@@ -31,13 +31,11 @@ public class FcomipHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 6 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 6
- return reg == 6 && mod == 3;
+ // Only handle F0-F7
+ return secondOpcode is >= 0xF0 and <= 0xF7;
}
///
@@ -54,33 +52,17 @@ public class FcomipHandler : InstructionHandler
}
// Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ var (mod, reg, rm, _) = ModRMDecoder.ReadModRMFpu();
// Set the instruction type
instruction.Type = InstructionType.Fcomip;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
- var destOperand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
- var srcOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var srcOperand = OperandFactory.CreateFPURegisterOperand(rm);
// Set the structured operands
instruction.StructuredOperands =
[
- destOperand,
srcOperand
];
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompFloat32Handler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompFloat32Handler.cs
index 0f07eec..9df0268 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompFloat32Handler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompFloat32Handler.cs
@@ -36,7 +36,7 @@ public class FcompFloat32Handler : InstructionHandler
byte reg = (byte)((modRm >> 3) & 0x7);
// special handling of modRM for D8 D8+i FCOMP ST(i)
- return reg == 3 && modRm is < 0xD8 or > 0xDE;
+ return reg == 3 && modRm is < 0xD8 or > 0xDF;
}
///
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompStHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompStHandler.cs
index 6946fb6..6f2ac5e 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompStHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FcompStHandler.cs
@@ -34,7 +34,7 @@ public class FcompStHandler : InstructionHandler
var opcodeSecond = Decoder.PeakByte();
// this is a special case of a handler, only handling FCOMP with ST(i)
- if (opcodeSecond < 0xD8 || opcodeSecond > 0xDF)
+ if (opcodeSecond is < 0xD8 or > 0xDF)
return false;
return true;
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomiHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomiHandler.cs
index bdd29fe..450d781 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomiHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomiHandler.cs
@@ -31,13 +31,11 @@ public class FucomiHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 6 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 6
- return reg == 6 && mod == 3;
+ // Only handle F0-F7
+ return secondOpcode is >= 0xE8 and <= 0xEF;
}
///
@@ -54,28 +52,14 @@ public class FucomiHandler : InstructionHandler
}
// Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ var (mod, reg, rm, _) = ModRMDecoder.ReadModRMFpu();
// Set the instruction type
instruction.Type = InstructionType.Fucomi;
-
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
// Create the FPU register operands
var destOperand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
- var srcOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var srcOperand = OperandFactory.CreateFPURegisterOperand(rm);
// Set the structured operands
instruction.StructuredOperands =
diff --git a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomipHandler.cs b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomipHandler.cs
index 04a5c61..23397f1 100644
--- a/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomipHandler.cs
+++ b/X86Disassembler/X86/Handlers/FloatingPoint/Comparison/FucomipHandler.cs
@@ -31,13 +31,11 @@ public class FucomipHandler : InstructionHandler
return false;
}
- // Check if the ModR/M byte has reg field = 5 and mod = 3
- byte modRm = Decoder.PeakByte();
- byte reg = (byte)((modRm >> 3) & 0x7);
- byte mod = (byte)((modRm >> 6) & 0x3);
+ // Check second opcode byte
+ byte secondOpcode = Decoder.PeakByte();
- // Only handle register operands (mod = 3) with reg = 5
- return reg == 5 && mod == 3;
+ // Only handle F0-F7
+ return secondOpcode is >= 0xE8 and <= 0xEF;
}
///
@@ -54,33 +52,17 @@ public class FucomipHandler : InstructionHandler
}
// Read the ModR/M byte
- var (mod, reg, rm, _) = ModRMDecoder.ReadModRM();
+ var (mod, reg, rm, _) = ModRMDecoder.ReadModRMFpu();
// Set the instruction type
instruction.Type = InstructionType.Fucomip;
- // Map rm field to FPU register index
- FpuRegisterIndex stIndex = rm switch
- {
- RegisterIndex.A => FpuRegisterIndex.ST0,
- RegisterIndex.C => FpuRegisterIndex.ST1,
- RegisterIndex.D => FpuRegisterIndex.ST2,
- RegisterIndex.B => FpuRegisterIndex.ST3,
- RegisterIndex.Sp => FpuRegisterIndex.ST4,
- RegisterIndex.Bp => FpuRegisterIndex.ST5,
- RegisterIndex.Si => FpuRegisterIndex.ST6,
- RegisterIndex.Di => FpuRegisterIndex.ST7,
- _ => FpuRegisterIndex.ST0 // Default case, should not happen
- };
-
// Create the FPU register operands
- var destOperand = OperandFactory.CreateFPURegisterOperand(FpuRegisterIndex.ST0);
- var srcOperand = OperandFactory.CreateFPURegisterOperand(stIndex);
+ var srcOperand = OperandFactory.CreateFPURegisterOperand(rm);
// Set the structured operands
instruction.StructuredOperands =
[
- destOperand,
srcOperand
];
diff --git a/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs b/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs
index 18a8d3d..8a0a3d4 100644
--- a/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs
+++ b/X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs
@@ -439,14 +439,14 @@ public class InstructionHandlerFactory
_handlers.Add(new FloatingPoint.Comparison.FcomiHandler(_decoder)); // FCOMI (DB F0-F7)
// D8 opcode handlers (register operations)
- _handlers.Add(new FloatingPoint.Arithmetic.FaddRegisterHandler(_decoder)); // FADD ST(0), ST(i) (D8 C0-C7)
- _handlers.Add(new FloatingPoint.Arithmetic.FmulRegisterHandler(_decoder)); // FMUL ST(0), ST(i) (D8 C8-CF)
+ _handlers.Add(new FloatingPoint.Arithmetic.FaddStStiHandler(_decoder)); // FADD ST, ST(i) (D8 C0-C7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FmulStStiHandler(_decoder)); // FMUL ST, ST(i) (D8 C8-CF)
_handlers.Add(new FloatingPoint.Comparison.FcomStHandler(_decoder)); // FCOM ST(i) (D8 D0-D7)
_handlers.Add(new FloatingPoint.Comparison.FcompStHandler(_decoder)); // FCOMP ST(i) (D8 D8-DF)
- _handlers.Add(new FloatingPoint.Arithmetic.FsubRegisterHandler(_decoder)); // FSUB ST(0), ST(i) (D8 E0-E7)
- _handlers.Add(new FloatingPoint.Arithmetic.FsubrRegisterHandler(_decoder)); // FSUBR ST(0), ST(i) (D8 E8-EF)
- _handlers.Add(new FloatingPoint.Arithmetic.FdivRegisterHandler(_decoder)); // FDIV ST(0), ST(i) (D8 F0-F7)
- _handlers.Add(new FloatingPoint.Arithmetic.FdivrRegisterHandler(_decoder)); // FDIVR ST(0), ST(i) (D8 F8-FF)
+ _handlers.Add(new FloatingPoint.Arithmetic.FsubStStiHandler(_decoder)); // FSUB ST, ST(i) (D8 E0-E7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FsubrStStiHandler(_decoder)); // FSUBR ST, ST(i) (D8 E8-EF)
+ _handlers.Add(new FloatingPoint.Arithmetic.FdivStStiHandler(_decoder)); // FDIV ST, ST(i) (D8 F0-F7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FdivrStStiHandler(_decoder)); // FDIVR ST, ST(i) (D8 F8-FF)
// DC opcode handlers (memory operations - float64)
_handlers.Add(new FloatingPoint.Arithmetic.FaddFloat64Handler(_decoder)); // FADD float64 (DC /0)
@@ -459,7 +459,13 @@ public class InstructionHandlerFactory
_handlers.Add(new FloatingPoint.Arithmetic.FdivrFloat64Handler(_decoder)); // FDIVR float64 (DC /7)
// DC opcode handlers (register operations)
+ _handlers.Add(new FloatingPoint.Arithmetic.FaddStiStHandler(_decoder)); // FADD ST(i), ST (DC C0-C7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FmulStiStHandler(_decoder)); // FMUL ST(i), ST (DC C8-CF)
_handlers.Add(new FloatingPoint.Comparison.FcomRegisterHandler(_decoder)); // FCOM ST(i), ST(0) (DC D0-D7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FsubStiStHandler(_decoder)); // FSUB ST(i), ST (DC E0-E7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FsubrStiStHandler(_decoder)); // FSUBR ST(i), ST (DC E8-EF)
+ _handlers.Add(new FloatingPoint.Arithmetic.FdivStiStHandler(_decoder)); // FDIV ST(i), ST (DC F0-F7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FdivrStiStHandler(_decoder)); // FDIVR ST(i), ST (DC F8-FF)
_handlers.Add(new FloatingPoint.Comparison.FcompRegisterHandler(_decoder)); // FCOMP ST(i), ST(0) (DC D8-DF)
// DD opcode handlers (register operations)
@@ -485,14 +491,13 @@ public class InstructionHandlerFactory
_handlers.Add(new FloatingPoint.Arithmetic.FidivrInt16Handler(_decoder)); // FIDIVR int16 (DE /7)
// DE opcode handlers (register operations)
- _handlers.Add(new FloatingPoint.Arithmetic.FaddpHandler(_decoder)); // FADDP ST(i), ST(0) (DE C0-C7)
- _handlers.Add(new FloatingPoint.Arithmetic.FmulpHandler(_decoder)); // FMULP ST(i), ST(0) (DE C8-CF)
- _handlers.Add(new FloatingPoint.Comparison.FcompStHandler(_decoder)); // FCOMP ST(0) (DE D3)
+ _handlers.Add(new FloatingPoint.Arithmetic.FaddpStiStHandler(_decoder)); // FADDP ST(i), ST (DE C0-C7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FmulpStiStHandler(_decoder)); // FMULP ST(i), ST (DE C8-CF)
_handlers.Add(new FloatingPoint.Comparison.FcomppHandler(_decoder)); // FCOMPP (DE D9)
- _handlers.Add(new FloatingPoint.Arithmetic.FsubpHandler(_decoder)); // FSUBP ST(i), ST(0) (DE E0-E7)
- _handlers.Add(new FloatingPoint.Arithmetic.FsubrpHandler(_decoder)); // FSUBRP ST(i), ST(0) (DE E8-EF)
- _handlers.Add(new FloatingPoint.Arithmetic.FdivpHandler(_decoder)); // FDIVP ST(i), ST(0) (DE F0-F7)
- _handlers.Add(new FloatingPoint.Arithmetic.FdivrpHandler(_decoder)); // FDIVRP ST(i), ST(0) (DE F8-FF)
+ _handlers.Add(new FloatingPoint.Arithmetic.FsubpStiStHandler(_decoder)); // FSUBP ST(i), ST (DE E0-E7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FsubrpStiStHandler(_decoder)); // FSUBRP ST(i), ST (DE E8-EF)
+ _handlers.Add(new FloatingPoint.Arithmetic.FdivpStiStHandler(_decoder)); // FDIVP ST(i), ST (DE F0-F7)
+ _handlers.Add(new FloatingPoint.Arithmetic.FdivrpStiStHandler(_decoder)); // FDIVRP ST(i), ST (DE F8-FF)
// DF opcode handlers (memory operations)
_handlers.Add(new FloatingPoint.LoadStore.FildInt16Handler(_decoder)); // FILD int16 (DF /0)
diff --git a/X86DisassemblerTests/TestData/fcom_tests.csv b/X86DisassemblerTests/TestData/fcom_tests.csv
index 4dcfe5c..70e4265 100644
--- a/X86DisassemblerTests/TestData/fcom_tests.csv
+++ b/X86DisassemblerTests/TestData/fcom_tests.csv
@@ -39,8 +39,8 @@ D8DF;[{ "Type": "Fcomp", "Operands": ["ST(7)"] }]
# Memory operands
D81C2510000000;[{ "Type": "Fcomp", "Operands": ["dword ptr [0x10]"] }]
DC1C2510000000;[{ "Type": "Fcomp", "Operands": ["qword ptr [0x10]"] }]
-D81C25;[{ "Type": "Fcomp", "Operands": ["dword ptr [eax]"] }]
-DC1C25;[{ "Type": "Fcomp", "Operands": ["qword ptr [eax]"] }]
+D818;[{ "Type": "Fcomp", "Operands": ["dword ptr [eax]"] }]
+DC18;[{ "Type": "Fcomp", "Operands": ["qword ptr [eax]"] }]
# FCOMPP - Compare floating point values and pop twice
DED9;[{ "Type": "Fcompp", "Operands": [] }]