compute addresses

pkg/vm/memory/relocatable.go

@@ -15,8 +15,23 @@ type Relocatable struct {
 
 // Creates a new Relocatable struct with the specified segment index
 // and offset.
-func NewRelocatable(segment_idx int, offset uint) *Relocatable {
-	return &Relocatable{segment_idx, offset}
+func NewRelocatable(segment_idx int, offset uint) Relocatable {
+	return Relocatable{segment_idx, offset}
+}
+
+func (relocatable *Relocatable) SubRelocatable(other uint) (Relocatable, error) {
+	if relocatable.offset < other {
+		return NewRelocatable(0, 0), &SubReloctableError{Msg: "RelocatableSubUsizeNegOffset"}
+	} else {
+		new_offset := relocatable.offset - other
+		return NewRelocatable(relocatable.segmentIndex, new_offset), nil
+	}
+}
+
+func (relocatable *Relocatable) AddRelocatable(other uint) (Relocatable, error) {
+	new_offset := relocatable.offset + other
+	return NewRelocatable(relocatable.segmentIndex, new_offset), nil
+
 }
 
 // Get the the indexes of the Relocatable struct.
@@ -33,8 +48,6 @@ func (r *Relocatable) into_indexes() (uint, uint) {
 // Int in the Cairo VM represents a value in memory that
 // is not an address.
 type Int struct {
-	// FIXME: Here we should use Lambdaworks felt, just mocking
-	// this for now.
 	felt lambdaworks.Felt
 }
 

pkg/vm/memory/relocatable_err.go

@@ -0,0 +1,9 @@
+package memory
+
+type SubReloctableError struct {
+	Msg string
+}
+
+func (e *SubReloctableError) Error() string {
+	return e.Msg
+}

pkg/vm/memory/segments.go

@@ -4,6 +4,6 @@ package memory
 // Also holds metadata useful for the relocation process of
 // the memory at the end of the VM run.
 type MemorySegmentManager struct {
-	segmentSizes map[uint]uint
-	memory       Memory
+	SegmentSizes map[uint]uint
+	Memory       Memory
 }

pkg/vm/run_context.go

@@ -1,6 +1,11 @@
 package vm
 
-import "github.com/lambdaclass/cairo-vm.go/pkg/vm/memory"
+import (
+	"math"
+
+	"github.com/lambdaclass/cairo-vm.go/pkg/lambdaworks"
+	"github.com/lambdaclass/cairo-vm.go/pkg/vm/memory"
+)
 
 // RunContext containts the register states of the
 // Cairo VM.
@@ -9,3 +14,72 @@ type RunContext struct {
 	ap uint
 	fp uint
 }
+
+func (run_context RunContext) GetAp() memory.Relocatable {
+	return memory.NewRelocatable(1, run_context.ap)
+}
+
+func (run_context RunContext) GetFP() memory.Relocatable {
+	return memory.NewRelocatable(1, run_context.fp)
+}
+
+func (run_context RunContext) get_pc() memory.Relocatable {
+	return run_context.pc
+}
+
+func (run_context RunContext) ComputeDstAddr(instruction Instruction) (memory.Relocatable, error) {
+	var base_addr memory.Relocatable
+	switch instruction.DstReg {
+	case AP:
+		base_addr = run_context.GetAp()
+	case FP:
+		base_addr = run_context.GetFP()
+	}
+
+	if instruction.OffOp0 < 0 {
+		return base_addr.SubRelocatable(uint(math.Abs(float64(instruction.OffDst))))
+	} else {
+		return base_addr.AddRelocatable(uint(instruction.OffDst))
+	}
+
+}
+
+func (run_context RunContext) ComputeOp0Addr(instruction Instruction) (memory.Relocatable, error) {
+	var base_addr memory.Relocatable
+	switch instruction.Op0Reg {
+	case AP:
+		base_addr = run_context.GetAp()
+	case FP:
+		base_addr = run_context.GetFP()
+	}
+
+	if instruction.OffOp1 < 0 {
+		return base_addr.SubRelocatable(uint(math.Abs(float64(instruction.OffOp0))))
+	} else {
+		return base_addr.AddRelocatable(uint(instruction.OffOp0))
+	}
+}
+
+func (run_context RunContext) ComputeOp1Addr(instruction Instruction, op0 memory.MaybeRelocatable) (memory.Relocatable, error) {
+	var base_addr memory.Relocatable
+
+	switch instruction.Op1Addr {
+	case Op1SrcFP:
+		base_addr = run_context.GetFP()
+	case Op1SrcAP:
+		base_addr = run_context.GetAp()
+	case Op1SrcImm:
+		if instruction.OffOp1 == 1 {
+			base_addr = run_context.get_pc()
+		} else {
+			base_addr = memory.NewRelocatable(-1, 0)
+			return base_addr, VirtualMachineError{Msg: "UnknownOp0"}
+		}
+		// Todo:check case op0
+	}
+	if instruction.OffOp1 < 0 {
+		return base_addr.SubRelocatable(uint(math.Abs(float64(instruction.OffOp1))))
+	} else {
+		return base_addr.AddRelocatable(uint(instruction.OffOp1))
+	}
+}

pkg/vm/vm_core.go

@@ -5,6 +5,14 @@ import (
 	"github.com/lambdaclass/cairo-vm.go/pkg/vm/memory"
 )
 
+type VirtualMachineError struct {
+	Msg string
+}
+
+func (e VirtualMachineError) Error() string {
+	return fmt.Sprintf(e.Msg)
+}
+
 // VirtualMachine represents the Cairo VM.
 // Runs Cairo assembly and produces an execution trace.
 type VirtualMachine struct {
@@ -26,7 +34,34 @@ type OperandsAddresses struct {
 	op1_addr memory.Relocatable
 }
 
-func (vm VirtualMachine) compute_operands(instruction Instruction) {}
+type DeducedOperands struct {
+	operands uint8
+}
+
+func (vm VirtualMachine) compute_operands(instruction Instruction) (Operands, OperandsAddresses, DeducedOperands, VirtualMachineError) {
+
+	dst_addr, err := vm.runContext.ComputeDstAddr(instruction)
+	if err != nil {
+		return Operands{}, OperandsAddresses{}, DeducedOperands{}, VirtualMachineError{Msg: "FailtToComputeDstAddr"}
+	}
+
+	dst_op, err_dst = vm.segments.Memory.Get(&dst_addr)
+
+	op0_addr, err := vm.runContext.ComputeOp0Addr(instruction)
+	if err != nil {
+		return Operands{}, OperandsAddresses{}, DeducedOperands{}, VirtualMachineError{Msg: "FailtToComputeOp0Addr"}
+	}
+
+	op0_op, err_op0 := vm.segments.Memory.Get(&op0_addr)
+
+	op1_addr, err := vm.runContext.ComputeOp1Addr(instruction)
+	if err != nil {
+		return Operands{}, OperandsAddresses{}, DeducedOperands{}, VirtualMachineError{Msg: "FailtToComputeOp1Addr"}
+	}
+	op1_op, err_op1 := vm.segments.Memory.Get(&op1_addr)
+
+	deduced_operands := DeducedOperands{operands: 0}
+}
 
 func (vm VirtualMachine) run_instrucion(instruction Instruction) {
 	fmt.Println("hello from instruction")