Default exec command logger to error level

internal/cli/cmd/exec.go

@@ -6,7 +6,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"log/slog"
 	"os"
 	"time"
 
@@ -18,13 +17,17 @@ import (
 )
 
 func Executor() cli.Command {
-	exec := &executor{log: log.DefaultLogger()}
+	exec := &executor{
+		log:      log.DefaultLogger(),
+		logLevel: log.Error,
+	}
+
 	return exec
 }
 
 type executor struct {
-	logLevel slog.Level
 	log      *log.Logger
+	logLevel log.Level
 }
 
 func (executor) Description() string {
@@ -42,6 +45,7 @@ Runs an executable in the emulator.`)
 
 func (ex *executor) FlagSet() *cli.FlagSet {
 	fs := flag.NewFlagSet("exec", flag.ExitOnError)
+
 	fs.Func("loglevel", "set log `level`", func(s string) error {
 		return ex.logLevel.UnmarshalText([]byte(s))
 	})

internal/vm/ops.go

@@ -198,7 +198,10 @@ func (op *addImm) Decode(vm *LC3) {
 }
 
 func (op *addImm) Execute() {
-	op.vm.REG[op.dr] = Register(int16(op.vm.REG[op.sr]) + int16(op.lit))
+	operand := int16(op.vm.REG[op.sr])
+	lit := int16(op.lit)
+
+	op.vm.REG[op.dr] = Register(operand + lit)
 	op.vm.PSR.Set(op.vm.REG[op.dr])
 }
 

internal/vm/vm_test.go

@@ -314,6 +314,39 @@ func TestInstructions(tt *testing.T) {
 		}
 	})
 
+	tt.Run("ADDIMM zeroed", func(tt *testing.T) {
+		var (
+			t   = NewTestHarness(tt)
+			cpu = t.Make()
+		)
+
+		_ = cpu.Mem.store(Word(cpu.PC), 0b0001_000_000_1_00000|(-9&0x1f))
+		cpu.REG[R0] = 9
+
+		err := cpu.Step()
+		if err != nil {
+			t.Error(err)
+		}
+
+		if op := cpu.IR.Opcode(); op != ADD {
+			t.Errorf("instr: %s, want: %04b, got: %04b",
+				cpu.IR, AND, op)
+		}
+
+		oper := cpu.Decode()
+		t.Logf("oper: %#+v", oper)
+
+		if cpu.REG[R0] != 0x0000 {
+			t.Errorf("r0 incorrect, want: %s, got: %s",
+				Register(0x0000), cpu.REG[R0])
+		}
+
+		if !cpu.PSR.Zero() {
+			t.Errorf("cond incorrect, want: %s, got: %s",
+				StatusNegative, cpu.PSR)
+		}
+	})
+
 	tt.Run("LD", func(tt *testing.T) {
 		var (
 			t   = NewTestHarness(tt)