1 files changed, 55 insertions, 0 deletions
diff --git a/benchmark/index.ts b/benchmark/index.ts
new file mode 100644
index 0000000..b90b6bd
--- /dev/null
+++ b/benchmark/index.ts
@@ -0,0 +1,55 @@
+import { CPU } from '../src/cpu';
+import { avrInstruction } from '../src/instruction';
+import { createBenchmark } from './benchmark';
+import { instLDY } from './instruction-fn';
+
+/* Approach 1: use large Uint16Array with all possible opcodes */
+const instructionMap = new Uint16Array(65536);
+instructionMap[0x8088] = 0x5;
+
+function avrInstructionUintArray(cpu: CPU) {
+  const opcode = cpu.progMem[cpu.pc];
+  const mapped = instructionMap[opcode];
+  switch (mapped) {
+    case 5:
+      instLDY(cpu, opcode);
+      break;
+  }
+}
+
+/* Approach 1: use Map() */
+const objMap = new Map<number, (cpu: CPU, opcode: number) => void>();
+objMap.set(0x8088, instLDY);
+
+function avrInstructionObjMap(cpu: CPU) {
+  const opcode = cpu.progMem[cpu.pc];
+  objMap.get(cpu.progMem[cpu.pc])(cpu, opcode);
+}
+
+function run() {
+  const benchmark = createBenchmark('cpu-benchmark');
+
+  const cpu = new CPU(new Uint16Array(0x1000));
+  cpu.progMem[0] = 0x8088;
+  const timeA = benchmark('avrInstruction');
+  while (timeA()) {
+    cpu.pc = 0;
+    avrInstruction(cpu);
+  }
+
+  const timeB = benchmark('avrInstructionObjMap');
+  while (timeB()) {
+    cpu.pc = 0;
+    avrInstructionObjMap(cpu);
+  }
+
+  const timeC = benchmark('avrInstructionUintArray');
+  while (timeC()) {
+    cpu.pc = 0;
+    avrInstructionUintArray(cpu);
+  }
+
+  benchmark.report();
+}
+
+run();