Merge pull request #21 from Tcode-Motion/optimize-vm-fetch-decode-11168865889127833758

⚡ Bolt: Optimize VM instruction fetch by removing redundant array lookup

Author: Tcode-Motion

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2026-08-19 - Removed redundant instruction array lookup in VM loop
+**Learning:** The inner loop of the VM interpreter (`execute_loop`) had an expensive, redundant deep indexing operation to fetch `inst_operands` which was already available on the `inst` reference. Re-fetching it via `self.module.functions[...].chunk.instructions[...].operands` adds unnecessary bounds checks and pointer chasing in the hottest part of the VM.
+**Action:** Always prefer using existing local references over redundant deep lookups, especially in tight loops like an interpreter fetch-decode-execute loop.

runtime/vm/src/executor.rs

@@ -28,12 +28,7 @@ impl VM {
             let ip = frame.ip;
             frame.ip += 1;
 
-            let inst_operands = self.module.functions
-                [self.frames.last().unwrap().function_idx as usize]
-                .chunk
-                .instructions[ip]
-                .operands
-                .as_slice();
+            let inst_operands = inst.operands.as_slice();
 
             // Diagnostics and tracing
             self.profiler.record_instruction();