Start on compiler optimizations

_drafts/compiler-optimizations.md

@@ -4,4 +4,36 @@ title: "Compiler Optimizations: What It's Done Lately"
 description: "A lot. The answer is a lot."
 category: 
 tags: [rust, understanding-allocations]
----
+---
+
+Up to this point, we've been discussing memory usage in the Rust language
+by focusing on simple rules that are mostly right for small chunks of code.
+We've spent time showing how those rules work themselves out in practice,
+and become familiar with reading the assembly code needed to see each memory
+type (global, stack, heap) in action.
+
+But throughout the content so far, we've put a handicap on the code.
+In the name of consistent and understandable results, we've asked the
+compiler to pretty please leave the training wheels on. Now is the time
+where we throw out all the rules and take the kid gloves off. As it turns out,
+both the Rust compiler and the LLVM optimizers are incredibly sophisticated,
+and we'll step back and let them do their job.
+
+We'll still be looking at assembly code to understand what's going on,
+but it's important to mention again: **please use automated tools like
+[qadapt](https://crates.io/crates/qadapt) to double-check memory behavior**. 
+It's far too easy to mis-read assembly in large code sections, you should
+always have an automated tool verify behavior if you care about memory usage.
+Similar to ["What Has My Compiler Done For Me Lately?"](https://www.youtube.com/watch?v=bSkpMdDe4g4),
+we're just focused on interesting things the Rust language can do.
+
+The guiding principal as we move forward is this: *optimizing compilers
+won't produce worse assembly than we started with.* There won't be any
+situations where stack allocations get moved to heap allocations.
+There will, however,  be an opera of optimization.
+
+# The Case of the Disappearing Box
+
+# Vectors of Usual Size
+
+# Dr. Array or: How I Learned to Love the Optimizer