optimize release binary

.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+rustflags = ["-C", "target-cpu=native"]

Cargo.toml

@@ -6,6 +6,9 @@ edition = "2018"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[profile.release]
+lto = true
+
 [dependencies]
 toml = "0.5"
 serde = { version = "1.0", features = ["derive"] }

README.md

@@ -11,6 +11,10 @@ Then run `cargo build --release`
 .exe/elf is inside target/release/
 You can also run `cargo run --release` instead to directly build & execute the resulting binary.
 
+### Build optimization
+
+The default release build is heavily optimized, using native target-cpu instructions and LTO. You can disable LTO in the Cargo.toml under `[profile.release]`, which can reduce the build time by a lot. And you can disable the target-cpu flags in `.cargo/config.toml`.
+
 ## Starting
 Setup your credentials inside .credentials.toml by copying credentials.example.toml