Rename the 'cretonne' crate to 'cretonne-codegen'.

This fixes the next part of #287.

lib/codegen/src/isa/x86/settings.rs

@@ -0,0 +1,52 @@
+//! x86 Settings.
+
+use settings::{self, detail, Builder};
+use std::fmt;
+
+// Include code generated by `lib/codegen/meta/gen_settings.py`. This file contains a public
+// `Flags` struct with an impl for all of the settings defined in
+// `lib/codegen/meta/isa/x86/settings.py`.
+include!(concat!(env!("OUT_DIR"), "/settings-x86.rs"));
+
+#[cfg(test)]
+mod tests {
+    use super::{builder, Flags};
+    use settings::{self, Configurable};
+
+    #[test]
+    fn presets() {
+        let shared = settings::Flags::new(&settings::builder());
+
+        // Nehalem has SSE4.1 but not BMI1.
+        let mut b1 = builder();
+        b1.enable("nehalem").unwrap();
+        let f1 = Flags::new(&shared, &b1);
+        assert_eq!(f1.has_sse41(), true);
+        assert_eq!(f1.has_bmi1(), false);
+
+        let mut b2 = builder();
+        b2.enable("haswell").unwrap();
+        let f2 = Flags::new(&shared, &b2);
+        assert_eq!(f2.has_sse41(), true);
+        assert_eq!(f2.has_bmi1(), true);
+    }
+    #[test]
+    fn display_presets() {
+        // Spot check that the flags Display impl does not cause a panic
+        let shared = settings::Flags::new(&settings::builder());
+
+        let b1 = builder();
+        let f1 = Flags::new(&shared, &b1);
+        let _ = format!("{}", f1);
+
+        let mut b2 = builder();
+        b2.enable("nehalem").unwrap();
+        let f2 = Flags::new(&shared, &b1);
+        let _ = format!("{}", f2);
+
+        let mut b3 = builder();
+        b3.enable("haswell").unwrap();
+        let f3 = Flags::new(&shared, &b1);
+        let _ = format!("{}", f3);
+    }
+}