Some Cava optimization

• Optimize Cava's CPU schedule.
• Add fork-fusion pass for fusing unrelated but adjacent fork-joins.
• Add intrinsic functions to math expressions.
• Add print pass for debugging schedules.
• Avoid some edges in dot output to help little xdot out.
• TODO: need more relaxed bounds for forkify to parallelize demosaic.

juno_samples/cava/src/cava.jn

@@ -207,8 +207,8 @@ fn cava<r, c, num_ctrl_pts : usize>(
   coefs : f32[4, CHAN],
   tonemap : f32[256, CHAN],
 ) -> u8[CHAN, r, c] {
-  let scaled = scale::<r, c>(input);
-  let demosc = demosaic::<r, c>(scaled);
+  @fuse1 let scaled = scale::<r, c>(input);
+  @fuse1 let demosc = demosaic::<r, c>(scaled);
   let denosd = denoise::<r, c>(demosc);
   let transf = transform::<r, c>(denosd, TsTw);
   let gamutd = gamut::<r, c, num_ctrl_pts>(transf, ctrl_pts, weights, coefs);