bors 2e0edc0f28 Auto merge of #75119 - simonvandel:early-otherwise, r=oli-obk ... New MIR optimization pass to reduce branches on match of tuples of enums Fixes #68867 by adding a new pass that turns something like ```rust let x: Option<()>; let y: Option<()>; match (x,y) { (Some(_), Some(_)) => {0}, _ => {1} } ``` into something like ```rust let x: Option<()>; let y: Option<()>; let discriminant_x = // get discriminant of x let discriminant_y = // get discriminant of x if discriminant_x != discriminant_y {1} else {0} ``` The opt-diffs still have the old basic blocks like ``` bb3: { _8 = discriminant((*(_4.1: &ViewportPercentageLength))); // scope 0 at $DIR/early-otherwise-branch-68867.rs:21:21: 21:30 switchInt(move _8) -> [1_isize: bb7, otherwise: bb2]; // scope 0 at $DIR/early-otherwise-branch-68867.rs:21:21: 21:30 } bb4: { _9 = discriminant((*(_4.1: &ViewportPercentageLength))); // scope 0 at $DIR/early-otherwise-branch-68867.rs:22:23: 22:34 switchInt(move _9) -> [2_isize: bb8, otherwise: bb2]; // scope 0 at $DIR/early-otherwise-branch-68867.rs:22:23: 22:34 } bb5: { _10 = discriminant((*(_4.1: &ViewportPercentageLength))); // scope 0 at $DIR/early-otherwise-branch-68867.rs:23:23: 23:34 switchInt(move _10) -> [3_isize: bb9, otherwise: bb2]; // scope 0 at $DIR/early-otherwise-branch-68867.rs:23:23: 23:34 } ``` These do get removed on later passes. I'm not sure if I should include those passes in the test to make it clear?		2020-09-20 17:54:44 +00:00
..
src	Auto merge of #75119 - simonvandel:early-otherwise, r=oli-obk	2020-09-20 17:54:44 +00:00
Cargo.toml	update the version of itertools and parking_lot	2020-09-12 08:26:53 +02:00