Commit Graph

8 Commits

Author SHA1 Message Date
nils
8e6c5ad696 Fix typo in UnreachableProp 2022-08-23 08:18:18 +02:00
Nilstrieb
bc79557311 Enable UnreachablePropagation under mir-opt-level >= 2
It was disabled because of pathological behaviour of LLVM in some
benchmarks. As of #77680, this has been fixed. The problem there was
that it caused pessimizations in some cases. These have now been fixed
as well.
2022-08-21 21:15:28 +02:00
Nilstrieb
eafab66096 UnreachableProp: Preserve unreachable branches for multiple targets
Before, UnreachablePropagation removed all unreachable branches.
This was a pessimization, as it removed information about
reachability that was used later in the optimization pipeline.

For example, this code
```rust
pub enum Two { A, B }
pub fn identity(x: Two) -> Two {
    match x {
        Two::A => Two::A,
        Two::B => Two::B,
    }
}
```

basically has `switchInt() -> [0: 0, 1: 1, otherwise: unreachable]` for the match.
This allows it to be transformed into a simple `x`. If we remove the
unreachable branch, the transformation becomes illegal.
2022-08-21 21:15:28 +02:00
Tomasz Miąsko
000b36c505 Remove deprecated LLVM-style inline assembly 2022-01-12 18:51:31 +01:00
Scott McMurray
a124924061 Remove in_band_lifetimes from rustc_mir_transform
This one is a heavy `'tcx` user.

Two interesting ones:

This one had the `'tcx` declared on the function, despite the trait taking a `'tcx`:
```diff
-impl Visitor<'_> for UsedLocals {
+impl<'tcx> Visitor<'tcx> for UsedLocals {
     fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
```

This one use in-band for one, and underscore for the other:
```diff
-pub fn remove_dead_blocks(tcx: TyCtxt<'tcx>, body: &mut Body<'_>) {
+pub fn remove_dead_blocks<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
```
2021-12-07 21:04:40 -08:00
Dylan MacKenzie
fd18b45e11 Update passes with new interface 2021-12-02 17:31:38 -08:00
Matthias Krüger
0a5640b55f use matches!() macro in more places 2021-11-06 16:13:14 +01:00
Camille GILLOT
bba4be681d Move rustc_mir::transform to rustc_mir_transform. 2021-09-07 00:43:14 +02:00