bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Remove duplicate switch targets

Browse source
This commit is contained in:
Ben Kimock 2023-02-24 16:32:59 -05:00
parent 41eda69516
commit 2a628bd99c
3 changed files with 63 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

16
compiler/rustc_mir_transform/src/instcombine.rs
View file

@ -4,7 +4,7 @@ use crate::MirPass;
use rustc_hir::Mutability;
use rustc_middle::mir::{
BinOp, Body, Constant, ConstantKind, LocalDecls, Operand, Place, ProjectionElem, Rvalue,
SourceInfo, Statement, StatementKind, Terminator, TerminatorKind, UnOp,
SourceInfo, Statement, StatementKind, SwitchTargets, Terminator, TerminatorKind, UnOp,
};
use rustc_middle::ty::layout::ValidityRequirement;
use rustc_middle::ty::{self, ParamEnv, SubstsRef, Ty, TyCtxt};
@ -44,6 +44,7 @@ impl<'tcx> MirPass<'tcx> for InstCombine {
&mut block.terminator.as_mut().unwrap(),
&mut block.statements,
);
ctx.combine_duplicate_switch_targets(&mut block.terminator.as_mut().unwrap());
}
}
}
@ -217,6 +218,19 @@ impl<'tcx> InstCombineContext<'tcx, '_> {
terminator.kind = TerminatorKind::Goto { target: destination_block };
}
fn combine_duplicate_switch_targets(&self, terminator: &mut Terminator<'tcx>) {
let TerminatorKind::SwitchInt { targets, .. } = &mut terminator.kind
else { return };
let otherwise = targets.otherwise();
if targets.iter().any(|t| t.1 == otherwise) {
*targets = SwitchTargets::new(
targets.iter().filter(|t| t.1 != otherwise),
targets.otherwise(),
);
}
}
fn combine_intrinsic_assert(
&self,
terminator: &mut Terminator<'tcx>,