diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/simplify_branches.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/simplify_branches.rs | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/compiler/rustc_mir_transform/src/simplify_branches.rs b/compiler/rustc_mir_transform/src/simplify_branches.rs index 886f4d6e509..ed94a058ec6 100644 --- a/compiler/rustc_mir_transform/src/simplify_branches.rs +++ b/compiler/rustc_mir_transform/src/simplify_branches.rs @@ -2,6 +2,8 @@ use rustc_middle::mir::*; use rustc_middle::ty::TyCtxt; use tracing::trace; +use crate::patch::MirPatch; + pub(super) enum SimplifyConstCondition { AfterConstProp, Final, @@ -19,8 +21,10 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyConstCondition { fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { trace!("Running SimplifyConstCondition on {:?}", body.source); let typing_env = body.typing_env(tcx); - 'blocks: for block in body.basic_blocks_mut() { - for stmt in block.statements.iter_mut() { + let mut patch = MirPatch::new(body); + + 'blocks: for (bb, block) in body.basic_blocks.iter_enumerated() { + for (statement_index, stmt) in block.statements.iter().enumerate() { // Simplify `assume` of a known value: either a NOP or unreachable. if let StatementKind::Intrinsic(box ref intrinsic) = stmt.kind && let NonDivergingIntrinsic::Assume(discr) = intrinsic @@ -28,17 +32,16 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyConstCondition { && let Some(constant) = c.const_.try_eval_bool(tcx, typing_env) { if constant { - stmt.make_nop(); + patch.nop_statement(Location { block: bb, statement_index }); } else { - block.statements.clear(); - block.terminator_mut().kind = TerminatorKind::Unreachable; + patch.patch_terminator(bb, TerminatorKind::Unreachable); continue 'blocks; } } } - let terminator = block.terminator_mut(); - terminator.kind = match terminator.kind { + let terminator = block.terminator(); + let terminator = match terminator.kind { TerminatorKind::SwitchInt { discr: Operand::Constant(ref c), ref targets, .. } => { @@ -58,7 +61,9 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyConstCondition { }, _ => continue, }; + patch.patch_terminator(bb, terminator); } + patch.apply(body); } fn is_required(&self) -> bool { |