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mir: Run copy propagation on constant mir

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Now that miri is merged, this seems to Just Work!
This commit is contained in:
Nick Fitzgerald 2018-04-27 06:27:25 -07:00
parent ada45fd49a
commit 937f9bac5d
1 changed files with 1 additions and 20 deletions
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21
src/librustc_mir/transform/copy_prop.rs
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@ -29,7 +29,6 @@
//! (non-mutating) use of `SRC`. These restrictions are conservative and may be relaxed in the
//! future.
use rustc::hir;
use rustc::mir::{Constant, Local, LocalKind, Location, Place, Mir, Operand, Rvalue, StatementKind};
use rustc::mir::visit::MutVisitor;
use rustc::ty::TyCtxt;
@ -41,26 +40,8 @@ pub struct CopyPropagation;
impl MirPass for CopyPropagation {
fn run_pass<'a, 'tcx>(&self,
tcx: TyCtxt<'a, 'tcx, 'tcx>,
source: MirSource,
_source: MirSource,
mir: &mut Mir<'tcx>) {
// Don't run on constant MIR, because trans might not be able to
// evaluate the modified MIR.
// FIXME(eddyb) Remove check after miri is merged.
let id = tcx.hir.as_local_node_id(source.def_id).unwrap();
match (tcx.hir.body_owner_kind(id), source.promoted) {
(_, Some(_)) |
(hir::BodyOwnerKind::Const, _) |
(hir::BodyOwnerKind::Static(_), _) => return,
(hir::BodyOwnerKind::Fn, _) => {
if tcx.is_const_fn(source.def_id) {
// Don't run on const functions, as, again, trans might not be able to evaluate
// the optimized IR.
return
}
}
}
// We only run when the MIR optimization level is > 1.
// This avoids a slow pass, and messing up debug info.
if tcx.sess.opts.debugging_opts.mir_opt_level <= 1 {