Make instance an option in CostChecker.

This commit is contained in:
Camille GILLOT 2023-02-03 16:47:11 +00:00
parent 8252ad02c4
commit 3cb0c2e385
2 changed files with 15 additions and 10 deletions

View File

@ -1,6 +1,6 @@
use rustc_middle::mir::visit::*;
use rustc_middle::mir::*;
use rustc_middle::ty::{self, ParamEnv, TyCtxt};
use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
const INSTR_COST: usize = 5;
const CALL_PENALTY: usize = 25;
@ -14,14 +14,14 @@ pub(crate) struct CostChecker<'b, 'tcx> {
param_env: ParamEnv<'tcx>,
cost: usize,
callee_body: &'b Body<'tcx>,
instance: ty::Instance<'tcx>,
instance: Option<ty::Instance<'tcx>>,
}
impl<'b, 'tcx> CostChecker<'b, 'tcx> {
pub fn new(
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>,
instance: ty::Instance<'tcx>,
instance: Option<ty::Instance<'tcx>>,
callee_body: &'b Body<'tcx>,
) -> CostChecker<'b, 'tcx> {
CostChecker { tcx, param_env, callee_body, instance, cost: 0 }
@ -30,6 +30,14 @@ impl<'b, 'tcx> CostChecker<'b, 'tcx> {
pub fn cost(&self) -> usize {
self.cost
}
fn instantiate_ty(&self, v: Ty<'tcx>) -> Ty<'tcx> {
if let Some(instance) = self.instance {
instance.instantiate_mir(self.tcx, ty::EarlyBinder::bind(&v))
} else {
v
}
}
}
impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
@ -49,10 +57,7 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
match terminator.kind {
TerminatorKind::Drop { ref place, unwind, .. } => {
// If the place doesn't actually need dropping, treat it like a regular goto.
let ty = self.instance.instantiate_mir(
tcx,
ty::EarlyBinder::bind(&place.ty(self.callee_body, tcx).ty),
);
let ty = self.instantiate_ty(place.ty(self.callee_body, tcx).ty);
if ty.needs_drop(tcx, self.param_env) {
self.cost += CALL_PENALTY;
if let UnwindAction::Cleanup(_) = unwind {
@ -63,8 +68,7 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
}
}
TerminatorKind::Call { func: Operand::Constant(ref f), unwind, .. } => {
let fn_ty =
self.instance.instantiate_mir(tcx, ty::EarlyBinder::bind(&f.const_.ty()));
let fn_ty = self.instantiate_ty(f.const_.ty());
self.cost += if let ty::FnDef(def_id, _) = *fn_ty.kind() && tcx.is_intrinsic(def_id) {
// Don't give intrinsics the extra penalty for calls
INSTR_COST

View File

@ -475,7 +475,8 @@ impl<'tcx> Inliner<'tcx> {
// FIXME: Give a bonus to functions with only a single caller
let mut checker = CostChecker::new(self.tcx, self.param_env, callsite.callee, callee_body);
let mut checker =
CostChecker::new(self.tcx, self.param_env, Some(callsite.callee), callee_body);
// Traverse the MIR manually so we can account for the effects of inlining on the CFG.
let mut work_list = vec![START_BLOCK];