Rollup merge of #68018 - petrochenkov:nosoft, r=Centril

[rust.git] / src / librustc_mir / monomorphize / collector.rs

diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index 231ee792918b37a8cdece151142408dcbfa23718..511a5fbc617951e94343a1cb6bc5ac8ba4cfab77 100644 (file)
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -176,9 +176,6 @@
 
 use crate::monomorphize;
 
-use rustc::hir;
-use rustc::hir::def_id::{DefId, DefIdMap, LOCAL_CRATE};
-use rustc::hir::itemlikevisit::ItemLikeVisitor;
 use rustc::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc::middle::lang_items::{ExchangeMallocFnLangItem, StartFnLangItem};
 use rustc::mir::interpret::{AllocId, ConstValue};
@@ -193,8 +190,11 @@
 use rustc::ty::{self, GenericParamDefKind, Instance, Ty, TyCtxt, TypeFoldable};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::{par_iter, MTLock, MTRef, ParallelIterator};
+use rustc_hir as hir;
+use rustc_hir::def_id::{DefId, DefIdMap, LOCAL_CRATE};
+use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_index::bit_set::GrowableBitSet;
-
+use smallvec::SmallVec;
 use std::iter;
 
 #[derive(PartialEq)]
@@ -227,12 +227,7 @@ fn new() -> InliningMap<'tcx> {
         }
     }
 
-    fn record_accesses<I>(&mut self, source: MonoItem<'tcx>, new_targets: I)
-    where
-        I: Iterator<Item = (MonoItem<'tcx>, bool)> + ExactSizeIterator,
-    {
-        assert!(!self.index.contains_key(&source));
-
+    fn record_accesses(&mut self, source: MonoItem<'tcx>, new_targets: &[(MonoItem<'tcx>, bool)]) {
         let start_index = self.targets.len();
         let new_items_count = new_targets.len();
         let new_items_count_total = new_items_count + self.targets.len();
@@ -240,15 +235,15 @@ fn record_accesses<I>(&mut self, source: MonoItem<'tcx>, new_targets: I)
         self.targets.reserve(new_items_count);
         self.inlines.ensure(new_items_count_total);
 
-        for (i, (target, inline)) in new_targets.enumerate() {
-            self.targets.push(target);
-            if inline {
+        for (i, (target, inline)) in new_targets.iter().enumerate() {
+            self.targets.push(*target);
+            if *inline {
                 self.inlines.insert(i + start_index);
             }
         }
 
         let end_index = self.targets.len();
-        self.index.insert(source, (start_index, end_index));
+        assert!(self.index.insert(source, (start_index, end_index)).is_none());
     }
 
     // Internally iterate over all items referenced by `source` which will be
@@ -283,10 +278,8 @@ pub fn collect_crate_mono_items(
 ) -> (FxHashSet<MonoItem<'_>>, InliningMap<'_>) {
     let _prof_timer = tcx.prof.generic_activity("monomorphization_collector");
 
-    let roots = tcx.sess.time("collecting roots", || {
-        let _prof_timer = tcx.prof.generic_activity("monomorphization_collector_root_collections");
-        collect_roots(tcx, mode)
-    });
+    let roots =
+        tcx.sess.time("monomorphization_collector_root_collections", || collect_roots(tcx, mode));
 
     debug!("building mono item graph, beginning at roots");
 
@@ -297,7 +290,7 @@ pub fn collect_crate_mono_items(
         let visited: MTRef<'_, _> = &mut visited;
         let inlining_map: MTRef<'_, _> = &mut inlining_map;
 
-        tcx.sess.time("collecting mono items", || {
+        tcx.sess.time("monomorphization_collector_graph_walk", || {
             par_iter(roots).for_each(|root| {
                 let mut recursion_depths = DefIdMap::default();
                 collect_items_rec(tcx, root, visited, &mut recursion_depths, inlining_map);
@@ -358,7 +351,7 @@ fn collect_items_rec<'tcx>(
             // Sanity check whether this ended up being collected accidentally
             debug_assert!(should_monomorphize_locally(tcx, &instance));
 
-            let ty = instance.ty(tcx);
+            let ty = instance.monomorphic_ty(tcx);
             visit_drop_use(tcx, ty, true, &mut neighbors);
 
             recursion_depth_reset = None;
@@ -405,10 +398,15 @@ fn record_accesses<'tcx>(
         mono_item.instantiation_mode(tcx) == InstantiationMode::LocalCopy
     };
 
-    let accesses =
-        callees.into_iter().map(|mono_item| (*mono_item, is_inlining_candidate(mono_item)));
+    // We collect this into a `SmallVec` to avoid calling `is_inlining_candidate` in the lock.
+    // FIXME: Call `is_inlining_candidate` when pushing to `neighbors` in `collect_items_rec`
+    // instead to avoid creating this `SmallVec`.
+    let accesses: SmallVec<[_; 128]> = callees
+        .into_iter()
+        .map(|mono_item| (*mono_item, is_inlining_candidate(mono_item)))
+        .collect();
 
-    inlining_map.lock_mut().record_accesses(caller, accesses);
+    inlining_map.lock_mut().record_accesses(caller, &accesses);
 }
 
 fn check_recursion_limit<'tcx>(
@@ -1002,7 +1000,8 @@ fn visit_item(&mut self, item: &'v hir::Item<'v>) {
                             def_id_to_string(self.tcx, def_id)
                         );
 
-                        let ty = Instance::new(def_id, InternalSubsts::empty()).ty(self.tcx);
+                        let ty =
+                            Instance::new(def_id, InternalSubsts::empty()).monomorphic_ty(self.tcx);
                         visit_drop_use(self.tcx, ty, true, self.output);
                     }
                 }