Auto merge of #147138 - jackh726:split-canonical-bound, r=lcnr

Split Bound index into Canonical and Bound

See [#t-types/trait-system-refactor > perf `async-closures/post-mono-higher-ranked-hang.rs`](https://rust-lang.zulipchat.com/#narrow/channel/364551-t-types.2Ftrait-system-refactor/topic/perf.20.60async-closures.2Fpost-mono-higher-ranked-hang.2Ers.60/with/541535613) for context

Things compile and tests pass, but not sure if this actually solves the perf issue (edit: it does). Opening up this to do a perf (and maybe crater) run.

r? lcnr

2 files changed, 13 insertions, 9 deletions

diff --git a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
index 9841fafc82c..129b26d8ff0 100644
--- a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
+++ b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
@@ -181,21 +181,25 @@ fn remap_gat_vars_and_recurse_into_nested_projections<'tcx>(
     for (param, var) in std::iter::zip(&generics.own_params, gat_vars) {
         let existing = match var.kind() {
             ty::GenericArgKind::Lifetime(re) => {
-                if let ty::RegionKind::ReBound(ty::INNERMOST, bv) = re.kind() {
+                if let ty::RegionKind::ReBound(ty::BoundVarIndexKind::Bound(ty::INNERMOST), bv) =
+                    re.kind()
+                {
                     mapping.insert(bv.var, tcx.mk_param_from_def(param))
                 } else {
                     return None;
                 }
             }
             ty::GenericArgKind::Type(ty) => {
-                if let ty::Bound(ty::INNERMOST, bv) = *ty.kind() {
+                if let ty::Bound(ty::BoundVarIndexKind::Bound(ty::INNERMOST), bv) = *ty.kind() {
                     mapping.insert(bv.var, tcx.mk_param_from_def(param))
                 } else {
                     return None;
                 }
             }
             ty::GenericArgKind::Const(ct) => {
-                if let ty::ConstKind::Bound(ty::INNERMOST, bv) = ct.kind() {
+                if let ty::ConstKind::Bound(ty::BoundVarIndexKind::Bound(ty::INNERMOST), bv) =
+                    ct.kind()
+                {
                     mapping.insert(bv.var, tcx.mk_param_from_def(param))
                 } else {
                     return None;
@@ -260,7 +264,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for MapAndCompressBoundVars<'tcx> {
             return ty;
         }
 
-        if let ty::Bound(binder, old_bound) = *ty.kind()
+        if let ty::Bound(ty::BoundVarIndexKind::Bound(binder), old_bound) = *ty.kind()
             && self.binder == binder
         {
             let mapped = if let Some(mapped) = self.mapping.get(&old_bound.var) {
@@ -286,7 +290,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for MapAndCompressBoundVars<'tcx> {
     }
 
     fn fold_region(&mut self, re: ty::Region<'tcx>) -> ty::Region<'tcx> {
-        if let ty::ReBound(binder, old_bound) = re.kind()
+        if let ty::ReBound(ty::BoundVarIndexKind::Bound(binder), old_bound) = re.kind()
             && self.binder == binder
         {
             let mapped = if let Some(mapped) = self.mapping.get(&old_bound.var) {
@@ -314,7 +318,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for MapAndCompressBoundVars<'tcx> {
             return ct;
         }
 
-        if let ty::ConstKind::Bound(binder, old_bound) = ct.kind()
+        if let ty::ConstKind::Bound(ty::BoundVarIndexKind::Bound(binder), old_bound) = ct.kind()
             && self.binder == binder
         {
             let mapped = if let Some(mapped) = self.mapping.get(&old_bound.var) {
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
index 8682fdc5494..7accab8df87 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
@@ -921,7 +921,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for GenericParamAndBoundVarCollector<'_, 't
             ty::Param(param) => {
                 self.params.insert(param.index);
             }
-            ty::Bound(db, bt) if *db >= self.depth => {
+            ty::Bound(ty::BoundVarIndexKind::Bound(db), bt) if *db >= self.depth => {
                 self.vars.insert(match bt.kind {
                     ty::BoundTyKind::Param(def_id) => def_id,
                     ty::BoundTyKind::Anon => {
@@ -944,7 +944,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for GenericParamAndBoundVarCollector<'_, 't
             ty::ReEarlyParam(param) => {
                 self.params.insert(param.index);
             }
-            ty::ReBound(db, br) if db >= self.depth => {
+            ty::ReBound(ty::BoundVarIndexKind::Bound(db), br) if db >= self.depth => {
                 self.vars.insert(match br.kind {
                     ty::BoundRegionKind::Named(def_id) => def_id,
                     ty::BoundRegionKind::Anon | ty::BoundRegionKind::ClosureEnv => {
@@ -967,7 +967,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for GenericParamAndBoundVarCollector<'_, 't
             ty::ConstKind::Param(param) => {
                 self.params.insert(param.index);
             }
-            ty::ConstKind::Bound(db, _) if db >= self.depth => {
+            ty::ConstKind::Bound(ty::BoundVarIndexKind::Bound(db), _) if db >= self.depth => {
                 let guar = self.cx.dcx().delayed_bug("unexpected escaping late-bound const var");
                 return ControlFlow::Break(guar);
             }