rustc: slightly optimize make_mono_id to not clone lots of vectors.

Author: eddyb

src/librustc/middle/trans/common.rs

@@ -690,6 +690,7 @@ pub fn is_null(val: ValueRef) -> bool {
 #[deriving(Eq, TotalEq, Hash)]
 pub struct MonoParamId {
     pub subst: ty::t,
+    // Do we really need the vtables to be hashed? Isn't the type enough?
     pub vtables: Vec<mono_id>
 }
 

src/librustc/middle/trans/meth.rs

@@ -427,29 +427,6 @@ pub fn trans_trait_callee_from_llval<'a>(bcx: &'a Block<'a>,
     };
 }
 
-pub fn vtable_id(ccx: &CrateContext,
-                 origin: &typeck::vtable_origin)
-              -> mono_id {
-    match origin {
-        &typeck::vtable_static(impl_id, ref substs, ref sub_vtables) => {
-            let psubsts = param_substs {
-                tys: (*substs).clone(),
-                vtables: Some(sub_vtables.clone()),
-                self_ty: None,
-                self_vtables: None
-            };
-
-            monomorphize::make_mono_id(
-                ccx,
-                impl_id,
-                &psubsts)
-        }
-
-        // can't this be checked at the callee?
-        _ => fail!("vtable_id")
-    }
-}
-
 /// Creates a returns a dynamic vtable for the given type and vtable origin.
 /// This is used only for objects.
 fn get_vtable(bcx: &Block,
@@ -460,7 +437,7 @@ fn get_vtable(bcx: &Block,
     let _icx = push_ctxt("meth::get_vtable");
 
     // Check the cache.
-    let hash_id = (self_ty, vtable_id(ccx, origins.get(0)));
+    let hash_id = (self_ty, monomorphize::make_vtable_id(ccx, origins.get(0)));
     match ccx.vtables.borrow().find(&hash_id) {
         Some(&val) => { return val }
         None => { }

src/librustc/middle/trans/monomorphize.rs

@@ -47,21 +47,51 @@ pub fn monomorphic_fn(ccx: &CrateContext,
            self_vtables.repr(ccx.tcx()),
            ref_id);
 
-    assert!(real_substs.tps.iter().all(|t| !ty::type_needs_infer(*t)));
+    assert!(real_substs.tps.iter().all(|t| {
+        !ty::type_needs_infer(*t) && !ty::type_has_params(*t)
+    }));
+
     let _icx = push_ctxt("monomorphic_fn");
 
+    let substs_iter = real_substs.self_ty.iter().chain(real_substs.tps.iter());
+    let param_ids: Vec<MonoParamId> = match vtables {
+        Some(ref vts) => {
+            debug!("make_mono_id vtables={} psubsts={}",
+                   vts.repr(ccx.tcx()), real_substs.tps.repr(ccx.tcx()));
+            let vts_iter = self_vtables.iter().chain(vts.iter());
+            vts_iter.zip(substs_iter).map(|(vtable, subst)| MonoParamId {
+                subst: *subst,
+                // Do we really need the vtables to be hashed? Isn't the type enough?
+                vtables: vtable.iter().map(|vt| make_vtable_id(ccx, vt)).collect()
+            }).collect()
+        }
+        None => substs_iter.map(|subst| MonoParamId {
+            subst: *subst,
+            vtables: Vec::new()
+        }).collect()
+    };
+
+    let hash_id = @mono_id_ {
+        def: fn_id,
+        params: param_ids
+    };
+
+    match ccx.monomorphized.borrow().find(&hash_id) {
+        Some(&val) => {
+            debug!("leaving monomorphic fn {}",
+            ty::item_path_str(ccx.tcx(), fn_id));
+            return (val, false);
+        }
+        None => ()
+    }
+
     let psubsts = @param_substs {
         tys: real_substs.tps.clone(),
         vtables: vtables,
         self_ty: real_substs.self_ty.clone(),
         self_vtables: self_vtables
     };
 
-    for s in real_substs.tps.iter() { assert!(!ty::type_has_params(*s)); }
-    for s in psubsts.tys.iter() { assert!(!ty::type_has_params(*s)); }
-
-    let hash_id = make_mono_id(ccx, fn_id, &*psubsts);
-
     debug!("monomorphic_fn(\
             fn_id={}, \
             psubsts={}, \
@@ -70,15 +100,6 @@ pub fn monomorphic_fn(ccx: &CrateContext,
            psubsts.repr(ccx.tcx()),
            hash_id);
 
-    match ccx.monomorphized.borrow().find(&hash_id) {
-        Some(&val) => {
-            debug!("leaving monomorphic fn {}",
-            ty::item_path_str(ccx.tcx(), fn_id));
-            return (val, false);
-        }
-        None => ()
-    }
-
     let tpt = ty::lookup_item_type(ccx.tcx(), fn_id);
     let llitem_ty = tpt.ty;
 
@@ -117,8 +138,8 @@ pub fn monomorphic_fn(ccx: &CrateContext,
 
     debug!("monomorphic_fn about to subst into {}", llitem_ty.repr(ccx.tcx()));
     let mono_ty = match is_static_provided {
-        None => ty::subst_tps(ccx.tcx(), psubsts.tys.as_slice(),
-                              psubsts.self_ty, llitem_ty),
+        None => ty::subst_tps(ccx.tcx(), real_substs.tps.as_slice(),
+                              real_substs.self_ty, llitem_ty),
         Some(num_method_ty_params) => {
             // Static default methods are a little unfortunate, in
             // that the "internal" and "external" type of them differ.
@@ -134,9 +155,9 @@ pub fn monomorphic_fn(ccx: &CrateContext,
             // stick a substitution for the self type in.
             // This is a bit unfortunate.
 
-            let idx = psubsts.tys.len() - num_method_ty_params;
-            let substs = psubsts.tys.slice(0, idx) +
-                &[psubsts.self_ty.unwrap()] + psubsts.tys.tailn(idx);
+            let idx = real_substs.tps.len() - num_method_ty_params;
+            let substs = real_substs.tps.slice(0, idx) +
+            &[real_substs.self_ty.unwrap()] + real_substs.tps.tailn(idx);
             debug!("static default: changed substitution to {}",
                    substs.repr(ccx.tcx()));
 
@@ -284,28 +305,25 @@ pub fn monomorphic_fn(ccx: &CrateContext,
     (lldecl, false)
 }
 
-pub fn make_mono_id(ccx: &CrateContext,
-                    item: ast::DefId,
-                    substs: &param_substs) -> mono_id {
-    let substs_iter = substs.self_ty.iter().chain(substs.tys.iter());
-    let param_ids: Vec<MonoParamId> = match substs.vtables {
-        Some(ref vts) => {
-            debug!("make_mono_id vtables={} substs={}",
-                   vts.repr(ccx.tcx()), substs.tys.repr(ccx.tcx()));
-            let vts_iter = substs.self_vtables.iter().chain(vts.iter());
-            vts_iter.zip(substs_iter).map(|(vtable, subst)| MonoParamId {
-                subst: *subst,
-                vtables: vtable.iter().map(|vt| meth::vtable_id(ccx, vt)).collect()
-            }).collect()
+pub fn make_vtable_id(ccx: &CrateContext,
+                      origin: &typeck::vtable_origin)
+                      -> mono_id {
+    match origin {
+        &typeck::vtable_static(impl_id, ref substs, ref sub_vtables) => {
+            let param_ids = sub_vtables.iter().zip(substs.iter()).map(|(vtable, subst)| {
+                MonoParamId {
+                    subst: *subst,
+                    vtables: vtable.iter().map(|vt| make_vtable_id(ccx, vt)).collect()
+                }
+            }).collect();
+
+            @mono_id_ {
+                def: impl_id,
+                params: param_ids
+            }
         }
-        None => substs_iter.map(|subst| MonoParamId {
-            subst: *subst,
-            vtables: Vec::new()
-        }).collect()
-    };
 
-    @mono_id_ {
-        def: item,
-        params: param_ids
+        // can't this be checked at the callee?
+        _ => fail!("make_vtable_id needs vtable_static")
     }
 }