From 3ee630bbee1e35933b6296e4749fcdd882a81f90 Mon Sep 17 00:00:00 2001
From: Marijn Haverbeke <marijnh@gmail.com>
Date: Thu, 22 Dec 2011 14:24:36 +0100
Subject: [PATCH] Add ty::new_ty_hash, clean up comparing of ty::t's

---
 src/comp/metadata/encoder.rs |  2 +-
 src/comp/middle/debuginfo.rs |  7 +++--
 src/comp/middle/trans.rs     | 19 +++++---------
 src/comp/middle/ty.rs        | 51 ++++++++++++++----------------------
 4 files changed, 30 insertions(+), 49 deletions(-)

diff --git a/src/comp/metadata/encoder.rs b/src/comp/metadata/encoder.rs
index 1e844d39bca..169a1354f98 100644
--- a/src/comp/metadata/encoder.rs
+++ b/src/comp/metadata/encoder.rs
@@ -653,7 +653,7 @@ fn encode_hash(ebml_w: ebml::writer, hash: str) {
 
 fn encode_metadata(cx: @crate_ctxt, crate: @crate) -> str {
 
-    let abbrevs = map::mk_hashmap(ty::hash_ty, ty::eq_ty);
+    let abbrevs = ty::new_ty_hash();
     let ecx = @{ccx: cx, type_abbrevs: abbrevs};
 
     let string_w = io::string_writer();
diff --git a/src/comp/middle/debuginfo.rs b/src/comp/middle/debuginfo.rs
index 96868cd0bf0..19b1578b29a 100644
--- a/src/comp/middle/debuginfo.rs
+++ b/src/comp/middle/debuginfo.rs
@@ -267,8 +267,7 @@ fn create_basic_type(cx: @crate_ctxt, t: ty::t, ty: @ast::ty)
     let cache = get_cache(cx);
     let tg = BasicTypeDescriptorTag;
     alt cached_metadata::<@metadata<tydesc_md>>(
-        cache, tg,
-        {|md| ty::hash_ty(t) == ty::hash_ty(md.data.hash)}) {
+        cache, tg, {|md| t == md.data.hash}) {
       option::some(md) { ret md; }
       option::none. {}
     }
@@ -311,7 +310,7 @@ fn create_basic_type(cx: @crate_ctxt, t: ty::t, ty: @ast::ty)
                   lli32(0), //XXX flags?
                   lli32(encoding)];
     let llnode = llmdnode(lldata);
-    let mdval = @{node: llnode, data: {hash: ty::hash_ty(t)}};
+    let mdval = @{node: llnode, data: {hash: t}};
     update_cache(cache, tg, tydesc_metadata(mdval));
     add_named_metadata(cx, "llvm.dbg.ty", llnode);
     ret mdval;
@@ -333,7 +332,7 @@ fn create_pointer_type(cx: @crate_ctxt, t: ty::t, span: codemap::span,
     //let cu_node = create_compile_unit(cx, fname);
     let llnode = create_derived_type(tg, file_node.node, "", 0, size * 8,
                                      align * 8, 0, pointee.node);
-    let mdval = @{node: llnode, data: {hash: ty::hash_ty(t)}};
+    let mdval = @{node: llnode, data: {hash: t}};
     //update_cache(cache, tg, tydesc_metadata(mdval));
     add_named_metadata(cx, "llvm.dbg.ty", llnode);
     ret mdval;
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index cc2259d6e0d..786ab1886c8 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -4348,7 +4348,7 @@ fn new_fn_ctxt_w_id(cx: @local_ctxt, sp: span, llfndecl: ValueRef,
           lllocals: new_int_hash::<local_val>(),
           llupvars: new_int_hash::<ValueRef>(),
           mutable lltydescs: [],
-          derived_tydescs: map::mk_hashmap(ty::hash_ty, ty::eq_ty),
+          derived_tydescs: ty::new_ty_hash(),
           id: id,
           ret_style: rstyle,
           sp: sp,
@@ -5642,13 +5642,6 @@ fn trans_crate(sess: session::session, crate: @ast::crate, tcx: ty::ctxt,
     tn.associate("taskptr", taskptr_type);
     let tydesc_type = T_tydesc(targ_cfg);
     tn.associate("tydesc", tydesc_type);
-    let hasher = ty::hash_ty;
-    let eqer = ty::eq_ty;
-    let tag_sizes = map::mk_hashmap::<ty::t, uint>(hasher, eqer);
-    let tydescs = map::mk_hashmap::<ty::t, @tydesc_info>(hasher, eqer);
-    let lltypes = map::mk_hashmap::<ty::t, TypeRef>(hasher, eqer);
-    let sha1s = map::mk_hashmap::<ty::t, str>(hasher, eqer);
-    let short_names = map::mk_hashmap::<ty::t, str>(hasher, eqer);
     let crate_map = decl_crate_map(sess, link_meta.name, llmod);
     let dbg_cx = if sess.get_opts().debuginfo {
         option::some(@{llmetadata: map::new_int_hash(),
@@ -5669,18 +5662,18 @@ fn trans_crate(sess: session::session, crate: @ast::crate, tcx: ty::ctxt,
           item_symbols: new_int_hash::<str>(),
           mutable main_fn: none::<ValueRef>,
           link_meta: link_meta,
-          tag_sizes: tag_sizes,
+          tag_sizes: ty::new_ty_hash(),
           discrims: ast_util::new_def_id_hash::<ValueRef>(),
           discrim_symbols: new_int_hash::<str>(),
           consts: new_int_hash::<ValueRef>(),
           obj_methods: new_int_hash::<()>(),
-          tydescs: tydescs,
+          tydescs: ty::new_ty_hash(),
           module_data: new_str_hash::<ValueRef>(),
-          lltypes: lltypes,
+          lltypes: ty::new_ty_hash(),
           names: namegen(0),
           sha: sha,
-          type_sha1s: sha1s,
-          type_short_names: short_names,
+          type_sha1s: ty::new_ty_hash(),
+          type_short_names: ty::new_ty_hash(),
           tcx: tcx,
           mut_map: mut_map,
           copy_map: copy_map,
diff --git a/src/comp/middle/ty.rs b/src/comp/middle/ty.rs
index ef6177822e3..a1cb5cd371b 100644
--- a/src/comp/middle/ty.rs
+++ b/src/comp/middle/ty.rs
@@ -36,7 +36,6 @@ export constr_table;
 export count_ty_params;
 export ctxt;
 export def_has_ty_params;
-export eq_ty;
 export expr_has_ty_params;
 export expr_ty;
 export expr_ty_params_and_ty;
@@ -47,7 +46,6 @@ export field_idx;
 export get_field;
 export fm_general;
 export get_element_type;
-export hash_ty;
 export idx_nil;
 export is_binopable;
 export is_pred_ty;
@@ -103,6 +101,7 @@ export stmt_node_id;
 export sty;
 export substitute_type_params;
 export t;
+export new_ty_hash;
 export tag_variants;
 export tag_variant_with_id;
 export ty_param_substs_opt_and_ty;
@@ -398,12 +397,16 @@ fn mk_rcache() -> creader_cache {
     ret map::mk_hashmap(hash_cache_entry, eq_cache_entries);
 }
 
+fn new_ty_hash<copy V>() -> map::hashmap<t, V> { map::new_uint_hash() }
 
 fn mk_ctxt(s: session::session, dm: resolve::def_map, amap: ast_map::map,
            freevars: freevars::freevar_map) -> ctxt {
     let ntt: node_type_table =
         @smallintmap::mk::<ty::ty_param_substs_opt_and_ty>();
     let tcache = new_def_hash::<ty::ty_param_kinds_and_ty>();
+    fn eq_raw_ty(&&a: @raw_t, &&b: @raw_t) -> bool {
+        ret a.hash == b.hash && a.struct == b.struct;
+    }
     let ts = @interner::mk::<@raw_t>(hash_raw_ty, eq_raw_ty);
     let cx =
         @{ts: ts,
@@ -414,9 +417,9 @@ fn mk_ctxt(s: session::session, dm: resolve::def_map, amap: ast_map::map,
           freevars: freevars,
           tcache: tcache,
           rcache: mk_rcache(),
-          short_names_cache: map::mk_hashmap(ty::hash_ty, ty::eq_ty),
-          needs_drop_cache: map::mk_hashmap(ty::hash_ty, ty::eq_ty),
-          kind_cache: map::mk_hashmap(ty::hash_ty, ty::eq_ty),
+          short_names_cache: new_ty_hash(),
+          needs_drop_cache: new_ty_hash(),
+          kind_cache: new_ty_hash(),
           ast_ty_to_ty_cache:
               map::mk_hashmap(ast_util::hash_ty, ast_util::eq_ty),
           tag_var_cache: @smallintmap::mk()};
@@ -1233,8 +1236,7 @@ fn type_autoderef(cx: ctxt, t: ty::t) -> ty::t {
     ret t1;
 }
 
-// Type hashing. This function is private to this module (and slow); external
-// users should use `hash_ty()` instead.
+// Type hashing.
 fn hash_type_structure(st: sty) -> uint {
     fn hash_uint(id: uint, n: uint) -> uint {
         let h = id;
@@ -1249,7 +1251,7 @@ fn hash_type_structure(st: sty) -> uint {
     }
     fn hash_subty(id: uint, subty: t) -> uint {
         let h = id;
-        h += (h << 5u) + hash_ty(subty);
+        h += (h << 5u) + subty;
         ret h;
     }
     fn hash_subtys(id: uint, subtys: [t]) -> uint {
@@ -1284,8 +1286,8 @@ fn hash_type_structure(st: sty) -> uint {
 
     fn hash_fn(id: uint, args: [arg], rty: t) -> uint {
         let h = id;
-        for a: arg in args { h += (h << 5u) + hash_ty(a.ty); }
-        h += (h << 5u) + hash_ty(rty);
+        for a: arg in args { h += (h << 5u) + a.ty; }
+        h += (h << 5u) + rty;
         ret h;
     }
     alt st {
@@ -1308,14 +1310,14 @@ fn hash_type_structure(st: sty) -> uint {
       ty_str. { ret 17u; }
       ty_tag(did, tys) {
         let h = hash_def(18u, did);
-        for typ: t in tys { h += (h << 5u) + hash_ty(typ); }
+        for typ: t in tys { h += (h << 5u) + typ; }
         ret h;
       }
       ty_box(mt) { ret hash_subty(19u, mt.ty); }
       ty_vec(mt) { ret hash_subty(21u, mt.ty); }
       ty_rec(fields) {
         let h = 26u;
-        for f: field in fields { h += (h << 5u) + hash_ty(f.mt.ty); }
+        for f: field in fields { h += (h << 5u) + f.mt.ty; }
         ret h;
       }
       ty_tup(ts) { ret hash_subtys(25u, ts); }
@@ -1354,13 +1356,6 @@ fn hash_type_structure(st: sty) -> uint {
 
 fn hash_raw_ty(&&rt: @raw_t) -> uint { ret rt.hash; }
 
-fn hash_ty(&&typ: t) -> uint { ret typ; }
-
-
-// Type equality. This function is private to this module (and slow); external
-// users should use `eq_ty()` instead.
-fn eq_int(&&x: uint, &&y: uint) -> bool { ret x == y; }
-
 fn arg_eq<T>(eq: fn(T, T) -> bool, a: @sp_constr_arg<T>, b: @sp_constr_arg<T>)
    -> bool {
     alt a.node {
@@ -1389,6 +1384,7 @@ fn args_eq<T>(eq: fn(T, T) -> bool, a: [@sp_constr_arg<T>],
 }
 
 fn constr_eq(c: @constr, d: @constr) -> bool {
+    fn eq_int(&&x: uint, &&y: uint) -> bool { ret x == y; }
     ret path_to_str(c.node.path) == path_to_str(d.node.path) &&
             // FIXME: hack
             args_eq(eq_int, c.node.args, d.node.args);
@@ -1401,16 +1397,6 @@ fn constrs_eq(cs: [@constr], ds: [@constr]) -> bool {
     ret true;
 }
 
-// This function is private to this module.
-fn eq_raw_ty(&&a: @raw_t, &&b: @raw_t) -> bool {
-    ret a.hash == b.hash && a.struct == b.struct;
-}
-
-
-// This is the equality function the public should use. It works as long as
-// the types are interned.
-fn eq_ty(&&a: t, &&b: t) -> bool { a == b }
-
 // Type lookups
 fn node_id_to_ty_param_substs_opt_and_ty(cx: ctxt, id: ast::node_id) ->
    ty_param_substs_opt_and_ty {
@@ -2088,12 +2074,15 @@ mod unify {
 
     fn unify_step(cx: @ctxt, expected: t, actual: t,
                   variance: variance) -> result {
-        // TODO: rewrite this using tuple pattern matching when available, to
+        // FIXME: rewrite this using tuple pattern matching when available, to
         // avoid all this rightward drift and spikiness.
+        // NOTE: we have tuple matching now, but that involves copying the
+        // matched elements into a tuple first, which is expensive, since sty
+        // holds vectors, which are currently unique
 
         // Fast path.
+        if expected == actual { ret ures_ok(expected); }
 
-        if eq_ty(expected, actual) { ret ures_ok(expected); }
         // Stage 1: Handle the cases in which one side or another is a type
         // variable.