Get rid of spill_map and associated infrastructure.

Author: msullivan

src/rustc/driver/driver.rs

@@ -194,7 +194,7 @@ fn compile_upto(sess: session, cfg: ast::crate_cfg,
          bind middle::check_loop::check_crate(ty_cx, crate));
     time(time_passes, "alt checking",
          bind middle::check_alt::check_crate(ty_cx, crate));
-    let (last_use_map, spill_map) =
+    let last_use_map =
         time(time_passes, "liveness checking",
              bind middle::liveness::check_crate(ty_cx, method_map, crate));
     time(time_passes, "typestate checking",
@@ -216,7 +216,7 @@ fn compile_upto(sess: session, cfg: ast::crate_cfg,
     let maps = {mutbl_map: mutbl_map, root_map: root_map,
                 copy_map: copy_map, last_use_map: last_use_map,
                 impl_map: impl_map, method_map: method_map,
-                vtable_map: vtable_map, spill_map: spill_map};
+                vtable_map: vtable_map};
 
     let (llmod, link_meta) =
         time(time_passes, "translation",

src/rustc/middle/astencode.rs

@@ -57,7 +57,6 @@ type maps = {
     impl_map: middle::resolve::impl_map,
     method_map: middle::typeck::method_map,
     vtable_map: middle::typeck::vtable_map,
-    spill_map: middle::liveness::spill_map
 };
 
 type decode_ctxt = @{
@@ -839,12 +838,6 @@ fn encode_side_tables_for_id(ecx: @e::encode_ctxt,
         }
     }
 
-    option::iter(maps.spill_map.find(id)) {|_m|
-        ebml_w.tag(c::tag_table_spill) {||
-            ebml_w.id(id);
-        }
-    }
-
     option::iter(maps.last_use_map.find(id)) {|m|
         ebml_w.tag(c::tag_table_last_use) {||
             ebml_w.id(id);
@@ -953,8 +946,6 @@ fn decode_side_tables(xcx: extended_decode_ctxt,
             dcx.maps.mutbl_map.insert(id, ());
         } else if tag == (c::tag_table_copy as uint) {
             dcx.maps.copy_map.insert(id, ());
-        } else if tag == (c::tag_table_spill as uint) {
-            dcx.maps.spill_map.insert(id, ());
         } else {
             let val_doc = entry_doc[c::tag_table_val];
             let val_dsr = ebml::ebml_deserializer(val_doc);

src/rustc/middle/liveness.rs

@@ -57,7 +57,6 @@ import capture::{cap_move, cap_drop, cap_copy, cap_ref};
 
 export check_crate;
 export last_use_map;
-export spill_map;
 
 // Maps from an expr id to a list of variable ids for which this expr
 // is the last use.  Typically, the expr is a path and the node id is
@@ -66,13 +65,6 @@ export spill_map;
 // list of closed over variables that can be moved into the closure.
 type last_use_map = hashmap<node_id, @dvec<node_id>>;
 
-// A set of variable ids which must be spilled (stored on the stack).
-// We add in any variables or arguments where:
-// (1) the variables are moved;
-// (2) the address of the variable/argument is taken;
-// or (3) we find a last use (as they may be moved).
-type spill_map = hashmap<node_id, ()>;
-
 enum variable = uint;
 enum live_node = uint;
 
@@ -85,7 +77,7 @@ enum live_node_kind {
 
 fn check_crate(tcx: ty::ctxt,
                method_map: typeck::method_map,
-               crate: @crate) -> (last_use_map, spill_map) {
+               crate: @crate) -> last_use_map {
     let visitor = visit::mk_vt(@{
         visit_fn: visit_fn,
         visit_local: visit_local,
@@ -94,12 +86,11 @@ fn check_crate(tcx: ty::ctxt,
     });
 
     let last_use_map = int_hash();
-    let spill_map = int_hash();
     let initial_maps = @ir_maps(tcx, method_map,
-                                last_use_map, spill_map);
+                                last_use_map);
     visit::visit_crate(*crate, initial_maps, visitor);
     tcx.sess.abort_if_errors();
-    ret (last_use_map, spill_map);
+    ret last_use_map;
 }
 
 impl of to_str::to_str for live_node {
@@ -162,7 +153,6 @@ class ir_maps {
     let tcx: ty::ctxt;
     let method_map: typeck::method_map;
     let last_use_map: last_use_map;
-    let spill_map: spill_map;
 
     let mut num_live_nodes: uint;
     let mut num_vars: uint;
@@ -174,11 +164,10 @@ class ir_maps {
     let mut lnks: [live_node_kind];
 
     new(tcx: ty::ctxt, method_map: typeck::method_map,
-        last_use_map: last_use_map, spill_map: spill_map) {
+        last_use_map: last_use_map) {
         self.tcx = tcx;
         self.method_map = method_map;
         self.last_use_map = last_use_map;
-        self.spill_map = spill_map;
 
         self.num_live_nodes = 0u;
         self.num_vars = 0u;
@@ -264,17 +253,6 @@ class ir_maps {
         self.lnks[*ln]
     }
 
-    fn add_spill(var: variable) {
-        let vk = self.var_kinds[*var];
-        alt vk {
-          vk_local(id, _) | vk_arg(id, _, by_val) {
-            #debug["adding spill for %?", vk];
-            self.spill_map.insert(id, ());
-          }
-          vk_arg(*) | vk_field(_) | vk_self | vk_implicit_ret {}
-        }
-    }
-
     fn add_last_use(expr_id: node_id, var: variable) {
         let vk = self.var_kinds[*var];
         #debug["Node %d is a last use of variable %?", expr_id, vk];
@@ -308,7 +286,7 @@ fn visit_fn(fk: visit::fn_kind, decl: fn_decl, body: blk,
 
     // swap in a new set of IR maps for this function body:
     let fn_maps = @ir_maps(self.tcx, self.method_map,
-                           self.last_use_map, self.spill_map);
+                           self.last_use_map);
 
     #debug["creating fn_maps: %x", ptr::addr_of(*fn_maps) as uint];
 
@@ -1407,11 +1385,7 @@ fn check_expr(expr: @expr, &&self: @liveness, vt: vt<@liveness>) {
         vt.visit_expr(f, self, vt);
         vec::iter2(args, targs) { |arg_expr, arg_ty|
             alt ty::resolved_mode(self.tcx, arg_ty.mode) {
-              by_val | by_copy {
-                vt.visit_expr(arg_expr, self, vt);
-              }
-              by_ref | by_mutbl_ref {
-                self.spill_expr(arg_expr);
+              by_val | by_copy | by_ref | by_mutbl_ref{
                 vt.visit_expr(arg_expr, self, vt);
               }
               by_move {
@@ -1421,10 +1395,6 @@ fn check_expr(expr: @expr, &&self: @liveness, vt: vt<@liveness>) {
         }
       }
 
-      expr_addr_of(_, arg_expr) {
-        self.spill_expr(arg_expr);
-      }
-
       // no correctness conditions related to liveness
       expr_if_check(*) | expr_if(*) | expr_alt(*) |
       expr_while(*) | expr_loop(*) |
@@ -1434,7 +1404,7 @@ fn check_expr(expr: @expr, &&self: @liveness, vt: vt<@liveness>) {
       expr_assert(*) | expr_check(*) | expr_copy(*) |
       expr_loop_body(*) | expr_cast(*) | expr_unary(*) | expr_fail(*) |
       expr_ret(*) | expr_break | expr_cont | expr_lit(_) |
-      expr_block(*) | expr_swap(*) | expr_mac(*) {
+      expr_block(*) | expr_swap(*) | expr_mac(*) | expr_addr_of(*) {
         visit::visit_expr(expr, self, vt);
       }
     }
@@ -1501,10 +1471,7 @@ impl check_methods for @liveness {
                ln.to_str(), var.to_str()];
 
         alt (*self).live_on_exit(ln, var) {
-          none {
-            // update spill map to include this variable, as it is moved:
-            (*self.ir).add_spill(var);
-          }
+          none { }
           some(lnk) {
             self.report_illegal_move(span, lnk, var);
           }
@@ -1516,20 +1483,10 @@ impl check_methods for @liveness {
           some(_) {}
           none {
             (*self.ir).add_last_use(expr.id, var);
-
-            // update spill map to include this variable, as it may be moved:
-            (*self.ir).add_spill(var);
           }
        }
     }
 
-    fn spill_expr(expr: @expr) {
-        alt (*self).variable_from_path(expr) {
-          some(var) {(*self.ir).add_spill(var)}
-          none {}
-        }
-    }
-
     fn check_move_from_expr(expr: @expr, vt: vt<@liveness>) {
         #debug["check_move_from_expr(node %d: %s)",
                expr.id, expr_to_str(expr)];
@@ -1775,4 +1732,4 @@ impl check_methods for @liveness {
             }
         }
     }
- }
+ }