evacuate when allocating anon vars

src/prolog/allocator.rs

@@ -11,7 +11,7 @@ pub trait Allocator<'a>
 {
     fn new() -> Self;
 
-    fn mark_anon_var<Target>(&mut self, Level, &mut Vec<Target>)
+    fn mark_anon_var<Target>(&mut self, Level, GenContext, &mut Vec<Target>)
         where Target: CompilationTarget<'a>;
     fn mark_non_var<Target>(&mut self, Level, GenContext, &'a Cell<RegType>, &mut Vec<Target>)
         where Target: CompilationTarget<'a>;

src/prolog/codegen.rs

@@ -158,7 +158,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker>
     {
         match subterm {
             &Term::AnonVar if is_exposed =>
-                self.marker.mark_anon_var(Level::Deep, target),
+                self.marker.mark_anon_var(Level::Deep, term_loc, target),
             &Term::AnonVar =>
                 Self::add_or_increment_void_instr(target),
             &Term::Cons(ref cell, _, _) | &Term::Clause(ref cell, _, _, _) => {
@@ -207,7 +207,7 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker>
                     if let GenContext::Head = term_loc {
                         self.marker.advance_arg();
                     } else {
-                        self.marker.mark_anon_var(lvl, &mut target);
+                        self.marker.mark_anon_var(lvl, term_loc, &mut target);
                     },
                 TermRef::Var(lvl @ Level::Shallow, cell, ref var) if var.as_str() == "!" => {
                     if self.marker.is_unbound(var.clone()) {

src/prolog/debray_allocator.rs

@@ -211,7 +211,7 @@ impl<'a> Allocator<'a> for DebrayAllocator
         }
     }
 
-    fn mark_anon_var<Target>(&mut self, lvl: Level, target: &mut Vec<Target>)
+    fn mark_anon_var<Target>(&mut self, lvl: Level, term_loc: GenContext, target: &mut Vec<Target>)
         where Target: CompilationTarget<'a>
     {
         let r = RegType::Temp(self.alloc_reg_to_non_var());
@@ -220,6 +220,11 @@ impl<'a> Allocator<'a> for DebrayAllocator
             Level::Deep => target.push(Target::subterm_to_variable(r)),
             Level::Root | Level::Shallow => {
                 let k = self.arg_c;
+
+                if let GenContext::Last(chunk_num) = term_loc {
+                    self.evacuate_arg(chunk_num, target);
+                }
+
                 self.arg_c += 1;
                 
                 target.push(Target::argument_to_variable(r, k));

src/prolog/lib/between.pl

@@ -84,7 +84,7 @@ diag_ints(M, N, M0, N0) :-
     diag_nats_signs(M, N, M0, N0).
 
 diag_ints(M, N) :-
-    diag_ints(M0, N0, M, N).
+    diag_ints(_, _, M, N).
 
 gen_ints(L, U) :-
     can_be(integer, L), can_be(integer, U),