amd64: Move stack realloc calls out-of-line

asmcomp/amd64/emit.mlp

@@ -279,6 +279,19 @@ let emit_call_gc gc =
   def_label gc.gc_frame;
   I.jmp (label gc.gc_return_lbl)
 
+(* Record calls to local stack reallocation *)
+
+type local_realloc_call =
+  { lr_lbl: label;
+    lr_return_lbl: label; }
+
+let local_realloc_sites = ref ([] : local_realloc_call list)
+
+let emit_local_realloc lr =
+  def_label lr.lr_lbl;
+  emit_call "caml_call_local_realloc";
+  I.jmp (label lr.lr_return_lbl)
+
 (* Record calls to caml_ml_array_bound_error.
    In -g mode we maintain one call to
    caml_ml_array_bound_error per bound check site.  Without -g, we can share
@@ -657,12 +670,15 @@ let emit_instr fallthrough i =
       (* FIXME: before or after check? Calling conv w/ realloc *)
       I.mov r (domain_field Domainstate.Domain_local_sp);
       I.cmp (domain_field Domainstate.Domain_local_limit) r;
-      let lbl_ok = new_label () in
-      I.j GE (label lbl_ok);
-      emit_call "caml_call_local_realloc";
-      def_label lbl_ok;
+      let lbl_call = new_label () in
+      I.j L (label lbl_call);
+      let lbl_after_alloc = new_label () in
+      def_label lbl_after_alloc;
       I.add (domain_field Domainstate.Domain_local_top) r;
       I.add (int 8) r;
+      local_realloc_sites :=
+        { lr_lbl = lbl_call;
+          lr_return_lbl = lbl_after_alloc } :: !local_realloc_sites
   | Lop(Iintop(Icomp cmp)) ->
       I.cmp (arg i 1) (arg i 0);
       I.set (cond cmp) al;
@@ -885,6 +901,7 @@ let fundecl fundecl =
   tailrec_entry_point := fundecl.fun_tailrec_entry_point_label;
   stack_offset := 0;
   call_gc_sites := [];
+  local_realloc_sites := [];
   bound_error_sites := [];
   bound_error_call := 0;
   for i = 0 to Proc.num_register_classes - 1 do
@@ -908,6 +925,7 @@ let fundecl fundecl =
   cfi_startproc ();
   emit_all true fundecl.fun_body;
   List.iter emit_call_gc !call_gc_sites;
+  List.iter emit_local_realloc !local_realloc_sites;
   emit_call_bound_errors ();
   if !frame_required then begin
     let n = frame_size() - 8 - (if fp then 8 else 0) in