Merge branch 'egil/fix-maps-erts_debug-size'

* egil/fix-maps-erts_debug-size:
  erts: Fix erts_debug:size/1 for large Maps
  erts: Simple test of erts_debug:size/1 of Maps

2 files changed, 30 insertions, 22 deletions

diff --git a/erts/emulator/beam/erl_map.c b/erts/emulator/beam/erl_map.c
index bb2a2bcdf9..256d6a8e81 100644
--- a/erts/emulator/beam/erl_map.c
+++ b/erts/emulator/beam/erl_map.c
@@ -2586,12 +2586,12 @@ BIF_RETTYPE erts_internal_map_type_1(BIF_ALIST_1) {
     DECL_AM(hashmap);
     DECL_AM(hashmap_node);
     DECL_AM(flatmap);
-    if (is_flatmap(BIF_ARG_1)) {
-	BIF_RET(AM_flatmap);
-    } else if (is_hashmap(BIF_ARG_1)) {
+    if (is_map(BIF_ARG_1)) {
         Eterm hdr = *(boxed_val(BIF_ARG_1));
         ASSERT(is_header(hdr));
         switch (hdr & _HEADER_MAP_SUBTAG_MASK) {
+            case HAMT_SUBTAG_HEAD_FLATMAP:
+                BIF_RET(AM_flatmap);
             case HAMT_SUBTAG_HEAD_ARRAY:
             case HAMT_SUBTAG_HEAD_BITMAP:
                 BIF_RET(AM_hashmap);
@@ -2612,23 +2612,22 @@ BIF_RETTYPE erts_internal_map_type_1(BIF_ALIST_1) {
  */
 
 BIF_RETTYPE erts_internal_map_hashmap_children_1(BIF_ALIST_1) {
-    if (is_hashmap(BIF_ARG_1)) {
+    if (is_map(BIF_ARG_1)) {
         Eterm node = BIF_ARG_1;
         Eterm *ptr, hdr, *hp, res = NIL;
         Uint  sz = 0;
         ptr = boxed_val(node);
         hdr = *ptr;
-
         ASSERT(is_header(hdr));
 
         switch(hdr & _HEADER_MAP_SUBTAG_MASK) {
-            case HAMT_SUBTAG_NODE_BITMAP:
-                sz   = hashmap_bitcount(MAP_HEADER_VAL(hdr));
-                ptr += 1;
-                break;
+            case HAMT_SUBTAG_HEAD_FLATMAP:
+                BIF_ERROR(BIF_P, BADARG);
             case HAMT_SUBTAG_HEAD_BITMAP:
-                sz   = hashmap_bitcount(MAP_HEADER_VAL(hdr));
-                ptr += 2;
+                ptr++;
+            case HAMT_SUBTAG_NODE_BITMAP:
+                ptr++;
+                sz = hashmap_bitcount(MAP_HEADER_VAL(hdr));
                 break;
             case HAMT_SUBTAG_HEAD_ARRAY:
                 sz   = 16;
@@ -2642,12 +2641,9 @@ BIF_RETTYPE erts_internal_map_hashmap_children_1(BIF_ALIST_1) {
         hp = HAlloc(BIF_P, 2*sz);
         while(sz--) { res = CONS(hp, *ptr++, res); hp += 2; }
         BIF_RET(res);
-    } else if (is_flatmap(BIF_ARG_1)) {
-	BIF_ERROR(BIF_P, BADARG);
-    } else {
-	BIF_P->fvalue = BIF_ARG_1;
-	BIF_ERROR(BIF_P, BADMAP);
     }
+    BIF_P->fvalue = BIF_ARG_1;
+    BIF_ERROR(BIF_P, BADMAP);
 }
 
 
diff --git a/erts/emulator/test/erts_debug_SUITE.erl b/erts/emulator/test/erts_debug_SUITE.erl
index e5c904cfb9..bc5928436f 100644
--- a/erts/emulator/test/erts_debug_SUITE.erl
+++ b/erts/emulator/test/erts_debug_SUITE.erl
@@ -71,6 +71,11 @@ test_size(Config) when is_list(Config) ->
     4 = do_test_size(#{}),
     32 = do_test_size(#{b => 2,c => 3,txt => "hello world"}),
 
+    true = do_test_size(maps:from_list([{I,I}||I<-lists:seq(1,256)])) >= map_size_lower_bound(256),
+    true = do_test_size(maps:from_list([{I,I}||I<-lists:seq(1,4096)])) >= map_size_lower_bound(4096),
+    true = do_test_size(maps:from_list([{I,I}||I<-lists:seq(1,254)])) >= map_size_lower_bound(254),
+    true = do_test_size(maps:from_list([{I,I}||I<-lists:seq(1,239)])) >= map_size_lower_bound(239),
+
     %% Test internal consistency of sizes, but without testing
     %% exact sizes.
     Const = id(42),
@@ -92,14 +97,14 @@ test_size(Config) when is_list(Config) ->
 
     %% Test shared data structures.
     do_test_size([ConsCell1|ConsCell1],
-		 3*ConsCellSz,
-		 2*ConsCellSz),
+        	 3*ConsCellSz,
+        	 2*ConsCellSz),
     do_test_size(fun() -> {ConsCell1,ConsCell2} end,
-		 FunSz2 + 2*ConsCellSz,
-		 FunSz2 + ConsCellSz),
+        	 FunSz2 + 2*ConsCellSz,
+        	 FunSz2 + ConsCellSz),
     do_test_size({SimplestFun,SimplestFun},
-		 2*FunSz0+do_test_size({a,b}),
-		 FunSz0+do_test_size({a,b})),
+        	 2*FunSz0+do_test_size({a,b}),
+        	 FunSz0+do_test_size({a,b})),
 
     M = id(#{ "atom" => first, i => 0}),
     do_test_size([M,M#{ "atom" := other },M#{i := 42}],54,32),
@@ -113,6 +118,13 @@ do_test_size(Term, FlatSz, Sz) ->
     FlatSz = erts_debug:flat_size(Term),
     Sz = erts_debug:size(Term).
 
+map_size_lower_bound(N) ->
+    %% this est. is a bit lower that actual lower bound
+    %% number of internal nodes
+    T = (N - 1) div 15,
+    %% total words
+    2 + 17 * T + 2 * N.
+
 flat_size_big(Config) when is_list(Config) ->
     %% Build a term whose external size only fits in a big num (on 32-bit CPU).
     flat_size_big_1(16#11111111111111117777777777777777888889999, 0, 16#FFFFFFF).