Move allocation combining from beam_flatten to beam_ssa_codegen

Continuing the simplification of beam_flatten, move the optimization
that eliminates a test_heap instruction following a binary construction
by incorporating the allocation of the heap space into the bs_init*
instruction itself.

This change does not change the generated code in any way.

Also remove beam_utils:combine_heap_needs/2, because beam_flatten
was the last user of it.

1 files changed, 2 insertions, 30 deletions

diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index 686d314c2d..39916a2af8 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -24,13 +24,11 @@
 -export([is_killed/3,is_killed_at/3,is_not_used/3,
 	 empty_label_index/0,index_label/3,index_labels/1,replace_labels/4,
 	 code_at/2,bif_to_test/3,is_pure_test/1,
-	 combine_heap_needs/2,
-	 split_even/1
-        ]).
+	 split_even/1]).
 
 -export_type([code_index/0,module_code/0,instruction/0]).
 
--import(lists, [flatmap/2,map/2,member/2,sort/1,reverse/1]).
+-import(lists, [map/2,member/2,sort/1,reverse/1]).
 
 -define(is_const(Val), (Val =:= nil orelse
                         element(1, Val) =:= integer orelse
@@ -218,19 +216,6 @@ is_pure_test({test,is_function2,_,[_,_]}) -> true;
 is_pure_test({test,Op,_,Ops}) -> 
     erl_internal:new_type_test(Op, length(Ops)).
 
-%% combine_heap_needs(HeapNeed1, HeapNeed2) -> HeapNeed
-%%  Combine the heap need for two allocation instructions.
-
--type heap_need_tag() :: 'floats' | 'words'.
--type heap_need() :: non_neg_integer() |
-                     {'alloc',[{heap_need_tag(),non_neg_integer()}]}.
--spec combine_heap_needs(heap_need(), heap_need()) -> heap_need().
-
-combine_heap_needs(H1, H2) when is_integer(H1), is_integer(H2) ->
-    H1 + H2;
-combine_heap_needs(H1, H2) ->
-    {alloc,combine_alloc_lists([H1,H2])}.
-
 %% split_even/1
 %% [1,2,3,4,5,6] -> {[1,3,5],[2,4,6]}
 
@@ -734,19 +719,6 @@ label(Old, D, Fb) ->
         _ -> Fb(Old)
     end.
 
-%% Help function for combine_heap_needs.
-
-combine_alloc_lists(Al0) ->
-    Al1 = flatmap(fun(Words) when is_integer(Words) ->
-                         [{words,Words}];
-                    ({alloc,List}) ->
-                         List
-                 end, Al0),
-    Al2 = sofs:relation(Al1),
-    Al3 = sofs:relation_to_family(Al2),
-    Al4 = sofs:to_external(Al3),
-    [{Tag,lists:sum(L)} || {Tag,L} <- Al4].
-
 %% live_opt/4.
 
 split_even([], Ss, Ds) ->