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-rw-r--r--lib/compiler/src/beam_flatten.erl47
1 files changed, 16 insertions, 31 deletions
diff --git a/lib/compiler/src/beam_flatten.erl b/lib/compiler/src/beam_flatten.erl
index 4cca406f45..04232d8fd2 100644
--- a/lib/compiler/src/beam_flatten.erl
+++ b/lib/compiler/src/beam_flatten.erl
@@ -79,43 +79,28 @@ norm_allocate({nozero,Ns,Nh,Inits}, Regs) ->
%% insert_alloc_in_bs_init(ReverseInstructionStream, AllocationInfo) ->
%% impossible | ReverseInstructionStream'
-%% A bs_init2/6 instruction should not be followed by a test heap instruction.
+%% A bs_init/6 instruction should not be followed by a test heap instruction.
%% Given the AllocationInfo from a test heap instruction, merge the
-%% allocation amounts into the previous bs_init2/6 instruction (if any).
+%% allocation amounts into the previous bs_init/6 instruction (if any).
%%
-insert_alloc_in_bs_init([I|_]=Is, Alloc) ->
- case is_bs_constructor(I) of
- false -> impossible;
- true -> insert_alloc_1(Is, Alloc, [])
- end.
-
-insert_alloc_1([{bs_init2=Op,Fail,Bs,Ws1,Regs,F,Dst}|Is], {_,nostack,Ws2,[]}, Acc) ->
- Al = beam_utils:combine_heap_needs(Ws1, Ws2),
- I = {Op,Fail,Bs,Al,Regs,F,Dst},
- reverse(Acc, [I|Is]);
-insert_alloc_1([{bs_init_bits=Op,Fail,Bs,Ws1,Regs,F,Dst}|Is], {_,nostack,Ws2,[]}, Acc) ->
- Al = beam_utils:combine_heap_needs(Ws1, Ws2),
- I = {Op,Fail,Bs,Al,Regs,F,Dst},
- reverse(Acc, [I|Is]);
-insert_alloc_1([{bs_append,Fail,Sz,Ws1,Regs,U,Bin,Fl,Dst}|Is],
- {_,nostack,Ws2,[]}, Acc) ->
+insert_alloc_in_bs_init([{bs_put,_,_,_}=I|Is], Alloc) ->
+ %% The instruction sequence ends with an bs_put/4 instruction.
+ %% We'll need to search backwards for the bs_init/6 instruction.
+ insert_alloc_1(Is, Alloc, [I]);
+insert_alloc_in_bs_init(_, _) -> impossible.
+
+insert_alloc_1([{bs_init=Op,Fail,Info0,Live,Ss,Dst}|Is],
+ {_,nostack,Ws2,[]}, Acc) when is_integer(Live) ->
+ %% The number of extra heap words is always in the second position
+ %% in the Info tuple.
+ Ws1 = element(2, Info0),
Al = beam_utils:combine_heap_needs(Ws1, Ws2),
- I = {bs_append,Fail,Sz,Al,Regs,U,Bin,Fl,Dst},
+ Info = setelement(2, Info0, Al),
+ I = {Op,Fail,Info,Live,Ss,Dst},
reverse(Acc, [I|Is]);
-insert_alloc_1([I|Is], Alloc, Acc) ->
+insert_alloc_1([{bs_put,_,_,_}=I|Is], Alloc, Acc) ->
insert_alloc_1(Is, Alloc, [I|Acc]).
-
-%% is_bs_constructor(Instruction) -> true|false.
-%% Test whether the instruction is a bit syntax construction
-%% instruction that can occur at the end of a bit syntax
-%% construction. (Since an empty binary would be expressed
-%% as a literal, the bs_init2/6 instruction will not occur
-%% at the end and therefore it is no need to test for it here.)
-%%
-is_bs_constructor({bs_put,_,_,_}) -> true;
-is_bs_constructor(_) -> false.
-
%% opt(Is0) -> Is
%% Simple peep-hole optimization to move a {move,Any,{x,0}} past
%% any kill up to the next call instruction. (To give the loader