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authorBjörn Gustavsson <[email protected]>2017-02-24 16:01:32 +0100
committerBjörn Gustavsson <[email protected]>2017-02-27 12:13:40 +0100
commitbee8f839296e0424ddaf3a235ca285c2525cd28e (patch)
tree86b178213ebd1cc52fd5673b251285a009d7f37d
parent39b43dd10605f60d580ba9a73136713a776c635d (diff)
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v3_core: Combine binary strings to larger integers
Binary construction that mixes long literal strings with variables will make Dialyzer slow. Example: <<"long string (thousand of characters)",T/binary>> The string literals in binary construction is translated to one binary segment per character; all those segments will slow down Dialyzer. We can speed up Dialyzer if we combine several characters (up to 256) to a signle segment in the binary. It will also slightly speed up the compiler. This optimization will make core listings file with binary strings harder to read, but they were not that easy to read before this change. ERL-308
-rw-r--r--lib/compiler/src/v3_core.erl31
1 files changed, 24 insertions, 7 deletions
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index 14cd41ae27..8dea7ec03a 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -1059,13 +1059,30 @@ count_bits(Int) ->
count_bits_1(0, Bits) -> Bits;
count_bits_1(Int, Bits) -> count_bits_1(Int bsr 64, Bits+64).
-bin_expand_strings(Es) ->
- foldr(fun ({bin_element,Line,{string,_,S},Sz,Ts}, Es1) ->
- foldr(fun (C, Es2) ->
- [{bin_element,Line,{char,Line,C},Sz,Ts}|Es2]
- end, Es1, S);
- (E, Es1) -> [E|Es1]
- end, [], Es).
+bin_expand_strings(Es0) ->
+ foldr(fun ({bin_element,Line,{string,_,S},{integer,_,8},_}, Es) ->
+ bin_expand_string(S, Line, 0, 0) ++ Es;
+ ({bin_element,Line,{string,_,S},Sz,Ts}, Es1) ->
+ foldr(
+ fun (C, Es) ->
+ [{bin_element,Line,{char,Line,C},Sz,Ts}|Es]
+ end, Es1, S);
+ (E, Es) ->
+ [E|Es]
+ end, [], Es0).
+
+bin_expand_string(S, Line, Val, Size) when Size >= 2048 ->
+ Combined = make_combined(Line, Val, Size),
+ [Combined|bin_expand_string(S, Line, 0, 0)];
+bin_expand_string([H|T], Line, Val, Size) ->
+ bin_expand_string(T, Line, (Val bsl 8) bor H, Size+8);
+bin_expand_string([], Line, Val, Size) ->
+ [make_combined(Line, Val, Size)].
+
+make_combined(Line, Val, Size) ->
+ {bin_element,Line,{integer,Line,Val},
+ {integer,Line,Size},
+ [integer,{unit,1},unsigned,big]}.
expr_bin_1(Es, St) ->
foldr(fun (E, {Ces,Esp,St0}) ->