From b8c35cfdb858cc68a40d21e58b54e2362f3a456a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Wed, 12 Dec 2012 12:20:22 +0100 Subject: per: Slightly optimize encoding of fixed OCTET STRINGs Do the following optimizations: * Optimize construction of OCTET STRINGs of size 2 by using the 45 opcode instead of the 10 opcode for each character. * Use exact comparison (implicit by matching) instead of '=='. * Use list literals when more than one integer is added to a list (e.g. [[45,16,2],...] instead of [45,16,2,...]). Results in fewer BEAM instructions and less garbage. * Cons instead of building a nested list when possible. Example: [20,TempLen|TmpVal] instead of [20,TempLen,TmpVal]. * Omit the "2" opcode (align to byte boundary) before the "20" and "21" opcodes (because they imply alignment). * Assign the value to be encoded to a temporary variable, to avoid calling element/2 more than once. --- lib/asn1/src/asn1ct_gen_per_rt2ct.erl | 57 +++++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 23 deletions(-) (limited to 'lib/asn1') diff --git a/lib/asn1/src/asn1ct_gen_per_rt2ct.erl b/lib/asn1/src/asn1ct_gen_per_rt2ct.erl index fa9c3645b3..e6ffc0fb47 100644 --- a/lib/asn1/src/asn1ct_gen_per_rt2ct.erl +++ b/lib/asn1/src/asn1ct_gen_per_rt2ct.erl @@ -405,35 +405,46 @@ emit_enc_octet_string(_Erules,Constraint,Value) -> asn1ct_name:new(tmpval), emit({" begin",nl}), emit({" [",{curr,tmpval},"] = ",Value,",",nl}), - emit({" [10,8,",{curr,tmpval},"]",nl}), + emit([" [[10,8],",{curr,tmpval},"]",nl]), emit(" end"); 2 -> asn1ct_name:new(tmpval), - emit({" begin",nl}), - emit({" [",{curr,tmpval},",",{next,tmpval},"] = ", - Value,",",nl}), - emit({" [[10,8,",{curr,tmpval},"],[10,8,", - {next,tmpval},"]]",nl}), - emit(" end"), - asn1ct_name:new(tmpval); - Sv when is_integer(Sv),Sv < 256 -> + emit([" begin",nl, + " ",{curr,tmpval}," = ",Value,",",nl, + " case length(",{curr,tmpval},") of",nl, + " 2 ->",nl, + " [[45,16,2]|",{curr,tmpval},"];",nl, + " _ ->",nl, + " exit({error,{value_out_of_bounds,", + {curr,tmpval},"}})",nl, + " end",nl, + " end"]); + Sv when is_integer(Sv), Sv < 256 -> asn1ct_name:new(tmpval), - emit({" begin",nl}), - emit({" case length(",Value,") of",nl}), - emit([" ",{curr,tmpval}," when ",{curr,tmpval}," == ",Sv," ->"]), - emit([" [2,20,",{curr,tmpval},",",Value,"];",nl]), - emit({" _ -> exit({error,{value_out_of_bounds,", - Value,"}})", nl," end",nl}), - emit(" end"); + asn1ct_name:new(tmplen), + emit([" begin",nl, + " ",{curr,tmpval}," = ",Value,",",nl, + " case length(",{curr,tmpval},") of",nl, + " ",Sv,"=",{curr,tmplen}," ->",nl, + " [20,",{curr,tmplen},"|",{curr,tmpval},"];",nl, + " _ ->",nl, + " exit({error,{value_out_of_bounds,", + {curr,tmpval},"}})",nl, + " end",nl, + " end"]); Sv when is_integer(Sv),Sv =< 65535 -> asn1ct_name:new(tmpval), - emit({" begin",nl}), - emit({" case length(",Value,") of",nl}), - emit([" ",{curr,tmpval}," when ",{curr,tmpval}," == ",Sv," ->"]), - emit([" [<<21,",{curr,tmpval},":16>>|",Value,"];",nl]), - emit({" _ -> exit({error,{value_out_of_bounds,", - Value,"}})",nl," end",nl}), - emit(" end"); + asn1ct_name:new(tmplen), + emit([" begin",nl, + " ",{curr,tmpval}," = ",Value,",",nl, + " case length(",{curr,tmpval},") of",nl, + " ",Sv,"=",{curr,tmplen}," ->",nl, + " [<<21,",{curr,tmplen},":16>>|",Value,"];",nl, + " _ ->",nl, + " exit({error,{value_out_of_bounds,", + {curr,tmpval},"}})",nl, + " end",nl, + " end"]); C -> emit({" ?RT_PER:encode_octet_string(",{asis,C},",false,",Value,")",nl}) end. -- cgit v1.2.3