From 26849296883df7517af7d474210c343c943b48e2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Fri, 15 Mar 2013 11:59:45 +0100 Subject: erts: Use fast path for list_to_binary([Bin]) case A common case is to wrap an argument to list_to_binary in a list to ensure conversion can happen even though the argument may already be a binary. Use fast path for this case. --- erts/emulator/beam/binary.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/erts/emulator/beam/binary.c b/erts/emulator/beam/binary.c index 33abac2f3d..c7926f18af 100644 --- a/erts/emulator/beam/binary.c +++ b/erts/emulator/beam/binary.c @@ -447,6 +447,7 @@ BIF_RETTYPE bitstring_to_list_1(BIF_ALIST_1) BIF_RETTYPE erts_list_to_binary_bif(Process *p, Eterm arg) { Eterm bin; + Eterm h,t; ErlDrvSizeT size; byte* bytes; #ifdef DEBUG @@ -459,6 +460,16 @@ BIF_RETTYPE erts_list_to_binary_bif(Process *p, Eterm arg) if (is_not_list(arg)) { goto error; } + /* check for [binary()] case */ + h = CAR(list_val(arg)); + t = CDR(list_val(arg)); + if (is_binary(h) && is_nil(t) && !( + HEADER_SUB_BIN == *(binary_val(h)) && ( + ((ErlSubBin *)binary_val(h))->bitoffs != 0 || + ((ErlSubBin *)binary_val(h))->bitsize != 0 + ))) { + return h; + } switch (erts_iolist_size(arg, &size)) { case ERTS_IOLIST_OVERFLOW: BIF_ERROR(p, SYSTEM_LIMIT); case ERTS_IOLIST_TYPE: goto error; -- cgit v1.2.3