aboutsummaryrefslogtreecommitdiffstats
path: root/lib/erl_interface/src/decode
diff options
context:
space:
mode:
authorSverker Eriksson <[email protected]>2018-03-19 19:13:29 +0100
committerSverker Eriksson <[email protected]>2018-04-19 15:18:58 +0200
commit1ab478a7ce281f7cdce01df2fe04953c0770fdbc (patch)
treef20f9caf78faad66129c9059276f281c7908387c /lib/erl_interface/src/decode
parent1d3acb70debd134c8346b7e98347171d5cf6fc62 (diff)
downloadotp-1ab478a7ce281f7cdce01df2fe04953c0770fdbc.tar.gz
otp-1ab478a7ce281f7cdce01df2fe04953c0770fdbc.tar.bz2
otp-1ab478a7ce281f7cdce01df2fe04953c0770fdbc.zip
erl_interface: Optimize latin1_to_utf8 and friend
to do word wise check/copy for pure ASCII if ARCH allows it (x86 and amd64).
Diffstat (limited to 'lib/erl_interface/src/decode')
-rw-r--r--lib/erl_interface/src/decode/decode_atom.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/lib/erl_interface/src/decode/decode_atom.c b/lib/erl_interface/src/decode/decode_atom.c
index b3bba82434..87cd75b1be 100644
--- a/lib/erl_interface/src/decode/decode_atom.c
+++ b/lib/erl_interface/src/decode/decode_atom.c
@@ -92,6 +92,51 @@ int ei_decode_atom_as(const char *buf, int *index, char* p, int destlen,
}
+
+#ifdef HAVE_UNALIGNED_WORD_ACCESS
+
+#if SIZEOF_VOID_P == SIZEOF_LONG
+typedef unsigned long AsciiWord;
+#elif SIZEOF_VOID_P == SIZEOF_LONG_LONG
+typedef unsigned long long AsciiWord;
+#else
+# error "Uknown word type"
+#endif
+
+#if SIZEOF_VOID_P == 4
+# define ASCII_CHECK_MASK ((AsciiWord)0x80808080U)
+#elif SIZEOF_VOID_P == 8
+# define ASCII_CHECK_MASK ((AsciiWord)0x8080808080808080U)
+#endif
+
+static int ascii_fast_track(char* dst, const char* src, int slen, int destlen)
+{
+ const AsciiWord* src_word = (AsciiWord*) src;
+ const AsciiWord* const src_word_end = src_word + (slen / sizeof(AsciiWord));
+
+ if (destlen < slen)
+ return 0;
+
+ if (dst) {
+ AsciiWord* dst_word = (AsciiWord*)dst;
+
+ while (src_word < src_word_end) {
+ if ((*src_word & ASCII_CHECK_MASK) != 0)
+ break;
+ *dst_word++ = *src_word++;
+ }
+ }
+ else {
+ while (src_word < src_word_end) {
+ if ((*src_word & ASCII_CHECK_MASK) != 0)
+ break;
+ src_word++;
+ }
+ }
+ return (char*)src_word - src;
+}
+#endif /* HAVE_UNALIGNED_WORD_ACCESS */
+
int utf8_to_latin1(char* dst, const char* src, int slen, int destlen,
erlang_char_encoding* res_encp)
{
@@ -99,6 +144,15 @@ int utf8_to_latin1(char* dst, const char* src, int slen, int destlen,
const char* const dst_end = dst + destlen;
int found_non_ascii = 0;
+#ifdef HAVE_UNALIGNED_WORD_ACCESS
+ {
+ int aft = ascii_fast_track(dst, src, slen, destlen);
+ src += aft;
+ slen -= aft;
+ dst += aft;
+ }
+#endif
+
while (slen > 0) {
if (dst >= dst_end) return -1;
if ((src[0] & 0x80) == 0) {
@@ -136,6 +190,14 @@ int latin1_to_utf8(char* dst, const char* src, int slen, int destlen,
const char* const dst_end = dst + destlen;
int found_non_ascii = 0;
+#ifdef HAVE_UNALIGNED_WORD_ACCESS
+ {
+ int aft = ascii_fast_track(dst, src, slen, destlen);
+ dst += aft;
+ src += aft;
+ }
+#endif
+
while (src < src_end) {
if (dst >= dst_end) return -1;
if ((src[0] & 0x80) == 0) {