diff options
| author | Arseny Kapoulkine <arseny.kapoulkine@gmail.com> | 2014-10-04 05:03:33 +0000 |
|---|---|---|
| committer | Arseny Kapoulkine <arseny.kapoulkine@gmail.com> | 2014-10-04 05:03:33 +0000 |
| commit | 42219590f3ea1e88e41f8250da5a123f3a9236b2 (patch) | |
| tree | 060acf61be3252d7e5b42550b79a6268b8acc079 /src/pugixml.cpp | |
| parent | 8a402b480fc88efec8ce0897fb6cdddac147992d (diff) | |
Optimize unrolled scanning for MSVC
While gcc and clang can eliminate dependency on s in the inner loop of
PUGI__SCANWHILE_UNROLL, MSVC emits a series of register increments.
Rewriting the code to explicitly remove the dependency keeps similar
codegen on gcc/clang but improves codegen on MSVC for a 10% performance
boost.
Also use unrolled scanning in text_output_escaped (2% faster).
git-svn-id: https://pugixml.googlecode.com/svn/trunk@1048 99668b35-9821-0410-8761-19e4c4f06640
Diffstat (limited to 'src/pugixml.cpp')
| -rw-r--r-- | src/pugixml.cpp | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/src/pugixml.cpp b/src/pugixml.cpp index 6506a5e..55dd8ec 100644 --- a/src/pugixml.cpp +++ b/src/pugixml.cpp @@ -1916,7 +1916,7 @@ PUGI__NS_BEGIN #define PUGI__POPNODE() { cursor = cursor->parent; } #define PUGI__SCANFOR(X) { while (*s != 0 && !(X)) ++s; } #define PUGI__SCANWHILE(X) { while (X) ++s; } - #define PUGI__SCANWHILE_UNROLL(X) { while (X) { ++s; if (PUGI__UNLIKELY(!(X))) break; ++s; if (PUGI__UNLIKELY(!(X))) break; ++s; if (PUGI__UNLIKELY(!(X))) break; ++s; } } + #define PUGI__SCANWHILE_UNROLL(X) { for (;;) { char_t ss = s[0]; if (PUGI__UNLIKELY(!(X))) { break; } ss = s[1]; if (PUGI__UNLIKELY(!(X))) { s += 1; break; } ss = s[2]; if (PUGI__UNLIKELY(!(X))) { s += 2; break; } ss = s[3]; if (PUGI__UNLIKELY(!(X))) { s += 3; break; } s += 4; } } #define PUGI__ENDSEG() { ch = *s; *s = 0; ++s; } #define PUGI__THROW_ERROR(err, m) return error_offset = m, error_status = err, static_cast<char_t*>(0) #define PUGI__CHECK_ERROR(err, m) { if (*s == 0) PUGI__THROW_ERROR(err, m); } @@ -1927,7 +1927,7 @@ PUGI__NS_BEGIN while (true) { - PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(*s, ct_parse_comment)); + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_comment)); if (*s == '\r') // Either a single 0x0d or 0x0d 0x0a pair { @@ -1955,7 +1955,7 @@ PUGI__NS_BEGIN while (true) { - PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(*s, ct_parse_cdata)); + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_cdata)); if (*s == '\r') // Either a single 0x0d or 0x0d 0x0a pair { @@ -1989,7 +1989,7 @@ PUGI__NS_BEGIN while (true) { - PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(*s, ct_parse_pcdata)); + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_pcdata)); if (*s == '<') // PCDATA ends here { @@ -2069,7 +2069,7 @@ PUGI__NS_BEGIN while (true) { - PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(*s, ct_parse_attr_ws | ct_space)); + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws | ct_space)); if (*s == end_quote) { @@ -2110,7 +2110,7 @@ PUGI__NS_BEGIN while (true) { - PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(*s, ct_parse_attr_ws)); + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws)); if (*s == end_quote) { @@ -2146,7 +2146,7 @@ PUGI__NS_BEGIN while (true) { - PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(*s, ct_parse_attr)); + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr)); if (*s == end_quote) { @@ -2178,7 +2178,7 @@ PUGI__NS_BEGIN while (true) { - PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(*s, ct_parse_attr)); + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr)); if (*s == end_quote) { @@ -2580,7 +2580,7 @@ PUGI__NS_BEGIN cursor->name = s; - PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(*s, ct_symbol)); // Scan for a terminator. + PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol)); // Scan for a terminator. PUGI__ENDSEG(); // Save char in 'ch', terminate & step over. if (ch == '>') @@ -2601,7 +2601,7 @@ PUGI__NS_BEGIN a->name = s; // Save the offset. - PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(*s, ct_symbol)); // Scan for a terminator. + PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol)); // Scan for a terminator. PUGI__CHECK_ERROR(status_bad_attribute, s); //$ redundant, left for performance PUGI__ENDSEG(); // Save char in 'ch', terminate & step over. @@ -3257,7 +3257,7 @@ PUGI__NS_BEGIN const char_t* prev = s; // While *s is a usual symbol - while (!PUGI__IS_CHARTYPEX(*s, type)) ++s; + PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPEX(ss, type)); writer.write_buffer(prev, static_cast<size_t>(s - prev)); |