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| author | Thiago Macieira <thiago.macieira@nokia.com> | 2010-08-18 10:26:36 (GMT) |
|---|---|---|
| committer | Thiago Macieira <thiago.macieira@nokia.com> | 2010-08-24 10:36:40 (GMT) |
| commit | 6cea948a0ceabe5493bb2a75f236b008b47fd71e (patch) | |
| tree | bc34de5aa33fc63ed00bd3059f498ed96eb380e1 /tests/benchmarks | |
| parent | 6f913f94c6b6aaf8514bc62d4f9939ac44e211fb (diff) | |
| download | Qt-6cea948a0ceabe5493bb2a75f236b008b47fd71e.zip Qt-6cea948a0ceabe5493bb2a75f236b008b47fd71e.tar.gz Qt-6cea948a0ceabe5493bb2a75f236b008b47fd71e.tar.bz2 | |
Optimise the tail comparison of ucstrncmp
Diffstat (limited to 'tests/benchmarks')
| -rw-r--r-- | tests/benchmarks/corelib/tools/qstring/main.cpp | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/tests/benchmarks/corelib/tools/qstring/main.cpp b/tests/benchmarks/corelib/tools/qstring/main.cpp index 608e2bc..0b7254f 100644 --- a/tests/benchmarks/corelib/tools/qstring/main.cpp +++ b/tests/benchmarks/corelib/tools/qstring/main.cpp @@ -881,6 +881,40 @@ static int ucstrncmp_intwise(const ushort *a, const ushort *b, int len) } #ifdef __SSE2__ +static inline int ucstrncmp_short_tail(const ushort *p1, const ushort *p2, int len) +{ + if (len) { + if (*p1 != *p2) + return *p1 - *p2; + if (--len) { + if (p1[1] != p2[1]) + return p1[1] - p2[1]; + if (--len) { + if (p1[2] != p2[2]) + return p1[2] - p2[2]; + if (--len) { + if (p1[3] != p2[3]) + return p1[3] - p2[3]; + if (--len) { + if (p1[4] != p2[4]) + return p1[4] - p2[4]; + if (--len) { + if (p1[5] != p2[5]) + return p1[5] - p2[5]; + if (--len) { + if (p1[6] != p2[6]) + return p1[6] - p2[6]; + return p1[7] - p2[7]; + } + } + } + } + } + } + } + return 0; +} + static inline int bsf_nonzero(register long val) { int result; @@ -911,7 +945,7 @@ static __attribute__((optimize("no-unroll-loops"))) int ucstrncmp_sse2(const ush counter += 8; len -= 8; } - return ucstrncmp_shortwise(a + counter, b + counter, len); + return ucstrncmp_short_tail(a + counter, b + counter, len); } static __attribute__((optimize("no-unroll-loops"))) int ucstrncmp_sse2_aligning(const ushort *a, const ushort *b, int len) @@ -950,7 +984,7 @@ static __attribute__((optimize("no-unroll-loops"))) int ucstrncmp_sse2_aligning( counter += 8; len -= 8; } - return ucstrncmp_shortwise(a + counter, b + counter, len); + return ucstrncmp_short_tail(a + counter, b + counter, len); } #endif |