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author | Thiago Macieira <thiago.macieira@nokia.com> | 2010-08-24 10:15:36 (GMT) |
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committer | Thiago Macieira <thiago.macieira@nokia.com> | 2010-08-24 10:36:45 (GMT) |
commit | 9a468f59472e8978aa18b75e9786718a8823bbec (patch) | |
tree | f4d10c172a4b1adf836dcdd4551b70c412a8255e /tests | |
parent | 469210fdf9287dc8a4933e0761bbff91a031045f (diff) | |
download | Qt-9a468f59472e8978aa18b75e9786718a8823bbec.zip Qt-9a468f59472e8978aa18b75e9786718a8823bbec.tar.gz Qt-9a468f59472e8978aa18b75e9786718a8823bbec.tar.bz2 |
Unroll the SSSE3 code even more to avoid the need to keep an extra variable for inverting the result
On 32-bit, we're out of registers already, so this variable ended up in memory
Diffstat (limited to 'tests')
-rw-r--r-- | tests/benchmarks/corelib/tools/qstring/main.cpp | 88 |
1 files changed, 53 insertions, 35 deletions
diff --git a/tests/benchmarks/corelib/tools/qstring/main.cpp b/tests/benchmarks/corelib/tools/qstring/main.cpp index 3b86792..9616052 100644 --- a/tests/benchmarks/corelib/tools/qstring/main.cpp +++ b/tests/benchmarks/corelib/tools/qstring/main.cpp @@ -1218,42 +1218,60 @@ static int ucstrncmp_ssse3_aligning2(const ushort *a, const ushort *b, int len) // both a and b are misaligned // we'll call the alignr function with the alignment *difference* between the two - int val = (quintptr(a) & 0xf) - (quintptr(b) & 0xf); - bool invert = false; - if (val < 0) { - val = -val; - //qSwap(a, b); - asm ("xchg %0, %1" : "+r" (a), "+r" (b)); - invert = true; - } - - // from this point on, b has the shortest alignment - // and align(a) = align(b) + val - // round down the alignment so align(b) == align(a) == 0 - int garbage = (quintptr(b) & 0xf); - a = (const ushort*)(quintptr(a) & ~0xf); - b = (const ushort*)(quintptr(b) & ~0xf); - - // now the first load of b will load 'garbage' extra bytes - // and the first load of a will load 'garbage + val' extra bytes - if (val == 8) - return conditional_invert(ucstrncmp_ssse3_aligning2_alignr<8>(a, b, len, garbage), invert); - else if (val == 0) - return conditional_invert(ucstrncmp_ssse3_aligning2_aligned(a, b, len, garbage), invert); - if (val < 8) { - if (val < 4) - return conditional_invert(ucstrncmp_ssse3_aligning2_alignr<2>(a, b, len, garbage), invert); - else if (val == 4) - return conditional_invert(ucstrncmp_ssse3_aligning2_alignr<4>(a, b, len, garbage), invert); - else - return conditional_invert(ucstrncmp_ssse3_aligning2_alignr<6>(a, b, len, garbage), invert); + int offset = (quintptr(a) & 0xf) - (quintptr(b) & 0xf); + if (offset >= 0) { + // from this point on, b has the shortest alignment + // and align(a) = align(b) + offset + // round down the alignment so align(b) == align(a) == 0 + int garbage = (quintptr(b) & 0xf); + a = (const ushort*)(quintptr(a) & ~0xf); + b = (const ushort*)(quintptr(b) & ~0xf); + + // now the first load of b will load 'garbage' extra bytes + // and the first load of a will load 'garbage + offset' extra bytes + if (offset == 8) + return ucstrncmp_ssse3_aligning2_alignr<8>(a, b, len, garbage); + if (offset == 0) + return ucstrncmp_ssse3_aligning2_aligned(a, b, len, garbage); + if (offset < 8) { + if (offset < 4) + return ucstrncmp_ssse3_aligning2_alignr<2>(a, b, len, garbage); + else if (offset == 4) + return ucstrncmp_ssse3_aligning2_alignr<4>(a, b, len, garbage); + else + return ucstrncmp_ssse3_aligning2_alignr<6>(a, b, len, garbage); + } else { + if (offset < 12) + return ucstrncmp_ssse3_aligning2_alignr<10>(a, b, len, garbage); + else if (offset == 12) + return ucstrncmp_ssse3_aligning2_alignr<12>(a, b, len, garbage); + else + return ucstrncmp_ssse3_aligning2_alignr<14>(a, b, len, garbage); + } } else { - if (val < 12) - return conditional_invert(ucstrncmp_ssse3_aligning2_alignr<10>(a, b, len, garbage), invert); - else if (val == 12) - return conditional_invert(ucstrncmp_ssse3_aligning2_alignr<12>(a, b, len, garbage), invert); - else - return conditional_invert(ucstrncmp_ssse3_aligning2_alignr<14>(a, b, len, garbage), invert); + // same as above but inverted + int garbage = (quintptr(a) & 0xf); + a = (const ushort*)(quintptr(a) & ~0xf); + b = (const ushort*)(quintptr(b) & ~0xf); + + offset = -offset; + if (offset == 8) + return -ucstrncmp_ssse3_aligning2_alignr<8>(b, a, len, garbage); + if (offset < 8) { + if (offset < 4) + return -ucstrncmp_ssse3_aligning2_alignr<2>(b, a, len, garbage); + else if (offset == 4) + return -ucstrncmp_ssse3_aligning2_alignr<4>(b, a, len, garbage); + else + return -ucstrncmp_ssse3_aligning2_alignr<6>(b, a, len, garbage); + } else { + if (offset < 12) + return -ucstrncmp_ssse3_aligning2_alignr<10>(b, a, len, garbage); + else if (offset == 12) + return -ucstrncmp_ssse3_aligning2_alignr<12>(b, a, len, garbage); + else + return -ucstrncmp_ssse3_aligning2_alignr<14>(b, a, len, garbage); + } } } |