Make the two IncrementalCopy* functions take in an ssize_t instead of a len,
in order to avoid having to do 32-to-64-bit signed conversions on a hot path
during decompression. (Also fixes some MSVC warnings, mentioned in public
issue 75, but more of those remain.) They cannot be size_t because we expect
them to go negative and test for that.
This saves a few movzwl instructions, yielding ~2% speedup in decompression.
Sandy Bridge:
Benchmark Base (ns) New (ns) Improvement
-------------------------------------------------------------------------------------------------
BM_UFlat/0 48009 41283 2.3GB/s html +16.3%
BM_UFlat/1 531274 513419 1.3GB/s urls +3.5%
BM_UFlat/2 7378 7062 16.8GB/s jpg +4.5%
BM_UFlat/3 92 92 2.0GB/s jpg_200 +0.0%
BM_UFlat/4 15057 14974 5.9GB/s pdf +0.6%
BM_UFlat/5 204323 193140 2.0GB/s html4 +5.8%
BM_UFlat/6 13282 12611 1.8GB/s cp +5.3%
BM_UFlat/7 6511 6504 1.6GB/s c +0.1%
BM_UFlat/8 2014 2030 1.7GB/s lsp -0.8%
BM_UFlat/9 775909 768336 1.3GB/s xls +1.0%
BM_UFlat/10 182 184 1043.2MB/s xls_200 -1.1%
BM_UFlat/11 167352 161630 901.2MB/s txt1 +3.5%
BM_UFlat/12 147393 142246 842.8MB/s txt2 +3.6%
BM_UFlat/13 449960 432853 944.4MB/s txt3 +4.0%
BM_UFlat/14 620497 594845 775.9MB/s txt4 +4.3%
BM_UFlat/15 265610 267356 1.8GB/s bin -0.7%
BM_UFlat/16 206 205 932.7MB/s bin_200 +0.5%
BM_UFlat/17 25561 24730 1.4GB/s sum +3.4%
BM_UFlat/18 2620 2644 1.5GB/s man -0.9%
BM_UFlat/19 45766 38589 2.9GB/s pb +18.6%
BM_UFlat/20 171107 169832 1039.5MB/s gaviota +0.8%
Sum of all benchmarks 3500103 3394565 +3.1%
Westmere:
Benchmark Base (ns) New (ns) Improvement
-------------------------------------------------------------------------------------------------
BM_UFlat/0 72624 71526 1.3GB/s html +1.5%
BM_UFlat/1 735821 722917 930.8MB/s urls +1.8%
BM_UFlat/2 10450 10172 11.7GB/s jpg +2.7%
BM_UFlat/3 117 117 1.6GB/s jpg_200 +0.0%
BM_UFlat/4 29817 29648 3.0GB/s pdf +0.6%
BM_UFlat/5 297126 293073 1.3GB/s html4 +1.4%
BM_UFlat/6 28252 27994 842.0MB/s cp +0.9%
BM_UFlat/7 12672 12391 862.1MB/s c +2.3%
BM_UFlat/8 3507 3425 1040.9MB/s lsp +2.4%
BM_UFlat/9 1004268 969395 1018.0MB/s xls +3.6%
BM_UFlat/10 233 227 844.8MB/s xls_200 +2.6%
BM_UFlat/11 230054 224981 647.8MB/s txt1 +2.3%
BM_UFlat/12 201229 196447 610.5MB/s txt2 +2.4%
BM_UFlat/13 609547 596761 685.3MB/s txt3 +2.1%
BM_UFlat/14 824362 804821 573.8MB/s txt4 +2.4%
BM_UFlat/15 371095 374899 1.3GB/s bin -1.0%
BM_UFlat/16 267 267 717.8MB/s bin_200 +0.0%
BM_UFlat/17 44623 43828 835.9MB/s sum +1.8%
BM_UFlat/18 5077 4815 841.0MB/s man +5.4%
BM_UFlat/19 74964 73210 1.5GB/s pb +2.4%
BM_UFlat/20 237987 236745 746.0MB/s gaviota +0.5%
Sum of all benchmarks 4794092 4697659 +2.1%
Istanbul:
Benchmark Base (ns) New (ns) Improvement
-------------------------------------------------------------------------------------------------
BM_UFlat/0 98614 96376 1020.4MB/s html +2.3%
BM_UFlat/1 963740 953241 707.2MB/s urls +1.1%
BM_UFlat/2 25042 24769 4.8GB/s jpg +1.1%
BM_UFlat/3 180 180 1065.6MB/s jpg_200 +0.0%
BM_UFlat/4 45942 45403 1.9GB/s pdf +1.2%
BM_UFlat/5 400135 390226 1008.2MB/s html4 +2.5%
BM_UFlat/6 37768 37392 631.9MB/s cp +1.0%
BM_UFlat/7 18585 18200 588.2MB/s c +2.1%
BM_UFlat/8 5751 5690 627.7MB/s lsp +1.1%
BM_UFlat/9 1543154 1542209 641.4MB/s xls +0.1%
BM_UFlat/10 381 388 494.6MB/s xls_200 -1.8%
BM_UFlat/11 339715 331973 440.1MB/s txt1 +2.3%
BM_UFlat/12 294807 289418 415.4MB/s txt2 +1.9%
BM_UFlat/13 906160 884094 463.3MB/s txt3 +2.5%
BM_UFlat/14 1224221 1198435 386.1MB/s txt4 +2.2%
BM_UFlat/15 516277 502923 979.5MB/s bin +2.7%
BM_UFlat/16 405 402 477.2MB/s bin_200 +0.7%
BM_UFlat/17 61640 60621 605.6MB/s sum +1.7%
BM_UFlat/18 7326 7383 549.5MB/s man -0.8%
BM_UFlat/19 94720 92653 1.2GB/s pb +2.2%
BM_UFlat/20 360435 346687 510.6MB/s gaviota +4.0%
Sum of all benchmarks 6944998 6828663 +1.7%
git-svn-id: https://snappy.googlecode.com/svn/trunk@77 03e5f5b5-db94-4691-08a0-1a8bf15f6143
1 file changed
