On Mon, Feb 8, 2021 at 6:08 AM H.J. Lu wrote: > > On Tue, Feb 2, 2021 at 9:39 PM wrote: > > > > From: noah > > > > This patch adds additional benchmarks and tests for string size of > > 4096 and several benchmarks for string size 256 with different > > alignments. > > > > Signed-off-by: noah > > --- > > Added 2 additional benchmark and test sizes: > > > > 4096: Just feels like a natural "large" size to test > > > > 256 with multiple alignments: This essentially is to test how > > expensive the initial work prior to the 4x loop is depending on > > different alignments. > > > > results from bench-strchr: All times are in seconds and the medium of > > 100 runs. Old is current strchr-avx2.S implementation. New is this > > patch. > > > > Summary: New is definetly faster for medium -> large sizes. Once the > > 4x loop is hit there is a 10%+ speedup and New always wins out. For > > smaller sizes there is more variance as to which is faster and the > > differences are small. Generally it seems the New version wins > > out. This is likely because 0 - 31 sized strings are the fast path for > > new (no jmp). Also something that is neat is the significant > > performance improved for alignment 96 and 112. This is because the 5x > > vectors before 4x loop really favor that alignment. > > > > Benchmarking CPU: > > Icelake: Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz > > > > size, algn, Old T , New T -------- Win Dif > > 0 , 0 , 2.54 , 2.52 -------- New -0.02 > > 1 , 0 , 2.57 , 2.52 -------- New -0.05 > > 2 , 0 , 2.56 , 2.52 -------- New -0.04 > > 3 , 0 , 2.58 , 2.54 -------- New -0.04 > > 4 , 0 , 2.61 , 2.55 -------- New -0.06 > > 5 , 0 , 2.65 , 2.62 -------- New -0.03 > > 6 , 0 , 2.73 , 2.74 -------- Old -0.01 > > 7 , 0 , 2.75 , 2.74 -------- New -0.01 > > 8 , 0 , 2.62 , 2.6 -------- New -0.02 > > 9 , 0 , 2.73 , 2.75 -------- Old -0.02 > > 10 , 0 , 2.74 , 2.74 -------- Eq N/A > > 11 , 0 , 2.76 , 2.72 -------- New -0.04 > > 12 , 0 , 2.74 , 2.72 -------- New -0.02 > > 13 , 0 , 2.75 , 2.72 -------- New -0.03 > > 14 , 0 , 2.74 , 2.73 -------- New -0.01 > > 15 , 0 , 2.74 , 2.73 -------- New -0.01 > > 16 , 0 , 2.74 , 2.73 -------- New -0.01 > > 17 , 0 , 2.74 , 2.74 -------- Eq N/A > > 18 , 0 , 2.73 , 2.73 -------- Eq N/A > > 19 , 0 , 2.73 , 2.73 -------- Eq N/A > > 20 , 0 , 2.73 , 2.73 -------- Eq N/A > > 21 , 0 , 2.73 , 2.72 -------- New -0.01 > > 22 , 0 , 2.71 , 2.74 -------- Old -0.03 > > 23 , 0 , 2.71 , 2.69 -------- New -0.02 > > 24 , 0 , 2.68 , 2.67 -------- New -0.01 > > 25 , 0 , 2.66 , 2.62 -------- New -0.04 > > 26 , 0 , 2.64 , 2.62 -------- New -0.02 > > 27 , 0 , 2.71 , 2.64 -------- New -0.07 > > 28 , 0 , 2.67 , 2.69 -------- Old -0.02 > > 29 , 0 , 2.72 , 2.72 -------- Eq N/A > > 30 , 0 , 2.68 , 2.69 -------- Old -0.01 > > 31 , 0 , 2.68 , 2.68 -------- Eq N/A > > 32 , 0 , 3.51 , 3.52 -------- Old -0.01 > > 32 , 1 , 3.52 , 3.51 -------- New -0.01 > > 64 , 0 , 3.97 , 3.93 -------- New -0.04 > > 64 , 2 , 3.95 , 3.9 -------- New -0.05 > > 64 , 1 , 4.0 , 3.93 -------- New -0.07 > > 64 , 3 , 3.97 , 3.88 -------- New -0.09 > > 64 , 4 , 3.95 , 3.89 -------- New -0.06 > > 64 , 5 , 3.94 , 3.9 -------- New -0.04 > > 64 , 6 , 3.97 , 3.9 -------- New -0.07 > > 64 , 7 , 3.97 , 3.91 -------- New -0.06 > > 96 , 0 , 4.74 , 4.52 -------- New -0.22 > > 128 , 0 , 5.29 , 5.19 -------- New -0.1 > > 128 , 2 , 5.29 , 5.15 -------- New -0.14 > > 128 , 3 , 5.31 , 5.22 -------- New -0.09 > > 256 , 0 , 11.19 , 9.81 -------- New -1.38 > > 256 , 3 , 11.19 , 9.84 -------- New -1.35 > > 256 , 4 , 11.2 , 9.88 -------- New -1.32 > > 256 , 16 , 11.21 , 9.79 -------- New -1.42 > > 256 , 32 , 11.39 , 10.34 -------- New -1.05 > > 256 , 48 , 11.88 , 10.56 -------- New -1.32 > > 256 , 64 , 11.82 , 10.83 -------- New -0.99 > > 256 , 80 , 11.85 , 10.86 -------- New -0.99 > > 256 , 96 , 9.56 , 8.76 -------- New -0.8 > > 256 , 112 , 9.55 , 8.9 -------- New -0.65 > > 512 , 0 , 15.76 , 13.72 -------- New -2.04 > > 512 , 4 , 15.72 , 13.74 -------- New -1.98 > > 512 , 5 , 15.73 , 13.74 -------- New -1.99 > > 1024, 0 , 24.85 , 21.33 -------- New -3.52 > > 1024, 5 , 24.86 , 21.27 -------- New -3.59 > > 1024, 6 , 24.87 , 21.32 -------- New -3.55 > > 2048, 0 , 45.75 , 36.7 -------- New -9.05 > > 2048, 6 , 43.91 , 35.42 -------- New -8.49 > > 2048, 7 , 44.43 , 36.37 -------- New -8.06 > > 4096, 0 , 96.94 , 81.34 -------- New -15.6 > > 4096, 7 , 97.01 , 81.32 -------- New -15.69 > > > > benchtests/bench-strchr.c | 26 +++++++++++++++++++++++++- > > string/test-strchr.c | 26 +++++++++++++++++++++++++- > > 2 files changed, 50 insertions(+), 2 deletions(-) > > > > diff --git a/benchtests/bench-strchr.c b/benchtests/bench-strchr.c > > index bf493fe458..4ce2369d9b 100644 > > --- a/benchtests/bench-strchr.c > > +++ b/benchtests/bench-strchr.c > > @@ -100,7 +100,7 @@ do_test (size_t align, size_t pos, size_t len, int seek_char, int max_char) > > size_t i; > > CHAR *result; > > CHAR *buf = (CHAR *) buf1; > > - align &= 15; > > + align &= 127; > > if ((align + len) * sizeof (CHAR) >= page_size) > > return; > > > > @@ -151,12 +151,24 @@ test_main (void) > > do_test (i, 16 << i, 2048, SMALL_CHAR, MIDDLE_CHAR); > > } > > > > + for (i = 1; i < 8; ++i) > > + { > > + do_test (0, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > > + do_test (i, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > > + } > > + > > for (i = 1; i < 8; ++i) > > { > > do_test (i, 64, 256, SMALL_CHAR, MIDDLE_CHAR); > > do_test (i, 64, 256, SMALL_CHAR, BIG_CHAR); > > } > > > > + for (i = 0; i < 8; ++i) > > + { > > + do_test (16 * i, 256, 512, SMALL_CHAR, MIDDLE_CHAR); > > + do_test (16 * i, 256, 512, SMALL_CHAR, BIG_CHAR); > > + } > > + > > for (i = 0; i < 32; ++i) > > { > > do_test (0, i, i + 1, SMALL_CHAR, MIDDLE_CHAR); > > @@ -169,12 +181,24 @@ test_main (void) > > do_test (i, 16 << i, 2048, 0, MIDDLE_CHAR); > > } > > > > + for (i = 1; i < 8; ++i) > > + { > > + do_test (0, 16 << i, 4096, 0, MIDDLE_CHAR); > > + do_test (i, 16 << i, 4096, 0, MIDDLE_CHAR); > > + } > > + > > for (i = 1; i < 8; ++i) > > { > > do_test (i, 64, 256, 0, MIDDLE_CHAR); > > do_test (i, 64, 256, 0, BIG_CHAR); > > } > > > > + for (i = 0; i < 8; ++i) > > + { > > + do_test (16 * i, 256, 512, 0, MIDDLE_CHAR); > > + do_test (16 * i, 256, 512, 0, BIG_CHAR); > > + } > > + > > for (i = 0; i < 32; ++i) > > { > > do_test (0, i, i + 1, 0, MIDDLE_CHAR); > > diff --git a/string/test-strchr.c b/string/test-strchr.c > > index 5b6022746c..2cf4ea2add 100644 > > --- a/string/test-strchr.c > > +++ b/string/test-strchr.c > > @@ -130,7 +130,7 @@ do_test (size_t align, size_t pos, size_t len, int seek_char, int max_char) > > size_t i; > > CHAR *result; > > CHAR *buf = (CHAR *) buf1; > > - align &= 15; > > + align &= 127; > > if ((align + len) * sizeof (CHAR) >= page_size) > > return; > > > > @@ -259,12 +259,24 @@ test_main (void) > > do_test (i, 16 << i, 2048, SMALL_CHAR, MIDDLE_CHAR); > > } > > > > + for (i = 1; i < 8; ++i) > > + { > > + do_test (0, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > > + do_test (i, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > > + } > > + > > for (i = 1; i < 8; ++i) > > { > > do_test (i, 64, 256, SMALL_CHAR, MIDDLE_CHAR); > > do_test (i, 64, 256, SMALL_CHAR, BIG_CHAR); > > } > > > > + for (i = 0; i < 8; ++i) > > + { > > + do_test (16 * i, 256, 512, SMALL_CHAR, MIDDLE_CHAR); > > + do_test (16 * i, 256, 512, SMALL_CHAR, BIG_CHAR); > > + } > > + > > for (i = 0; i < 32; ++i) > > { > > do_test (0, i, i + 1, SMALL_CHAR, MIDDLE_CHAR); > > @@ -277,12 +289,24 @@ test_main (void) > > do_test (i, 16 << i, 2048, 0, MIDDLE_CHAR); > > } > > > > + for (i = 1; i < 8; ++i) > > + { > > + do_test (0, 16 << i, 4096, 0, MIDDLE_CHAR); > > + do_test (i, 16 << i, 4096, 0, MIDDLE_CHAR); > > + } > > + > > for (i = 1; i < 8; ++i) > > { > > do_test (i, 64, 256, 0, MIDDLE_CHAR); > > do_test (i, 64, 256, 0, BIG_CHAR); > > } > > > > + for (i = 0; i < 8; ++i) > > + { > > + do_test (16 * i, 256, 512, 0, MIDDLE_CHAR); > > + do_test (16 * i, 256, 512, 0, BIG_CHAR); > > + } > > + > > for (i = 0; i < 32; ++i) > > { > > do_test (0, i, i + 1, 0, MIDDLE_CHAR); > > -- > > 2.29.2 > > > > LGTM. > > Thanks. > > -- > H.J. This is the updated patch with extra white spaces fixed I am checking in. -- H.J.