[PATCH v1 3/3] x86: Optimize memchr-evex.S
H.J. Lu
hjl.tools@gmail.com
Mon May 3 18:58:43 GMT 2021
On Mon, May 03, 2021 at 04:44:38AM -0400, Noah Goldstein wrote:
> No bug. This commit optimizes memchr-evex.S. The optimizations include
> replacing some branches with cmovcc, avoiding some branches entirely
> in the less_4x_vec case, making the page cross logic less strict,
> saving some ALU in the alignment process, and most importantly
> increasing ILP in the 4x loop. test-memchr, test-rawmemchr, and
> test-wmemchr are all passing.
>
> Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
> ---
> Tests where run on the following CPUs:
>
> Tigerlake: https://ark.intel.com/content/www/us/en/ark/products/208921/intel-core-i7-1165g7-processor-12m-cache-up-to-4-70-ghz-with-ipu.html
>
> Icelake: https://ark.intel.com/content/www/us/en/ark/products/196597/intel-core-i7-1065g7-processor-8m-cache-up-to-3-90-ghz.html
>
> Skylake: https://ark.intel.com/content/www/us/en/ark/products/149091/intel-core-i7-8565u-processor-8m-cache-up-to-4-60-ghz.html
>
> All times are the geometric mean of N=20. The unit of time is
> seconds.
>
> "Cur" refers to the current implementation
> "New" refers to this patches implementation
>
> Note: The numbers for size = [1, 32] are highly dependent on function
> alignment. That being said the new implementation which uses cmovcc
> instead of a branch (mostly for the reason of high variance with
> different alignments) for the [1, 32] case is far more consistent and
> performs about as well (and should only be a bigger improvement in
> cases where the sizes / position are not 100% predictable).
>
> For memchr-evex the numbers are a near universal improvement. The case
> where the current implement as better is for size = 0 and for size =
> [1, 32] with pos < size the two implementations are about the
> same. For size = [1, 32] with pos > size, for medium range sizes, and
> large size, however, the new implementation is faster.
>
> Results For Tigerlake memchr-evex
> size , algn , Pos , Cur T , New T , Win , Dif
> 2048 , 0 , , 32 5.58 , 5.22 , New , 0.36
> 256 , 1 , , 64 5.22 , 4.93 , New , 0.29
> 2048 , 0 , , 64 5.22 , 4.89 , New , 0.33
> 256 , 2 , , 64 5.14 , 4.81 , New , 0.33
> 2048 , 0 , , 128 6.3 , 5.67 , New , 0.63
> 256 , 3 , , 64 5.22 , 4.9 , New , 0.32
> 2048 , 0 , , 256 11.07 , 10.92 , New , 0.15
> 256 , 4 , , 64 5.16 , 4.86 , New , 0.3
> 2048 , 0 , , 512 15.66 , 14.81 , New , 0.85
> 256 , 5 , , 64 5.15 , 4.84 , New , 0.31
> 2048 , 0 , , 1024 25.7 , 23.02 , New , 2.68
> 256 , 6 , , 64 5.12 , 4.89 , New , 0.23
> 2048 , 0 , , 2048 42.34 , 37.71 , New , 4.63
> 256 , 7 , , 64 5.03 , 4.62 , New , 0.41
> 192 , 1 , , 32 4.96 , 4.28 , New , 0.68
> 256 , 1 , , 32 4.95 , 4.28 , New , 0.67
> 512 , 1 , , 32 4.94 , 4.29 , New , 0.65
> 192 , 2 , , 64 5.1 , 4.8 , New , 0.3
> 512 , 2 , , 64 5.12 , 4.72 , New , 0.4
> 192 , 3 , , 96 5.54 , 5.12 , New , 0.42
> 256 , 3 , , 96 5.52 , 5.15 , New , 0.37
> 512 , 3 , , 96 5.51 , 5.16 , New , 0.35
> 192 , 4 , , 128 6.1 , 5.53 , New , 0.57
> 256 , 4 , , 128 6.09 , 5.49 , New , 0.6
> 512 , 4 , , 128 6.08 , 5.48 , New , 0.6
> 192 , 5 , , 160 7.42 , 6.71 , New , 0.71
> 256 , 5 , , 160 6.86 , 6.71 , New , 0.15
> 512 , 5 , , 160 9.28 , 8.68 , New , 0.6
> 192 , 6 , , 192 7.94 , 7.47 , New , 0.47
> 256 , 6 , , 192 7.62 , 7.17 , New , 0.45
> 512 , 6 , , 192 9.2 , 9.16 , New , 0.04
> 192 , 7 , , 224 8.02 , 7.43 , New , 0.59
> 256 , 7 , , 224 8.34 , 7.85 , New , 0.49
> 512 , 7 , , 224 9.89 , 9.16 , New , 0.73
> 2 , 0 , , 1 3.0 , 3.0 , Eq , 0.0
> 2 , 1 , , 1 3.0 , 3.0 , Eq , 0.0
> 0 , 0 , , 1 3.01 , 3.6 , Cur , 0.59
> 0 , 1 , , 1 3.01 , 3.6 , Cur , 0.59
> 3 , 0 , , 2 3.0 , 3.0 , Eq , 0.0
> 3 , 2 , , 2 3.0 , 3.0 , Eq , 0.0
> 1 , 0 , , 2 3.6 , 3.0 , New , 0.6
> 1 , 2 , , 2 3.6 , 3.0 , New , 0.6
> 4 , 0 , , 3 3.01 , 3.01 , Eq , 0.0
> 4 , 3 , , 3 3.01 , 3.01 , Eq , 0.0
> 2 , 0 , , 3 3.62 , 3.02 , New , 0.6
> 2 , 3 , , 3 3.62 , 3.03 , New , 0.59
> 5 , 0 , , 4 3.02 , 3.03 , Cur , 0.01
> 5 , 4 , , 4 3.02 , 3.02 , Eq , 0.0
> 3 , 0 , , 4 3.63 , 3.02 , New , 0.61
> 3 , 4 , , 4 3.63 , 3.04 , New , 0.59
> 6 , 0 , , 5 3.05 , 3.04 , New , 0.01
> 6 , 5 , , 5 3.02 , 3.02 , Eq , 0.0
> 4 , 0 , , 5 3.63 , 3.02 , New , 0.61
> 4 , 5 , , 5 3.64 , 3.03 , New , 0.61
> 7 , 0 , , 6 3.03 , 3.03 , Eq , 0.0
> 7 , 6 , , 6 3.02 , 3.02 , Eq , 0.0
> 5 , 0 , , 6 3.64 , 3.01 , New , 0.63
> 5 , 6 , , 6 3.64 , 3.03 , New , 0.61
> 8 , 0 , , 7 3.03 , 3.04 , Cur , 0.01
> 8 , 7 , , 7 3.04 , 3.04 , Eq , 0.0
> 6 , 0 , , 7 3.67 , 3.04 , New , 0.63
> 6 , 7 , , 7 3.65 , 3.05 , New , 0.6
> 9 , 0 , , 8 3.05 , 3.05 , Eq , 0.0
> 7 , 0 , , 8 3.67 , 3.05 , New , 0.62
> 10 , 0 , , 9 3.06 , 3.06 , Eq , 0.0
> 10 , 1 , , 9 3.06 , 3.06 , Eq , 0.0
> 8 , 0 , , 9 3.67 , 3.06 , New , 0.61
> 8 , 1 , , 9 3.67 , 3.06 , New , 0.61
> 11 , 0 , , 10 3.06 , 3.06 , Eq , 0.0
> 11 , 2 , , 10 3.07 , 3.06 , New , 0.01
> 9 , 0 , , 10 3.67 , 3.05 , New , 0.62
> 9 , 2 , , 10 3.67 , 3.06 , New , 0.61
> 12 , 0 , , 11 3.06 , 3.06 , Eq , 0.0
> 12 , 3 , , 11 3.06 , 3.06 , Eq , 0.0
> 10 , 0 , , 11 3.67 , 3.06 , New , 0.61
> 10 , 3 , , 11 3.67 , 3.06 , New , 0.61
> 13 , 0 , , 12 3.06 , 3.07 , Cur , 0.01
> 13 , 4 , , 12 3.06 , 3.07 , Cur , 0.01
> 11 , 0 , , 12 3.67 , 3.11 , New , 0.56
> 11 , 4 , , 12 3.68 , 3.12 , New , 0.56
> 14 , 0 , , 13 3.07 , 3.1 , Cur , 0.03
> 14 , 5 , , 13 3.06 , 3.07 , Cur , 0.01
> 12 , 0 , , 13 3.67 , 3.07 , New , 0.6
> 12 , 5 , , 13 3.67 , 3.08 , New , 0.59
> 15 , 0 , , 14 3.06 , 3.06 , Eq , 0.0
> 15 , 6 , , 14 3.07 , 3.06 , New , 0.01
> 13 , 0 , , 14 3.67 , 3.06 , New , 0.61
> 13 , 6 , , 14 3.68 , 3.06 , New , 0.62
> 16 , 0 , , 15 3.06 , 3.06 , Eq , 0.0
> 16 , 7 , , 15 3.06 , 3.05 , New , 0.01
> 14 , 0 , , 15 3.68 , 3.06 , New , 0.62
> 14 , 7 , , 15 3.67 , 3.06 , New , 0.61
> 17 , 0 , , 16 3.07 , 3.06 , New , 0.01
> 15 , 0 , , 16 3.68 , 3.06 , New , 0.62
> 18 , 0 , , 17 3.06 , 3.06 , Eq , 0.0
> 18 , 1 , , 17 3.06 , 3.06 , Eq , 0.0
> 16 , 0 , , 17 3.67 , 3.06 , New , 0.61
> 16 , 1 , , 17 3.67 , 3.05 , New , 0.62
> 19 , 0 , , 18 3.07 , 3.06 , New , 0.01
> 19 , 2 , , 18 3.06 , 3.06 , Eq , 0.0
> 17 , 0 , , 18 3.68 , 3.08 , New , 0.6
> 17 , 2 , , 18 3.68 , 3.06 , New , 0.62
> 20 , 0 , , 19 3.06 , 3.06 , Eq , 0.0
> 20 , 3 , , 19 3.06 , 3.06 , Eq , 0.0
> 18 , 0 , , 19 3.68 , 3.06 , New , 0.62
> 18 , 3 , , 19 3.68 , 3.06 , New , 0.62
> 21 , 0 , , 20 3.06 , 3.06 , Eq , 0.0
> 21 , 4 , , 20 3.06 , 3.06 , Eq , 0.0
> 19 , 0 , , 20 3.67 , 3.06 , New , 0.61
> 19 , 4 , , 20 3.67 , 3.06 , New , 0.61
> 22 , 0 , , 21 3.06 , 3.06 , Eq , 0.0
> 22 , 5 , , 21 3.06 , 3.06 , Eq , 0.0
> 20 , 0 , , 21 3.67 , 3.05 , New , 0.62
> 20 , 5 , , 21 3.68 , 3.06 , New , 0.62
> 23 , 0 , , 22 3.07 , 3.06 , New , 0.01
> 23 , 6 , , 22 3.06 , 3.06 , Eq , 0.0
> 21 , 0 , , 22 3.68 , 3.07 , New , 0.61
> 21 , 6 , , 22 3.67 , 3.06 , New , 0.61
> 24 , 0 , , 23 3.19 , 3.06 , New , 0.13
> 24 , 7 , , 23 3.08 , 3.06 , New , 0.02
> 22 , 0 , , 23 3.69 , 3.06 , New , 0.63
> 22 , 7 , , 23 3.68 , 3.06 , New , 0.62
> 25 , 0 , , 24 3.07 , 3.06 , New , 0.01
> 23 , 0 , , 24 3.68 , 3.06 , New , 0.62
> 26 , 0 , , 25 3.06 , 3.05 , New , 0.01
> 26 , 1 , , 25 3.07 , 3.06 , New , 0.01
> 24 , 0 , , 25 3.67 , 3.05 , New , 0.62
> 24 , 1 , , 25 3.68 , 3.06 , New , 0.62
> 27 , 0 , , 26 3.12 , 3.06 , New , 0.06
> 27 , 2 , , 26 3.08 , 3.06 , New , 0.02
> 25 , 0 , , 26 3.69 , 3.06 , New , 0.63
> 25 , 2 , , 26 3.67 , 3.06 , New , 0.61
> 28 , 0 , , 27 3.06 , 3.06 , Eq , 0.0
> 28 , 3 , , 27 3.06 , 3.06 , Eq , 0.0
> 26 , 0 , , 27 3.67 , 3.06 , New , 0.61
> 26 , 3 , , 27 3.67 , 3.06 , New , 0.61
> 29 , 0 , , 28 3.06 , 3.06 , Eq , 0.0
> 29 , 4 , , 28 3.06 , 3.06 , Eq , 0.0
> 27 , 0 , , 28 3.68 , 3.05 , New , 0.63
> 27 , 4 , , 28 3.67 , 3.06 , New , 0.61
> 30 , 0 , , 29 3.06 , 3.06 , Eq , 0.0
> 30 , 5 , , 29 3.06 , 3.06 , Eq , 0.0
> 28 , 0 , , 29 3.67 , 3.06 , New , 0.61
> 28 , 5 , , 29 3.68 , 3.06 , New , 0.62
> 31 , 0 , , 30 3.06 , 3.06 , Eq , 0.0
> 31 , 6 , , 30 3.06 , 3.06 , Eq , 0.0
> 29 , 0 , , 30 3.68 , 3.06 , New , 0.62
> 29 , 6 , , 30 3.7 , 3.06 , New , 0.64
> 32 , 0 , , 31 3.17 , 3.06 , New , 0.11
> 32 , 7 , , 31 3.12 , 3.06 , New , 0.06
> 30 , 0 , , 31 3.68 , 3.06 , New , 0.62
> 30 , 7 , , 31 3.68 , 3.06 , New , 0.62
>
> Results For Icelake memchr-evex
> size , algn , Pos , Cur T , New T , Win , Dif
> 2048 , 0 , , 32 4.94 , 4.26 , New , 0.68
> 256 , 1 , , 64 4.5 , 4.13 , New , 0.37
> 2048 , 0 , , 64 4.19 , 3.9 , New , 0.29
> 256 , 2 , , 64 4.19 , 3.87 , New , 0.32
> 2048 , 0 , , 128 4.96 , 4.53 , New , 0.43
> 256 , 3 , , 64 4.07 , 3.86 , New , 0.21
> 2048 , 0 , , 256 8.77 , 8.61 , New , 0.16
> 256 , 4 , , 64 4.08 , 3.87 , New , 0.21
> 2048 , 0 , , 512 12.22 , 11.67 , New , 0.55
> 256 , 5 , , 64 4.12 , 3.83 , New , 0.29
> 2048 , 0 , , 1024 20.06 , 18.09 , New , 1.97
> 256 , 6 , , 64 4.2 , 3.95 , New , 0.25
> 2048 , 0 , , 2048 33.83 , 30.62 , New , 3.21
> 256 , 7 , , 64 4.3 , 4.04 , New , 0.26
> 192 , 1 , , 32 4.2 , 3.71 , New , 0.49
> 256 , 1 , , 32 4.24 , 3.76 , New , 0.48
> 512 , 1 , , 32 4.29 , 3.74 , New , 0.55
> 192 , 2 , , 64 4.42 , 4.0 , New , 0.42
> 512 , 2 , , 64 4.17 , 3.83 , New , 0.34
> 192 , 3 , , 96 4.44 , 4.26 , New , 0.18
> 256 , 3 , , 96 4.45 , 4.14 , New , 0.31
> 512 , 3 , , 96 4.42 , 4.15 , New , 0.27
> 192 , 4 , , 128 4.93 , 4.45 , New , 0.48
> 256 , 4 , , 128 4.93 , 4.47 , New , 0.46
> 512 , 4 , , 128 4.95 , 4.47 , New , 0.48
> 192 , 5 , , 160 5.95 , 5.44 , New , 0.51
> 256 , 5 , , 160 5.59 , 5.47 , New , 0.12
> 512 , 5 , , 160 7.59 , 7.34 , New , 0.25
> 192 , 6 , , 192 6.53 , 6.08 , New , 0.45
> 256 , 6 , , 192 6.2 , 5.88 , New , 0.32
> 512 , 6 , , 192 7.53 , 7.62 , Cur , 0.09
> 192 , 7 , , 224 6.62 , 6.12 , New , 0.5
> 256 , 7 , , 224 6.79 , 6.51 , New , 0.28
> 512 , 7 , , 224 8.12 , 7.61 , New , 0.51
> 2 , 0 , , 1 2.5 , 2.54 , Cur , 0.04
> 2 , 1 , , 1 2.56 , 2.55 , New , 0.01
> 0 , 0 , , 1 2.57 , 3.12 , Cur , 0.55
> 0 , 1 , , 1 2.59 , 3.14 , Cur , 0.55
> 3 , 0 , , 2 2.62 , 2.63 , Cur , 0.01
> 3 , 2 , , 2 2.66 , 2.67 , Cur , 0.01
> 1 , 0 , , 2 3.24 , 2.72 , New , 0.52
> 1 , 2 , , 2 3.28 , 2.75 , New , 0.53
> 4 , 0 , , 3 2.78 , 2.8 , Cur , 0.02
> 4 , 3 , , 3 2.8 , 2.82 , Cur , 0.02
> 2 , 0 , , 3 3.38 , 2.86 , New , 0.52
> 2 , 3 , , 3 3.41 , 2.89 , New , 0.52
> 5 , 0 , , 4 2.88 , 2.91 , Cur , 0.03
> 5 , 4 , , 4 2.88 , 2.92 , Cur , 0.04
> 3 , 0 , , 4 3.48 , 2.93 , New , 0.55
> 3 , 4 , , 4 3.47 , 2.93 , New , 0.54
> 6 , 0 , , 5 2.95 , 2.94 , New , 0.01
> 6 , 5 , , 5 2.91 , 2.92 , Cur , 0.01
> 4 , 0 , , 5 3.47 , 2.9 , New , 0.57
> 4 , 5 , , 5 3.43 , 2.91 , New , 0.52
> 7 , 0 , , 6 2.87 , 2.9 , Cur , 0.03
> 7 , 6 , , 6 2.87 , 2.89 , Cur , 0.02
> 5 , 0 , , 6 3.44 , 2.88 , New , 0.56
> 5 , 6 , , 6 3.41 , 2.87 , New , 0.54
> 8 , 0 , , 7 2.86 , 2.87 , Cur , 0.01
> 8 , 7 , , 7 2.86 , 2.87 , Cur , 0.01
> 6 , 0 , , 7 3.43 , 2.87 , New , 0.56
> 6 , 7 , , 7 3.44 , 2.87 , New , 0.57
> 9 , 0 , , 8 2.86 , 2.88 , Cur , 0.02
> 7 , 0 , , 8 3.41 , 2.89 , New , 0.52
> 10 , 0 , , 9 2.83 , 2.87 , Cur , 0.04
> 10 , 1 , , 9 2.82 , 2.87 , Cur , 0.05
> 8 , 0 , , 9 3.4 , 2.89 , New , 0.51
> 8 , 1 , , 9 3.41 , 2.87 , New , 0.54
> 11 , 0 , , 10 2.83 , 2.88 , Cur , 0.05
> 11 , 2 , , 10 2.84 , 2.88 , Cur , 0.04
> 9 , 0 , , 10 3.41 , 2.87 , New , 0.54
> 9 , 2 , , 10 3.41 , 2.88 , New , 0.53
> 12 , 0 , , 11 2.83 , 2.89 , Cur , 0.06
> 12 , 3 , , 11 2.85 , 2.87 , Cur , 0.02
> 10 , 0 , , 11 3.41 , 2.87 , New , 0.54
> 10 , 3 , , 11 3.42 , 2.88 , New , 0.54
> 13 , 0 , , 12 2.86 , 2.87 , Cur , 0.01
> 13 , 4 , , 12 2.84 , 2.88 , Cur , 0.04
> 11 , 0 , , 12 3.43 , 2.87 , New , 0.56
> 11 , 4 , , 12 3.49 , 2.87 , New , 0.62
> 14 , 0 , , 13 2.85 , 2.86 , Cur , 0.01
> 14 , 5 , , 13 2.85 , 2.86 , Cur , 0.01
> 12 , 0 , , 13 3.41 , 2.86 , New , 0.55
> 12 , 5 , , 13 3.44 , 2.85 , New , 0.59
> 15 , 0 , , 14 2.83 , 2.87 , Cur , 0.04
> 15 , 6 , , 14 2.82 , 2.86 , Cur , 0.04
> 13 , 0 , , 14 3.41 , 2.86 , New , 0.55
> 13 , 6 , , 14 3.4 , 2.86 , New , 0.54
> 16 , 0 , , 15 2.84 , 2.86 , Cur , 0.02
> 16 , 7 , , 15 2.83 , 2.85 , Cur , 0.02
> 14 , 0 , , 15 3.41 , 2.85 , New , 0.56
> 14 , 7 , , 15 3.39 , 2.87 , New , 0.52
> 17 , 0 , , 16 2.83 , 2.87 , Cur , 0.04
> 15 , 0 , , 16 3.4 , 2.85 , New , 0.55
> 18 , 0 , , 17 2.83 , 2.86 , Cur , 0.03
> 18 , 1 , , 17 2.85 , 2.84 , New , 0.01
> 16 , 0 , , 17 3.41 , 2.85 , New , 0.56
> 16 , 1 , , 17 3.4 , 2.86 , New , 0.54
> 19 , 0 , , 18 2.8 , 2.84 , Cur , 0.04
> 19 , 2 , , 18 2.82 , 2.83 , Cur , 0.01
> 17 , 0 , , 18 3.39 , 2.86 , New , 0.53
> 17 , 2 , , 18 3.39 , 2.84 , New , 0.55
> 20 , 0 , , 19 2.85 , 2.87 , Cur , 0.02
> 20 , 3 , , 19 2.88 , 2.87 , New , 0.01
> 18 , 0 , , 19 3.38 , 2.85 , New , 0.53
> 18 , 3 , , 19 3.4 , 2.85 , New , 0.55
> 21 , 0 , , 20 2.83 , 2.85 , Cur , 0.02
> 21 , 4 , , 20 2.88 , 2.85 , New , 0.03
> 19 , 0 , , 20 3.39 , 2.84 , New , 0.55
> 19 , 4 , , 20 3.39 , 2.96 , New , 0.43
> 22 , 0 , , 21 2.84 , 2.9 , Cur , 0.06
> 22 , 5 , , 21 2.81 , 2.84 , Cur , 0.03
> 20 , 0 , , 21 3.41 , 2.81 , New , 0.6
> 20 , 5 , , 21 3.38 , 2.83 , New , 0.55
> 23 , 0 , , 22 2.8 , 2.82 , Cur , 0.02
> 23 , 6 , , 22 2.81 , 2.83 , Cur , 0.02
> 21 , 0 , , 22 3.35 , 2.81 , New , 0.54
> 21 , 6 , , 22 3.34 , 2.81 , New , 0.53
> 24 , 0 , , 23 2.77 , 2.84 , Cur , 0.07
> 24 , 7 , , 23 2.78 , 2.8 , Cur , 0.02
> 22 , 0 , , 23 3.34 , 2.79 , New , 0.55
> 22 , 7 , , 23 3.32 , 2.79 , New , 0.53
> 25 , 0 , , 24 2.77 , 2.8 , Cur , 0.03
> 23 , 0 , , 24 3.29 , 2.79 , New , 0.5
> 26 , 0 , , 25 2.73 , 2.78 , Cur , 0.05
> 26 , 1 , , 25 2.75 , 2.79 , Cur , 0.04
> 24 , 0 , , 25 3.27 , 2.79 , New , 0.48
> 24 , 1 , , 25 3.27 , 2.77 , New , 0.5
> 27 , 0 , , 26 2.72 , 2.78 , Cur , 0.06
> 27 , 2 , , 26 2.75 , 2.76 , Cur , 0.01
> 25 , 0 , , 26 3.29 , 2.73 , New , 0.56
> 25 , 2 , , 26 3.3 , 2.76 , New , 0.54
> 28 , 0 , , 27 2.75 , 2.79 , Cur , 0.04
> 28 , 3 , , 27 2.77 , 2.77 , Eq , 0.0
> 26 , 0 , , 27 3.28 , 2.78 , New , 0.5
> 26 , 3 , , 27 3.29 , 2.78 , New , 0.51
> 29 , 0 , , 28 2.74 , 2.76 , Cur , 0.02
> 29 , 4 , , 28 2.74 , 2.77 , Cur , 0.03
> 27 , 0 , , 28 3.3 , 2.76 , New , 0.54
> 27 , 4 , , 28 3.3 , 2.74 , New , 0.56
> 30 , 0 , , 29 2.72 , 2.76 , Cur , 0.04
> 30 , 5 , , 29 2.74 , 2.75 , Cur , 0.01
> 28 , 0 , , 29 3.25 , 2.73 , New , 0.52
> 28 , 5 , , 29 3.3 , 2.73 , New , 0.57
> 31 , 0 , , 30 2.73 , 2.77 , Cur , 0.04
> 31 , 6 , , 30 2.74 , 2.76 , Cur , 0.02
> 29 , 0 , , 30 3.25 , 2.73 , New , 0.52
> 29 , 6 , , 30 3.26 , 2.74 , New , 0.52
> 32 , 0 , , 31 2.73 , 2.74 , Cur , 0.01
> 32 , 7 , , 31 2.73 , 2.75 , Cur , 0.02
> 30 , 0 , , 31 3.24 , 2.72 , New , 0.52
> 30 , 7 , , 31 3.24 , 2.72 , New , 0.52
>
> For memchr-avx2 the improvements are more modest though again near
> universal. The improvement is most significant for medium sizes and
> small sizes with pos > size. For small sizes with pos < size and large
> sizes the two implementations perform roughly the same for large
> sizes.
>
> Results For Tigerlake memchr-avx2
> size , algn , Pos , Cur T , New T , Win , Dif
> 2048 , 0 , , 32 6.15 , 6.27 , Cur , 0.12
> 256 , 1 , , 64 6.21 , 6.03 , New , 0.18
> 2048 , 0 , , 64 6.07 , 5.95 , New , 0.12
> 256 , 2 , , 64 6.01 , 5.8 , New , 0.21
> 2048 , 0 , , 128 7.05 , 6.55 , New , 0.5
> 256 , 3 , , 64 6.14 , 5.83 , New , 0.31
> 2048 , 0 , , 256 11.78 , 11.78 , Eq , 0.0
> 256 , 4 , , 64 6.1 , 5.85 , New , 0.25
> 2048 , 0 , , 512 16.32 , 15.96 , New , 0.36
> 256 , 5 , , 64 6.1 , 5.77 , New , 0.33
> 2048 , 0 , , 1024 25.38 , 25.18 , New , 0.2
> 256 , 6 , , 64 6.08 , 5.88 , New , 0.2
> 2048 , 0 , , 2048 38.56 , 38.32 , New , 0.24
> 256 , 7 , , 64 5.93 , 5.68 , New , 0.25
> 192 , 1 , , 32 5.49 , 5.3 , New , 0.19
> 256 , 1 , , 32 5.5 , 5.28 , New , 0.22
> 512 , 1 , , 32 5.48 , 5.32 , New , 0.16
> 192 , 2 , , 64 6.1 , 5.73 , New , 0.37
> 512 , 2 , , 64 5.88 , 5.72 , New , 0.16
> 192 , 3 , , 96 6.31 , 5.93 , New , 0.38
> 256 , 3 , , 96 6.32 , 5.93 , New , 0.39
> 512 , 3 , , 96 6.2 , 5.94 , New , 0.26
> 192 , 4 , , 128 6.65 , 6.4 , New , 0.25
> 256 , 4 , , 128 6.6 , 6.37 , New , 0.23
> 512 , 4 , , 128 6.74 , 6.33 , New , 0.41
> 192 , 5 , , 160 7.78 , 7.4 , New , 0.38
> 256 , 5 , , 160 7.18 , 7.4 , Cur , 0.22
> 512 , 5 , , 160 9.81 , 9.44 , New , 0.37
> 192 , 6 , , 192 9.12 , 7.77 , New , 1.35
> 256 , 6 , , 192 7.97 , 7.66 , New , 0.31
> 512 , 6 , , 192 10.14 , 9.95 , New , 0.19
> 192 , 7 , , 224 8.96 , 7.78 , New , 1.18
> 256 , 7 , , 224 8.52 , 8.23 , New , 0.29
> 512 , 7 , , 224 10.33 , 9.98 , New , 0.35
> 2 , 0 , , 1 3.61 , 3.6 , New , 0.01
> 2 , 1 , , 1 3.6 , 3.6 , Eq , 0.0
> 0 , 0 , , 1 3.02 , 3.0 , New , 0.02
> 0 , 1 , , 1 3.0 , 3.0 , Eq , 0.0
> 3 , 0 , , 2 3.6 , 3.6 , Eq , 0.0
> 3 , 2 , , 2 3.61 , 3.6 , New , 0.01
> 1 , 0 , , 2 4.82 , 3.6 , New , 1.22
> 1 , 2 , , 2 4.81 , 3.6 , New , 1.21
> 4 , 0 , , 3 3.61 , 3.61 , Eq , 0.0
> 4 , 3 , , 3 3.62 , 3.61 , New , 0.01
> 2 , 0 , , 3 4.82 , 3.62 , New , 1.2
> 2 , 3 , , 3 4.83 , 3.63 , New , 1.2
> 5 , 0 , , 4 3.63 , 3.64 , Cur , 0.01
> 5 , 4 , , 4 3.63 , 3.62 , New , 0.01
> 3 , 0 , , 4 4.84 , 3.62 , New , 1.22
> 3 , 4 , , 4 4.84 , 3.64 , New , 1.2
> 6 , 0 , , 5 3.66 , 3.64 , New , 0.02
> 6 , 5 , , 5 3.65 , 3.62 , New , 0.03
> 4 , 0 , , 5 4.83 , 3.63 , New , 1.2
> 4 , 5 , , 5 4.85 , 3.64 , New , 1.21
> 7 , 0 , , 6 3.76 , 3.79 , Cur , 0.03
> 7 , 6 , , 6 3.76 , 3.72 , New , 0.04
> 5 , 0 , , 6 4.84 , 3.62 , New , 1.22
> 5 , 6 , , 6 4.85 , 3.64 , New , 1.21
> 8 , 0 , , 7 3.64 , 3.65 , Cur , 0.01
> 8 , 7 , , 7 3.65 , 3.65 , Eq , 0.0
> 6 , 0 , , 7 4.88 , 3.64 , New , 1.24
> 6 , 7 , , 7 4.87 , 3.65 , New , 1.22
> 9 , 0 , , 8 3.66 , 3.66 , Eq , 0.0
> 7 , 0 , , 8 4.89 , 3.66 , New , 1.23
> 10 , 0 , , 9 3.67 , 3.67 , Eq , 0.0
> 10 , 1 , , 9 3.67 , 3.67 , Eq , 0.0
> 8 , 0 , , 9 4.9 , 3.67 , New , 1.23
> 8 , 1 , , 9 4.9 , 3.67 , New , 1.23
> 11 , 0 , , 10 3.68 , 3.67 , New , 0.01
> 11 , 2 , , 10 3.69 , 3.67 , New , 0.02
> 9 , 0 , , 10 4.9 , 3.67 , New , 1.23
> 9 , 2 , , 10 4.9 , 3.67 , New , 1.23
> 12 , 0 , , 11 3.71 , 3.68 , New , 0.03
> 12 , 3 , , 11 3.71 , 3.67 , New , 0.04
> 10 , 0 , , 11 4.9 , 3.67 , New , 1.23
> 10 , 3 , , 11 4.9 , 3.67 , New , 1.23
> 13 , 0 , , 12 4.24 , 4.23 , New , 0.01
> 13 , 4 , , 12 4.23 , 4.23 , Eq , 0.0
> 11 , 0 , , 12 4.9 , 3.7 , New , 1.2
> 11 , 4 , , 12 4.9 , 3.73 , New , 1.17
> 14 , 0 , , 13 3.99 , 4.01 , Cur , 0.02
> 14 , 5 , , 13 3.98 , 3.98 , Eq , 0.0
> 12 , 0 , , 13 4.9 , 3.69 , New , 1.21
> 12 , 5 , , 13 4.9 , 3.69 , New , 1.21
> 15 , 0 , , 14 3.99 , 3.97 , New , 0.02
> 15 , 6 , , 14 4.0 , 4.0 , Eq , 0.0
> 13 , 0 , , 14 4.9 , 3.67 , New , 1.23
> 13 , 6 , , 14 4.9 , 3.67 , New , 1.23
> 16 , 0 , , 15 3.99 , 4.02 , Cur , 0.03
> 16 , 7 , , 15 4.01 , 3.96 , New , 0.05
> 14 , 0 , , 15 4.93 , 3.67 , New , 1.26
> 14 , 7 , , 15 4.92 , 3.67 , New , 1.25
> 17 , 0 , , 16 4.04 , 3.99 , New , 0.05
> 15 , 0 , , 16 5.42 , 4.22 , New , 1.2
> 18 , 0 , , 17 4.01 , 3.97 , New , 0.04
> 18 , 1 , , 17 3.99 , 3.98 , New , 0.01
> 16 , 0 , , 17 5.22 , 3.98 , New , 1.24
> 16 , 1 , , 17 5.19 , 3.98 , New , 1.21
> 19 , 0 , , 18 4.0 , 3.99 , New , 0.01
> 19 , 2 , , 18 4.03 , 3.97 , New , 0.06
> 17 , 0 , , 18 5.18 , 3.99 , New , 1.19
> 17 , 2 , , 18 5.18 , 3.98 , New , 1.2
> 20 , 0 , , 19 4.02 , 3.98 , New , 0.04
> 20 , 3 , , 19 4.0 , 3.98 , New , 0.02
> 18 , 0 , , 19 5.19 , 3.97 , New , 1.22
> 18 , 3 , , 19 5.21 , 3.98 , New , 1.23
> 21 , 0 , , 20 3.98 , 4.0 , Cur , 0.02
> 21 , 4 , , 20 4.0 , 4.0 , Eq , 0.0
> 19 , 0 , , 20 5.19 , 3.99 , New , 1.2
> 19 , 4 , , 20 5.17 , 3.99 , New , 1.18
> 22 , 0 , , 21 4.03 , 3.98 , New , 0.05
> 22 , 5 , , 21 4.01 , 3.95 , New , 0.06
> 20 , 0 , , 21 5.19 , 4.0 , New , 1.19
> 20 , 5 , , 21 5.21 , 3.99 , New , 1.22
> 23 , 0 , , 22 4.06 , 3.97 , New , 0.09
> 23 , 6 , , 22 4.02 , 3.98 , New , 0.04
> 21 , 0 , , 22 5.2 , 4.02 , New , 1.18
> 21 , 6 , , 22 5.22 , 4.0 , New , 1.22
> 24 , 0 , , 23 4.15 , 3.98 , New , 0.17
> 24 , 7 , , 23 4.0 , 4.01 , Cur , 0.01
> 22 , 0 , , 23 5.28 , 4.0 , New , 1.28
> 22 , 7 , , 23 5.22 , 3.99 , New , 1.23
> 25 , 0 , , 24 4.1 , 4.04 , New , 0.06
> 23 , 0 , , 24 5.23 , 4.04 , New , 1.19
> 26 , 0 , , 25 4.1 , 4.06 , New , 0.04
> 26 , 1 , , 25 4.07 , 3.99 , New , 0.08
> 24 , 0 , , 25 5.26 , 4.02 , New , 1.24
> 24 , 1 , , 25 5.21 , 4.0 , New , 1.21
> 27 , 0 , , 26 4.17 , 4.03 , New , 0.14
> 27 , 2 , , 26 4.09 , 4.03 , New , 0.06
> 25 , 0 , , 26 5.29 , 4.1 , New , 1.19
> 25 , 2 , , 26 5.25 , 4.0 , New , 1.25
> 28 , 0 , , 27 4.06 , 4.1 , Cur , 0.04
> 28 , 3 , , 27 4.09 , 4.04 , New , 0.05
> 26 , 0 , , 27 5.26 , 4.04 , New , 1.22
> 26 , 3 , , 27 5.28 , 4.01 , New , 1.27
> 29 , 0 , , 28 4.07 , 4.02 , New , 0.05
> 29 , 4 , , 28 4.07 , 4.05 , New , 0.02
> 27 , 0 , , 28 5.25 , 4.02 , New , 1.23
> 27 , 4 , , 28 5.25 , 4.03 , New , 1.22
> 30 , 0 , , 29 4.14 , 4.06 , New , 0.08
> 30 , 5 , , 29 4.08 , 4.04 , New , 0.04
> 28 , 0 , , 29 5.26 , 4.07 , New , 1.19
> 28 , 5 , , 29 5.28 , 4.04 , New , 1.24
> 31 , 0 , , 30 4.09 , 4.08 , New , 0.01
> 31 , 6 , , 30 4.1 , 4.08 , New , 0.02
> 29 , 0 , , 30 5.28 , 4.05 , New , 1.23
> 29 , 6 , , 30 5.24 , 4.07 , New , 1.17
> 32 , 0 , , 31 4.1 , 4.13 , Cur , 0.03
> 32 , 7 , , 31 4.16 , 4.09 , New , 0.07
> 30 , 0 , , 31 5.31 , 4.09 , New , 1.22
> 30 , 7 , , 31 5.28 , 4.08 , New , 1.2
>
> Results For Icelake memchr-avx2
> size , algn , Pos , Cur T , New T , Win , Dif
> 2048 , 0 , , 32 5.74 , 5.08 , New , 0.66
> 256 , 1 , , 64 5.16 , 4.93 , New , 0.23
> 2048 , 0 , , 64 4.86 , 4.69 , New , 0.17
> 256 , 2 , , 64 4.78 , 4.7 , New , 0.08
> 2048 , 0 , , 128 5.64 , 5.0 , New , 0.64
> 256 , 3 , , 64 4.64 , 4.59 , New , 0.05
> 2048 , 0 , , 256 9.07 , 9.17 , Cur , 0.1
> 256 , 4 , , 64 4.7 , 4.6 , New , 0.1
> 2048 , 0 , , 512 12.56 , 12.33 , New , 0.23
> 256 , 5 , , 64 4.72 , 4.61 , New , 0.11
> 2048 , 0 , , 1024 19.36 , 19.49 , Cur , 0.13
> 256 , 6 , , 64 4.82 , 4.69 , New , 0.13
> 2048 , 0 , , 2048 29.99 , 30.53 , Cur , 0.54
> 256 , 7 , , 64 4.9 , 4.85 , New , 0.05
> 192 , 1 , , 32 4.89 , 4.45 , New , 0.44
> 256 , 1 , , 32 4.93 , 4.44 , New , 0.49
> 512 , 1 , , 32 4.97 , 4.45 , New , 0.52
> 192 , 2 , , 64 5.04 , 4.65 , New , 0.39
> 512 , 2 , , 64 4.75 , 4.66 , New , 0.09
> 192 , 3 , , 96 5.14 , 4.66 , New , 0.48
> 256 , 3 , , 96 5.12 , 4.66 , New , 0.46
> 512 , 3 , , 96 5.13 , 4.62 , New , 0.51
> 192 , 4 , , 128 5.65 , 4.95 , New , 0.7
> 256 , 4 , , 128 5.63 , 4.95 , New , 0.68
> 512 , 4 , , 128 5.68 , 4.96 , New , 0.72
> 192 , 5 , , 160 6.1 , 5.84 , New , 0.26
> 256 , 5 , , 160 5.58 , 5.84 , Cur , 0.26
> 512 , 5 , , 160 7.95 , 7.74 , New , 0.21
> 192 , 6 , , 192 7.07 , 6.23 , New , 0.84
> 256 , 6 , , 192 6.34 , 6.09 , New , 0.25
> 512 , 6 , , 192 8.17 , 8.13 , New , 0.04
> 192 , 7 , , 224 7.06 , 6.23 , New , 0.83
> 256 , 7 , , 224 6.76 , 6.65 , New , 0.11
> 512 , 7 , , 224 8.29 , 8.08 , New , 0.21
> 2 , 0 , , 1 3.0 , 3.04 , Cur , 0.04
> 2 , 1 , , 1 3.06 , 3.07 , Cur , 0.01
> 0 , 0 , , 1 2.57 , 2.59 , Cur , 0.02
> 0 , 1 , , 1 2.6 , 2.61 , Cur , 0.01
> 3 , 0 , , 2 3.15 , 3.17 , Cur , 0.02
> 3 , 2 , , 2 3.19 , 3.21 , Cur , 0.02
> 1 , 0 , , 2 4.32 , 3.25 , New , 1.07
> 1 , 2 , , 2 4.36 , 3.31 , New , 1.05
> 4 , 0 , , 3 3.5 , 3.52 , Cur , 0.02
> 4 , 3 , , 3 3.52 , 3.54 , Cur , 0.02
> 2 , 0 , , 3 4.51 , 3.43 , New , 1.08
> 2 , 3 , , 3 4.56 , 3.47 , New , 1.09
> 5 , 0 , , 4 3.61 , 3.65 , Cur , 0.04
> 5 , 4 , , 4 3.63 , 3.67 , Cur , 0.04
> 3 , 0 , , 4 4.64 , 3.51 , New , 1.13
> 3 , 4 , , 4 4.7 , 3.51 , New , 1.19
> 6 , 0 , , 5 3.66 , 3.68 , Cur , 0.02
> 6 , 5 , , 5 3.69 , 3.65 , New , 0.04
> 4 , 0 , , 5 4.7 , 3.49 , New , 1.21
> 4 , 5 , , 5 4.58 , 3.48 , New , 1.1
> 7 , 0 , , 6 3.6 , 3.65 , Cur , 0.05
> 7 , 6 , , 6 3.59 , 3.64 , Cur , 0.05
> 5 , 0 , , 6 4.74 , 3.65 , New , 1.09
> 5 , 6 , , 6 4.73 , 3.64 , New , 1.09
> 8 , 0 , , 7 3.6 , 3.61 , Cur , 0.01
> 8 , 7 , , 7 3.6 , 3.61 , Cur , 0.01
> 6 , 0 , , 7 4.73 , 3.6 , New , 1.13
> 6 , 7 , , 7 4.73 , 3.62 , New , 1.11
> 9 , 0 , , 8 3.59 , 3.62 , Cur , 0.03
> 7 , 0 , , 8 4.72 , 3.64 , New , 1.08
> 10 , 0 , , 9 3.57 , 3.62 , Cur , 0.05
> 10 , 1 , , 9 3.56 , 3.61 , Cur , 0.05
> 8 , 0 , , 9 4.69 , 3.63 , New , 1.06
> 8 , 1 , , 9 4.71 , 3.61 , New , 1.1
> 11 , 0 , , 10 3.58 , 3.62 , Cur , 0.04
> 11 , 2 , , 10 3.59 , 3.63 , Cur , 0.04
> 9 , 0 , , 10 4.72 , 3.61 , New , 1.11
> 9 , 2 , , 10 4.7 , 3.61 , New , 1.09
> 12 , 0 , , 11 3.58 , 3.63 , Cur , 0.05
> 12 , 3 , , 11 3.58 , 3.62 , Cur , 0.04
> 10 , 0 , , 11 4.7 , 3.6 , New , 1.1
> 10 , 3 , , 11 4.73 , 3.64 , New , 1.09
> 13 , 0 , , 12 3.6 , 3.6 , Eq , 0.0
> 13 , 4 , , 12 3.57 , 3.62 , Cur , 0.05
> 11 , 0 , , 12 4.73 , 3.62 , New , 1.11
> 11 , 4 , , 12 4.79 , 3.61 , New , 1.18
> 14 , 0 , , 13 3.61 , 3.62 , Cur , 0.01
> 14 , 5 , , 13 3.59 , 3.59 , Eq , 0.0
> 12 , 0 , , 13 4.7 , 3.61 , New , 1.09
> 12 , 5 , , 13 4.75 , 3.58 , New , 1.17
> 15 , 0 , , 14 3.58 , 3.62 , Cur , 0.04
> 15 , 6 , , 14 3.59 , 3.62 , Cur , 0.03
> 13 , 0 , , 14 4.68 , 3.6 , New , 1.08
> 13 , 6 , , 14 4.68 , 3.63 , New , 1.05
> 16 , 0 , , 15 3.57 , 3.6 , Cur , 0.03
> 16 , 7 , , 15 3.55 , 3.59 , Cur , 0.04
> 14 , 0 , , 15 4.69 , 3.61 , New , 1.08
> 14 , 7 , , 15 4.69 , 3.61 , New , 1.08
> 17 , 0 , , 16 3.56 , 3.61 , Cur , 0.05
> 15 , 0 , , 16 4.71 , 3.58 , New , 1.13
> 18 , 0 , , 17 3.57 , 3.65 , Cur , 0.08
> 18 , 1 , , 17 3.58 , 3.59 , Cur , 0.01
> 16 , 0 , , 17 4.7 , 3.58 , New , 1.12
> 16 , 1 , , 17 4.68 , 3.59 , New , 1.09
> 19 , 0 , , 18 3.51 , 3.58 , Cur , 0.07
> 19 , 2 , , 18 3.55 , 3.58 , Cur , 0.03
> 17 , 0 , , 18 4.69 , 3.61 , New , 1.08
> 17 , 2 , , 18 4.68 , 3.61 , New , 1.07
> 20 , 0 , , 19 3.57 , 3.6 , Cur , 0.03
> 20 , 3 , , 19 3.59 , 3.59 , Eq , 0.0
> 18 , 0 , , 19 4.68 , 3.59 , New , 1.09
> 18 , 3 , , 19 4.67 , 3.57 , New , 1.1
> 21 , 0 , , 20 3.61 , 3.58 , New , 0.03
> 21 , 4 , , 20 3.62 , 3.6 , New , 0.02
> 19 , 0 , , 20 4.74 , 3.57 , New , 1.17
> 19 , 4 , , 20 4.69 , 3.7 , New , 0.99
> 22 , 0 , , 21 3.57 , 3.64 , Cur , 0.07
> 22 , 5 , , 21 3.55 , 3.6 , Cur , 0.05
> 20 , 0 , , 21 4.72 , 3.55 , New , 1.17
> 20 , 5 , , 21 4.66 , 3.55 , New , 1.11
> 23 , 0 , , 22 3.56 , 3.56 , Eq , 0.0
> 23 , 6 , , 22 3.54 , 3.56 , Cur , 0.02
> 21 , 0 , , 22 4.65 , 3.53 , New , 1.12
> 21 , 6 , , 22 4.62 , 3.56 , New , 1.06
> 24 , 0 , , 23 3.5 , 3.54 , Cur , 0.04
> 24 , 7 , , 23 3.52 , 3.53 , Cur , 0.01
> 22 , 0 , , 23 4.61 , 3.51 , New , 1.1
> 22 , 7 , , 23 4.6 , 3.51 , New , 1.09
> 25 , 0 , , 24 3.5 , 3.53 , Cur , 0.03
> 23 , 0 , , 24 4.54 , 3.5 , New , 1.04
> 26 , 0 , , 25 3.47 , 3.49 , Cur , 0.02
> 26 , 1 , , 25 3.46 , 3.51 , Cur , 0.05
> 24 , 0 , , 25 4.53 , 3.51 , New , 1.02
> 24 , 1 , , 25 4.51 , 3.51 , New , 1.0
> 27 , 0 , , 26 3.44 , 3.51 , Cur , 0.07
> 27 , 2 , , 26 3.51 , 3.52 , Cur , 0.01
> 25 , 0 , , 26 4.56 , 3.46 , New , 1.1
> 25 , 2 , , 26 4.55 , 3.47 , New , 1.08
> 28 , 0 , , 27 3.47 , 3.5 , Cur , 0.03
> 28 , 3 , , 27 3.48 , 3.47 , New , 0.01
> 26 , 0 , , 27 4.52 , 3.44 , New , 1.08
> 26 , 3 , , 27 4.55 , 3.46 , New , 1.09
> 29 , 0 , , 28 3.45 , 3.49 , Cur , 0.04
> 29 , 4 , , 28 3.5 , 3.5 , Eq , 0.0
> 27 , 0 , , 28 4.56 , 3.49 , New , 1.07
> 27 , 4 , , 28 4.5 , 3.49 , New , 1.01
> 30 , 0 , , 29 3.44 , 3.48 , Cur , 0.04
> 30 , 5 , , 29 3.46 , 3.47 , Cur , 0.01
> 28 , 0 , , 29 4.49 , 3.43 , New , 1.06
> 28 , 5 , , 29 4.57 , 3.45 , New , 1.12
> 31 , 0 , , 30 3.48 , 3.48 , Eq , 0.0
> 31 , 6 , , 30 3.46 , 3.49 , Cur , 0.03
> 29 , 0 , , 30 4.49 , 3.44 , New , 1.05
> 29 , 6 , , 30 4.53 , 3.44 , New , 1.09
> 32 , 0 , , 31 3.44 , 3.45 , Cur , 0.01
> 32 , 7 , , 31 3.46 , 3.51 , Cur , 0.05
> 30 , 0 , , 31 4.48 , 3.42 , New , 1.06
> 30 , 7 , , 31 4.48 , 3.44 , New , 1.04
>
>
> Results For Skylake memchr-avx2
> size , algn , Pos , Cur T , New T , Win , Dif
> 2048 , 0 , , 32 6.61 , 5.4 , New , 1.21
> 256 , 1 , , 64 6.52 , 5.68 , New , 0.84
> 2048 , 0 , , 64 6.03 , 5.47 , New , 0.56
> 256 , 2 , , 64 6.07 , 5.42 , New , 0.65
> 2048 , 0 , , 128 7.01 , 5.83 , New , 1.18
> 256 , 3 , , 64 6.24 , 5.68 , New , 0.56
> 2048 , 0 , , 256 11.03 , 9.86 , New , 1.17
> 256 , 4 , , 64 6.17 , 5.49 , New , 0.68
> 2048 , 0 , , 512 14.11 , 13.41 , New , 0.7
> 256 , 5 , , 64 6.03 , 5.45 , New , 0.58
> 2048 , 0 , , 1024 19.82 , 19.92 , Cur , 0.1
> 256 , 6 , , 64 6.14 , 5.7 , New , 0.44
> 2048 , 0 , , 2048 30.9 , 30.59 , New , 0.31
> 256 , 7 , , 64 6.05 , 5.64 , New , 0.41
> 192 , 1 , , 32 5.6 , 4.89 , New , 0.71
> 256 , 1 , , 32 5.59 , 5.07 , New , 0.52
> 512 , 1 , , 32 5.58 , 4.93 , New , 0.65
> 192 , 2 , , 64 6.14 , 5.46 , New , 0.68
> 512 , 2 , , 64 5.95 , 5.38 , New , 0.57
> 192 , 3 , , 96 6.6 , 5.74 , New , 0.86
> 256 , 3 , , 96 6.48 , 5.37 , New , 1.11
> 512 , 3 , , 96 6.56 , 5.44 , New , 1.12
> 192 , 4 , , 128 7.04 , 6.02 , New , 1.02
> 256 , 4 , , 128 6.96 , 5.89 , New , 1.07
> 512 , 4 , , 128 6.97 , 5.99 , New , 0.98
> 192 , 5 , , 160 8.49 , 7.07 , New , 1.42
> 256 , 5 , , 160 8.1 , 6.96 , New , 1.14
> 512 , 5 , , 160 10.48 , 9.14 , New , 1.34
> 192 , 6 , , 192 8.46 , 8.52 , Cur , 0.06
> 256 , 6 , , 192 8.53 , 7.58 , New , 0.95
> 512 , 6 , , 192 10.88 , 9.06 , New , 1.82
> 192 , 7 , , 224 8.59 , 8.35 , New , 0.24
> 256 , 7 , , 224 8.86 , 7.91 , New , 0.95
> 512 , 7 , , 224 10.89 , 8.98 , New , 1.91
> 2 , 0 , , 1 4.28 , 3.62 , New , 0.66
> 2 , 1 , , 1 4.32 , 3.75 , New , 0.57
> 0 , 0 , , 1 3.76 , 3.24 , New , 0.52
> 0 , 1 , , 1 3.7 , 3.19 , New , 0.51
> 3 , 0 , , 2 4.16 , 3.67 , New , 0.49
> 3 , 2 , , 2 4.21 , 3.68 , New , 0.53
> 1 , 0 , , 2 4.25 , 3.74 , New , 0.51
> 1 , 2 , , 2 4.4 , 3.82 , New , 0.58
> 4 , 0 , , 3 4.43 , 3.88 , New , 0.55
> 4 , 3 , , 3 4.34 , 3.8 , New , 0.54
> 2 , 0 , , 3 4.33 , 3.79 , New , 0.54
> 2 , 3 , , 3 4.37 , 3.84 , New , 0.53
> 5 , 0 , , 4 4.45 , 3.87 , New , 0.58
> 5 , 4 , , 4 4.41 , 3.84 , New , 0.57
> 3 , 0 , , 4 4.34 , 3.83 , New , 0.51
> 3 , 4 , , 4 4.35 , 3.82 , New , 0.53
> 6 , 0 , , 5 4.41 , 3.88 , New , 0.53
> 6 , 5 , , 5 4.41 , 3.88 , New , 0.53
> 4 , 0 , , 5 4.35 , 3.84 , New , 0.51
> 4 , 5 , , 5 4.37 , 3.85 , New , 0.52
> 7 , 0 , , 6 4.4 , 3.84 , New , 0.56
> 7 , 6 , , 6 4.39 , 3.83 , New , 0.56
> 5 , 0 , , 6 4.37 , 3.85 , New , 0.52
> 5 , 6 , , 6 4.4 , 3.86 , New , 0.54
> 8 , 0 , , 7 4.39 , 3.88 , New , 0.51
> 8 , 7 , , 7 4.4 , 3.83 , New , 0.57
> 6 , 0 , , 7 4.39 , 3.85 , New , 0.54
> 6 , 7 , , 7 4.38 , 3.87 , New , 0.51
> 9 , 0 , , 8 4.47 , 3.96 , New , 0.51
> 7 , 0 , , 8 4.37 , 3.85 , New , 0.52
> 10 , 0 , , 9 4.61 , 4.08 , New , 0.53
> 10 , 1 , , 9 4.61 , 4.09 , New , 0.52
> 8 , 0 , , 9 4.37 , 3.85 , New , 0.52
> 8 , 1 , , 9 4.37 , 3.85 , New , 0.52
> 11 , 0 , , 10 4.68 , 4.06 , New , 0.62
> 11 , 2 , , 10 4.56 , 4.1 , New , 0.46
> 9 , 0 , , 10 4.36 , 3.83 , New , 0.53
> 9 , 2 , , 10 4.37 , 3.83 , New , 0.54
> 12 , 0 , , 11 4.62 , 4.05 , New , 0.57
> 12 , 3 , , 11 4.63 , 4.06 , New , 0.57
> 10 , 0 , , 11 4.38 , 3.86 , New , 0.52
> 10 , 3 , , 11 4.41 , 3.86 , New , 0.55
> 13 , 0 , , 12 4.57 , 4.08 , New , 0.49
> 13 , 4 , , 12 4.59 , 4.12 , New , 0.47
> 11 , 0 , , 12 4.45 , 4.0 , New , 0.45
> 11 , 4 , , 12 4.51 , 4.04 , New , 0.47
> 14 , 0 , , 13 4.64 , 4.16 , New , 0.48
> 14 , 5 , , 13 4.67 , 4.1 , New , 0.57
> 12 , 0 , , 13 4.58 , 4.08 , New , 0.5
> 12 , 5 , , 13 4.6 , 4.1 , New , 0.5
> 15 , 0 , , 14 4.61 , 4.05 , New , 0.56
> 15 , 6 , , 14 4.59 , 4.06 , New , 0.53
> 13 , 0 , , 14 4.57 , 4.06 , New , 0.51
> 13 , 6 , , 14 4.57 , 4.05 , New , 0.52
> 16 , 0 , , 15 4.62 , 4.05 , New , 0.57
> 16 , 7 , , 15 4.63 , 4.06 , New , 0.57
> 14 , 0 , , 15 4.61 , 4.06 , New , 0.55
> 14 , 7 , , 15 4.59 , 4.05 , New , 0.54
> 17 , 0 , , 16 4.58 , 4.08 , New , 0.5
> 15 , 0 , , 16 4.64 , 4.06 , New , 0.58
> 18 , 0 , , 17 4.56 , 4.17 , New , 0.39
> 18 , 1 , , 17 4.59 , 4.09 , New , 0.5
> 16 , 0 , , 17 4.59 , 4.07 , New , 0.52
> 16 , 1 , , 17 4.58 , 4.04 , New , 0.54
> 19 , 0 , , 18 4.61 , 4.05 , New , 0.56
> 19 , 2 , , 18 4.6 , 4.08 , New , 0.52
> 17 , 0 , , 18 4.64 , 4.11 , New , 0.53
> 17 , 2 , , 18 4.56 , 4.13 , New , 0.43
> 20 , 0 , , 19 4.77 , 4.3 , New , 0.47
> 20 , 3 , , 19 4.6 , 4.14 , New , 0.46
> 18 , 0 , , 19 4.72 , 4.02 , New , 0.7
> 18 , 3 , , 19 4.53 , 4.01 , New , 0.52
> 21 , 0 , , 20 4.66 , 4.26 , New , 0.4
> 21 , 4 , , 20 4.74 , 4.07 , New , 0.67
> 19 , 0 , , 20 4.62 , 4.12 , New , 0.5
> 19 , 4 , , 20 4.57 , 4.04 , New , 0.53
> 22 , 0 , , 21 4.61 , 4.13 , New , 0.48
> 22 , 5 , , 21 4.64 , 4.08 , New , 0.56
> 20 , 0 , , 21 4.49 , 4.01 , New , 0.48
> 20 , 5 , , 21 4.58 , 4.06 , New , 0.52
> 23 , 0 , , 22 4.62 , 4.13 , New , 0.49
> 23 , 6 , , 22 4.72 , 4.27 , New , 0.45
> 21 , 0 , , 22 4.65 , 3.97 , New , 0.68
> 21 , 6 , , 22 4.5 , 4.02 , New , 0.48
> 24 , 0 , , 23 4.78 , 4.07 , New , 0.71
> 24 , 7 , , 23 4.67 , 4.23 , New , 0.44
> 22 , 0 , , 23 4.49 , 3.99 , New , 0.5
> 22 , 7 , , 23 4.56 , 4.03 , New , 0.53
> 25 , 0 , , 24 4.6 , 4.15 , New , 0.45
> 23 , 0 , , 24 4.57 , 4.06 , New , 0.51
> 26 , 0 , , 25 4.54 , 4.14 , New , 0.4
> 26 , 1 , , 25 4.72 , 4.1 , New , 0.62
> 24 , 0 , , 25 4.52 , 4.13 , New , 0.39
> 24 , 1 , , 25 4.55 , 4.0 , New , 0.55
> 27 , 0 , , 26 4.51 , 4.06 , New , 0.45
> 27 , 2 , , 26 4.53 , 4.16 , New , 0.37
> 25 , 0 , , 26 4.59 , 4.09 , New , 0.5
> 25 , 2 , , 26 4.55 , 4.01 , New , 0.54
> 28 , 0 , , 27 4.59 , 3.99 , New , 0.6
> 28 , 3 , , 27 4.57 , 3.95 , New , 0.62
> 26 , 0 , , 27 4.55 , 4.15 , New , 0.4
> 26 , 3 , , 27 4.57 , 3.99 , New , 0.58
> 29 , 0 , , 28 4.41 , 4.03 , New , 0.38
> 29 , 4 , , 28 4.59 , 4.02 , New , 0.57
> 27 , 0 , , 28 4.63 , 4.08 , New , 0.55
> 27 , 4 , , 28 4.44 , 4.02 , New , 0.42
> 30 , 0 , , 29 4.53 , 3.93 , New , 0.6
> 30 , 5 , , 29 4.55 , 3.88 , New , 0.67
> 28 , 0 , , 29 4.49 , 3.9 , New , 0.59
> 28 , 5 , , 29 4.44 , 3.94 , New , 0.5
> 31 , 0 , , 30 4.41 , 3.85 , New , 0.56
> 31 , 6 , , 30 4.48 , 3.86 , New , 0.62
> 29 , 0 , , 30 4.55 , 3.94 , New , 0.61
> 29 , 6 , , 30 4.32 , 3.95 , New , 0.37
> 32 , 0 , , 31 4.36 , 3.91 , New , 0.45
> 32 , 7 , , 31 4.37 , 3.89 , New , 0.48
> 30 , 0 , , 31 4.65 , 3.9 , New , 0.75
> 30 , 7 , , 31 4.42 , 3.93 , New , 0.49
>
> sysdeps/x86_64/multiarch/memchr-evex.S | 580 +++++++++++++++----------
> 1 file changed, 349 insertions(+), 231 deletions(-)
>
> diff --git a/sysdeps/x86_64/multiarch/memchr-evex.S b/sysdeps/x86_64/multiarch/memchr-evex.S
> index 6dd5d67b90..65c16ef8a4 100644
> --- a/sysdeps/x86_64/multiarch/memchr-evex.S
> +++ b/sysdeps/x86_64/multiarch/memchr-evex.S
> @@ -26,14 +26,28 @@
>
> # ifdef USE_AS_WMEMCHR
> # define VPBROADCAST vpbroadcastd
> -# define VPCMP vpcmpd
> -# define SHIFT_REG r8d
> +# define VPMINU vpminud
> +# define VPCMP vpcmpd
> +# define VPCMPEQ vpcmpeqd
> +# define CHAR_SIZE 4
> # else
> # define VPBROADCAST vpbroadcastb
> -# define VPCMP vpcmpb
> -# define SHIFT_REG ecx
> +# define VPMINU vpminub
> +# define VPCMP vpcmpb
> +# define VPCMPEQ vpcmpeqb
> +# define CHAR_SIZE 1
> # endif
>
> +# ifdef USE_AS_RAWMEMCHR
> +# define RAW_PTR_REG rcx
> +# define ALGN_PTR_REG rdi
> +# else
> +# define RAW_PTR_REG rdi
> +# define ALGN_PTR_REG rcx
> +# endif
> +
> +#define XZERO xmm23
Add a space before define. Rename XZERO to XMMZERO.
> +#define YZERO ymm23
Add a space before define. Rename YZERO to YMMZERO.
> # define XMMMATCH xmm16
> # define YMMMATCH ymm16
> # define YMM1 ymm17
> @@ -44,18 +58,16 @@
> # define YMM6 ymm22
>
> # define VEC_SIZE 32
> +# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
> +# define PAGE_SIZE 4096
>
> .section .text.evex,"ax",@progbits
> -ENTRY (MEMCHR)
> +ENTRY(MEMCHR)
No need for this change.
> # ifndef USE_AS_RAWMEMCHR
> /* Check for zero length. */
> test %RDX_LP, %RDX_LP
> jz L(zero)
> -# endif
> - movl %edi, %ecx
> -# ifdef USE_AS_WMEMCHR
> - shl $2, %RDX_LP
> -# else
> +
> # ifdef __ILP32__
> /* Clear the upper 32 bits. */
> movl %edx, %edx
> @@ -63,319 +75,425 @@ ENTRY (MEMCHR)
> # endif
> /* Broadcast CHAR to YMMMATCH. */
> VPBROADCAST %esi, %YMMMATCH
> - /* Check if we may cross page boundary with one vector load. */
> - andl $(2 * VEC_SIZE - 1), %ecx
> - cmpl $VEC_SIZE, %ecx
> - ja L(cros_page_boundary)
> + /* Check if we may cross page boundary with one
> + vector load. */
Fit comments to 72 columns.
> + movl %edi, %eax
> + andl $(PAGE_SIZE - 1), %eax
> + cmpl $(PAGE_SIZE - VEC_SIZE), %eax
> + ja L(cross_page_boundary)
>
> /* Check the first VEC_SIZE bytes. */
> - VPCMP $0, (%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> - testl %eax, %eax
> -
> + VPCMP $0, (%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> # ifndef USE_AS_RAWMEMCHR
> - jnz L(first_vec_x0_check)
> - /* Adjust length and check the end of data. */
> - subq $VEC_SIZE, %rdx
> - jbe L(zero)
> + /* If length < CHAR_PER_VEC handle special. */
> + cmpq $CHAR_PER_VEC, %rdx
> + jbe L(first_vec_x0)
> +# endif
> + testl %eax, %eax
> + jz L(aligned_more)
> + tzcntl %eax, %eax
> +# ifdef USE_AS_WMEMCHR
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
Fit comments to 72 columns.
> + leaq (%rdi, %rax, CHAR_SIZE), %rax
> # else
> - jnz L(first_vec_x0)
> + addq %rdi, %rax
> # endif
> -
> - /* Align data for aligned loads in the loop. */
> - addq $VEC_SIZE, %rdi
> - andl $(VEC_SIZE - 1), %ecx
> - andq $-VEC_SIZE, %rdi
> + ret
>
> # ifndef USE_AS_RAWMEMCHR
> - /* Adjust length. */
> - addq %rcx, %rdx
> -
> - subq $(VEC_SIZE * 4), %rdx
> - jbe L(last_4x_vec_or_less)
> -# endif
> - jmp L(more_4x_vec)
> +L(zero):
> + xorl %eax, %eax
> + ret
>
> + .p2align 5
> +L(first_vec_x0):
> + /* Check if first match was before length. */
> + tzcntl %eax, %eax
> + xorl %ecx, %ecx
> + cmpl %eax, %edx
> + leaq (%rdi, %rax, CHAR_SIZE), %rax
> + cmovle %rcx, %rax
> + ret
> +# else
> + /* NB: first_vec_x0 is 17 bytes which will leave
> + cross_page_boundary (which is relatively cold) close
> + enough to ideal alignment. So only realign
> + L(cross_page_boundary) if rawmemchr. */
Fit comments to 72 columns.
> .p2align 4
> -L(cros_page_boundary):
> - andl $(VEC_SIZE - 1), %ecx
> +# endif
> +L(cross_page_boundary):
> + /* Save pointer before aligning as its original
> + value is necessary for computer return address if byte is
> + found or adjusting length if it is not and this is
> + memchr. */
Fit comments to 72 columns.
> + movq %rdi, %rcx
> + /* Align data to VEC_SIZE. ALGN_PTR_REG is rcx
> + for memchr and rdi for rawmemchr. */
Fit comments to 72 columns.
> + andq $-VEC_SIZE, %ALGN_PTR_REG
> + VPCMP $0, (%ALGN_PTR_REG), %YMMMATCH, %k0
> + kmovd %k0, %r8d
> # ifdef USE_AS_WMEMCHR
> - /* NB: Divide shift count by 4 since each bit in K1 represent 4
> - bytes. */
> - movl %ecx, %SHIFT_REG
> - sarl $2, %SHIFT_REG
> + /* NB: Divide shift count by 4 since each bit in
> + K0 represent 4 bytes. */
> + sarl $2, %eax
> +# endif
> +# ifndef USE_AS_RAWMEMCHR
> + movl $(PAGE_SIZE / CHAR_SIZE), %esi
> + subl %eax, %esi
> # endif
> - andq $-VEC_SIZE, %rdi
> - VPCMP $0, (%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> - /* Remove the leading bytes. */
> - sarxl %SHIFT_REG, %eax, %eax
> - testl %eax, %eax
> - jz L(aligned_more)
> - tzcntl %eax, %eax
> # ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - sall $2, %eax
> + andl $(CHAR_PER_VEC - 1), %eax
> # endif
> + /* Remove the leading bytes. */
> + sarxl %eax, %r8d, %eax
> # ifndef USE_AS_RAWMEMCHR
> /* Check the end of data. */
> - cmpq %rax, %rdx
> - jbe L(zero)
> + cmpq %rsi, %rdx
> + jbe L(first_vec_x0)
> +# endif
> + testl %eax, %eax
> + jz L(cross_page_continue)
> + tzcntl %eax, %eax
> +# ifdef USE_AS_WMEMCHR
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
> + leaq (%RAW_PTR_REG, %rax, CHAR_SIZE), %rax
> +# else
> + addq %RAW_PTR_REG, %rax
> # endif
> - addq %rdi, %rax
> - addq %rcx, %rax
> ret
>
> .p2align 4
> -L(aligned_more):
> -# ifndef USE_AS_RAWMEMCHR
> - /* Calculate "rdx + rcx - VEC_SIZE" with "rdx - (VEC_SIZE - rcx)"
> - instead of "(rdx + rcx) - VEC_SIZE" to void possible addition
> - overflow. */
> - negq %rcx
> - addq $VEC_SIZE, %rcx
> +L(first_vec_x1):
> + tzcntl %eax, %eax
> + leaq VEC_SIZE(%rdi, %rax, CHAR_SIZE), %rax
> + ret
>
> - /* Check the end of data. */
> - subq %rcx, %rdx
> - jbe L(zero)
> -# endif
> + .p2align 4
> +L(first_vec_x2):
> + tzcntl %eax, %eax
> + leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> + ret
>
> - addq $VEC_SIZE, %rdi
> + .p2align 4
> +L(first_vec_x3):
> + tzcntl %eax, %eax
> + leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
> + ret
> +
> + .p2align 4
> +L(first_vec_x4):
> + tzcntl %eax, %eax
> + leaq (VEC_SIZE * 4)(%rdi, %rax, CHAR_SIZE), %rax
> + ret
> +
> + .p2align 5
> +L(aligned_more):
> + /* Check the first 4 * VEC_SIZE. Only one
> + VEC_SIZE at a time since data is only aligned to
> + VEC_SIZE. */
Fit comments to 72 columns.
>
> # ifndef USE_AS_RAWMEMCHR
> - subq $(VEC_SIZE * 4), %rdx
> + /* Align data to VEC_SIZE. */
> +L(cross_page_continue):
> + xorl %ecx, %ecx
> + subl %edi, %ecx
> + andq $-VEC_SIZE, %rdi
> + /* esi is for adjusting length to see if near the
> + end. */
Fit comments to 72 columns.
> + leal (VEC_SIZE * 5)(%rdi, %rcx), %esi
> +# ifdef USE_AS_WMEMCHR
> + /* NB: Divide bytes by 4 to get the wchar_t
> + count. */
> + sarl $2, %esi
> +# endif
> +# else
> + andq $-VEC_SIZE, %rdi
> +L(cross_page_continue):
> +# endif
> + /* Load first VEC regardless. */
> + VPCMP $0, (VEC_SIZE)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> +# ifndef USE_AS_RAWMEMCHR
> + /* Adjust length. If near end handle specially.
> + */
Fit comments to 72 columns.
> + subq %rsi, %rdx
> jbe L(last_4x_vec_or_less)
> # endif
> -
> -L(more_4x_vec):
> - /* Check the first 4 * VEC_SIZE. Only one VEC_SIZE at a time
> - since data is only aligned to VEC_SIZE. */
> - VPCMP $0, (%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> - testl %eax, %eax
> - jnz L(first_vec_x0)
> -
> - VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> testl %eax, %eax
> jnz L(first_vec_x1)
>
> - VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> + VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> testl %eax, %eax
> jnz L(first_vec_x2)
>
> - VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> + VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> testl %eax, %eax
> jnz L(first_vec_x3)
>
> - addq $(VEC_SIZE * 4), %rdi
> + VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> + testl %eax, %eax
> + jnz L(first_vec_x4)
> +
>
> # ifndef USE_AS_RAWMEMCHR
> - subq $(VEC_SIZE * 4), %rdx
> - jbe L(last_4x_vec_or_less)
> -# endif
> + /* Check if at last CHAR_PER_VEC * 4 length. */
> + subq $(CHAR_PER_VEC * 4), %rdx
> + jbe L(last_4x_vec_or_less_cmpeq)
> + addq $VEC_SIZE, %rdi
>
> - /* Align data to 4 * VEC_SIZE. */
> - movq %rdi, %rcx
> - andl $(4 * VEC_SIZE - 1), %ecx
> + /* Align data to VEC_SIZE * 4 for the loop and
> + readjust length. */
Fit comments to 72 columns.
> +# ifdef USE_AS_WMEMCHR
> + movl %edi, %ecx
> andq $-(4 * VEC_SIZE), %rdi
> -
> -# ifndef USE_AS_RAWMEMCHR
> - /* Adjust length. */
> + andl $(VEC_SIZE * 4 - 1), %ecx
> + /* NB: Divide bytes by 4 to get the wchar_t
> + count. */
Fit comments to 72 columns.
> + sarl $2, %ecx
> addq %rcx, %rdx
> +# else
> + addq %rdi, %rdx
> + andq $-(4 * VEC_SIZE), %rdi
> + subq %rdi, %rdx
> +# endif
> +# else
> + addq $VEC_SIZE, %rdi
> + andq $-(4 * VEC_SIZE), %rdi
> # endif
>
> + vpxorq %XZERO, %XZERO, %XZERO
> +
> + /* Compare 4 * VEC at a time forward. */
> .p2align 4
> L(loop_4x_vec):
> - /* Compare 4 * VEC at a time forward. */
> - VPCMP $0, (%rdi), %YMMMATCH, %k1
> - VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k2
> - kord %k1, %k2, %k5
> - VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k3
> - VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k4
> -
> - kord %k3, %k4, %k6
> - kortestd %k5, %k6
> - jnz L(4x_vec_end)
> -
> - addq $(VEC_SIZE * 4), %rdi
> -
> + /* It would be possible to save some instructions
> + using 4x VPCMP but bottleneck on port 5 makes it not woth
> + it. */
Fit comments to 72 columns.
> + VPCMP $4, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k1
> + /* xor will set bytes match esi to zero. */
> + vpxorq (VEC_SIZE * 5)(%rdi), %YMMMATCH, %YMM2
> + vpxorq (VEC_SIZE * 6)(%rdi), %YMMMATCH, %YMM3
> + VPCMP $0, (VEC_SIZE * 7)(%rdi), %YMMMATCH, %k3
> + /* Reduce VEC2 / VEC3 with min and VEC1 with zero
> + mask. */
Fit comments to 72 columns.
> + VPMINU %YMM2, %YMM3, %YMM3 {%k1} {z}
> + VPCMP $0, %YMM3, %YZERO, %k2
> # ifdef USE_AS_RAWMEMCHR
> - jmp L(loop_4x_vec)
> + subq $-(VEC_SIZE * 4), %rdi
> + kortestd %k2, %k3
> + jz L(loop_4x_vec)
> # else
> - subq $(VEC_SIZE * 4), %rdx
> - ja L(loop_4x_vec)
> + kortestd %k2, %k3
> + jnz L(loop_4x_vec_end)
>
> -L(last_4x_vec_or_less):
> - /* Less than 4 * VEC and aligned to VEC_SIZE. */
> - addl $(VEC_SIZE * 2), %edx
> - jle L(last_2x_vec)
> + subq $-(VEC_SIZE * 4), %rdi
>
> - VPCMP $0, (%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> - testl %eax, %eax
> - jnz L(first_vec_x0)
> + subq $(CHAR_PER_VEC * 4), %rdx
> + ja L(loop_4x_vec)
>
> - VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> + /* Fall through into less than 4 remaining
> + vectors of length case. */
Fit comments to 72 columns.
> + VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> + addq $(VEC_SIZE * 3), %rdi
> + .p2align 4
> +L(last_4x_vec_or_less):
> + /* Check if first VEC contained match. */
> testl %eax, %eax
> - jnz L(first_vec_x1)
> + jnz L(first_vec_x1_check)
>
> - VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> - testl %eax, %eax
> + /* If remaining length > CHAR_PER_VEC * 2. */
> + addl $(CHAR_PER_VEC * 2), %edx
> + jg L(last_4x_vec)
>
> - jnz L(first_vec_x2_check)
> - subl $VEC_SIZE, %edx
> - jle L(zero)
> +L(last_2x_vec):
> + /* If remaining length < CHAR_PER_VEC. */
> + addl $CHAR_PER_VEC, %edx
> + jle L(zero_end)
> +
> + /* Check VEC2 and compare any match with
> + remaining length. */
Fit comments to 72 columns.
> + VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> + tzcntl %eax, %eax
> + cmpl %eax, %edx
> + jbe L(set_zero_end)
> + leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> +L(zero_end):
> + ret
>
> - VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> - testl %eax, %eax
>
> - jnz L(first_vec_x3_check)
> + .p2align 4
> +L(first_vec_x1_check):
> + tzcntl %eax, %eax
> + /* Adjust length. */
> + subl $-(CHAR_PER_VEC * 4), %edx
> + /* Check if match within remaining length. */
> + cmpl %eax, %edx
> + jbe L(set_zero_end)
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
Fit comments to 72 columns.
> + leaq VEC_SIZE(%rdi, %rax, CHAR_SIZE), %rax
> + ret
> +L(set_zero_end):
> xorl %eax, %eax
> ret
>
> .p2align 4
> -L(last_2x_vec):
> - addl $(VEC_SIZE * 2), %edx
> - VPCMP $0, (%rdi), %YMMMATCH, %k1
> +L(loop_4x_vec_end):
> +# endif
> + /* rawmemchr will fall through into this if match
> + was found in loop. */
Fit comments to 72 columns.
> +
> + /* k1 has not of matches with VEC1. */
> kmovd %k1, %eax
> - testl %eax, %eax
> +# ifdef USE_AS_WMEMCHR
> + subl $((1 << CHAR_PER_VEC) - 1), %eax
> +# else
> + incl %eax
> +# endif
> + jnz L(last_vec_x1_return)
>
> - jnz L(first_vec_x0_check)
> - subl $VEC_SIZE, %edx
> - jle L(zero)
> + VPCMP $0, %YMM2, %YZERO, %k0
> + kmovd %k0, %eax
> + testl %eax, %eax
> + jnz L(last_vec_x2_return)
>
> - VPCMP $0, VEC_SIZE(%rdi), %YMMMATCH, %k1
> - kmovd %k1, %eax
> + kmovd %k2, %eax
> testl %eax, %eax
> - jnz L(first_vec_x1_check)
> - xorl %eax, %eax
> - ret
> + jnz L(last_vec_x3_return)
>
> - .p2align 4
> -L(first_vec_x0_check):
> + kmovd %k3, %eax
> tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - sall $2, %eax
> +# ifdef USE_AS_RAWMEMCHR
> + leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
> +# else
> + leaq (VEC_SIZE * 7)(%rdi, %rax, CHAR_SIZE), %rax
> # endif
> - /* Check the end of data. */
> - cmpq %rax, %rdx
> - jbe L(zero)
> - addq %rdi, %rax
> ret
>
> .p2align 4
> -L(first_vec_x1_check):
> +L(last_vec_x1_return):
> tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - sall $2, %eax
> -# endif
> - /* Check the end of data. */
> - cmpq %rax, %rdx
> - jbe L(zero)
> - addq $VEC_SIZE, %rax
> +# ifdef USE_AS_RAWMEMCHR
> +# ifdef USE_AS_WMEMCHR
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
Fit comments to 72 columns.
> + leaq (%rdi, %rax, CHAR_SIZE), %rax
> +# else
> addq %rdi, %rax
> - ret
> -
> - .p2align 4
> -L(first_vec_x2_check):
> - tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - sall $2, %eax
> +# endif
> +# else
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
Fit comments to 72 columns.
> + leaq (VEC_SIZE * 4)(%rdi, %rax, CHAR_SIZE), %rax
> # endif
> - /* Check the end of data. */
> - cmpq %rax, %rdx
> - jbe L(zero)
> - addq $(VEC_SIZE * 2), %rax
> - addq %rdi, %rax
> ret
>
> .p2align 4
> -L(first_vec_x3_check):
> +L(last_vec_x2_return):
> tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - sall $2, %eax
> +# ifdef USE_AS_RAWMEMCHR
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
> + leaq VEC_SIZE(%rdi, %rax, CHAR_SIZE), %rax
> +# else
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
> + leaq (VEC_SIZE * 5)(%rdi, %rax, CHAR_SIZE), %rax
> # endif
> - /* Check the end of data. */
> - cmpq %rax, %rdx
> - jbe L(zero)
> - addq $(VEC_SIZE * 3), %rax
> - addq %rdi, %rax
> ret
>
> .p2align 4
> -L(zero):
> - xorl %eax, %eax
> - ret
> -# endif
> -
> - .p2align 4
> -L(first_vec_x0):
> +L(last_vec_x3_return):
> tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - leaq (%rdi, %rax, 4), %rax
> +# ifdef USE_AS_RAWMEMCHR
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
Fit comments to 72 columns.
> + leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> # else
> - addq %rdi, %rax
> + /* NB: Multiply bytes by CHAR_SIZE to get the
> + wchar_t count. */
Fit comments to 72 columns.
> + leaq (VEC_SIZE * 6)(%rdi, %rax, CHAR_SIZE), %rax
> # endif
> ret
>
> +
> +# ifndef USE_AS_RAWMEMCHR
> +L(last_4x_vec_or_less_cmpeq):
> + VPCMP $0, (VEC_SIZE * 5)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> + subq $-(VEC_SIZE * 4), %rdi
> + /* Check first VEC regardless. */
> + testl %eax, %eax
> + jnz L(first_vec_x1_check)
> +
> + /* If remaining length <= CHAR_PER_VEC * 2. */
> + addl $(CHAR_PER_VEC * 2), %edx
> + jle L(last_2x_vec)
> +
> .p2align 4
> -L(first_vec_x1):
> +L(last_4x_vec):
> + VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> + testl %eax, %eax
> + jnz L(last_vec_x2)
> +
> +
> + VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> + /* Create mask for possible matches within
> + remaining length. */
Fit comments to 72 columns.
> +# ifdef USE_AS_WMEMCHR
> + movl $((1 << (CHAR_PER_VEC * 2)) - 1), %ecx
> + bzhil %edx, %ecx, %ecx
> +# else
> + movq $-1, %rcx
> + bzhiq %rdx, %rcx, %rcx
> +# endif
> + /* Test matches in data against length match. */
> + andl %ecx, %eax
> + jnz L(last_vec_x3)
> +
> + /* if remaining length <= CHAR_PER_VEC * 3 (Note
> + this is after remaining length was found to be >
> + CHAR_PER_VEC * 2. */
Fit comments to 72 columns.
> + subl $CHAR_PER_VEC, %edx
> + jbe L(zero_end2)
> +
> +
> + VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMMATCH, %k0
> + kmovd %k0, %eax
> + /* Shift remaining length mask for last VEC. */
> +# ifdef USE_AS_WMEMCHR
> + shrl $CHAR_PER_VEC, %ecx
> +# else
> + shrq $CHAR_PER_VEC, %rcx
> +# endif
> + andl %ecx, %eax
> + jz L(zero_end2)
> tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - leaq VEC_SIZE(%rdi, %rax, 4), %rax
> -# else
> - addq $VEC_SIZE, %rax
> - addq %rdi, %rax
> -# endif
> + leaq (VEC_SIZE * 4)(%rdi, %rax, CHAR_SIZE), %rax
> +L(zero_end2):
> ret
>
> - .p2align 4
> -L(first_vec_x2):
> +L(last_vec_x2):
> tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - leaq (VEC_SIZE * 2)(%rdi, %rax, 4), %rax
> -# else
> - addq $(VEC_SIZE * 2), %rax
> - addq %rdi, %rax
> -# endif
> + leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> ret
>
> .p2align 4
> -L(4x_vec_end):
> - kmovd %k1, %eax
> - testl %eax, %eax
> - jnz L(first_vec_x0)
> - kmovd %k2, %eax
> - testl %eax, %eax
> - jnz L(first_vec_x1)
> - kmovd %k3, %eax
> - testl %eax, %eax
> - jnz L(first_vec_x2)
> - kmovd %k4, %eax
> - testl %eax, %eax
> -L(first_vec_x3):
> +L(last_vec_x3):
> tzcntl %eax, %eax
> -# ifdef USE_AS_WMEMCHR
> - /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
> - leaq (VEC_SIZE * 3)(%rdi, %rax, 4), %rax
> -# else
> - addq $(VEC_SIZE * 3), %rax
> - addq %rdi, %rax
> -# endif
> + leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
> ret
> +# endif
>
> -END (MEMCHR)
> +END(MEMCHR)
No need for this change.
> #endif
> --
> 2.29.2
>
Thanks.
H.J.
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