runtime: add ARM64 vectorized support for Green Tea GC

[mishaglik]

Proposal Details

This proposal introduce ARM64 SVE based implementation of Green Tea GC scan kernel.

Implementation details

Current AMD64 Green Tea GC kernel consists of 2 main parts: expander and scan kernel.
Expander makes objmask same size as ptrmask.
Scan kernel intersects expanded mask with ptrmask and then loads and filters valid pointers from span.

Scan kernel on ARM64

Implementation of scan kernel for ARM64 are almost the same as for AMD64.
However there are several key differences.

1. Mask register semantic: on AVX512 operation on any vector element size take consecutive bits from mask register.
   On ARM64 bits must be interleaved according to vector element size.
   Example: compact/compress operation used in scan kernel:
   
   
   Chain of punpklo/hi instructions used to interleave bits.
   It looks like:

  ldr p0, [x4]
  punpkhi p4.h, p0.b
  punpklo p0.h, p0.b

  punpkhi p2.h, p0.b
  punpklo p0.h, p0.b
  punpkhi p6.h, p4.b
  punpklo p4.h, p4.b

  punpkhi p1.h, p0.b
  punpklo p0.h, p0.b
  punpkhi p3.h, p2.b
  punpklo p2.h, p2.b
  punpkhi p5.h, p4.b
  punpklo p4.h, p4.b
  punpkhi p7.h, p6.b
  punpklo p6.h, p6.b

In this snippet dense bitmask is loaded to p0 and then unpacked to p0-p7 register.

1. Vectors scalability. SVE vector size may be different across architectures.
   On my machine SVE vector size is 256 bit.

Main scan kernel logic can be seen in following snippet:

  // Load next line to z0 register
  ldr z0, [x0, 0, mul vl]
  // Filter out nil pointers
  cmpne p0.d, p0/z, z0.d, #0
  compact z0.d, p0, z0.d 
  // Count how much pointers we got
  cntp x5, p0, p0.d 
  // Put in output buffer
  str z0, [x1]
  // Advanve outbuf buffer pointer to number of valid pointers
  add x1, x1, x5, lsl #3

Issue with expand kernel. Proposal of sparse inline mark bits

AMD64 expand kernel implementation relies on GF2P8AFFINEQB instruction.
There is nothing like it in ARM64 SIMD extensions.
Emulating it would be too costly.
In order to overcome this issue I propose change semantic of inline mark bits.
Inline make bits has fixed size, enough to fit all objects in Green Tea span.
In other words it has pageSize / 16 bits.
Now i'th bit corresponds to i'th object.
In proposed change i'th bit corresponds to object starting on offset 16*i bytes (if such object exists).
This require span.elemsize be multiple of 16. Now it only excludes elemsize == 24.
In this implementation expand operation is replaced by multiplication to 2^(elemsize/16)-1 which is much more simple and does not require GF2P8AFFINEQB instruction.

Implementation

Proposed changes has 2 commits:

• First one introduces sparse inline mark bits and ready to merge.
  It is tested using Intel SDE. So I was unable to measure performance impact of this change.

• Second one has ARM64 SVE Green Tea kernel implementation.
  As for now go does not have support of SVE instructions, implementation is done using WORD directives.
  It may be worth waiting official SVE support.

Benchmark results

I measured this implementation on tests in src/internal/runtime/gc/scan and got following results:

goos: linux

goarch: arm64

pkg: internal/runtime/gc/scan

                                                         │      Go       │               Platform               │
                                                         │    sec/op     │    sec/op     vs base                │
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=0-4       20.95n ±  3%   27.64n ±  6%  +31.90% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=10-4      296.8n ±  3%   277.9n ±  0%   -6.34% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=20-4      568.9n ±  3%   323.9n ±  0%  -43.07% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=30-4      864.9n ±  3%   323.5n ±  0%  -62.59% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=40-4     1169.0n ±  2%   323.7n ±  0%  -72.31% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=50-4     1451.5n ±  3%   324.7n ±  0%  -77.63% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=60-4     1687.0n ±  2%   323.2n ±  0%  -80.84% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=70-4     1971.5n ±  4%   323.8n ±  0%  -83.57% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=80-4     2244.0n ±  1%   323.9n ±  0%  -85.57% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=90-4     2481.5n ±  2%   324.0n ±  0%  -86.94% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=2/pct=100-4    2804.0n ±  3%   323.1n ±  0%  -88.48% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=0-4       21.25n ±  3%   27.00n ± 17%  +27.03% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=10-4      257.6n ±  6%   324.0n ±  0%  +25.77% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=20-4      490.4n ±  4%   323.3n ±  0%  -34.07% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=30-4      742.0n ±  6%   323.8n ±  0%  -56.36% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=40-4     1005.3n ±  8%   324.9n ±  0%  -67.68% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=50-4     1182.5n ±  5%   323.8n ±  1%  -72.62% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=60-4     1444.5n ±  8%   323.9n ±  0%  -77.58% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=70-4     1747.0n ±  4%   323.3n ±  0%  -81.49% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=80-4     1893.0n ±  5%   323.7n ±  0%  -82.90% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=90-4     2141.0n ±  4%   323.6n ±  0%  -84.89% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=4/pct=100-4    2361.5n ±  8%   324.1n ±  0%  -86.28% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=0-4       21.04n ±  4%   29.79n ±  9%  +41.62% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=10-4      236.3n ±  6%   323.6n ±  1%  +36.89% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=20-4      480.0n ±  5%   323.8n ±  0%  -32.54% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=30-4      687.7n ±  8%   324.0n ±  0%  -52.88% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=40-4      931.9n ± 10%   325.0n ±  0%  -65.13% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=50-4     1137.0n ±  7%   323.4n ±  0%  -71.56% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=60-4     1350.5n ±  3%   323.6n ±  1%  -76.04% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=70-4     1612.0n ±  7%   324.1n ±  0%  -79.89% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=80-4     1877.0n ±  7%   324.2n ±  0%  -82.73% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=90-4     2056.5n ±  6%   323.9n ±  0%  -84.25% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=5/pct=100-4    2212.5n ±  7%   324.2n ±  0%  -85.34% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=0-4       21.04n ±  4%   27.41n ± 11%  +30.24% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=10-4      234.8n ±  6%   286.7n ±  1%  +22.10% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=20-4      465.0n ±  4%   323.9n ±  0%  -30.34% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=30-4      636.6n ±  5%   323.5n ±  1%  -49.18% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=40-4      890.9n ± 10%   324.0n ±  0%  -63.63% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=50-4     1124.5n ±  9%   323.8n ±  0%  -71.21% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=60-4     1338.0n ±  5%   323.8n ±  1%  -75.80% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=70-4     1534.5n ±  3%   323.8n ±  0%  -78.90% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=80-4     1725.5n ±  8%   323.9n ±  0%  -81.23% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=90-4     1991.0n ±  4%   323.6n ±  0%  -83.75% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=6/pct=100-4    2180.0n ±  4%   323.2n ±  0%  -85.17% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=0-4       21.33n ±  2%   28.49n ±  6%  +33.57% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=10-4      232.5n ±  9%   304.2n ±  0%  +30.89% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=20-4      423.2n ± 10%   323.9n ±  1%  -23.45% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=30-4      682.4n ±  9%   323.8n ±  0%  -52.55% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=40-4      893.4n ±  6%   324.0n ±  0%  -63.73% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=50-4     1088.0n ±  3%   324.1n ±  1%  -70.21% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=60-4     1343.0n ±  6%   323.9n ±  0%  -75.89% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=70-4     1494.0n ±  3%   323.8n ±  1%  -78.33% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=80-4     1761.0n ±  6%   324.0n ±  0%  -81.60% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=90-4     1939.5n ±  3%   324.4n ±  0%  -83.27% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=7/pct=100-4    2132.5n ±  8%   323.8n ±  0%  -84.82% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=0-4       21.50n ±  7%   29.52n ± 15%  +37.30% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=10-4      244.7n ±  5%   266.2n ±  1%   +8.83% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=20-4      422.1n ± 10%   323.7n ±  0%  -23.30% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=30-4      661.6n ±  4%   323.9n ±  0%  -51.05% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=40-4      883.4n ±  6%   323.9n ±  0%  -63.34% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=50-4     1091.0n ±  6%   323.7n ±  0%  -70.33% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=60-4     1298.0n ±  7%   323.8n ±  0%  -75.06% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=70-4     1491.0n ±  5%   323.8n ±  1%  -78.28% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=80-4     1688.0n ±  9%   323.9n ±  0%  -80.81% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=90-4     1985.5n ± 13%   323.9n ±  1%  -83.69% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=8/pct=100-4    2115.5n ±  2%   323.8n ±  1%  -84.69% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=0-4       21.81n ±  4%   28.50n ± 15%  +30.67% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=10-4      219.0n ±  9%   266.8n ±  0%  +21.80% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=20-4      470.2n ±  6%   304.6n ±  0%  -35.20% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=30-4      637.2n ±  7%   323.8n ±  0%  -49.19% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=40-4      861.1n ±  3%   323.8n ±  1%  -62.40% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=50-4     1123.5n ±  6%   323.8n ±  1%  -71.18% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=60-4     1274.5n ±  9%   323.9n ±  0%  -74.58% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=70-4     1537.5n ±  5%   324.4n ±  0%  -78.90% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=80-4     1690.5n ±  4%   324.4n ±  0%  -80.81% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=90-4     1904.5n ±  9%   324.3n ±  1%  -82.97% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=9/pct=100-4    2128.5n ±  3%   323.9n ±  0%  -84.78% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=0-4      20.82n ±  2%   27.99n ±  6%  +34.44% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=10-4     212.3n ±  6%   304.9n ±  0%  +43.56% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=20-4     445.8n ± 12%   305.0n ±  0%  -31.59% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=30-4     606.9n ± 10%   304.9n ±  0%  -49.77% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=40-4     852.8n ± 11%   304.4n ±  0%  -64.30% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=50-4    1030.0n ±  6%   305.0n ±  0%  -70.39% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=60-4    1297.5n ±  7%   323.2n ±  1%  -75.09% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=70-4    1456.0n ±  3%   323.4n ±  0%  -77.79% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=80-4    1641.0n ± 14%   324.1n ±  1%  -80.25% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=90-4    1858.5n ±  4%   323.4n ±  0%  -82.60% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=10/pct=100-4   2099.0n ±  9%   324.4n ±  0%  -84.55% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=0-4      21.21n ±  7%   27.86n ± 15%  +31.35% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=10-4     237.5n ±  7%   190.4n ±  0%  -19.85% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=20-4     409.2n ±  6%   287.9n ±  0%  -29.64% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=30-4     623.0n ±  6%   304.7n ±  0%  -51.10% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=40-4     817.6n ±  6%   304.9n ±  0%  -62.71% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=50-4    1036.5n ±  5%   324.4n ±  0%  -68.70% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=60-4    1241.0n ±  7%   325.1n ±  0%  -73.80% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=70-4    1421.0n ±  4%   323.9n ±  1%  -77.20% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=80-4    1622.5n ± 14%   324.3n ±  0%  -80.01% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=90-4    1802.0n ± 16%   324.6n ±  0%  -81.99% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=11/pct=100-4   2074.0n ± 13%   323.4n ±  0%  -84.41% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=0-4      21.20n ±  6%   27.80n ± 10%  +31.14% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=10-4     220.7n ± 12%   304.7n ±  0%  +38.09% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=20-4     425.4n ±  3%   304.7n ±  0%  -28.37% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=30-4     601.4n ±  2%   323.9n ±  0%  -46.15% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=40-4     815.1n ±  7%   323.9n ±  1%  -60.26% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=50-4    1031.5n ±  5%   323.9n ±  0%  -68.59% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=60-4    1246.5n ± 16%   324.1n ±  0%  -74.00% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=70-4    1471.0n ± 13%   324.7n ±  0%  -77.93% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=80-4    1649.5n ± 12%   323.8n ±  0%  -80.37% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=90-4    1842.0n ±  4%   323.4n ±  0%  -82.45% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=12/pct=100-4   2061.5n ± 15%   324.1n ±  0%  -84.28% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=0-4      21.14n ±  4%   27.25n ± 11%  +28.91% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=10-4     238.2n ±  4%   305.1n ±  0%  +28.09% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=20-4     414.8n ±  8%   324.4n ±  0%  -21.80% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=30-4     641.1n ±  7%   325.4n ±  1%  -49.25% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=40-4     829.1n ±  3%   324.0n ±  0%  -60.92% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=50-4    1079.5n ±  8%   323.8n ±  0%  -70.00% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=60-4    1222.5n ± 12%   323.8n ±  0%  -73.52% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=70-4    1512.5n ±  5%   323.4n ±  0%  -78.61% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=80-4    1628.0n ±  7%   323.4n ±  0%  -80.14% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=90-4    1774.0n ± 14%   323.2n ±  0%  -81.78% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=13/pct=100-4   2035.5n ± 13%   323.9n ±  0%  -84.08% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=0-4      20.97n ±  5%   27.97n ±  6%  +33.37% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=10-4     207.6n ± 11%   323.8n ±  1%  +55.95% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=20-4     399.1n ± 15%   323.9n ±  0%  -18.84% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=30-4     631.8n ±  8%   323.6n ±  0%  -48.79% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=40-4     844.3n ±  9%   324.0n ±  1%  -61.63% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=50-4    1040.0n ±  5%   324.5n ±  0%  -68.80% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=60-4    1223.0n ±  8%   323.8n ±  1%  -73.53% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=70-4    1422.0n ±  8%   324.1n ±  0%  -77.21% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=80-4    1707.0n ± 10%   323.4n ±  0%  -81.06% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=90-4    1797.0n ±  3%   323.9n ±  0%  -81.98% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=14/pct=100-4   1945.0n ±  9%   323.8n ±  0%  -83.35% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=0-4      21.49n ±  6%   27.88n ±  7%  +29.71% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=10-4     232.5n ±  4%   324.1n ±  0%  +39.39% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=20-4     451.7n ±  4%   324.0n ±  0%  -28.26% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=30-4     637.0n ± 11%   323.4n ±  1%  -49.23% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=40-4     822.9n ±  6%   324.4n ±  0%  -60.57% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=50-4    1084.5n ±  9%   323.8n ±  0%  -70.15% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=60-4    1177.5n ± 10%   324.2n ±  0%  -72.47% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=70-4    1410.5n ±  4%   323.8n ±  0%  -77.04% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=80-4    1636.5n ± 10%   324.1n ±  1%  -80.20% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=90-4    1828.0n ±  6%   324.1n ±  0%  -82.27% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=15/pct=100-4   2008.0n ± 10%   323.6n ±  0%  -83.88% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=0-4      21.45n ±  9%   27.45n ±  4%  +27.98% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=10-4     248.8n ±  6%   323.8n ±  1%  +30.14% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=20-4     397.3n ±  7%   323.9n ±  1%  -18.46% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=30-4     644.7n ±  6%   323.3n ±  0%  -49.85% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=40-4     830.7n ±  8%   324.0n ±  1%  -60.99% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=50-4    1043.0n ±  7%   323.9n ±  0%  -68.95% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=60-4    1274.0n ± 10%   323.7n ±  1%  -74.59% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=70-4    1410.5n ±  9%   324.4n ±  0%  -77.00% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=80-4    1586.5n ±  3%   323.4n ±  0%  -79.61% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=90-4    1757.5n ±  5%   324.0n ±  1%  -81.56% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=16/pct=100-4   1953.0n ±  7%   323.4n ±  0%  -83.44% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=0-4      21.30n ±  3%   28.39n ±  5%  +33.31% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=10-4     200.2n ±  5%   171.3n ±  0%  -14.43% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=20-4     422.7n ±  8%   323.3n ±  0%  -23.51% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=30-4     618.7n ±  7%   323.7n ±  0%  -47.69% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=40-4     843.8n ±  9%   323.2n ±  0%  -61.69% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=50-4    1015.0n ±  7%   323.5n ±  0%  -68.13% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=60-4    1205.0n ±  6%   323.1n ±  0%  -73.19% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=70-4    1440.0n ±  5%   323.6n ±  1%  -77.53% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=80-4    1614.5n ±  3%   323.2n ±  1%  -79.98% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=90-4    1844.5n ±  6%   324.6n ±  0%  -82.40% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=17/pct=100-4   1961.5n ±  5%   323.6n ±  0%  -83.50% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=0-4      21.27n ±  4%   28.50n ±  9%  +33.99% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=10-4     208.7n ±  2%   305.5n ±  0%  +46.42% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=20-4     388.5n ±  8%   324.2n ±  0%  -16.53% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=30-4     650.4n ±  8%   324.6n ±  0%  -50.10% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=40-4     808.0n ±  8%   324.1n ±  0%  -59.89% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=50-4    1045.5n ±  8%   323.8n ±  0%  -69.03% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=60-4    1218.0n ±  7%   323.3n ±  0%  -73.46% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=70-4    1435.0n ± 11%   323.5n ±  0%  -77.46% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=80-4    1664.5n ±  9%   323.7n ±  1%  -80.56% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=90-4    1822.5n ± 12%   323.7n ±  1%  -82.24% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=18/pct=100-4   1978.5n ±  2%   323.6n ±  0%  -83.65% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=0-4      21.58n ±  5%   28.55n ±  7%  +32.28% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=10-4     229.5n ±  9%   324.0n ±  1%  +41.21% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=20-4     451.8n ±  2%   323.6n ±  0%  -28.39% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=30-4     613.0n ±  4%   324.0n ±  0%  -47.14% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=40-4     799.5n ±  4%   323.9n ±  0%  -59.48% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=50-4    1029.5n ±  6%   324.0n ±  1%  -68.53% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=60-4    1182.5n ±  5%   324.2n ±  0%  -72.58% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=70-4    1456.0n ±  5%   323.6n ±  0%  -77.77% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=80-4    1596.5n ±  6%   323.8n ±  0%  -79.72% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=90-4    1791.0n ±  6%   323.6n ±  0%  -81.93% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=19/pct=100-4   1915.5n ± 15%   323.6n ±  0%  -83.11% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=0-4      21.50n ±  4%   27.33n ± 12%  +27.12% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=10-4     252.4n ± 10%   172.2n ±  0%  -31.81% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=20-4     410.7n ±  3%   322.6n ±  0%  -21.44% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=30-4     672.3n ±  8%   324.2n ±  0%  -51.78% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=40-4     804.0n ±  8%   323.8n ±  0%  -59.73% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=50-4    1035.5n ±  6%   323.8n ±  0%  -68.73% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=60-4    1235.5n ±  6%   323.4n ±  0%  -73.82% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=70-4    1480.0n ± 11%   323.4n ±  0%  -78.15% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=80-4    1580.5n ±  3%   324.1n ±  0%  -79.50% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=90-4    1823.0n ±  9%   324.6n ±  0%  -82.20% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=20/pct=100-4   1955.0n ±  6%   323.2n ±  1%  -83.47% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=0-4      21.57n ±  5%   28.27n ±  6%  +31.06% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=10-4     193.0n ±  7%   317.6n ±  0%  +64.58% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=20-4     446.0n ±  7%   323.4n ±  0%  -27.49% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=30-4     618.7n ±  4%   323.9n ±  0%  -47.65% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=40-4     795.0n ± 10%   323.9n ±  0%  -59.27% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=50-4    1047.0n ±  6%   323.3n ±  0%  -69.12% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=60-4    1222.5n ±  4%   323.6n ±  1%  -73.53% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=70-4    1368.5n ±  6%   324.2n ±  1%  -76.31% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=80-4    1621.0n ± 13%   324.1n ±  1%  -80.01% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=90-4    1813.0n ±  6%   323.7n ±  0%  -82.15% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=21/pct=100-4   1986.5n ±  7%   324.2n ±  1%  -83.68% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=0-4      21.42n ±  6%   27.22n ± 11%  +27.13% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=10-4     209.6n ±  4%   313.1n ±  0%  +49.32% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=20-4     413.0n ±  6%   313.8n ±  0%  -24.03% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=30-4     585.9n ±  8%   313.8n ±  0%  -46.45% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=40-4     798.0n ±  7%   314.0n ±  0%  -60.65% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=50-4    1033.0n ± 10%   313.8n ±  0%  -69.62% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=60-4    1224.5n ±  6%   313.7n ±  0%  -74.38% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=70-4    1423.0n ±  7%   323.7n ±  1%  -77.25% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=80-4    1584.5n ±  8%   323.7n ±  0%  -79.57% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=90-4    1776.0n ± 10%   324.1n ±  0%  -81.75% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=22/pct=100-4   1980.0n ±  3%   323.8n ±  0%  -83.64% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=0-4      21.27n ±  3%   29.02n ± 15%  +36.44% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=10-4     235.6n ±  5%   313.1n ±  0%  +32.92% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=20-4     430.0n ± 12%   313.3n ±  0%  -27.14% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=30-4     625.8n ±  5%   313.6n ±  0%  -49.89% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=40-4     837.5n ±  8%   313.9n ±  0%  -62.51% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=50-4    1019.5n ±  6%   313.4n ±  0%  -69.25% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=60-4    1133.0n ±  7%   314.2n ±  0%  -72.26% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=70-4    1318.0n ±  6%   324.0n ±  0%  -75.42% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=80-4    1526.0n ±  6%   323.8n ±  0%  -78.78% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=90-4    1674.0n ± 13%   323.8n ±  1%  -80.66% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=23/pct=100-4   1892.5n ± 11%   323.7n ±  0%  -82.90% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=0-4      21.31n ±  2%   28.23n ± 13%  +32.45% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=10-4     235.5n ±  4%   205.2n ±  0%  -12.87% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=20-4     460.9n ± 12%   305.1n ±  0%  -33.82% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=30-4     551.9n ± 11%   305.3n ±  1%  -44.69% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=40-4     778.9n ±  4%   305.0n ±  1%  -60.85% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=50-4    1056.5n ± 10%   296.1n ±  0%  -71.97% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=60-4    1230.0n ±  4%   324.5n ±  0%  -73.62% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=70-4    1440.5n ±  7%   323.9n ±  0%  -77.51% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=80-4    1558.0n ±  6%   324.5n ±  0%  -79.17% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=90-4    1734.0n ±  7%   324.0n ±  0%  -81.31% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=24/pct=100-4   1983.5n ±  6%   323.5n ±  0%  -83.69% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=0-4      21.14n ±  5%   27.69n ± 21%  +30.95% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=10-4    247.65n ±  4%   67.96n ±  2%  -72.56% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=20-4     389.9n ±  7%   121.8n ±  0%  -68.76% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=30-4     606.6n ± 11%   182.1n ±  0%  -69.98% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=40-4     844.1n ± 10%   238.4n ±  0%  -71.76% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=50-4    1084.5n ±  8%   313.6n ±  0%  -71.08% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=60-4    1234.5n ±  8%   323.7n ±  0%  -73.78% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=70-4    1356.5n ±  6%   323.5n ±  0%  -76.16% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=80-4    1667.5n ± 11%   324.4n ±  1%  -80.54% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=90-4    1763.5n ± 10%   323.5n ±  1%  -81.66% (p=0.000 n=10)
ScanSpanPacked/cache=tiny/pages=1/sizeclass=25/pct=100-4   2036.0n ±  6%   323.4n ±  0%  -84.12% (p=0.000 n=10)
geomean                                                     685.1n         251.3n        -63.32%

[gopherbot]

Change https://go.dev/cl/789122 mentions this issue: runtime: add ARM64 SVE GreenTea GC kernel

[gopherbot]

Change https://go.dev/cl/789120 mentions this issue: runtime: add sparse inline mark bits

[gopherbot]

Change https://go.dev/cl/789121 mentions this issue: internal/cpu add SVE feature detection

[gabyhelp]

Related Issues

• runtime: green tea garbage collector #73581 (closed)
• runtime: enhance mallocgc on ARM64 via prefetch #69224 (closed)
• runtime: moving invariant code out of function and loop gives small gains in GreenTea GC #76212 (closed)

Related Code Changes

• runtime: add sparse inline mark bits
• runtime: add ARM64 SVE GreenTea GC kernel
• runtime: mark and scan small objects in whole spans [green tea]
• runtime: use Haswell instructions in scanobject
• [dev.simd] internal/runtime/gc: add simd package based greentea kernels
• cmd/compile/internal/ssa: combine zero stores into larger stores on arm64
• [dev.simd] runtime: use scan kernels in scanSpan [green tea]

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[JunyangShao]

Thanks for the work! Just a note that SVE is going to be supported in Go 1.27 under goexperiment=simd, do you consider using that? I assume this will be for Go 1.28, at that time the SVE assembler should have graduated from goexperiment.

[seankhliao]

a proposal seems unnecessary if it's just tracking an implementation without api change.