doc/benchmarks.md - external/github.com/google/wuffs - Git at Google

 # Benchmarks

 `wuffs bench -mimic` summarized throughput numbers for various codecs are
 below. Higher is better.

 "Mimic" tests check that Wuffs' output mimics (i.e. exactly matches) other
 libraries' output. "Mimic" benchmarks give the numbers for those other
 libraries, as shipped with Debian. These were measured on a Debian Testing
 system as of October 2019, which meant these compiler versions:

 - clang/llvm 8.0.1
 - gcc 9.2.1

 and these "mimic" library versions, all written in C:

 - libgif 5.1.4
 - zlib 1.2.11

 Unless otherwise stated, the numbers below were measured on an Intel x86\_64
 Broadwell, and were taken as of Wuffs git commit ffdce5ef "Have bench-rust-gif
 process animated / RGBA images".


 ## Reproducing

 The benchmark programs aim to be runnable "out of the box" without any
 configuration or installation. For example, to run the `std/zlib` benchmarks:

     git clone https://github.com/google/wuffs.git
     cd wuffs
     gcc -O3 test/c/std/zlib.c
     ./a.out -bench
     rm a.out

 A comment near the top of that `.c` file says how to run the mimic benchmarks.

 The output of those benchmark programs is compatible with the
 [benchstat](https://godoc.org/golang.org/x/perf/cmd/benchstat) tool. For
 example, that tool can calculate confidence intervals based on multiple
 benchmark runs, or calculate p-values when comparing numbers before and after a
 code change. To install it, first install Go, then run `go install
 golang.org/x/perf/cmd/benchstat`.


 ## wuffs bench

 As mentioned above, individual benchmark programs can be run manually. However,
 the canonical way to run the benchmarks (across multiple compilers and multiple
 packages like GIF and PNG) for Wuffs' standard library is to use the `wuffs`
 command line tool, as it will also re-generate (transpile) the C code whenever
 you edit the `std/*/*.wuffs` code. Running `go install -v
 github.com/google/wuffs/cmd/...` will install the Wuffs tools. After that, you
 can say

     wuffs bench

 or

     wuffs bench -mimic std/deflate

 or

     wuffs bench -ccompilers=gcc -reps=3 -focus=wuffs_gif_decode_20k std/gif


 ## Clang versus GCC

 On some of the benchmarks below, clang performs noticeably worse (e.g. 1.3x
 slower) than gcc, on the same C code. A relatively simple reproduction was
 filed as [LLVM bug 35567](https://bugs.llvm.org/show_bug.cgi?id=35567).


 ## CPU Scaling

 CPU power management can inject noise in benchmark times. On a Linux system,
 power management can be controlled with:

     # Query.
     cpupower --cpu all frequency-info --policy
     # Turn on.
     sudo cpupower frequency-set --governor powersave
     # Turn off.
     sudo cpupower frequency-set --governor performance


 ---

 # Adler-32

 The `1k`, `10k`, etc. numbers are approximately how many bytes are hashed.

     name                                             speed     vs_mimic

     wuffs_adler32_10k/clang8                         2.41GB/s  0.84x
     wuffs_adler32_100k/clang8                        2.42GB/s  0.84x

     wuffs_adler32_10k/gcc9                           3.24GB/s  1.13x
     wuffs_adler32_100k/gcc9                          3.24GB/s  1.12x

     mimic_adler32_10k                                2.87GB/s  1.00x
     mimic_adler32_100k                               2.90GB/s  1.00x


 # CRC-32

 The `1k`, `10k`, etc. numbers are approximately how many bytes are hashed.

     name                                             speed     vs_mimic

     wuffs_crc32_ieee_10k/clang8                      2.85GB/s  2.11x
     wuffs_crc32_ieee_100k/clang8                     2.87GB/s  2.13x

     wuffs_crc32_ieee_10k/gcc9                        3.38GB/s  2.50x
     wuffs_crc32_ieee_100k/gcc9                       3.40GB/s  2.52x

     mimic_crc32_ieee_10k                             1.35GB/s  1.00x
     mimic_crc32_ieee_100k                            1.35GB/s  1.00x


 # Deflate

 The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
 decoded output.

 The `full_init` vs `part_init` suffixes are whether
 [`WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED`](/doc/note/initialization.md#partial-zero-initialization)
 is unset or set.

     name                                             speed     vs_mimic

     wuffs_deflate_decode_1k_full_init/clang8          160MB/s  0.74x
     wuffs_deflate_decode_1k_part_init/clang8          199MB/s  0.92x
     wuffs_deflate_decode_10k_full_init/clang8         255MB/s  0.94x
     wuffs_deflate_decode_10k_part_init/clang8         263MB/s  0.97x
     wuffs_deflate_decode_100k_just_one_read/clang8    306MB/s  0.93x
     wuffs_deflate_decode_100k_many_big_reads/clang8   250MB/s  0.98x

     wuffs_deflate_decode_1k_full_init/gcc9            164MB/s  0.76x
     wuffs_deflate_decode_1k_part_init/gcc9            207MB/s  0.95x
     wuffs_deflate_decode_10k_full_init/gcc9           247MB/s  0.91x
     wuffs_deflate_decode_10k_part_init/gcc9           254MB/s  0.94x
     wuffs_deflate_decode_100k_just_one_read/gcc9      333MB/s  1.01x
     wuffs_deflate_decode_100k_many_big_reads/gcc9     261MB/s  1.02x

     mimic_deflate_decode_1k                           217MB/s  1.00x
     mimic_deflate_decode_10k                          270MB/s  1.00x
     mimic_deflate_decode_100k_just_one_read           329MB/s  1.00x
     mimic_deflate_decode_100k_many_big_reads          256MB/s  1.00x

 32-bit ARMv7 (2012 era Samsung Exynos 5 Chromebook), Debian Stretch (2017):

     name                                             speed     vs_mimic

     wuffs_deflate_decode_1k_full_init/clang5         30.4MB/s  0.60x
     wuffs_deflate_decode_1k_part_init/clang5         37.9MB/s  0.74x
     wuffs_deflate_decode_10k_full_init/clang5        72.8MB/s  0.81x
     wuffs_deflate_decode_10k_part_init/clang5        76.2MB/s  0.85x
     wuffs_deflate_decode_100k_just_one_read/clang5   96.5MB/s  0.82x
     wuffs_deflate_decode_100k_many_big_reads/clang5  81.1MB/s  0.90x

     wuffs_deflate_decode_1k_full_init/gcc6           31.6MB/s  0.62x
     wuffs_deflate_decode_1k_part_init/gcc6           39.9MB/s  0.78x
     wuffs_deflate_decode_10k_full_init/gcc6          69.6MB/s  0.78x
     wuffs_deflate_decode_10k_part_init/gcc6          72.4MB/s  0.81x
     wuffs_deflate_decode_100k_just_one_read/gcc6     87.3MB/s  0.74x
     wuffs_deflate_decode_100k_many_big_reads/gcc6    73.8MB/s  0.82x

     mimic_deflate_decode_1k                          51.0MB/s  1.00x
     mimic_deflate_decode_10k                         89.7MB/s  1.00x
     mimic_deflate_decode_100k_just_one_read           118MB/s  1.00x
     mimic_deflate_decode_100k_many_big_reads         90.0MB/s  1.00x


 ## Deflate (C, miniz)

 For comparison, here are [miniz](https://github.com/richgel999/miniz) 2.1.0's
 numbers.

     name                                             speed     vs_mimic

     miniz_deflate_decode_1k/clang8                    174MB/s  0.80x
     miniz_deflate_decode_10k/clang8                   245MB/s  0.91x
     miniz_deflate_decode_100k_just_one_read/clang8    309MB/s  0.94x

     miniz_deflate_decode_1k/gcc9                      158MB/s  0.73x
     miniz_deflate_decode_10k/gcc9                     221MB/s  0.82x
     miniz_deflate_decode_100k_just_one_read/gcc9      250MB/s  0.76x

 To reproduce these numbers, look in `test/c/mimiclib/deflate-gzip-zlib.c`.


 ## Deflate (Go)

 For comparison, here are Go 1.12.10's numbers, using Go's standard library's
 `compress/flate` package.

     name                                             speed     vs_mimic

     go_deflate_decode_1k                             45.4MB/s  0.21x
     go_deflate_decode_10k                            82.5MB/s  0.31x
     go_deflate_decode_100k                           94.0MB/s  0.29x

 To reproduce these numbers:

     git clone https://github.com/google/wuffs.git
     cd wuffs/script/bench-go-deflate/
     go run main.go


 ## Deflate (Rust)

 For comparison, here are Rust 1.37.0's numbers, using the
 [alexcrichton/flate2-rs](https://github.com/alexcrichton/flate2-rs) and
 [Frommi/miniz_oxide](https://github.com/Frommi/miniz_oxide) crates, which [this
 file](https://github.com/sile/libflate/blob/77a1004edf6518a0badab7ce8837bc5338ff9bc3/README.md#an-informal-benchmark)
 suggests is the fastest pure-Rust Deflate decoder.

     name                                             speed     vs_mimic

     rust_deflate_decode_1k                            104MB/s  0.48x
     rust_deflate_decode_10k                           202MB/s  0.75x
     rust_deflate_decode_100k                          218MB/s  0.66x

 To reproduce these numbers:

     git clone https://github.com/google/wuffs.git
     cd wuffs/script/bench-rust-deflate/
     cargo run --release


 # GIF

 The `1k`, `10k`, etc. numbers are approximately how many pixels there are in
 the decoded image. For example, the `test/data/harvesters.*` images are 1165 ×
 859, approximately 1000k pixels.

 The `bgra` vs `indexed` suffixes are whether to decode to 4 bytes (BGRA or
 RGBA) or 1 byte (a palette index) per pixel, even if the underlying file format
 gives 1 byte per pixel.

 The `full_init` vs `part_init` suffixes are whether
 [`WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED`](/doc/note/initialization.md#partial-zero-initialization)
 is unset or set.

 The libgif library doesn't export any API for decode-to-BGRA or decode-to-RGBA,
 so there are no mimic numbers to compare to for the `bgra` suffix.

     name                                             speed     vs_mimic

     wuffs_gif_decode_1k_bw/clang8                     461MB/s  3.18x
     wuffs_gif_decode_1k_color_full_init/clang8        141MB/s  1.85x
     wuffs_gif_decode_1k_color_part_init/clang8        189MB/s  2.48x
     wuffs_gif_decode_10k_bgra/clang8                  743MB/s  n/a
     wuffs_gif_decode_10k_indexed/clang8               200MB/s  2.11x
     wuffs_gif_decode_20k/clang8                       245MB/s  2.50x
     wuffs_gif_decode_100k_artificial/clang8           531MB/s  3.43x
     wuffs_gif_decode_100k_realistic/clang8            218MB/s  2.27x
     wuffs_gif_decode_1000k_full_init/clang8           221MB/s  2.25x
     wuffs_gif_decode_1000k_part_init/clang8           221MB/s  2.25x
     wuffs_gif_decode_anim_screencap/clang8           1.07GB/s  6.01x

     wuffs_gif_decode_1k_bw/gcc9                       478MB/s  3.30x
     wuffs_gif_decode_1k_color_full_init/gcc9          148MB/s  1.94x
     wuffs_gif_decode_1k_color_part_init/gcc9          194MB/s  2.54x
     wuffs_gif_decode_10k_bgra/gcc9                    645MB/s  n/a
     wuffs_gif_decode_10k_indexed/gcc9                 203MB/s  2.14x
     wuffs_gif_decode_20k/gcc9                         244MB/s  2.49x
     wuffs_gif_decode_100k_artificial/gcc9             532MB/s  3.43x
     wuffs_gif_decode_100k_realistic/gcc9              214MB/s  2.23x
     wuffs_gif_decode_1000k_full_init/gcc9             217MB/s  2.21x
     wuffs_gif_decode_1000k_part_init/gcc9             218MB/s  2.22x
     wuffs_gif_decode_anim_screencap/gcc9             1.11GB/s  6.24x

     mimic_gif_decode_1k_bw                            145MB/s  1.00x
     mimic_gif_decode_1k_color                        76.3MB/s  1.00x
     mimic_gif_decode_10k_indexed                     94.9MB/s  1.00x
     mimic_gif_decode_20k                             98.1MB/s  1.00x
     mimic_gif_decode_100k_artificial                  155MB/s  1.00x
     mimic_gif_decode_100k_realistic                  96.1MB/s  1.00x
     mimic_gif_decode_1000k                           98.4MB/s  1.00x
     mimic_gif_decode_anim_screencap                   178MB/s  1.00x

 32-bit ARMv7 (2012 era Samsung Exynos 5 Chromebook), Debian Stretch (2017):

     name                                             speed     vs_mimic

     wuffs_gif_decode_1k_bw/clang5                    49.1MB/s  1.76x
     wuffs_gif_decode_1k_color_full_init/clang5       22.3MB/s  1.35x
     wuffs_gif_decode_1k_color_part_init/clang5       27.4MB/s  1.66x
     wuffs_gif_decode_10k_bgra/clang5                  157MB/s  n/a
     wuffs_gif_decode_10k_indexed/clang5              42.0MB/s  1.79x
     wuffs_gif_decode_20k/clang5                      49.3MB/s  1.68x
     wuffs_gif_decode_100k_artificial/clang5           132MB/s  2.62x
     wuffs_gif_decode_100k_realistic/clang5           47.8MB/s  1.62x
     wuffs_gif_decode_1000k_full_init/clang5          46.4MB/s  1.62x
     wuffs_gif_decode_1000k_part_init/clang5          46.4MB/s  1.62x
     wuffs_gif_decode_anim_screencap/clang5            243MB/s  4.03x

     wuffs_gif_decode_1k_bw/gcc6                      46.6MB/s  1.67x
     wuffs_gif_decode_1k_color_full_init/gcc6         20.1MB/s  1.22x
     wuffs_gif_decode_1k_color_part_init/gcc6         24.2MB/s  1.47x
     wuffs_gif_decode_10k_bgra/gcc6                    124MB/s  n/a
     wuffs_gif_decode_10k_indexed/gcc6                34.8MB/s  1.49x
     wuffs_gif_decode_20k/gcc6                        43.8MB/s  1.49x
     wuffs_gif_decode_100k_artificial/gcc6             123MB/s  2.44x
     wuffs_gif_decode_100k_realistic/gcc6             42.7MB/s  1.44x
     wuffs_gif_decode_1000k_full_init/gcc6            41.6MB/s  1.45x
     wuffs_gif_decode_1000k_part_init/gcc6            41.7MB/s  1.45x
     wuffs_gif_decode_anim_screencap/gcc6              227MB/s  3.76x

     mimic_gif_decode_1k_bw                           27.9MB/s  1.00x
     mimic_gif_decode_1k_color                        16.5MB/s  1.00x
     mimic_gif_decode_10k_indexed                     23.4MB/s  1.00x
     mimic_gif_decode_20k                             29.4MB/s  1.00x
     mimic_gif_decode_100k_artificial                 50.4MB/s  1.00x
     mimic_gif_decode_100k_realistic                  29.5MB/s  1.00x
     mimic_gif_decode_1000k                           28.7MB/s  1.00x
     mimic_gif_decode_anim_screencap                  60.3MB/s  1.00x


 ## GIF (Go)

 For comparison, here are Go 1.12.10's numbers, using Go's standard library's
 `image/gif` package.

     name                                             speed     vs_mimic

     go_gif_decode_1k_bw                               107MB/s  0.74x
     go_gif_decode_1k_color                           39.2MB/s  0.51x
     go_gif_decode_10k_bgra                            117MB/s  n/a
     go_gif_decode_10k_indexed                        57.8MB/s  0.61x
     go_gif_decode_20k                                67.2MB/s  0.69x
     go_gif_decode_100k_artificial                     151MB/s  0.97x
     go_gif_decode_100k_realistic                     67.2MB/s  0.70x
     go_gif_decode_1000k                              68.1MB/s  0.69x
     go_gif_decode_anim_screencap                      206MB/s  1.16x

 To reproduce these numbers:

     git clone https://github.com/google/wuffs.git
     cd wuffs/script/bench-go-gif/
     go run main.go


 ## GIF (Rust)

 For comparison, here are Rust 1.37.0's numbers, using the
 [image-rs/image-gif](https://github.com/image-rs/image-gif) crate, easily the
 top `crates.io` result for ["gif"](https://crates.io/search?q=gif).

     name                                             speed     vs_mimic

     rust_gif_decode_1k_bw                            89.2MB/s  0.62x
     rust_gif_decode_1k_color                         20.7MB/s  0.27x
     rust_gif_decode_10k_bgra                         74.5MB/s  n/a
     rust_gif_decode_10k_indexed                      20.4MB/s  0.21x
     rust_gif_decode_20k                              28.9MB/s  0.29x
     rust_gif_decode_100k_artificial                  79.1MB/s  0.51x
     rust_gif_decode_100k_realistic                   27.9MB/s  0.29x
     rust_gif_decode_1000k                            27.9MB/s  0.28x
     rust_gif_decode_anim_screencap                    144MB/s  0.81x

 To reproduce these numbers:

     git clone https://github.com/google/wuffs.git
     cd wuffs/script/bench-rust-gif/
     cargo run --release


 # Gzip (Deflate + CRC-32)

 The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
 decoded output.

     name                                             speed     vs_mimic

     wuffs_gzip_decode_10k/clang8                      238MB/s  1.05x
     wuffs_gzip_decode_100k/clang8                     273MB/s  1.03x

     wuffs_gzip_decode_10k/gcc9                        239MB/s  1.06x
     wuffs_gzip_decode_100k/gcc9                       297MB/s  1.12x

     mimic_gzip_decode_10k                             226MB/s  1.00x
     mimic_gzip_decode_100k                            265MB/s  1.00x


 # LZW

 The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
 decoded output.

 The libgif library doesn't export its LZW decoder in its API, so there are no
 mimic numbers to compare to.

     name                                             speed     vs_mimic

     wuffs_lzw_decode_20k/clang8                       263MB/s  n/a
     wuffs_lzw_decode_100k/clang8                      438MB/s  n/a

     wuffs_lzw_decode_20k/gcc9                         266MB/s  n/a
     wuffs_lzw_decode_100k/gcc9                        450MB/s  n/a


 # Zlib (Deflate + Adler-32)

 The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
 decoded output.

     name                                             speed     vs_mimic

     wuffs_zlib_decode_10k/clang8                      237MB/s  0.96x
     wuffs_zlib_decode_100k/clang8                     272MB/s  0.92x

     wuffs_zlib_decode_10k/gcc9                        242MB/s  0.98x
     wuffs_zlib_decode_100k/gcc9                       294MB/s  0.99x

     mimic_zlib_decode_10k                             247MB/s  1.00x
     mimic_zlib_decode_100k                            296MB/s  1.00x


 ---

 Updated on December 2019.
	# Benchmarks

	`wuffs bench -mimic` summarized throughput numbers for various codecs are
	below. Higher is better.

	"Mimic" tests check that Wuffs' output mimics (i.e. exactly matches) other
	libraries' output. "Mimic" benchmarks give the numbers for those other
	libraries, as shipped with Debian. These were measured on a Debian Testing
	system as of October 2019, which meant these compiler versions:

	- clang/llvm 8.0.1
	- gcc 9.2.1

	and these "mimic" library versions, all written in C:

	- libgif 5.1.4
	- zlib 1.2.11

	Unless otherwise stated, the numbers below were measured on an Intel x86\_64
	Broadwell, and were taken as of Wuffs git commit ffdce5ef "Have bench-rust-gif
	process animated / RGBA images".


	## Reproducing

	The benchmark programs aim to be runnable "out of the box" without any
	configuration or installation. For example, to run the `std/zlib` benchmarks:

	git clone https://github.com/google/wuffs.git
	cd wuffs
	gcc -O3 test/c/std/zlib.c
	./a.out -bench
	rm a.out

	A comment near the top of that `.c` file says how to run the mimic benchmarks.

	The output of those benchmark programs is compatible with the
	[benchstat](https://godoc.org/golang.org/x/perf/cmd/benchstat) tool. For
	example, that tool can calculate confidence intervals based on multiple
	benchmark runs, or calculate p-values when comparing numbers before and after a
	code change. To install it, first install Go, then run `go install
	golang.org/x/perf/cmd/benchstat`.


	## wuffs bench

	As mentioned above, individual benchmark programs can be run manually. However,
	the canonical way to run the benchmarks (across multiple compilers and multiple
	packages like GIF and PNG) for Wuffs' standard library is to use the `wuffs`
	command line tool, as it will also re-generate (transpile) the C code whenever
	you edit the `std//.wuffs` code. Running `go install -v
	github.com/google/wuffs/cmd/...` will install the Wuffs tools. After that, you
	can say

	wuffs bench

	or

	wuffs bench -mimic std/deflate

	or

	wuffs bench -ccompilers=gcc -reps=3 -focus=wuffs_gif_decode_20k std/gif


	## Clang versus GCC

	On some of the benchmarks below, clang performs noticeably worse (e.g. 1.3x
	slower) than gcc, on the same C code. A relatively simple reproduction was
	filed as [LLVM bug 35567](https://bugs.llvm.org/show_bug.cgi?id=35567).


	## CPU Scaling

	CPU power management can inject noise in benchmark times. On a Linux system,
	power management can be controlled with:

	# Query.
	cpupower --cpu all frequency-info --policy
	# Turn on.
	sudo cpupower frequency-set --governor powersave
	# Turn off.
	sudo cpupower frequency-set --governor performance


	---

	# Adler-32

	The `1k`, `10k`, etc. numbers are approximately how many bytes are hashed.

	name speed vs_mimic

	wuffs_adler32_10k/clang8 2.41GB/s 0.84x
	wuffs_adler32_100k/clang8 2.42GB/s 0.84x

	wuffs_adler32_10k/gcc9 3.24GB/s 1.13x
	wuffs_adler32_100k/gcc9 3.24GB/s 1.12x

	mimic_adler32_10k 2.87GB/s 1.00x
	mimic_adler32_100k 2.90GB/s 1.00x


	# CRC-32

	The `1k`, `10k`, etc. numbers are approximately how many bytes are hashed.

	name speed vs_mimic

	wuffs_crc32_ieee_10k/clang8 2.85GB/s 2.11x
	wuffs_crc32_ieee_100k/clang8 2.87GB/s 2.13x

	wuffs_crc32_ieee_10k/gcc9 3.38GB/s 2.50x
	wuffs_crc32_ieee_100k/gcc9 3.40GB/s 2.52x

	mimic_crc32_ieee_10k 1.35GB/s 1.00x
	mimic_crc32_ieee_100k 1.35GB/s 1.00x


	# Deflate

	The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
	decoded output.

	The `full_init` vs `part_init` suffixes are whether
	[`WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED`](/doc/note/initialization.md#partial-zero-initialization)
	is unset or set.

	name speed vs_mimic

	wuffs_deflate_decode_1k_full_init/clang8 160MB/s 0.74x
	wuffs_deflate_decode_1k_part_init/clang8 199MB/s 0.92x
	wuffs_deflate_decode_10k_full_init/clang8 255MB/s 0.94x
	wuffs_deflate_decode_10k_part_init/clang8 263MB/s 0.97x
	wuffs_deflate_decode_100k_just_one_read/clang8 306MB/s 0.93x
	wuffs_deflate_decode_100k_many_big_reads/clang8 250MB/s 0.98x

	wuffs_deflate_decode_1k_full_init/gcc9 164MB/s 0.76x
	wuffs_deflate_decode_1k_part_init/gcc9 207MB/s 0.95x
	wuffs_deflate_decode_10k_full_init/gcc9 247MB/s 0.91x
	wuffs_deflate_decode_10k_part_init/gcc9 254MB/s 0.94x
	wuffs_deflate_decode_100k_just_one_read/gcc9 333MB/s 1.01x
	wuffs_deflate_decode_100k_many_big_reads/gcc9 261MB/s 1.02x

	mimic_deflate_decode_1k 217MB/s 1.00x
	mimic_deflate_decode_10k 270MB/s 1.00x
	mimic_deflate_decode_100k_just_one_read 329MB/s 1.00x
	mimic_deflate_decode_100k_many_big_reads 256MB/s 1.00x

	32-bit ARMv7 (2012 era Samsung Exynos 5 Chromebook), Debian Stretch (2017):

	name speed vs_mimic

	wuffs_deflate_decode_1k_full_init/clang5 30.4MB/s 0.60x
	wuffs_deflate_decode_1k_part_init/clang5 37.9MB/s 0.74x
	wuffs_deflate_decode_10k_full_init/clang5 72.8MB/s 0.81x
	wuffs_deflate_decode_10k_part_init/clang5 76.2MB/s 0.85x
	wuffs_deflate_decode_100k_just_one_read/clang5 96.5MB/s 0.82x
	wuffs_deflate_decode_100k_many_big_reads/clang5 81.1MB/s 0.90x

	wuffs_deflate_decode_1k_full_init/gcc6 31.6MB/s 0.62x
	wuffs_deflate_decode_1k_part_init/gcc6 39.9MB/s 0.78x
	wuffs_deflate_decode_10k_full_init/gcc6 69.6MB/s 0.78x
	wuffs_deflate_decode_10k_part_init/gcc6 72.4MB/s 0.81x
	wuffs_deflate_decode_100k_just_one_read/gcc6 87.3MB/s 0.74x
	wuffs_deflate_decode_100k_many_big_reads/gcc6 73.8MB/s 0.82x

	mimic_deflate_decode_1k 51.0MB/s 1.00x
	mimic_deflate_decode_10k 89.7MB/s 1.00x
	mimic_deflate_decode_100k_just_one_read 118MB/s 1.00x
	mimic_deflate_decode_100k_many_big_reads 90.0MB/s 1.00x


	## Deflate (C, miniz)

	For comparison, here are [miniz](https://github.com/richgel999/miniz) 2.1.0's
	numbers.

	name speed vs_mimic

	miniz_deflate_decode_1k/clang8 174MB/s 0.80x
	miniz_deflate_decode_10k/clang8 245MB/s 0.91x
	miniz_deflate_decode_100k_just_one_read/clang8 309MB/s 0.94x

	miniz_deflate_decode_1k/gcc9 158MB/s 0.73x
	miniz_deflate_decode_10k/gcc9 221MB/s 0.82x
	miniz_deflate_decode_100k_just_one_read/gcc9 250MB/s 0.76x

	To reproduce these numbers, look in `test/c/mimiclib/deflate-gzip-zlib.c`.


	## Deflate (Go)

	For comparison, here are Go 1.12.10's numbers, using Go's standard library's
	`compress/flate` package.

	name speed vs_mimic

	go_deflate_decode_1k 45.4MB/s 0.21x
	go_deflate_decode_10k 82.5MB/s 0.31x
	go_deflate_decode_100k 94.0MB/s 0.29x

	To reproduce these numbers:

	git clone https://github.com/google/wuffs.git
	cd wuffs/script/bench-go-deflate/
	go run main.go


	## Deflate (Rust)

	For comparison, here are Rust 1.37.0's numbers, using the
	[alexcrichton/flate2-rs](https://github.com/alexcrichton/flate2-rs) and
	[Frommi/miniz_oxide](https://github.com/Frommi/miniz_oxide) crates, which [this
	file](https://github.com/sile/libflate/blob/77a1004edf6518a0badab7ce8837bc5338ff9bc3/README.md#an-informal-benchmark)
	suggests is the fastest pure-Rust Deflate decoder.

	name speed vs_mimic

	rust_deflate_decode_1k 104MB/s 0.48x
	rust_deflate_decode_10k 202MB/s 0.75x
	rust_deflate_decode_100k 218MB/s 0.66x

	To reproduce these numbers:

	git clone https://github.com/google/wuffs.git
	cd wuffs/script/bench-rust-deflate/
	cargo run --release


	# GIF

	The `1k`, `10k`, etc. numbers are approximately how many pixels there are in
	the decoded image. For example, the `test/data/harvesters.*` images are 1165 ×
	859, approximately 1000k pixels.

	The `bgra` vs `indexed` suffixes are whether to decode to 4 bytes (BGRA or
	RGBA) or 1 byte (a palette index) per pixel, even if the underlying file format
	gives 1 byte per pixel.

	The `full_init` vs `part_init` suffixes are whether
	[`WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED`](/doc/note/initialization.md#partial-zero-initialization)
	is unset or set.

	The libgif library doesn't export any API for decode-to-BGRA or decode-to-RGBA,
	so there are no mimic numbers to compare to for the `bgra` suffix.

	name speed vs_mimic

	wuffs_gif_decode_1k_bw/clang8 461MB/s 3.18x
	wuffs_gif_decode_1k_color_full_init/clang8 141MB/s 1.85x
	wuffs_gif_decode_1k_color_part_init/clang8 189MB/s 2.48x
	wuffs_gif_decode_10k_bgra/clang8 743MB/s n/a
	wuffs_gif_decode_10k_indexed/clang8 200MB/s 2.11x
	wuffs_gif_decode_20k/clang8 245MB/s 2.50x
	wuffs_gif_decode_100k_artificial/clang8 531MB/s 3.43x
	wuffs_gif_decode_100k_realistic/clang8 218MB/s 2.27x
	wuffs_gif_decode_1000k_full_init/clang8 221MB/s 2.25x
	wuffs_gif_decode_1000k_part_init/clang8 221MB/s 2.25x
	wuffs_gif_decode_anim_screencap/clang8 1.07GB/s 6.01x

	wuffs_gif_decode_1k_bw/gcc9 478MB/s 3.30x
	wuffs_gif_decode_1k_color_full_init/gcc9 148MB/s 1.94x
	wuffs_gif_decode_1k_color_part_init/gcc9 194MB/s 2.54x
	wuffs_gif_decode_10k_bgra/gcc9 645MB/s n/a
	wuffs_gif_decode_10k_indexed/gcc9 203MB/s 2.14x
	wuffs_gif_decode_20k/gcc9 244MB/s 2.49x
	wuffs_gif_decode_100k_artificial/gcc9 532MB/s 3.43x
	wuffs_gif_decode_100k_realistic/gcc9 214MB/s 2.23x
	wuffs_gif_decode_1000k_full_init/gcc9 217MB/s 2.21x
	wuffs_gif_decode_1000k_part_init/gcc9 218MB/s 2.22x
	wuffs_gif_decode_anim_screencap/gcc9 1.11GB/s 6.24x

	mimic_gif_decode_1k_bw 145MB/s 1.00x
	mimic_gif_decode_1k_color 76.3MB/s 1.00x
	mimic_gif_decode_10k_indexed 94.9MB/s 1.00x
	mimic_gif_decode_20k 98.1MB/s 1.00x
	mimic_gif_decode_100k_artificial 155MB/s 1.00x
	mimic_gif_decode_100k_realistic 96.1MB/s 1.00x
	mimic_gif_decode_1000k 98.4MB/s 1.00x
	mimic_gif_decode_anim_screencap 178MB/s 1.00x

	32-bit ARMv7 (2012 era Samsung Exynos 5 Chromebook), Debian Stretch (2017):

	name speed vs_mimic

	wuffs_gif_decode_1k_bw/clang5 49.1MB/s 1.76x
	wuffs_gif_decode_1k_color_full_init/clang5 22.3MB/s 1.35x
	wuffs_gif_decode_1k_color_part_init/clang5 27.4MB/s 1.66x
	wuffs_gif_decode_10k_bgra/clang5 157MB/s n/a
	wuffs_gif_decode_10k_indexed/clang5 42.0MB/s 1.79x
	wuffs_gif_decode_20k/clang5 49.3MB/s 1.68x
	wuffs_gif_decode_100k_artificial/clang5 132MB/s 2.62x
	wuffs_gif_decode_100k_realistic/clang5 47.8MB/s 1.62x
	wuffs_gif_decode_1000k_full_init/clang5 46.4MB/s 1.62x
	wuffs_gif_decode_1000k_part_init/clang5 46.4MB/s 1.62x
	wuffs_gif_decode_anim_screencap/clang5 243MB/s 4.03x

	wuffs_gif_decode_1k_bw/gcc6 46.6MB/s 1.67x
	wuffs_gif_decode_1k_color_full_init/gcc6 20.1MB/s 1.22x
	wuffs_gif_decode_1k_color_part_init/gcc6 24.2MB/s 1.47x
	wuffs_gif_decode_10k_bgra/gcc6 124MB/s n/a
	wuffs_gif_decode_10k_indexed/gcc6 34.8MB/s 1.49x
	wuffs_gif_decode_20k/gcc6 43.8MB/s 1.49x
	wuffs_gif_decode_100k_artificial/gcc6 123MB/s 2.44x
	wuffs_gif_decode_100k_realistic/gcc6 42.7MB/s 1.44x
	wuffs_gif_decode_1000k_full_init/gcc6 41.6MB/s 1.45x
	wuffs_gif_decode_1000k_part_init/gcc6 41.7MB/s 1.45x
	wuffs_gif_decode_anim_screencap/gcc6 227MB/s 3.76x

	mimic_gif_decode_1k_bw 27.9MB/s 1.00x
	mimic_gif_decode_1k_color 16.5MB/s 1.00x
	mimic_gif_decode_10k_indexed 23.4MB/s 1.00x
	mimic_gif_decode_20k 29.4MB/s 1.00x
	mimic_gif_decode_100k_artificial 50.4MB/s 1.00x
	mimic_gif_decode_100k_realistic 29.5MB/s 1.00x
	mimic_gif_decode_1000k 28.7MB/s 1.00x
	mimic_gif_decode_anim_screencap 60.3MB/s 1.00x


	## GIF (Go)

	For comparison, here are Go 1.12.10's numbers, using Go's standard library's
	`image/gif` package.

	name speed vs_mimic

	go_gif_decode_1k_bw 107MB/s 0.74x
	go_gif_decode_1k_color 39.2MB/s 0.51x
	go_gif_decode_10k_bgra 117MB/s n/a
	go_gif_decode_10k_indexed 57.8MB/s 0.61x
	go_gif_decode_20k 67.2MB/s 0.69x
	go_gif_decode_100k_artificial 151MB/s 0.97x
	go_gif_decode_100k_realistic 67.2MB/s 0.70x
	go_gif_decode_1000k 68.1MB/s 0.69x
	go_gif_decode_anim_screencap 206MB/s 1.16x

	To reproduce these numbers:

	git clone https://github.com/google/wuffs.git
	cd wuffs/script/bench-go-gif/
	go run main.go


	## GIF (Rust)

	For comparison, here are Rust 1.37.0's numbers, using the
	[image-rs/image-gif](https://github.com/image-rs/image-gif) crate, easily the
	top `crates.io` result for ["gif"](https://crates.io/search?q=gif).

	name speed vs_mimic

	rust_gif_decode_1k_bw 89.2MB/s 0.62x
	rust_gif_decode_1k_color 20.7MB/s 0.27x
	rust_gif_decode_10k_bgra 74.5MB/s n/a
	rust_gif_decode_10k_indexed 20.4MB/s 0.21x
	rust_gif_decode_20k 28.9MB/s 0.29x
	rust_gif_decode_100k_artificial 79.1MB/s 0.51x
	rust_gif_decode_100k_realistic 27.9MB/s 0.29x
	rust_gif_decode_1000k 27.9MB/s 0.28x
	rust_gif_decode_anim_screencap 144MB/s 0.81x

	To reproduce these numbers:

	git clone https://github.com/google/wuffs.git
	cd wuffs/script/bench-rust-gif/
	cargo run --release


	# Gzip (Deflate + CRC-32)

	The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
	decoded output.

	name speed vs_mimic

	wuffs_gzip_decode_10k/clang8 238MB/s 1.05x
	wuffs_gzip_decode_100k/clang8 273MB/s 1.03x

	wuffs_gzip_decode_10k/gcc9 239MB/s 1.06x
	wuffs_gzip_decode_100k/gcc9 297MB/s 1.12x

	mimic_gzip_decode_10k 226MB/s 1.00x
	mimic_gzip_decode_100k 265MB/s 1.00x


	# LZW

	The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
	decoded output.

	The libgif library doesn't export its LZW decoder in its API, so there are no
	mimic numbers to compare to.

	name speed vs_mimic

	wuffs_lzw_decode_20k/clang8 263MB/s n/a
	wuffs_lzw_decode_100k/clang8 438MB/s n/a

	wuffs_lzw_decode_20k/gcc9 266MB/s n/a
	wuffs_lzw_decode_100k/gcc9 450MB/s n/a


	# Zlib (Deflate + Adler-32)

	The `1k`, `10k`, etc. numbers are approximately how many bytes there in the
	decoded output.

	name speed vs_mimic

	wuffs_zlib_decode_10k/clang8 237MB/s 0.96x
	wuffs_zlib_decode_100k/clang8 272MB/s 0.92x

	wuffs_zlib_decode_10k/gcc9 242MB/s 0.98x
	wuffs_zlib_decode_100k/gcc9 294MB/s 0.99x

	mimic_zlib_decode_10k 247MB/s 1.00x
	mimic_zlib_decode_100k 296MB/s 1.00x


	---

	Updated on December 2019.