Test Linux on ARM64

[pauldreik]

Summary

• add a native Ubuntu 24.04 ARM64 CI job
• build and test with GCC 14 in Debug mode
• cap compilation and testing at four parallel jobs
• assert the runner architecture is AArch64

Validation

• YAML formatting and parsing
• equivalent GCC 14/Ninja job commands locally on x86-64
• 330 of 330 tests passed with four-way CTest parallelism

[github-actions]

Compile-time performance diff

Compiler: g++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 5 per configuration.

psychicstd compile time, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 0.4%.

No significant changes (🟡 3 within noise).

🟡 3 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
all-headers	205.9ms	205.3ms	🟡 -0.3% [-1.3, +0.2]	6.7x
iostream	74.5ms	73.2ms	🟡 -1.6% [-4.8, +0.4]	3.5x
wordcounter	171.7ms	171.6ms	🟡 -0.1% [-0.3, +1.8]	3.2x

---

Reproduce this on your machine: scripts/compare_compile_time_to_ref.py --reps 5 g++ origin/main

[github-actions]

simdutf build-time diff (compile / run tests)

Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 1 per configuration.

simdutf build time with psychicstd, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 2.3%.

No significant changes (🟡 2 within noise).

🟡 2 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
compile	16798.4ms	16790.3ms	🟡 -0.0%	2.1x
run tests	50447.1ms	50878.9ms	🟡 +0.9%	1.0x

---

Reproduce this on your machine: scripts/compare_realworld_to_ref.py simdutf --build-type debug --reps 1

[github-actions]

rdfind build-time diff (configure / compile / run tests)

Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 5 per configuration.

rdfind build time with psychicstd, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 0.5%.

No significant changes (🟡 3 within noise).

🟡 3 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
compile	469.8ms	470.0ms	🟡 +0.1% [-5.1, +0.9]	4.0x
configure	1262.3ms	1262.8ms	🟡 +0.0% [-0.5, +0.1]	1.0x
run tests	1750.9ms	1754.6ms	🟡 +0.2% [-2.6, +1.8]	1.0x

---

Reproduce this on your machine: scripts/compare_realworld_to_ref.py rdfind --build-type debug --reps 5

[github-actions]

fmt build-time diff (compile / run tests)

Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 2 per configuration.

fmt build time with psychicstd, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 21.4%.

No significant changes (🟡 2 within noise).

🟡 2 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
compile	30629.8ms	30778.8ms	🟡 +0.5% [-0.5, +1.5]	1.6x
run tests	225.9ms	229.9ms	🟡 +1.8% [-1.2, +4.9]	1.7x

---

Reproduce this on your machine: scripts/compare_realworld_to_ref.py fmt --build-type debug --reps 2

[github-actions]

eigen build-time diff (compile / run tests)

Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 2 per configuration.

eigen build time with psychicstd, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 2.0%.

No significant changes (🟡 2 within noise).

🟡 2 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
compile	17139.0ms	17077.5ms	🟡 -0.4% [-4.4, +3.9]	1.8x
run tests	32.9ms	33.0ms	🟡 +0.2% [-1.9, +2.5]	1.3x

---

Reproduce this on your machine: scripts/compare_realworld_to_ref.py eigen --build-type debug --reps 2

[github-actions]

Sanitizer diff (ASan/UBSan)

No changes detected.

72 header(s) unchanged

header	passes/sampled
algorithm	5/25
any	6/18
array	17/25
atomic	13/25
bit	2/15
bitset	3/25
cassert	3/9
cctype	2/5
cerrno	4/25
cfloat	4/25
chrono	0/25
ciso646	4/25
climits	11/25
clocale	4/25
cmath	1/19
compare	5/14
complex	11/25
concepts	2/25
condition_variable	13/25
csetjmp	3/9
csignal	4/25
cstddef	13/21
cstdint	3/5
cstdio	4/25
cstdlib	3/9
cstring	2/5
ctime	4/25
cwchar	4/25
deque	17/25
exception	20/21
filesystem	2/25
forward_list	6/25
fstream	8/25
functional	10/25
initializer_list	0/0
iomanip	14/25
ios	12/25
iostream	0/2
istream	10/25
iterator	4/25
limits	24/25
list	4/25
locale	6/25
map	7/25
memory	8/25
mutex	13/25
new	6/25
numeric	3/25
optional	8/25
ostream	19/25
random	3/25
ranges	0/25
ratio	13/13
regex	1/25
set	0/25
sstream	5/25
stack	9/25
stdexcept	9/9
streambuf	18/25
string	1/25
string_view	9/25
system_error	20/25
thread	5/25
tuple	7/25
type_traits	15/25
typeinfo	2/5
unordered_map	10/25
unordered_set	7/25
utility	6/25
valarray	0/25
vector	18/25
version	0/25

---

Reproduce this on your machine: LLVM_ROOT=$PWD/llvm-project cp sanitize_base_cache.json .compliance_cache.sanitize.json && tools/compliance.py --sanitize --recheck

[github-actions]

Compliance diff

🔴 1 header(s) regressed.

header	before	after	Δ
memory	15/40	14/40	🔴 -1

71 header(s) unchanged

header	passes/sampled
algorithm	8/40
any	9/18
array	27/40
atomic	17/40
bit	2/15
bitset	9/40
cassert	3/9
cctype	2/5
cerrno	5/29
cfloat	5/29
chrono	1/40
ciso646	5/29
climits	15/40
clocale	5/29
cmath	1/19
compare	5/14
complex	17/40
concepts	2/35
condition_variable	13/26
csetjmp	3/9
csignal	5/29
cstddef	13/21
cstdint	3/5
cstdio	5/29
cstdlib	3/9
cstring	2/5
ctime	5/29
cwchar	5/29
deque	29/40
exception	20/21
filesystem	3/40
forward_list	9/40
fstream	14/40
functional	17/40
initializer_list	0/0
iomanip	24/40
ios	17/40
iostream	0/2
istream	23/40
iterator	5/40
limits	36/37
list	6/40
locale	9/40
map	13/40
mutex	15/40
new	19/40
numeric	4/40
optional	11/40
ostream	33/40
random	4/40
ranges	0/40
ratio	13/13
regex	3/40
set	1/40
sstream	7/40
stack	16/36
stdexcept	9/9
streambuf	30/37
string	2/40
string_view	15/40
system_error	30/40
thread	6/40
tuple	10/40
type_traits	22/40
typeinfo	2/5
unordered_map	15/40
unordered_set	12/40
utility	8/40
valarray	1/40
vector	29/40
version	0/40

---

Reproduce this on your machine: LLVM_ROOT=$PWD/llvm-project cp base_cache.json .compliance_cache.json && tools/compliance.py --recheck

[github-actions]

catch2 build-time diff (compile / run tests)

Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 3 per configuration.

catch2 build time with psychicstd, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 0.6%.

No significant changes (🟡 2 within noise).

🟡 2 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
compile	15795.0ms	16345.2ms	🟡 +3.5% [-4.0, +4.6]	3.5x
run tests	4109.0ms	4096.1ms	🟡 -0.3% [-3.2, +2.4]	0.9x

---

Reproduce this on your machine: scripts/compare_realworld_to_ref.py catch2 --build-type debug --reps 3

[github-actions]

flatbuffers build-time diff (configure / compile / run tests)

Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 1 per configuration.

flatbuffers build time with psychicstd, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 64.7%.

No significant changes (🟡 3 within noise).

🟡 3 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
compile	26312.4ms	26711.4ms	🟡 +1.5%	2.2x
configure	609.9ms	611.3ms	🟡 +0.2%	1.0x
run tests	119.3ms	120.8ms	🟡 +1.2%	1.2x

---

Reproduce this on your machine: scripts/compare_realworld_to_ref.py flatbuffers --build-type debug --reps 1

[github-actions]

cppcheck build-time diff (compile)

Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0.

Repetitions: 2 per configuration.

cppcheck build time with psychicstd, main vs this PR (same runner). 🟢 faster · 🔴 slower · 🟡 within noise. A change is colored only when its bootstrap 95% CI excludes 0 and it clears ±5% / 3ms. vs system is this PR's speedup over system libstdc++, for context -- a regression is less alarming if psychicstd is still far ahead. Median system-time drift (noise proxy): 0.2%.

No significant changes (🟡 1 within noise).

🟡 1 benchmark(s) within noise

benchmark	main	PR	Δ (95% CI)	vs system
compile	51880.9ms	51822.3ms	🟡 -0.1% [-0.8, +0.6]	2.0x

---

Reproduce this on your machine: scripts/compare_realworld_to_ref.py cppcheck --build-type debug --reps 2