Introduce global config and reorganize backends

[hanno-becker]

This commit introduces a global configuration file mlkem/config.h
which should contain all user-configurable parameters. With this
commit, it contains:

• MLKEM_K
• MLKEM_NAMESPACE
• FIPS202_NAMESPACE
• MLKEM_USE_NATIVE
• MLKEM_NATIVE_ARITH_BACKEND
• MLKEM_NATIVE_FIPS202_BACKEND

The backends have been reorganized to follow a simpler file structure:

Every backend profile is identified by metadata file in the toplevel
directory of the backend. For example, aarch64 has opt.h and clean.h.
Those metadata files so far only set the name of the backend, and point
to the actual implementation. The reason why the metadata file and the
implementation are kept separate is so that assembly files can include
the metadata file and know if they should be assembled: For example,
aarch64/opt.h sets MLKEM_NATIVE_ARITH_BACKEND_AARCH64_OPT which all
relevant files are guarded by; similar for clean. Previously, they were
all guarded more coarsely by MLKEM_USE_NATIVE_AARCH64 or
MLKEM_USE_NATIVE_X86_64 -- those have been removed.

The source code of the backends has been moved into src directories.

Ultimately, we may want to split aarch64 into aarch64_opt and aarch64_clean,
so the distinction between profile and backend goes away, but this is not yet
attempted.

====

An example in examples/ is added which demonstrates how to use a custom
backend and custom config.

[oqs-bot]

Arm Cortex-A76 (Raspberry Pi 5) benchmarks

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	29186 cycles	29184 cycles	1.00
ML-KEM-512 encaps	35547 cycles	35554 cycles	1.00
ML-KEM-512 decaps	46136 cycles	46098 cycles	1.00
ML-KEM-768 keypair	49229 cycles	49232 cycles	1.00
ML-KEM-768 encaps	55399 cycles	55386 cycles	1.00
ML-KEM-768 decaps	70203 cycles	70236 cycles	1.00
ML-KEM-1024 keypair	72171 cycles	72218 cycles	1.00
ML-KEM-1024 encaps	81016 cycles	81129 cycles	1.00
ML-KEM-1024 decaps	100875 cycles	100871 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

Intel Xeon 4th gen (c7i)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	13523 cycles	13505 cycles	1.00
ML-KEM-512 encaps	17257 cycles	17476 cycles	0.99
ML-KEM-512 decaps	22741 cycles	22734 cycles	1.00
ML-KEM-768 keypair	22524 cycles	22497 cycles	1.00
ML-KEM-768 encaps	24529 cycles	24466 cycles	1.00
ML-KEM-768 decaps	32530 cycles	32453 cycles	1.00
ML-KEM-1024 keypair	31376 cycles	31374 cycles	1.00
ML-KEM-1024 encaps	34922 cycles	34930 cycles	1.00
ML-KEM-1024 decaps	45729 cycles	45768 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

AMD EPYC 3rd gen (c6a)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	18158 cycles	18216 cycles	1.00
ML-KEM-512 encaps	23194 cycles	23145 cycles	1.00
ML-KEM-512 decaps	30526 cycles	30478 cycles	1.00
ML-KEM-768 keypair	31067 cycles	31108 cycles	1.00
ML-KEM-768 encaps	34152 cycles	34212 cycles	1.00
ML-KEM-768 decaps	44834 cycles	44770 cycles	1.00
ML-KEM-1024 keypair	44603 cycles	44518 cycles	1.00
ML-KEM-1024 encaps	49935 cycles	49892 cycles	1.00
ML-KEM-1024 decaps	64438 cycles	64383 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

Intel Xeon 3rd gen (c6i)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	20331 cycles	20332 cycles	1.00
ML-KEM-512 encaps	27000 cycles	27002 cycles	1.00
ML-KEM-512 decaps	35809 cycles	35838 cycles	1.00
ML-KEM-768 keypair	34889 cycles	34882 cycles	1.00
ML-KEM-768 encaps	38113 cycles	38175 cycles	1.00
ML-KEM-768 decaps	50917 cycles	50904 cycles	1.00
ML-KEM-1024 keypair	47988 cycles	47974 cycles	1.00
ML-KEM-1024 encaps	54179 cycles	54135 cycles	1.00
ML-KEM-1024 decaps	71615 cycles	71703 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

AMD EPYC 4th gen (c7a)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	15086 cycles	15078 cycles	1.00
ML-KEM-512 encaps	19688 cycles	19663 cycles	1.00
ML-KEM-512 decaps	26339 cycles	26313 cycles	1.00
ML-KEM-768 keypair	25688 cycles	25609 cycles	1.00
ML-KEM-768 encaps	28250 cycles	28179 cycles	1.00
ML-KEM-768 decaps	37912 cycles	37856 cycles	1.00
ML-KEM-1024 keypair	35680 cycles	35661 cycles	1.00
ML-KEM-1024 encaps	41087 cycles	40971 cycles	1.00
ML-KEM-1024 decaps	54544 cycles	54496 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

Intel Xeon 4th gen (c7i) (no-opt)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	34852 cycles	34833 cycles	1.00
ML-KEM-512 encaps	45035 cycles	45065 cycles	1.00
ML-KEM-512 decaps	58906 cycles	58937 cycles	1.00
ML-KEM-768 keypair	59125 cycles	59101 cycles	1.00
ML-KEM-768 encaps	71782 cycles	71728 cycles	1.00
ML-KEM-768 decaps	89196 cycles	89239 cycles	1.00
ML-KEM-1024 keypair	87509 cycles	87839 cycles	1.00
ML-KEM-1024 encaps	104651 cycles	104235 cycles	1.00
ML-KEM-1024 decaps	127490 cycles	126864 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

Graviton3

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	19000 cycles	18993 cycles	1.00
ML-KEM-512 encaps	23609 cycles	23579 cycles	1.00
ML-KEM-512 decaps	30774 cycles	30754 cycles	1.00
ML-KEM-768 keypair	32288 cycles	32245 cycles	1.00
ML-KEM-768 encaps	35729 cycles	35712 cycles	1.00
ML-KEM-768 decaps	45855 cycles	45882 cycles	1.00
ML-KEM-1024 keypair	46847 cycles	46847 cycles	1
ML-KEM-1024 encaps	52618 cycles	52634 cycles	1.00
ML-KEM-1024 decaps	66482 cycles	66481 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

Graviton4

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	18191 cycles	18202 cycles	1.00
ML-KEM-512 encaps	22232 cycles	22232 cycles	1
ML-KEM-512 decaps	28966 cycles	28996 cycles	1.00
ML-KEM-768 keypair	30676 cycles	30680 cycles	1.00
ML-KEM-768 encaps	33721 cycles	33736 cycles	1.00
ML-KEM-768 decaps	43285 cycles	43315 cycles	1.00
ML-KEM-1024 keypair	44360 cycles	44368 cycles	1.00
ML-KEM-1024 encaps	49783 cycles	49789 cycles	1.00
ML-KEM-1024 decaps	62851 cycles	62848 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

AMD EPYC 3rd gen (c6a) (no-opt)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	52423 cycles	52148 cycles	1.01
ML-KEM-512 encaps	65446 cycles	65745 cycles	1.00
ML-KEM-512 decaps	88563 cycles	88346 cycles	1.00
ML-KEM-768 keypair	84288 cycles	84709 cycles	1.00
ML-KEM-768 encaps	102049 cycles	101766 cycles	1.00
ML-KEM-768 decaps	131287 cycles	132010 cycles	0.99
ML-KEM-1024 keypair	124608 cycles	124006 cycles	1.00
ML-KEM-1024 encaps	145088 cycles	145709 cycles	1.00
ML-KEM-1024 decaps	182854 cycles	183602 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

Graviton2

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	29191 cycles	29193 cycles	1.00
ML-KEM-512 encaps	35560 cycles	35560 cycles	1
ML-KEM-512 decaps	46144 cycles	46109 cycles	1.00
ML-KEM-768 keypair	49208 cycles	49229 cycles	1.00
ML-KEM-768 encaps	55410 cycles	55407 cycles	1.00
ML-KEM-768 decaps	70226 cycles	70223 cycles	1.00
ML-KEM-1024 keypair	72208 cycles	72358 cycles	1.00
ML-KEM-1024 encaps	81022 cycles	81166 cycles	1.00
ML-KEM-1024 decaps	100891 cycles	100836 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

AMD EPYC 4th gen (c7a) (no-opt)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	45797 cycles	45723 cycles	1.00
ML-KEM-512 encaps	56953 cycles	56858 cycles	1.00
ML-KEM-512 decaps	76303 cycles	76248 cycles	1.00
ML-KEM-768 keypair	74600 cycles	74537 cycles	1.00
ML-KEM-768 encaps	88666 cycles	88586 cycles	1.00
ML-KEM-768 decaps	114607 cycles	114435 cycles	1.00
ML-KEM-1024 keypair	109558 cycles	109413 cycles	1.00
ML-KEM-1024 encaps	127641 cycles	127490 cycles	1.00
ML-KEM-1024 decaps	160203 cycles	160181 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[oqs-bot]

Intel Xeon 3rd gen (c6i) (no-opt)

Benchmark suite	Current: 8dff47b	Previous: 668dbab	Ratio
ML-KEM-512 keypair	56596 cycles	56618 cycles	1.00
ML-KEM-512 encaps	69451 cycles	69458 cycles	1.00
ML-KEM-512 decaps	91407 cycles	91377 cycles	1.00
ML-KEM-768 keypair	91821 cycles	91849 cycles	1.00
ML-KEM-768 encaps	107799 cycles	107762 cycles	1.00
ML-KEM-768 decaps	136350 cycles	136305 cycles	1.00
ML-KEM-1024 keypair	134787 cycles	134894 cycles	1.00
ML-KEM-1024 encaps	155210 cycles	155288 cycles	1.00
ML-KEM-1024 decaps	191544 cycles	191611 cycles	1.00

This comment was automatically generated by workflow using github-action-benchmark.

[mkannwischer]

LGTM. Thanks Hanno.