sortfast -- a laboratory to explore sorting performance

https://cantrip.org/sortfast.html

Examples:

make all
make CC=g++-9 INDEXED
make CC=clang++-9 ANDANDOR
make CC=clang++-9 INDEXED_PESSIMAL_ON_GCC
make CC=g++-9 CHECK=CHECK BOG

Same input, same algorithm, varying performance:

/tr>

Variant	Compiler	Haswell	SkylakeX	Zen2 -march=znver2	*
STD	G++	1 (10.2s)	1 (7.3s)	1 (9.0s)
	Clang	1 (10.0s)	1 (7.3s)	1 (8.5s)
BOG	G++	1.1 (11.5s)	1.1 (8.2s)	1.1 (10.3s)
	Clang	1.1 (11.3s)	1.1 (7.9s)	1.1 (9.4s)
&&|	G++	.56 (5.7s)	.61 (4.5s)	.82 (7.4s)
	Clang	.49 (4.9s)	.47 (3.4s)	.75 (6.4)	!
IX	G++	.79 (8.1s)	.89 (6.5s)	.94 (8.5s)
	Clang	.66 (6.6s)	.63 (4.6s)	.87 (7.4s)
IX-P	G++	1.2 (12.0s)	1.2 (8.4s)	2.7 (24s)	!
	Clang	.64 (6.4s)	.60 (4.4s)	.77 (7.4s)
ROT	G++	.72 (7.3s)	.70 (5.1s)	.73 (6.6s)
	Clang	.68 (6.8s)	.66 (4.8s)	1.2 (9.9s)
CMOV	G++	1.1 (11.3s)	1.1 (8.0s)	.82 (7.4s)
	Clang	.49 (4.9s)	.47 (3.4s)	.74 (6.3s)	!
IX1	G++	1.6 (15.9s)	1.6 (11.8s)	.82 (7.4)	!
	Clang	.61 (6.1s)	.62 (4.5s)	.73 (6.6s)
IX2	G++	1.1 (11.2s)	1.1 (8.2s)	2.1 (19s)	!
	Clang	.69 (6.9s)	.70 (5.1s)	2.2 (19s)	!

Note that compiler tunings for Zen2 are very immature, resulting in severely suboptimal code generation in several cases seen here.

Radix sorts, for reference

Variant	Compiler	Haswell	SkylakeX	Zen2 -march=znver2	*
RX256	G++	.13 (1.3s)	.14 (1.0s)	.20 (1.8s)	!
	Clang	.12 (1.2s)	.12 (0.9s)	.21 (1.8s)	!
RX2	G++	.66 (6.7s)	.62 (4.5s)	1.4 (12.7s)
	Clang	.71 (7.1s)	.66 (4.8s)	1.4 (11.7s)