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The P/Q left side optimization in the delta syndrome simply involves repeatedly multiplying a value by polynomial 'x' in GF(2^8). Given that 'x * x * x * x' equals 'x^4' even in the polynomial world, we can accelerate this substantially by performing up to 4 such operations at once, using the NEON instructions for polynomial multiplication. Results on a Cortex-A57 running in 64-bit mode: Before: ------- raid6: neonx1 xor() 1680 MB/s raid6: neonx2 xor() 2286 MB/s raid6: neonx4 xor() 3162 MB/s raid6: neonx8 xor() 3389 MB/s After: ------ raid6: neonx1 xor() 2281 MB/s raid6: neonx2 xor() 3362 MB/s raid6: neonx4 xor() 3787 MB/s raid6: neonx8 xor() 4239 MB/s While we're at it, simplify MASK() by using a signed shift rather than a vector compare involving a temp register. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> |
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| .. | ||
| test | ||
| .gitignore | ||
| algos.c | ||
| altivec.uc | ||
| avx2.c | ||
| avx512.c | ||
| int.uc | ||
| Makefile | ||
| mktables.c | ||
| mmx.c | ||
| neon.c | ||
| neon.uc | ||
| recov_avx2.c | ||
| recov_avx512.c | ||
| recov_s390xc.c | ||
| recov_ssse3.c | ||
| recov.c | ||
| s390vx.uc | ||
| sse1.c | ||
| sse2.c | ||
| tilegx.uc | ||
| unroll.awk | ||
| x86.h | ||