Spent one of the 4 scale bits on a signs of a 0.125 shift.
I.e., quants are now -1 + delta, delta, 1 + delta, where delta
is +/- 0.125.
CUDA works, same performance as before.
PPL(LLaMA-v2-7B) is now 11.85!
* Trying blocvks of 16 for IQ1_S - seems slightly better
* iq1s_blocks16: Adjust scale fudge factor to 1.125
* iq1s_blocks16: going to blocks of 32
with 2048 lattice points, so same bpw.
This is even better than blocks of 16.
Should I try blocks of 64? But to keep the same
bpw, when I go to 4096 lattice points, I need to
remove blocks alltogether and just have superblocks of
256 weights.
* iq1s_blocks16: Use 2*<x^2> as sigma2 in weight adjustment
* iq1s_blocks16: scalar and AVX2 dot products
* iq1s_blocks16: CUDA dot product
* iq1s_blocks16: Metal works, Neon does not
Metal works but TG is dog slow (35 t/s). PP is OKish (493 t/s).
Not seeing the bug in the Neon implementation for now.
* iq1s_blocks16: fixed Neon
* iq1s_blocks16: very slightly faster TG on Metal
Still pathetic at 37 t/s
* iq1s_blocks16: speedup Metal by packing codebook into uint32_t's
* Formatting
* iq1s_blocks16: uint32_t codebook is also better in CUDA
TG-128 is now 204 t/s up from 194 t/s.
PP-512 is 5890 t/s, so significantly better than other quants
* iq1s_blocks16: slightly faster Neon dot product
* iq1s_blocks16: faster AVX2 dot product
* iq1s_blocks16: adjust to ggml-common.h
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Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>
