summaryrefslogtreecommitdiff
path: root/sys/dev/microcode/tools/array2bin.c
diff options
context:
space:
mode:
authorriastradh <riastradh@NetBSD.org>2023-03-29 13:07:46 +0000
committerriastradh <riastradh@NetBSD.org>2023-03-29 13:07:46 +0000
commitb50068aedcf440f2870f54b2b97b4882954793ac (patch)
tree24d59e90d997b349b96651b6ad572b982fe5a5bc /sys/dev/microcode/tools/array2bin.c
parente4ef49ffa3b81d240148aab9cf712bd58d23fc05 (diff)
openssl: Remove local micro-optimization on AMD (but not Intel).
Upstream OpenSSL changed loop 1b to dec %rcx jnz 1b which has mostly the same semantics, in this change: https://github.com/openssl/openssl/pull/4743 For some reason, in one of the OpenSSL updates, we ended up with a local change to revert this. The Intel and AMD optimization guides are silent on the LOOP instruction, but Agner Fog's tables shows that while LOOP is one cycle shorter than DEC;JNZ on AMD Zen microarchitectures, it is a good half dozen cycles longer than DEC;JNZ on recent Intel microarchitectures. The history of the OpenSSL change suggests it was intended, and I can't find any indication other than `merge conflicts' that we intended to keep the LOOP version. So let's reduce the local diff by nixing it.
Diffstat (limited to 'sys/dev/microcode/tools/array2bin.c')
0 files changed, 0 insertions, 0 deletions