Commit Graph

3 Commits

Author SHA1 Message Date
Shengqi Chen
0ae4460c61 zcommon: add specialized versions of cityhash4
Specializing cityhash4 on 32-bit architectures can reduce the size
of stack frames as well as instruction count. This is a tiny but
useful optimization, since some callers invoke it frequently.

When specializing into 1/2/3/4-arg versions, the stack usage
(in bytes) on some 32-bit arches are listed as follows:

- x86: 32, 32, 32, 40
- arm-v7a: 20, 20, 28, 36
- riscv: 0, 0, 0, 16
- power: 16, 16, 16, 32
- mipsel: 8, 8, 8, 24

And each actual argument (even if passing 0) contributes evenly
to the number of multiplication instructions generated:

- x86: 9, 12, 15 ,18
- arm-v7a: 6, 8, 10, 12
- riscv / power: 12, 18, 20, 24
- mipsel: 9, 12, 15, 19

On 64-bit architectures, the tendencies are similar. But both stack
sizes and instruction counts are significantly smaller thus negligible.

Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Shengqi Chen <harry-chen@outlook.com>
Closes #16131
Closes #16483
2024-09-19 15:18:59 -07:00
наб
739cfb965b libzfs: convert to -fvisibility=hidden
Also mark all printf-like funxions in libzfs_impl.h as printf-like
and add --no-show-locs to storeabi, in hopes diffs will make more sense
in future

This removes these symbols from libzfs:
  D nfs_only
  T SHA256Init
  T SHA2Final
  T SHA2Init
  T SHA2Update
  T SHA384Init
  T SHA512Init
  D share_all_proto
  D smb_only
  T zfs_is_shared_proto
  W zpool_mount_datasets
  W zpool_unmount_datasets

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12048
2021-06-03 13:17:55 -07:00
Matthew Ahrens
3f38797338
Compile cityhash code into libzfs
Make the cityhash code compile into libzfs, in preparation for the new
"zstream" command.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10152
2020-03-27 09:11:22 -07:00