diff options
| author | Ian Moffett <ian@osmora.org> | 2025-02-20 13:12:27 -0500 |
|---|---|---|
| committer | Ian Moffett <ian@osmora.org> | 2025-02-20 13:12:27 -0500 |
| commit | 6bbe7ef049bc1b9d150a21ccd082c2f65f344682 (patch) | |
| tree | 49c040189ca5d9242297fbcdbfbfc1a7b1ea64de /sys/arch | |
| parent | 6018ed09c35b35343cf64133529850ddc8071138 (diff) | |
kernel/amd64: i8237: Optimize set channel select
There is no need for an intermediary register before setting %AL. This
commit removes redundant instructions to reduce the amount of cycles
used for this operation.
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'sys/arch')
| -rw-r--r-- | sys/arch/amd64/isa/i8237.S | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/sys/arch/amd64/isa/i8237.S b/sys/arch/amd64/isa/i8237.S index 00b5bd9..ef6090a 100644 --- a/sys/arch/amd64/isa/i8237.S +++ b/sys/arch/amd64/isa/i8237.S @@ -95,9 +95,8 @@ i8237_set_mode: jg 1f /* Set channel select bits */ - mov %dil, %bl - andb $3, %bl - mov %bl, %al + mov %dil, %al + andb $3, %al /* Set channel mode bits */ mov %sil, %dl |