mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 07:04:00 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
249 lines
6.1 KiB
ArmAsm
249 lines
6.1 KiB
ArmAsm
/*
|
|
* arch/alpha/lib/ev6-memcpy.S
|
|
* 21264 version by Rick Gorton <rick.gorton@alpha-processor.com>
|
|
*
|
|
* Reasonably optimized memcpy() routine for the Alpha 21264
|
|
*
|
|
* - memory accessed as aligned quadwords only
|
|
* - uses bcmpge to compare 8 bytes in parallel
|
|
*
|
|
* Much of the information about 21264 scheduling/coding comes from:
|
|
* Compiler Writer's Guide for the Alpha 21264
|
|
* abbreviated as 'CWG' in other comments here
|
|
* ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html
|
|
* Scheduling notation:
|
|
* E - either cluster
|
|
* U - upper subcluster; U0 - subcluster U0; U1 - subcluster U1
|
|
* L - lower subcluster; L0 - subcluster L0; L1 - subcluster L1
|
|
*
|
|
* Temp usage notes:
|
|
* $1,$2, - scratch
|
|
*/
|
|
|
|
.set noreorder
|
|
.set noat
|
|
|
|
.align 4
|
|
.globl memcpy
|
|
.ent memcpy
|
|
memcpy:
|
|
.frame $30,0,$26,0
|
|
.prologue 0
|
|
|
|
mov $16, $0 # E : copy dest to return
|
|
ble $18, $nomoredata # U : done with the copy?
|
|
xor $16, $17, $1 # E : are source and dest alignments the same?
|
|
and $1, 7, $1 # E : are they the same mod 8?
|
|
|
|
bne $1, $misaligned # U : Nope - gotta do this the slow way
|
|
/* source and dest are same mod 8 address */
|
|
and $16, 7, $1 # E : Are both 0mod8?
|
|
beq $1, $both_0mod8 # U : Yes
|
|
nop # E :
|
|
|
|
/*
|
|
* source and dest are same misalignment. move a byte at a time
|
|
* until a 0mod8 alignment for both is reached.
|
|
* At least one byte more to move
|
|
*/
|
|
|
|
$head_align:
|
|
ldbu $1, 0($17) # L : grab a byte
|
|
subq $18, 1, $18 # E : count--
|
|
addq $17, 1, $17 # E : src++
|
|
stb $1, 0($16) # L :
|
|
addq $16, 1, $16 # E : dest++
|
|
and $16, 7, $1 # E : Are we at 0mod8 yet?
|
|
ble $18, $nomoredata # U : done with the copy?
|
|
bne $1, $head_align # U :
|
|
|
|
$both_0mod8:
|
|
cmple $18, 127, $1 # E : Can we unroll the loop?
|
|
bne $1, $no_unroll # U :
|
|
and $16, 63, $1 # E : get mod64 alignment
|
|
beq $1, $do_unroll # U : no single quads to fiddle
|
|
|
|
$single_head_quad:
|
|
ldq $1, 0($17) # L : get 8 bytes
|
|
subq $18, 8, $18 # E : count -= 8
|
|
addq $17, 8, $17 # E : src += 8
|
|
nop # E :
|
|
|
|
stq $1, 0($16) # L : store
|
|
addq $16, 8, $16 # E : dest += 8
|
|
and $16, 63, $1 # E : get mod64 alignment
|
|
bne $1, $single_head_quad # U : still not fully aligned
|
|
|
|
$do_unroll:
|
|
addq $16, 64, $7 # E : Initial (+1 trip) wh64 address
|
|
cmple $18, 127, $1 # E : Can we go through the unrolled loop?
|
|
bne $1, $tail_quads # U : Nope
|
|
nop # E :
|
|
|
|
$unroll_body:
|
|
wh64 ($7) # L1 : memory subsystem hint: 64 bytes at
|
|
# ($7) are about to be over-written
|
|
ldq $6, 0($17) # L0 : bytes 0..7
|
|
nop # E :
|
|
nop # E :
|
|
|
|
ldq $4, 8($17) # L : bytes 8..15
|
|
ldq $5, 16($17) # L : bytes 16..23
|
|
addq $7, 64, $7 # E : Update next wh64 address
|
|
nop # E :
|
|
|
|
ldq $3, 24($17) # L : bytes 24..31
|
|
addq $16, 64, $1 # E : fallback value for wh64
|
|
nop # E :
|
|
nop # E :
|
|
|
|
addq $17, 32, $17 # E : src += 32 bytes
|
|
stq $6, 0($16) # L : bytes 0..7
|
|
nop # E :
|
|
nop # E :
|
|
|
|
stq $4, 8($16) # L : bytes 8..15
|
|
stq $5, 16($16) # L : bytes 16..23
|
|
subq $18, 192, $2 # E : At least two more trips to go?
|
|
nop # E :
|
|
|
|
stq $3, 24($16) # L : bytes 24..31
|
|
addq $16, 32, $16 # E : dest += 32 bytes
|
|
nop # E :
|
|
nop # E :
|
|
|
|
ldq $6, 0($17) # L : bytes 0..7
|
|
ldq $4, 8($17) # L : bytes 8..15
|
|
cmovlt $2, $1, $7 # E : Latency 2, extra map slot - Use
|
|
# fallback wh64 address if < 2 more trips
|
|
nop # E :
|
|
|
|
ldq $5, 16($17) # L : bytes 16..23
|
|
ldq $3, 24($17) # L : bytes 24..31
|
|
addq $16, 32, $16 # E : dest += 32
|
|
subq $18, 64, $18 # E : count -= 64
|
|
|
|
addq $17, 32, $17 # E : src += 32
|
|
stq $6, -32($16) # L : bytes 0..7
|
|
stq $4, -24($16) # L : bytes 8..15
|
|
cmple $18, 63, $1 # E : At least one more trip?
|
|
|
|
stq $5, -16($16) # L : bytes 16..23
|
|
stq $3, -8($16) # L : bytes 24..31
|
|
nop # E :
|
|
beq $1, $unroll_body
|
|
|
|
$tail_quads:
|
|
$no_unroll:
|
|
.align 4
|
|
subq $18, 8, $18 # E : At least a quad left?
|
|
blt $18, $less_than_8 # U : Nope
|
|
nop # E :
|
|
nop # E :
|
|
|
|
$move_a_quad:
|
|
ldq $1, 0($17) # L : fetch 8
|
|
subq $18, 8, $18 # E : count -= 8
|
|
addq $17, 8, $17 # E : src += 8
|
|
nop # E :
|
|
|
|
stq $1, 0($16) # L : store 8
|
|
addq $16, 8, $16 # E : dest += 8
|
|
bge $18, $move_a_quad # U :
|
|
nop # E :
|
|
|
|
$less_than_8:
|
|
.align 4
|
|
addq $18, 8, $18 # E : add back for trailing bytes
|
|
ble $18, $nomoredata # U : All-done
|
|
nop # E :
|
|
nop # E :
|
|
|
|
/* Trailing bytes */
|
|
$tail_bytes:
|
|
subq $18, 1, $18 # E : count--
|
|
ldbu $1, 0($17) # L : fetch a byte
|
|
addq $17, 1, $17 # E : src++
|
|
nop # E :
|
|
|
|
stb $1, 0($16) # L : store a byte
|
|
addq $16, 1, $16 # E : dest++
|
|
bgt $18, $tail_bytes # U : more to be done?
|
|
nop # E :
|
|
|
|
/* branching to exit takes 3 extra cycles, so replicate exit here */
|
|
ret $31, ($26), 1 # L0 :
|
|
nop # E :
|
|
nop # E :
|
|
nop # E :
|
|
|
|
$misaligned:
|
|
mov $0, $4 # E : dest temp
|
|
and $0, 7, $1 # E : dest alignment mod8
|
|
beq $1, $dest_0mod8 # U : life doesnt totally suck
|
|
nop
|
|
|
|
$aligndest:
|
|
ble $18, $nomoredata # U :
|
|
ldbu $1, 0($17) # L : fetch a byte
|
|
subq $18, 1, $18 # E : count--
|
|
addq $17, 1, $17 # E : src++
|
|
|
|
stb $1, 0($4) # L : store it
|
|
addq $4, 1, $4 # E : dest++
|
|
and $4, 7, $1 # E : dest 0mod8 yet?
|
|
bne $1, $aligndest # U : go until we are aligned.
|
|
|
|
/* Source has unknown alignment, but dest is known to be 0mod8 */
|
|
$dest_0mod8:
|
|
subq $18, 8, $18 # E : At least a quad left?
|
|
blt $18, $misalign_tail # U : Nope
|
|
ldq_u $3, 0($17) # L : seed (rotating load) of 8 bytes
|
|
nop # E :
|
|
|
|
$mis_quad:
|
|
ldq_u $16, 8($17) # L : Fetch next 8
|
|
extql $3, $17, $3 # U : masking
|
|
extqh $16, $17, $1 # U : masking
|
|
bis $3, $1, $1 # E : merged bytes to store
|
|
|
|
subq $18, 8, $18 # E : count -= 8
|
|
addq $17, 8, $17 # E : src += 8
|
|
stq $1, 0($4) # L : store 8 (aligned)
|
|
mov $16, $3 # E : "rotate" source data
|
|
|
|
addq $4, 8, $4 # E : dest += 8
|
|
bge $18, $mis_quad # U : More quads to move
|
|
nop
|
|
nop
|
|
|
|
$misalign_tail:
|
|
addq $18, 8, $18 # E : account for tail stuff
|
|
ble $18, $nomoredata # U :
|
|
nop
|
|
nop
|
|
|
|
$misalign_byte:
|
|
ldbu $1, 0($17) # L : fetch 1
|
|
subq $18, 1, $18 # E : count--
|
|
addq $17, 1, $17 # E : src++
|
|
nop # E :
|
|
|
|
stb $1, 0($4) # L : store
|
|
addq $4, 1, $4 # E : dest++
|
|
bgt $18, $misalign_byte # U : more to go?
|
|
nop
|
|
|
|
|
|
$nomoredata:
|
|
ret $31, ($26), 1 # L0 :
|
|
nop # E :
|
|
nop # E :
|
|
nop # E :
|
|
|
|
.end memcpy
|
|
|
|
/* For backwards module compatibility. */
|
|
__memcpy = memcpy
|
|
.globl __memcpy
|