mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 04:34:11 +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!
71 lines
1.9 KiB
ArmAsm
71 lines
1.9 KiB
ArmAsm
/*
|
|
* arch/alpha/lib/strchr.S
|
|
* Contributed by Richard Henderson (rth@tamu.edu)
|
|
*
|
|
* Return the address of a given character within a null-terminated
|
|
* string, or null if it is not found.
|
|
*/
|
|
|
|
#include <asm/regdef.h>
|
|
|
|
.set noreorder
|
|
.set noat
|
|
|
|
.align 3
|
|
.globl strchr
|
|
.ent strchr
|
|
strchr:
|
|
.frame sp, 0, ra
|
|
.prologue 0
|
|
|
|
zapnot a1, 1, a1 # e0 : zero extend the search character
|
|
ldq_u t0, 0(a0) # .. e1 : load first quadword
|
|
sll a1, 8, t5 # e0 : replicate the search character
|
|
andnot a0, 7, v0 # .. e1 : align our loop pointer
|
|
or t5, a1, a1 # e0 :
|
|
lda t4, -1 # .. e1 : build garbage mask
|
|
sll a1, 16, t5 # e0 :
|
|
cmpbge zero, t0, t2 # .. e1 : bits set iff byte == zero
|
|
mskqh t4, a0, t4 # e0 :
|
|
or t5, a1, a1 # .. e1 :
|
|
sll a1, 32, t5 # e0 :
|
|
cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage
|
|
or t5, a1, a1 # e0 :
|
|
xor t0, a1, t1 # .. e1 : make bytes == c zero
|
|
cmpbge zero, t1, t3 # e0 : bits set iff byte == c
|
|
or t2, t3, t0 # e1 : bits set iff char match or zero match
|
|
andnot t0, t4, t0 # e0 : clear garbage bits
|
|
bne t0, $found # .. e1 (zdb)
|
|
|
|
$loop: ldq t0, 8(v0) # e0 :
|
|
addq v0, 8, v0 # .. e1 :
|
|
nop # e0 :
|
|
xor t0, a1, t1 # .. e1 (ev5 data stall)
|
|
cmpbge zero, t0, t2 # e0 : bits set iff byte == 0
|
|
cmpbge zero, t1, t3 # .. e1 : bits set iff byte == c
|
|
or t2, t3, t0 # e0 :
|
|
beq t0, $loop # .. e1 (zdb)
|
|
|
|
$found: negq t0, t1 # e0 : clear all but least set bit
|
|
and t0, t1, t0 # e1 (stall)
|
|
|
|
and t0, t3, t1 # e0 : bit set iff byte was the char
|
|
beq t1, $retnull # .. e1 (zdb)
|
|
|
|
and t0, 0xf0, t2 # e0 : binary search for that set bit
|
|
and t0, 0xcc, t3 # .. e1 :
|
|
and t0, 0xaa, t4 # e0 :
|
|
cmovne t2, 4, t2 # .. e1 :
|
|
cmovne t3, 2, t3 # e0 :
|
|
cmovne t4, 1, t4 # .. e1 :
|
|
addq t2, t3, t2 # e0 :
|
|
addq v0, t4, v0 # .. e1 :
|
|
addq v0, t2, v0 # e0 :
|
|
ret # .. e1 :
|
|
|
|
$retnull:
|
|
mov zero, v0 # e0 :
|
|
ret # .. e1 :
|
|
|
|
.end strchr
|