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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/alpha/lib/strchr.S | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/alpha/lib/strchr.S')
-rw-r--r-- | arch/alpha/lib/strchr.S | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/alpha/lib/strchr.S b/arch/alpha/lib/strchr.S new file mode 100644 index 000000000..17871dd00 --- /dev/null +++ b/arch/alpha/lib/strchr.S @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * 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/export.h> +#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 + EXPORT_SYMBOL(strchr) |