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/*
Copyright (c) 2009 Nick Clifton <nickc@redhat.com>
*/
.file "strncmp.S"
.section .text
.global _strncmp
.type _strncmp,@function
_strncmp:
;; R1: string1
;; R2: string2
;; R3: max number of bytes to compare
#ifdef __RX_DISALLOW_STRING_INSNS__
cmp #0, r3 ; For a length of zero, return zero
beq 4f
2: mov.b [r1+], r4
mov.b [r2+], r5
cmp #0, r4
beq 3f
cmp #0, r5
beq 3f
sub #1, r3
beq 3f
cmp r4, r5
beq 2b
3: and #0xff, r4 ; We need to perform an unsigned comparison of the bytes.
and #0xff, r5
sub r5, r4, r1
rts
4: mov #0, r1
rts
#else
scmpu ; Perform the string comparison
bnc 1f ; If Carry is not set skip over
scne.L r1 ; Set result based on Z flag
rts ;
1: ;
mov #-1,r1 ; Carry not set, result should be negative
rts ;
#endif
.size _strncmp, . - _strncmp
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