tegrakernel/kernel/kernel-4.9/arch/ia64/lib/strnlen_user.S

48 lines
957 B
ArmAsm

/*
* Returns 0 if exception before NUL or reaching the supplied limit (N),
* a value greater than N if the string is longer than the limit, else
* strlen.
*
* Inputs:
* in0: address of buffer
* in1: string length limit N
* Outputs:
* r8: 0 in case of fault, strlen(buffer)+1 otherwise
*
* Copyright (C) 1999, 2001 David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <asm/asmmacro.h>
#include <asm/export.h>
GLOBAL_ENTRY(__strnlen_user)
.prologue
alloc r2=ar.pfs,2,0,0,0
.save ar.lc, r16
mov r16=ar.lc // preserve ar.lc
.body
add r3=-1,in1
;;
mov ar.lc=r3
mov r9=0
;;
// XXX braindead strlen loop---this needs to be optimized
.Loop1:
EXCLR(.Lexit, ld1 r8=[in0],1)
add r9=1,r9
;;
cmp.eq p6,p0=r8,r0
(p6) br.cond.dpnt .Lexit
br.cloop.dptk.few .Loop1
add r9=1,in1 // NUL not found---return N+1
;;
.Lexit:
mov r8=r9
mov ar.lc=r16 // restore ar.lc
br.ret.sptk.many rp
END(__strnlen_user)
EXPORT_SYMBOL(__strnlen_user)