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// TITLE("memchr")
//++
//
// Copyright (c) 1994 IBM Corporation
//
// Module Name:
//
// memchr.s
//
// Routine Description:
//
// Searches buffer for character, stopping when found
// or after checking count bytes.
//
// Author:
//
// Jeff Simon (jhs) 02-Aug-1994
//
// Environment:
//
// User or Kernel mode.
//
// Revision History:
//
// Includes
#include <kxppc.h>
//
// void * memchr (
// const void * buffer,
// int character,
// size_t count
// )
//
// Arguments:
//
// SRC1 (r.3) - A pointer to the block of memory
//
// SRC2 (r.4) - A character to base search
//
// LNGTH (r.5) - Max number of comparison in bytes
//
// Return Value:
//
// NULL if not found after count bytes
// ptr to character in buffer, if character is found
//
//
LEAF_ENTRY(memchr)
cmpi 0x7,0x0,r5,0 # chk cnt
cmpi 0x1,0x0,r5,1 # finish early
beq 0x7,Null # all done
lbz r6,0(r3) # read char
cmp 0x6,0x0,r6,r4 # char ?= c
subi r5,r5,1 # decr cnt
beq 0x6,Fini # all done
beq 0x1,Null # rd 1 char only
mtctr r5 # init ctr
L..1:
lbzu r6,1(r3)
cmp 0x0,0x0,r6,r4 # char ?= c
bdnzf eq,L..1 # dec ctr & ...
beq Fini # br ctr != 0 & !char
Null:
addi r3,r0,0 # return null
Fini:
LEAF_EXIT(memchr)
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