Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /* SPDX-License-Identifier: GPL-2.0-only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2013 ARM Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2013 Linaro.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * This code is based on glibc cortex strings work originally authored by Linaro
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * be found @
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * files/head:/src/aarch64/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/linkage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <asm/assembler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) * compare memory areas(when two memory areas' offset are different,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) * alignment handled by the hardware)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) * Parameters:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) *  x0 - const memory area 1 pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) *  x1 - const memory area 2 pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) *  x2 - the maximal compare byte length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) *  x0 - a compare result, maybe less than, equal to, or greater than ZERO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) /* Parameters and result.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) src1		.req	x0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) src2		.req	x1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) limit		.req	x2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) result		.req	x0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) /* Internal variables.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) data1		.req	x3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) data1w		.req	w3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) data2		.req	x4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) data2w		.req	w4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) has_nul		.req	x5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) diff		.req	x6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) endloop		.req	x7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) tmp1		.req	x8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) tmp2		.req	x9
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) tmp3		.req	x10
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) pos		.req	x11
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) limit_wd	.req	x12
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) mask		.req	x13
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) SYM_FUNC_START_WEAK_PI(memcmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	cbz	limit, .Lret0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	eor	tmp1, src1, src2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	tst	tmp1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	b.ne	.Lmisaligned8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	ands	tmp1, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	b.ne	.Lmutual_align
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	sub	limit_wd, limit, #1 /* limit != 0, so no underflow.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	lsr	limit_wd, limit_wd, #3 /* Convert to Dwords.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	* The input source addresses are at alignment boundary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	* Directly compare eight bytes each time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) .Lloop_aligned:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) .Lstart_realigned:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	subs	limit_wd, limit_wd, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	eor	diff, data1, data2	/* Non-zero if differences found.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	csinv	endloop, diff, xzr, cs	/* Last Dword or differences.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	cbz	endloop, .Lloop_aligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	/* Not reached the limit, must have found a diff.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	tbz	limit_wd, #63, .Lnot_limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	/* Limit % 8 == 0 => the diff is in the last 8 bytes. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	ands	limit, limit, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	b.eq	.Lnot_limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	* The remained bytes less than 8. It is needed to extract valid data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	* from last eight bytes of the intended memory range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	lsl	limit, limit, #3	/* bytes-> bits.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	mov	mask, #~0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) CPU_BE( lsr	mask, mask, limit )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) CPU_LE( lsl	mask, mask, limit )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	bic	data1, data1, mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	bic	data2, data2, mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	orr	diff, diff, mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	b	.Lnot_limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) .Lmutual_align:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	* Sources are mutually aligned, but are not currently at an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	* alignment boundary. Round down the addresses and then mask off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	* the bytes that precede the start point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	bic	src1, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	bic	src2, src2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	* We can not add limit with alignment offset(tmp1) here. Since the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	* addition probably make the limit overflown.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	sub	limit_wd, limit, #1/*limit != 0, so no underflow.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	and	tmp3, limit_wd, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	lsr	limit_wd, limit_wd, #3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	add	tmp3, tmp3, tmp1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	add	limit_wd, limit_wd, tmp3, lsr #3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	add	limit, limit, tmp1/* Adjust the limit for the extra.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	lsl	tmp1, tmp1, #3/* Bytes beyond alignment -> bits.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	neg	tmp1, tmp1/* Bits to alignment -64.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	mov	tmp2, #~0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	/*mask off the non-intended bytes before the start address.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) CPU_BE( lsl	tmp2, tmp2, tmp1 )/*Big-endian.Early bytes are at MSB*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	/* Little-endian.  Early bytes are at LSB.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) CPU_LE( lsr	tmp2, tmp2, tmp1 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	orr	data1, data1, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	orr	data2, data2, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	b	.Lstart_realigned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	/*src1 and src2 have different alignment offset.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) .Lmisaligned8:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	cmp	limit, #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	b.lo	.Ltiny8proc /*limit < 8: compare byte by byte*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	and	tmp1, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	neg	tmp1, tmp1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	add	tmp1, tmp1, #8/*valid length in the first 8 bytes of src1*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	and	tmp2, src2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	neg	tmp2, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	add	tmp2, tmp2, #8/*valid length in the first 8 bytes of src2*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	subs	tmp3, tmp1, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	csel	pos, tmp1, tmp2, hi /*Choose the maximum.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	sub	limit, limit, pos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	/*compare the proceeding bytes in the first 8 byte segment.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) .Ltinycmp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	ldrb	data1w, [src1], #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	ldrb	data2w, [src2], #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	subs	pos, pos, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	ccmp	data1w, data2w, #0, ne  /* NZCV = 0b0000.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	b.eq	.Ltinycmp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	cbnz	pos, 1f /*diff occurred before the last byte.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	cmp	data1w, data2w
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	b.eq	.Lstart_align
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	sub	result, data1, data2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) .Lstart_align:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	lsr	limit_wd, limit, #3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	cbz	limit_wd, .Lremain8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	ands	xzr, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	b.eq	.Lrecal_offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	/*process more leading bytes to make src1 aligned...*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	add	src1, src1, tmp3 /*backwards src1 to alignment boundary*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	add	src2, src2, tmp3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	sub	limit, limit, tmp3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	lsr	limit_wd, limit, #3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	cbz	limit_wd, .Lremain8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	/*load 8 bytes from aligned SRC1..*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	subs	limit_wd, limit_wd, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	eor	diff, data1, data2  /*Non-zero if differences found.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	csinv	endloop, diff, xzr, ne
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	cbnz	endloop, .Lunequal_proc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	/*How far is the current SRC2 from the alignment boundary...*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	and	tmp3, tmp3, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) .Lrecal_offset:/*src1 is aligned now..*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	neg	pos, tmp3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) .Lloopcmp_proc:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	* Divide the eight bytes into two parts. First,backwards the src2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	* to an alignment boundary,load eight bytes and compare from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	* the SRC2 alignment boundary. If all 8 bytes are equal,then start
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	* the second part's comparison. Otherwise finish the comparison.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	* This special handle can garantee all the accesses are in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	* thread/task space in avoid to overrange access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	ldr	data1, [src1,pos]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	ldr	data2, [src2,pos]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	eor	diff, data1, data2  /* Non-zero if differences found.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	cbnz	diff, .Lnot_limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	/*The second part process*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	eor	diff, data1, data2  /* Non-zero if differences found.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	subs	limit_wd, limit_wd, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	csinv	endloop, diff, xzr, ne/*if limit_wd is 0,will finish the cmp*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	cbz	endloop, .Lloopcmp_proc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) .Lunequal_proc:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	cbz	diff, .Lremain8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) /* There is difference occurred in the latest comparison. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) .Lnot_limit:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) * For little endian,reverse the low significant equal bits into MSB,then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) * following CLZ can find how many equal bits exist.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) CPU_LE( rev	diff, diff )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) CPU_LE( rev	data1, data1 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) CPU_LE( rev	data2, data2 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	* The MS-non-zero bit of DIFF marks either the first bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	* that is different, or the end of the significant data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	* Shifting left now will bring the critical information into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	* top bits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	clz	pos, diff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	lsl	data1, data1, pos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	lsl	data2, data2, pos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	* We need to zero-extend (char is unsigned) the value and then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	* perform a signed subtraction.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	lsr	data1, data1, #56
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	sub	result, data1, data2, lsr #56
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) .Lremain8:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	/* Limit % 8 == 0 =>. all data are equal.*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	ands	limit, limit, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	b.eq	.Lret0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) .Ltiny8proc:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	ldrb	data1w, [src1], #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	ldrb	data2w, [src2], #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	subs	limit, limit, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	ccmp	data1w, data2w, #0, ne  /* NZCV = 0b0000. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	b.eq	.Ltiny8proc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	sub	result, data1, data2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) .Lret0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	mov	result, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) SYM_FUNC_END_PI(memcmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) EXPORT_SYMBOL_NOKASAN(memcmp)