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Commit	Line	Data
	1	/*
	2	* Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29	#define ASSEMBLER
	30	#include <sys/appleapiopts.h>
	31	#include <ppc/asm.h>
	32	#include <machine/cpu_capabilities.h>
	33	#include <machine/commpage.h>
	34
	35	/*
	36	* WARNING: this code is written for 32-bit mode, and ported by the kernel if necessary
	37	* to 64-bit mode for use in the 64-bit commpage. This "port" consists of the following
	38	* simple transformations:
	39	* - all word compares are changed to doubleword
	40	* - all "srwi[.]" opcodes are changed to "srdi[.]"
	41	* Nothing else is done. For this to work, the following rules must be
	42	* carefully followed:
	43	* - do not use carry or overflow
	44	* - only use record mode if you are sure the results are mode-invariant
	45	* for example, all "andi." and almost all "rlwinm." are fine
	46	* - do not use "slwi", "slw", or "srw"
	47	* An imaginative programmer could break the porting model in other ways, but the above
	48	* are the most likely problem areas. It is perhaps surprising how well in practice
	49	* this simple method works.
	50	*/
	51
	52	.text
	53	.align 2
	54
	55
	56	/* *********************
	57	* * M E M S E T _ 6 4 *
	58	* *********************
	59	*
	60	* This is a subroutine called by Libc memset and _memset_pattern for large nonzero
	61	* operands (zero operands are funneled into bzero.) This version is for a
	62	* hypothetic processor that is 64-bit but not Altivec.
	63	* It is not optimized, since it would only be used during bringup.
	64	*
	65	* Registers at entry:
	66	* r4 = count of bytes to store (must be >= 32)
	67	* r8 = ptr to the 1st byte to store (16-byte aligned)
	68	* r9 = ptr to 16-byte pattern to store (16-byte aligned)
	69	* When we return:
	70	* r3 = not changed, since memset returns it
	71	* r4 = bytes remaining to store (will be <32)
	72	* r7 = not changed
	73	* r8 = ptr to next byte to store (still 16-byte aligned)
	74	* r12 = not changed (holds return value for memset)
	75	*/
	76
	77	memset_64:
	78	srwi r0,r4,5 // get number of 32-byte chunks (>0)
	79	ld r10,0(r9) // load pattern
	80	ld r11,8(r9)
	81	rlwinm r4,r4,0,0x1F // mask down count
	82	mtctr r0 // set up loop count
	83
	84	// Loop over 32-byte chunks.
	85	1:
	86	std r10,0(r8)
	87	std r11,8(r8)
	88	std r10,16(r8)
	89	std r11,24(r8)
	90	addi r8,r8,32
	91	bdnz++ 1b
	92
	93	blr
	94
	95
	96	COMMPAGE_DESCRIPTOR(memset_64,_COMM_PAGE_MEMSET_PATTERN,k64Bit,kHasAltivec, \
	97	kCommPageBoth+kPort32to64)