[apple/xnu.git] / osfmk / ppc / commpage / bcopy_g4.s

/*
 * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* =======================================
 * BCOPY, MEMCPY, and MEMMOVE for Mac OS X
 * =======================================
 *
 * Version of 2/20/2003, tuned for G4.  The inner loops use DCBA to avoid
 * reading destination cache lines.  Only the 7450 actually benefits from
 * this, and then only in the cold-cache case.  On 7400s and 7455s, we
 * patch the DCBAs into NOPs.
 *
 * Register usage.  Note we use R2, so this code will not run in a PEF/CFM
 * environment.  Note also the rather delicate way we assign multiple uses
 * to the same register.  Beware.
 *
 *   r0  = "w7" or temp (NB: cannot use r0 for any constant such as "c16")
 *   r2  = "w8" or vrsave ("rv")
 *   r3  = not used, as memcpy and memmove return 1st parameter as a value
 *   r4  = source ptr ("rs")
 *   r5  = count of bytes to move ("rc")
 *   r6  = "w1", "c16", or "cm17"
 *   r7  = "w2", "c32", or "cm33"
 *   r8  = "w3", "c48", or "cm49"
 *   r9  = "w4", or "cm1"
 *   r10 = "w5", "c96", or "cm97"
 *   r11 = "w6", "c128", or "cm129"
 *   r12 = destination ptr ("rd")
 *   v0  = permute vector ("vp") 
 * v1-v4 = qw's loaded from source
 * v5-v7 = permuted qw's ("vw", "vx", "vy")
 */
#define rs	r4
#define rd	r12
#define rc	r5
#define	rv	r2

#define w1	r6
#define w2	r7
#define w3	r8
#define	w4	r9
#define	w5	r10
#define	w6	r11
#define	w7	r0
#define	w8	r2

#define c16		r6
#define cm17	r6
#define c32		r7
#define cm33	r7
#define c48		r8
#define cm49	r8
#define cm1		r9
#define c96		r10
#define cm97	r10
#define c128	r11
#define cm129	r11

#define	vp	v0
#define	vw	v5
#define	vx	v6
#define	vy	v7

#define	ASSEMBLER
#include <sys/appleapiopts.h>
#include <ppc/asm.h>
#include <machine/cpu_capabilities.h>
#include <machine/commpage.h>

        .text

#define	kMedium		32				// too long for inline loopless code
#define	kLong		96				// long enough to justify use of Altivec


// Main entry points.

        .align 	5
bcopy_g4:							// void bcopy(const void *src, void *dst, size_t len)
        cmplwi	rc,kMedium			// short or long?
        sub		w1,r4,r3			// must move in reverse if (rd-rs)<rc
        cmplw	cr1,w1,rc			// set cr1 blt iff we must move reverse
        mr		rd,r4				// start to move registers to canonic spot
        mr		rs,r3
        blt+	LShort				// handle short operands
        dcbt	0,r3				// touch in destination
        b		LMedium				// join medium/long operand code

// NB: memmove() must be 8 words past bcopy(), to agree with comm page addresses.
        
        .align	5
Lmemcpy_g4:							// void* memcpy(void *dst, void *src, size_t len)
Lmemmove_g4:						// void* memmove(void *dst, const void *src, size_t len)
        cmplwi	rc,kMedium			// short or long?
        sub		w1,r3,r4			// must move in reverse if (rd-rs)<rc
        dcbt	0,r4				// touch in the first line of source
        cmplw	cr1,w1,rc			// set cr1 blt iff we must move reverse
        mr		rd,r3				// must leave r3 alone, it is return value for memcpy etc
        bge-	LMedium				// handle medium or long operands

// Handle short operands.
        
LShort:
        andi.	r0,rc,0x10			// test bit 27 separately (faster on G4)
        mtcrf	0x01,rc				// put length bits 28-31 in cr7
        blt-	cr1,LShortReverse
        
// Forward short operands.  This is the most frequent case, so it is inline.

        beq		LShort16			// quadword to move?
        lwz		w1,0(rs)
        lwz		w2,4(rs)
        lwz		w3,8(rs)
        lwz		w4,12(rs)
        addi	rs,rs,16
        stw		w1,0(rd)
        stw		w2,4(rd)
        stw		w3,8(rd)
        stw		w4,12(rd)
        addi	rd,rd,16
LShort16:							// join here to xfer 0-15 bytes
        bf		28,2f				// doubleword?
        lwz		w1,0(rs)
        lwz		w2,4(rs)
        addi	rs,rs,8
        stw		w1,0(rd)
        stw		w2,4(rd)
        addi	rd,rd,8
2:
        bf		29,3f				// word?
        lwz		w1,0(rs)
        addi	rs,rs,4
        stw		w1,0(rd)
        addi	rd,rd,4
3:
        bf		30,4f				// halfword to move?
        lhz		w1,0(rs)
        addi	rs,rs,2
        sth		w1,0(rd)
        addi	rd,rd,2
4:
        bflr	31					// skip if no odd byte
        lbz		w1,0(rs)
        stb		w1,0(rd)
        blr
        
        
// Handle short reverse operands.
//		cr0 = bne if bit 27 of length is set
//		cr7 = bits 28-31 of length      

LShortReverse:
        add		rs,rs,rc			// adjust ptrs for reverse move
        add		rd,rd,rc
        beq		LShortReverse16		// quadword to move?
        lwz		w1,-4(rs)
        lwz		w2,-8(rs)
        lwz		w3,-12(rs)
        lwzu	w4,-16(rs)
        stw		w1,-4(rd)
        stw		w2,-8(rd)
        stw		w3,-12(rd)
        stwu	w4,-16(rd)
LShortReverse16:					// join here to xfer 0-15 bytes and return
        bf		28,2f				// doubleword?
        lwz		w1,-4(rs)
        lwzu	w2,-8(rs)
        stw		w1,-4(rd)
        stwu	w2,-8(rd)
2:
        bf		29,3f				// word?
        lwzu	w1,-4(rs)
        stwu	w1,-4(rd)
3:
        bf		30,4f				// halfword to move?
        lhzu	w1,-2(rs)
        sthu	w1,-2(rd)
4:
        bflr	31					// done if no odd byte
        lbz 	w1,-1(rs)			// no update
        stb 	w1,-1(rd)
        blr
        

// Medium and long operands.  Use Altivec if long enough, else scalar loops.
//		w1 = (rd-rs), used to check for alignment
//     cr1 = blt iff we must move reverse

        .align	4
LMedium:
        dcbtst	0,rd				// touch in destination
        cmplwi	cr7,rc,kLong		// long enough for vectors?
        neg		w3,rd				// start to compute #bytes to align destination
        rlwinm	r0,w1,0,0x7			// check relative 8-byte alignment
        andi.	w6,w3,7				// w6 <- #bytes to 8-byte align destination
        blt		cr1,LMediumReverse	// handle reverse moves
        rlwinm	w4,w3,0,0x1F		// w4 <- #bytes to 32-byte align destination
        cmpwi	cr6,r0,0			// set cr6 beq if relatively aligned
        bge		cr7,LFwdLong		// long enough for vectors

// Medium length: use scalar loops.
//	w6/cr0 = #bytes to 8-byte align destination
//	   cr6 = beq if relatively doubleword aligned

        sub		rc,rc,w6			// decrement length remaining
        beq		1f					// skip if dest already doubleword aligned
        mtxer	w6					// set up count for move
        lswx	w1,0,rs				// move w6 bytes to align destination
        stswx	w1,0,rd
        add		rs,rs,w6			// bump ptrs past
        add		rd,rd,w6
1:        
        srwi	r0,rc,4				// get # 16-byte chunks (>=1)
        mtcrf	0x01,rc				// save remaining byte count here for LShort16
        mtctr	r0					// set up 16-byte loop
        bne		cr6,3f				// source not 4-byte aligned
        b		2f
        
        .align	4
2:									// loop over 16-byte  aligned chunks
        lfd		f0,0(rs)
        lfd		f1,8(rs)
        addi	rs,rs,16
        stfd	f0,0(rd)
        stfd	f1,8(rd)
        addi	rd,rd,16
        bdnz	2b
        
        b		LShort16
        
        .align	4
3:									// loop over 16-byte unaligned chunks
        lwz		w1,0(rs)
        lwz		w2,4(rs)
        lwz		w3,8(rs)
        lwz		w4,12(rs)
        addi	rs,rs,16
        stw		w1,0(rd)
        stw		w2,4(rd)
        stw		w3,8(rd)
        stw		w4,12(rd)
        addi	rd,rd,16
        bdnz	3b
        
        b		LShort16


// Vector loops.  First, we must 32-byte align the destination.
//		w1 = (rd-rs), used to check for reverse and alignment
//		w4 = #bytes to 32-byte align destination
//		rc = long enough for at least one vector loop

LFwdLong:
        cmpwi	w4,0				// dest already aligned?
        sub		rc,rc,w4			// adjust length
        mtcrf	0x01,w4				// cr7 <- #bytes to align dest
        rlwinm	w2,w1,0,0xF			// relatively 16-byte aligned?
        mtcrf	0x02,w4				// finish moving #bytes to align to cr6 and cr7
        srwi	r0,rc,6				// get # 64-byte chunks to xfer (>=1)
        cmpwi	cr5,w2,0			// set cr5 beq if relatively 16-byte aligned
        beq		LFwdAligned			// dest is already aligned
        
// 32-byte align destination.

        bf		31,1f				// byte to move?
        lbz		w1,0(rs)
        addi	rs,rs,1
        stb		w1,0(rd)
        addi	rd,rd,1
1:
        bf		30,2f				// halfword?
        lhz		w1,0(rs)
        addi	rs,rs,2
        sth		w1,0(rd)
        addi	rd,rd,2
2:
        bf		29,3f				// word?
        lwz		w1,0(rs)
        addi	rs,rs,4
        stw		w1,0(rd)
        addi	rd,rd,4
3:
        bf		28,4f				// doubleword?
        lwz		w1,0(rs)
        lwz		w2,4(rs)
        addi	rs,rs,8
        stw		w1,0(rd)
        stw		w2,4(rd)
        addi	rd,rd,8
4:	
        bf		27,LFwdAligned		// quadword?
        lwz		w1,0(rs)
        lwz		w2,4(rs)
        lwz		w3,8(rs)
        lwz		w4,12(rs)
        addi	rs,rs,16
        stw		w1,0(rd)
        stw		w2,4(rd)
        stw		w3,8(rd)
        stw		w4,12(rd)
        addi	rd,rd,16


// Destination is 32-byte aligned.
//		r0 = count of 64-byte chunks to move (not 0)
//		rd = 32-byte aligned
//		rc = bytes remaining
//	   cr5 = beq if source is 16-byte aligned
// We set up many registers:
//	   ctr = number of 64-byte chunks to move
//	r0/cr0 = leftover QWs to move
//	   cr7 = low 4 bits of rc (ie, leftover byte count 0-15)
//	   cr6 = beq if leftover byte count is 0
//		rv = original value of vrsave
// c16 etc = loaded

LFwdAligned:
        mfspr	rv,vrsave			// get bitmap of live vector registers
        mtcrf	0x01,rc				// move leftover count to cr7 for LShort16
        rlwinm	w3,rc,0,28,31		// move last 0-15 byte count to w3
        mtctr	r0					// set up loop count
        cmpwi	cr6,w3,0			// set cr6 on leftover byte count
        oris	w1,rv,0xFF00		// we use v0-v7
        rlwinm.	r0,rc,28,30,31		// get number of quadword leftovers (0-3) and set cr0
        mtspr	vrsave,w1			// update mask
        li		c16,16				// get constants used in ldvx/stvx
        li		c32,32
        li		c48,48
        li		c96,96
        li		c128,128
        bne		cr5,LForwardVecUnal	// handle unaligned operands
        b		1f

        .align	4
1:        							// loop over 64-byte chunks
        dcbt	c96,rs
        dcbt	c128,rs
        lvx		v1,0,rs
        lvx		v2,c16,rs
        lvx		v3,c32,rs
        lvx		v4,c48,rs
        addi	rs,rs,64
        dcba	0,rd				// patched to NOP on some machines
        stvx	v1,0,rd
        stvx	v2,c16,rd
        dcba	c32,rd				// patched to NOP on some machines
        stvx	v3,c32,rd
        stvx	v4,c48,rd
        addi	rd,rd,64
        bdnz	1b
                
        beq		4f					// no leftover quadwords
        mtctr	r0
3:									// loop over remaining quadwords (1-3)
        lvx		v1,0,rs
        addi	rs,rs,16
        stvx	v1,0,rd
        addi	rd,rd,16
        bdnz	3b
4:
        mtspr	vrsave,rv			// restore bitmap of live vr's
        bne		cr6,LShort16		// handle last 0-15 bytes if any
        blr
        

// Long, forward, unaligned vector loop.

LForwardVecUnal:
        lvsl	vp,0,rs				// get permute vector to shift left
        lvx		v1,0,rs				// prefetch 1st source quadword
        b		1f

        .align	4					// align inner loops
1:									// loop over 64-byte chunks
        lvx		v2,c16,rs
        dcbt	c96,rs
        lvx		v3,c32,rs
        dcbt	c128,rs
        lvx		v4,c48,rs
        addi	rs,rs,64
        vperm	vw,v1,v2,vp
        lvx		v1,0,rs
        vperm	vx,v2,v3,vp
        dcba	0,rd				// patched to NOP on some machines
        stvx	vw,0,rd
        vperm	vy,v3,v4,vp
        stvx	vx,c16,rd
        vperm	vw,v4,v1,vp
        dcba	c32,rd				// patched to NOP on some machines
        stvx	vy,c32,rd
        stvx	vw,c48,rd
        addi	rd,rd,64
        bdnz	1b

        beq-	4f					// no leftover quadwords
        mtctr	r0
3:									// loop over remaining quadwords
        lvx		v2,c16,rs
        addi	rs,rs,16
        vperm	vx,v1,v2,vp
        vor		v1,v2,v2			// v1 <- v2
        stvx	vx,0,rd
        addi	rd,rd,16
        bdnz	3b
4:
        mtspr	vrsave,rv			// restore bitmap of live vr's
        bne		cr6,LShort16		// handle last 0-15 bytes if any
        blr
        

// Medium and long, reverse moves.  We use altivec if the operands are long enough,
// else a lwz/stx loop.
//		w1 = (rd-rs), used to check for reverse and alignment
//	   cr7 = bge if long

LMediumReverse:
        add		rd,rd,rc			// point to end of operands
        add		rs,rs,rc
        andi.	w4,rd,0x1F			// w4 <- #bytes to 32-byte align destination
        rlwinm	w6,rd,0,0x3			// w6 <- #bytes to 4-byte align destination
        bge		cr7,LLongReverse	// long enough for vectors

// Scalar loop.
//	    w6 = #bytes to 4-byte align destination

        sub		rc,rc,w6			// decrement length remaining
        mtxer	w6					// set up count for move
        sub		rs,rs,w6			// back up ptrs
        sub		rd,rd,w6
        srwi	r0,rc,4				// get # 16-byte chunks (>=1)
        mtcrf	0x01,rc				// set remaining byte count here for LShortReverse16
        lswx	w1,0,rs				// move w6 bytes to align destination
        stswx	w1,0,rd
        mtctr	r0					// set up 16-byte loop
        b		1f
        
        .align	4
1:									// loop over 16-byte  aligned chunks
        lwz		w1,-4(rs)
        lwz		w2,-8(rs)
        lwz		w3,-12(rs)
        lwzu	w4,-16(rs)
        stw		w1,-4(rd)
        stw		w2,-8(rd)
        stw		w3,-12(rd)
        stwu	w4,-16(rd)
        bdnz	1b
        
        b		LShortReverse16
        

// Reverse vector loops.  First, we must 32-byte align the destination.
//		w1 = (rd-rs), used to check for reverse and alignment
//	w4/cr0 = #bytes to 32-byte align destination
//		rc = long enough for at least one vector loop

LLongReverse:
        sub		rc,rc,w4			// adjust length
        mtcrf	0x01,w4				// cr7 <- #bytes to align dest
        rlwinm	w2,w1,0,0xF			// relatively 16-byte aligned?
        mtcrf	0x02,w4				// finish moving #bytes to align to cr6 and cr7
        srwi	r0,rc,6				// get # 64-byte chunks to xfer (>=1)
        cmpwi	cr5,w2,0			// set cr5 beq if relatively 16-byte aligned
        beq		LReverseAligned		// dest is already aligned
        
// 32-byte align destination.

        bf		31,1f				// byte to move?
        lbzu 	w1,-1(rs)
        stbu 	w1,-1(rd)
1:
        bf		30,2f				// halfword?
        lhzu 	w1,-2(rs)
        sthu 	w1,-2(rd)
2:
        bf		29,3f				// word?
        lwzu 	w1,-4(rs)
        stwu 	w1,-4(rd)
3:
        bf		28,4f				// doubleword?
        lwz		w1,-4(rs)
        lwzu	w2,-8(rs)
        stw		w1,-4(rd)
        stwu	w2,-8(rd)
4:	
        bf		27,LReverseAligned	// quadword?
        lwz		w1,-4(rs)
        lwz		w2,-8(rs)
        lwz		w3,-12(rs)
        lwzu	w4,-16(rs)
        stw		w1,-4(rd)
        stw		w2,-8(rd)
        stw		w3,-12(rd)
        stwu	w4,-16(rd)

// Destination is 32-byte aligned.
//		r0 = count of 64-byte chunks to move (not 0)
//		rd = 32-byte aligned
//		rc = bytes remaining
//	   cr5 = beq if source is 16-byte aligned
// We set up many registers:
//	   ctr = number of 64-byte chunks to move
//	r0/cr0 = leftover QWs to move
//	   cr7 = low 4 bits of rc (ie, leftover byte count 0-15)
//	   cr6 = beq if leftover byte count is 0
//		rv = original value of vrsave
// cm1 etc = loaded
        
LReverseAligned:
        mfspr	rv,vrsave			// get bitmap of live vector registers
        mtcrf	0x01,rc				// move leftover count to cr7 for LShort16
        rlwinm	w3,rc,0,28,31		// move last 0-15 byte count to w3
        mtctr	r0					// set up loop count
        cmpwi	cr6,w3,0			// set cr6 on leftover byte count
        oris	w1,rv,0xFF00		// we use v0-v7
        rlwinm.	r0,rc,28,30,31		// get number of quadword leftovers (0-3) and set cr0
        mtspr	vrsave,w1			// update mask
        li		cm1,-1				// get constants used in ldvx/stvx
        li		cm17,-17
        li		cm33,-33
        li		cm49,-49
        li		cm97,-97
        li		cm129,-129        
        bne		cr5,LReverseVecUnal	// handle unaligned operands
        b		1f
      
        .align	4					// align inner loops
1:        							// loop over 64-byte chunks
        dcbt	cm97,rs
        dcbt	cm129,rs
        lvx		v1,cm1,rs
        lvx		v2,cm17,rs
        lvx		v3,cm33,rs
        lvx		v4,cm49,rs
        subi	rs,rs,64
        stvx	v1,cm1,rd
        stvx	v2,cm17,rd
        stvx	v3,cm33,rd
        stvx	v4,cm49,rd
        subi	rd,rd,64
        bdnz	1b

        beq		4f					// no leftover quadwords
        mtctr	r0
3:									// loop over remaining quadwords (1-7)
        lvx		v1,cm1,rs
        subi	rs,rs,16
        stvx	v1,cm1,rd
        subi	rd,rd,16
        bdnz	3b
4:
        mtspr	vrsave,rv			// restore bitmap of live vr's
        bne		cr6,LShortReverse16	// handle last 0-15 bytes if any
        blr


// Long, reverse, unaligned vector loop.

LReverseVecUnal:
        lvsl	vp,0,rs				// get permute vector to shift left
        lvx		v1,cm1,rs			// v1 always looks ahead
        b		1f
        
        .align	4					// align the inner loops
1:									// loop over 64-byte chunks
        lvx		v2,cm17,rs
        dcbt	cm97,rs
        lvx		v3,cm33,rs
        dcbt	cm129,rs
        lvx		v4,cm49,rs
        subi	rs,rs,64
        vperm	vw,v2,v1,vp
        lvx		v1,cm1,rs
        vperm	vx,v3,v2,vp
        stvx	vw,cm1,rd
        vperm	vy,v4,v3,vp
        stvx	vx,cm17,rd
        vperm	vw,v1,v4,vp
        stvx	vy,cm33,rd
        stvx	vw,cm49,rd
        subi	rd,rd,64
        bdnz	1b
        
        beq		3f					// no leftover quadwords
        mtctr	r0
2:									// loop over 1-3 quadwords
        lvx		v2,cm17,rs
        subi	rs,rs,16
        vperm	vx,v2,v1,vp
        vor		v1,v2,v2			// v1 <- v2
        stvx	vx,cm1,rd
        subi	rd,rd,16
        bdnz	2b
3:
        mtspr	vrsave,rv			// restore bitmap of live vr's
        bne		cr6,LShortReverse16	// handle last 0-15 bytes iff any
        blr

	COMMPAGE_DESCRIPTOR(bcopy_g4,_COMM_PAGE_BCOPY,kHasAltivec,k64Bit,kCommPageDCBA+kCommPage32)
Commit	Line	Data
55e303ae A	1	/*
	2	* Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
e5568f75 A	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
55e303ae	11	*
e5568f75 A	12	* This Original Code and all software distributed under the License are
e5568f75 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
55e303ae A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
55e303ae A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
e5568f75 A	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
55e303ae A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/* =======================================
	23	* BCOPY, MEMCPY, and MEMMOVE for Mac OS X
	24	* =======================================
	25	*
	26	* Version of 2/20/2003, tuned for G4. The inner loops use DCBA to avoid
	27	* reading destination cache lines. Only the 7450 actually benefits from
	28	* this, and then only in the cold-cache case. On 7400s and 7455s, we
	29	* patch the DCBAs into NOPs.
	30	*
	31	* Register usage. Note we use R2, so this code will not run in a PEF/CFM
	32	* environment. Note also the rather delicate way we assign multiple uses
	33	* to the same register. Beware.
	34	*
	35	* r0 = "w7" or temp (NB: cannot use r0 for any constant such as "c16")
	36	* r2 = "w8" or vrsave ("rv")
	37	* r3 = not used, as memcpy and memmove return 1st parameter as a value
	38	* r4 = source ptr ("rs")
	39	* r5 = count of bytes to move ("rc")
	40	* r6 = "w1", "c16", or "cm17"
	41	* r7 = "w2", "c32", or "cm33"
	42	* r8 = "w3", "c48", or "cm49"
	43	* r9 = "w4", or "cm1"
	44	* r10 = "w5", "c96", or "cm97"
	45	* r11 = "w6", "c128", or "cm129"
	46	* r12 = destination ptr ("rd")
	47	* v0 = permute vector ("vp")
	48	* v1-v4 = qw's loaded from source
	49	* v5-v7 = permuted qw's ("vw", "vx", "vy")
	50	*/
	51	#define rs r4
	52	#define rd r12
	53	#define rc r5
	54	#define rv r2
	55
	56	#define w1 r6
	57	#define w2 r7
	58	#define w3 r8
	59	#define w4 r9
	60	#define w5 r10
	61	#define w6 r11
	62	#define w7 r0
	63	#define w8 r2
	64
	65	#define c16 r6
	66	#define cm17 r6
	67	#define c32 r7
	68	#define cm33 r7
	69	#define c48 r8
	70	#define cm49 r8
	71	#define cm1 r9
	72	#define c96 r10
	73	#define cm97 r10
	74	#define c128 r11
	75	#define cm129 r11
	76
	77	#define vp v0
	78	#define vw v5
	79	#define vx v6
	80	#define vy v7
	81
	82	#define ASSEMBLER
83	#include <sys/appleapiopts.h>
84	#include <ppc/asm.h>
85	#include <machine/cpu_capabilities.h>
86	#include <machine/commpage.h>
87
88	.text
55e303ae A	89
	90	#define kMedium 32 // too long for inline loopless code
	91	#define kLong 96 // long enough to justify use of Altivec
	92
	93
	94	// Main entry points.
	95
	96	.align 5
	97	bcopy_g4: // void bcopy(const void src, void dst, size_t len)
	98	cmplwi rc,kMedium // short or long?
	99	sub w1,r4,r3 // must move in reverse if (rd-rs)<rc
	100	cmplw cr1,w1,rc // set cr1 blt iff we must move reverse
	101	mr rd,r4 // start to move registers to canonic spot
	102	mr rs,r3
	103	blt+ LShort // handle short operands
	104	dcbt 0,r3 // touch in destination
	105	b LMedium // join medium/long operand code
	106
	107	// NB: memmove() must be 8 words past bcopy(), to agree with comm page addresses.
	108
	109	.align 5
	110	Lmemcpy_g4: // void* memcpy(void dst, void src, size_t len)
	111	Lmemmove_g4: // void* memmove(void dst, const void src, size_t len)
	112	cmplwi rc,kMedium // short or long?
	113	sub w1,r3,r4 // must move in reverse if (rd-rs)<rc
	114	dcbt 0,r4 // touch in the first line of source
	115	cmplw cr1,w1,rc // set cr1 blt iff we must move reverse
	116	mr rd,r3 // must leave r3 alone, it is return value for memcpy etc
	117	bge- LMedium // handle medium or long operands
	118
	119	// Handle short operands.
	120
	121	LShort:
	122	andi. r0,rc,0x10 // test bit 27 separately (faster on G4)
	123	mtcrf 0x01,rc // put length bits 28-31 in cr7
	124	blt- cr1,LShortReverse
	125
	126	// Forward short operands. This is the most frequent case, so it is inline.
	127
	128	beq LShort16 // quadword to move?
	129	lwz w1,0(rs)
	130	lwz w2,4(rs)
	131	lwz w3,8(rs)
	132	lwz w4,12(rs)
	133	addi rs,rs,16
	134	stw w1,0(rd)
	135	stw w2,4(rd)
	136	stw w3,8(rd)
	137	stw w4,12(rd)
	138	addi rd,rd,16
	139	LShort16: // join here to xfer 0-15 bytes
	140	bf 28,2f // doubleword?
	141	lwz w1,0(rs)
	142	lwz w2,4(rs)
	143	addi rs,rs,8
	144	stw w1,0(rd)
	145	stw w2,4(rd)
	146	addi rd,rd,8
	147	2:
	148	bf 29,3f // word?
	149	lwz w1,0(rs)
	150	addi rs,rs,4
	151	stw w1,0(rd)
	152	addi rd,rd,4
153	3:
154	bf 30,4f // halfword to move?
155	lhz w1,0(rs)
156	addi rs,rs,2
157	sth w1,0(rd)
158	addi rd,rd,2
159	4:
160	bflr 31 // skip if no odd byte
161	lbz w1,0(rs)
162	stb w1,0(rd)
163	blr
164
165
166	// Handle short reverse operands.
167	// cr0 = bne if bit 27 of length is set
168	// cr7 = bits 28-31 of length
169
170	LShortReverse:
171	add rs,rs,rc // adjust ptrs for reverse move
172	add rd,rd,rc
173	beq LShortReverse16 // quadword to move?
174	lwz w1,-4(rs)
175	lwz w2,-8(rs)
176	lwz w3,-12(rs)
177	lwzu w4,-16(rs)
178	stw w1,-4(rd)
179	stw w2,-8(rd)
180	stw w3,-12(rd)
181	stwu w4,-16(rd)
182	LShortReverse16: // join here to xfer 0-15 bytes and return
183	bf 28,2f // doubleword?
184	lwz w1,-4(rs)
185	lwzu w2,-8(rs)
186	stw w1,-4(rd)
187	stwu w2,-8(rd)
188	2:
189	bf 29,3f // word?
190	lwzu w1,-4(rs)
191	stwu w1,-4(rd)
192	3:
193	bf 30,4f // halfword to move?
194	lhzu w1,-2(rs)
195	sthu w1,-2(rd)
196	4:
197	bflr 31 // done if no odd byte
198	lbz w1,-1(rs) // no update
199	stb w1,-1(rd)
200	blr
201
202
203	// Medium and long operands. Use Altivec if long enough, else scalar loops.
204	// w1 = (rd-rs), used to check for alignment
205	// cr1 = blt iff we must move reverse
206
207	.align 4
208	LMedium:
209	dcbtst 0,rd // touch in destination
210	cmplwi cr7,rc,kLong // long enough for vectors?
211	neg w3,rd // start to compute #bytes to align destination
212	rlwinm r0,w1,0,0x7 // check relative 8-byte alignment
213	andi. w6,w3,7 // w6 <- #bytes to 8-byte align destination
214	blt cr1,LMediumReverse // handle reverse moves
215	rlwinm w4,w3,0,0x1F // w4 <- #bytes to 32-byte align destination
216	cmpwi cr6,r0,0 // set cr6 beq if relatively aligned
217	bge cr7,LFwdLong // long enough for vectors
218
219	// Medium length: use scalar loops.
220	// w6/cr0 = #bytes to 8-byte align destination
221	// cr6 = beq if relatively doubleword aligned
222
223	sub rc,rc,w6 // decrement length remaining
224	beq 1f // skip if dest already doubleword aligned
225	mtxer w6 // set up count for move
226	lswx w1,0,rs // move w6 bytes to align destination
227	stswx w1,0,rd
228	add rs,rs,w6 // bump ptrs past
229	add rd,rd,w6
230	1:
231	srwi r0,rc,4 // get # 16-byte chunks (>=1)
232	mtcrf 0x01,rc // save remaining byte count here for LShort16
233	mtctr r0 // set up 16-byte loop
234	bne cr6,3f // source not 4-byte aligned
235	b 2f
236
237	.align 4
238	2: // loop over 16-byte aligned chunks
239	lfd f0,0(rs)
240	lfd f1,8(rs)
241	addi rs,rs,16
242	stfd f0,0(rd)
243	stfd f1,8(rd)
244	addi rd,rd,16
245	bdnz 2b
246
247	b LShort16
248
249	.align 4
250	3: // loop over 16-byte unaligned chunks
251	lwz w1,0(rs)
252	lwz w2,4(rs)
253	lwz w3,8(rs)
254	lwz w4,12(rs)
255	addi rs,rs,16
256	stw w1,0(rd)
257	stw w2,4(rd)
258	stw w3,8(rd)
259	stw w4,12(rd)
260	addi rd,rd,16
261	bdnz 3b
262
263	b LShort16
264
265
266	// Vector loops. First, we must 32-byte align the destination.
267	// w1 = (rd-rs), used to check for reverse and alignment
268	// w4 = #bytes to 32-byte align destination
269	// rc = long enough for at least one vector loop
270
271	LFwdLong:
272	cmpwi w4,0 // dest already aligned?
273	sub rc,rc,w4 // adjust length
274	mtcrf 0x01,w4 // cr7 <- #bytes to align dest
275	rlwinm w2,w1,0,0xF // relatively 16-byte aligned?
276	mtcrf 0x02,w4 // finish moving #bytes to align to cr6 and cr7
277	srwi r0,rc,6 // get # 64-byte chunks to xfer (>=1)
278	cmpwi cr5,w2,0 // set cr5 beq if relatively 16-byte aligned
279	beq LFwdAligned // dest is already aligned
280
281	// 32-byte align destination.
282
283	bf 31,1f // byte to move?
284	lbz w1,0(rs)
285	addi rs,rs,1
286	stb w1,0(rd)
287	addi rd,rd,1
288	1:
289	bf 30,2f // halfword?
290	lhz w1,0(rs)
291	addi rs,rs,2
292	sth w1,0(rd)
293	addi rd,rd,2
294	2:
295	bf 29,3f // word?
296	lwz w1,0(rs)
297	addi rs,rs,4
298	stw w1,0(rd)
299	addi rd,rd,4
300	3:
301	bf 28,4f // doubleword?
302	lwz w1,0(rs)
303	lwz w2,4(rs)
304	addi rs,rs,8
305	stw w1,0(rd)
306	stw w2,4(rd)
307	addi rd,rd,8
308	4:
309	bf 27,LFwdAligned // quadword?
310	lwz w1,0(rs)
311	lwz w2,4(rs)
312	lwz w3,8(rs)
313	lwz w4,12(rs)
314	addi rs,rs,16
315	stw w1,0(rd)
316	stw w2,4(rd)
317	stw w3,8(rd)
318	stw w4,12(rd)
319	addi rd,rd,16
320
321
322	// Destination is 32-byte aligned.
323	// r0 = count of 64-byte chunks to move (not 0)
324	// rd = 32-byte aligned
325	// rc = bytes remaining
326	// cr5 = beq if source is 16-byte aligned
327	// We set up many registers:
328	// ctr = number of 64-byte chunks to move
329	// r0/cr0 = leftover QWs to move
330	// cr7 = low 4 bits of rc (ie, leftover byte count 0-15)
331	// cr6 = beq if leftover byte count is 0
332	// rv = original value of vrsave
333	// c16 etc = loaded
334
335	LFwdAligned:
336	mfspr rv,vrsave // get bitmap of live vector registers
337	mtcrf 0x01,rc // move leftover count to cr7 for LShort16
338	rlwinm w3,rc,0,28,31 // move last 0-15 byte count to w3
339	mtctr r0 // set up loop count
340	cmpwi cr6,w3,0 // set cr6 on leftover byte count
341	oris w1,rv,0xFF00 // we use v0-v7
342	rlwinm. r0,rc,28,30,31 // get number of quadword leftovers (0-3) and set cr0
343	mtspr vrsave,w1 // update mask
344	li c16,16 // get constants used in ldvx/stvx
345	li c32,32
346	li c48,48
347	li c96,96
348	li c128,128
349	bne cr5,LForwardVecUnal // handle unaligned operands
350	b 1f
351
352	.align 4
353	1: // loop over 64-byte chunks
354	dcbt c96,rs
355	dcbt c128,rs
356	lvx v1,0,rs
357	lvx v2,c16,rs
358	lvx v3,c32,rs
359	lvx v4,c48,rs
360	addi rs,rs,64
361	dcba 0,rd // patched to NOP on some machines
362	stvx v1,0,rd
363	stvx v2,c16,rd
364	dcba c32,rd // patched to NOP on some machines
365	stvx v3,c32,rd
366	stvx v4,c48,rd
367	addi rd,rd,64
368	bdnz 1b
369
370	beq 4f // no leftover quadwords
371	mtctr r0
372	3: // loop over remaining quadwords (1-3)
373	lvx v1,0,rs
374	addi rs,rs,16
375	stvx v1,0,rd
376	addi rd,rd,16
377	bdnz 3b
378	4:
379	mtspr vrsave,rv // restore bitmap of live vr's
380	bne cr6,LShort16 // handle last 0-15 bytes if any
381	blr
382
383
384	// Long, forward, unaligned vector loop.
385
386	LForwardVecUnal:
387	lvsl vp,0,rs // get permute vector to shift left
388	lvx v1,0,rs // prefetch 1st source quadword
389	b 1f
390
391	.align 4 // align inner loops
392	1: // loop over 64-byte chunks
393	lvx v2,c16,rs
394	dcbt c96,rs
395	lvx v3,c32,rs
396	dcbt c128,rs
397	lvx v4,c48,rs
398	addi rs,rs,64
399	vperm vw,v1,v2,vp
400	lvx v1,0,rs
401	vperm vx,v2,v3,vp
402	dcba 0,rd // patched to NOP on some machines
403	stvx vw,0,rd
404	vperm vy,v3,v4,vp
405	stvx vx,c16,rd
406	vperm vw,v4,v1,vp
407	dcba c32,rd // patched to NOP on some machines
408	stvx vy,c32,rd
409	stvx vw,c48,rd
410	addi rd,rd,64
411	bdnz 1b
412
413	beq- 4f // no leftover quadwords
414	mtctr r0
415	3: // loop over remaining quadwords
416	lvx v2,c16,rs
417	addi rs,rs,16
418	vperm vx,v1,v2,vp
419	vor v1,v2,v2 // v1 <- v2
420	stvx vx,0,rd
421	addi rd,rd,16
422	bdnz 3b
423	4:
424	mtspr vrsave,rv // restore bitmap of live vr's
425	bne cr6,LShort16 // handle last 0-15 bytes if any
426	blr
427
428
429	// Medium and long, reverse moves. We use altivec if the operands are long enough,
430	// else a lwz/stx loop.
431	// w1 = (rd-rs), used to check for reverse and alignment
432	// cr7 = bge if long
433
434	LMediumReverse:
435	add rd,rd,rc // point to end of operands
436	add rs,rs,rc
437	andi. w4,rd,0x1F // w4 <- #bytes to 32-byte align destination
438	rlwinm w6,rd,0,0x3 // w6 <- #bytes to 4-byte align destination
439	bge cr7,LLongReverse // long enough for vectors
440
441	// Scalar loop.
442	// w6 = #bytes to 4-byte align destination
443
444	sub rc,rc,w6 // decrement length remaining
445	mtxer w6 // set up count for move
446	sub rs,rs,w6 // back up ptrs
447	sub rd,rd,w6
448	srwi r0,rc,4 // get # 16-byte chunks (>=1)
449	mtcrf 0x01,rc // set remaining byte count here for LShortReverse16
450	lswx w1,0,rs // move w6 bytes to align destination
451	stswx w1,0,rd
452	mtctr r0 // set up 16-byte loop
453	b 1f
454
455	.align 4
456	1: // loop over 16-byte aligned chunks
457	lwz w1,-4(rs)
458	lwz w2,-8(rs)
459	lwz w3,-12(rs)
460	lwzu w4,-16(rs)
461	stw w1,-4(rd)
462	stw w2,-8(rd)
463	stw w3,-12(rd)
464	stwu w4,-16(rd)
465	bdnz 1b
466
467	b LShortReverse16
468
469
470	// Reverse vector loops. First, we must 32-byte align the destination.
471	// w1 = (rd-rs), used to check for reverse and alignment
472	// w4/cr0 = #bytes to 32-byte align destination
473	// rc = long enough for at least one vector loop
474
475	LLongReverse:
476	sub rc,rc,w4 // adjust length
477	mtcrf 0x01,w4 // cr7 <- #bytes to align dest
478	rlwinm w2,w1,0,0xF // relatively 16-byte aligned?
479	mtcrf 0x02,w4 // finish moving #bytes to align to cr6 and cr7
480	srwi r0,rc,6 // get # 64-byte chunks to xfer (>=1)
481	cmpwi cr5,w2,0 // set cr5 beq if relatively 16-byte aligned
482	beq LReverseAligned // dest is already aligned
483
484	// 32-byte align destination.
485
486	bf 31,1f // byte to move?
487	lbzu w1,-1(rs)
488	stbu w1,-1(rd)
489	1:
490	bf 30,2f // halfword?
491	lhzu w1,-2(rs)
492	sthu w1,-2(rd)
493	2:
494	bf 29,3f // word?
495	lwzu w1,-4(rs)
496	stwu w1,-4(rd)
497	3:
498	bf 28,4f // doubleword?
499	lwz w1,-4(rs)
500	lwzu w2,-8(rs)
501	stw w1,-4(rd)
502	stwu w2,-8(rd)
503	4:
504	bf 27,LReverseAligned // quadword?
505	lwz w1,-4(rs)
506	lwz w2,-8(rs)
507	lwz w3,-12(rs)
508	lwzu w4,-16(rs)
509	stw w1,-4(rd)
510	stw w2,-8(rd)
511	stw w3,-12(rd)
512	stwu w4,-16(rd)
513
514	// Destination is 32-byte aligned.
515	// r0 = count of 64-byte chunks to move (not 0)
516	// rd = 32-byte aligned
517	// rc = bytes remaining
518	// cr5 = beq if source is 16-byte aligned
519	// We set up many registers:
520	// ctr = number of 64-byte chunks to move
521	// r0/cr0 = leftover QWs to move
522	// cr7 = low 4 bits of rc (ie, leftover byte count 0-15)
523	// cr6 = beq if leftover byte count is 0
524	// rv = original value of vrsave
525	// cm1 etc = loaded
526
527	LReverseAligned:
528	mfspr rv,vrsave // get bitmap of live vector registers
529	mtcrf 0x01,rc // move leftover count to cr7 for LShort16
530	rlwinm w3,rc,0,28,31 // move last 0-15 byte count to w3
531	mtctr r0 // set up loop count
532	cmpwi cr6,w3,0 // set cr6 on leftover byte count
533	oris w1,rv,0xFF00 // we use v0-v7
534	rlwinm. r0,rc,28,30,31 // get number of quadword leftovers (0-3) and set cr0
535	mtspr vrsave,w1 // update mask
536	li cm1,-1 // get constants used in ldvx/stvx
537	li cm17,-17
538	li cm33,-33
539	li cm49,-49
540	li cm97,-97
541	li cm129,-129
542	bne cr5,LReverseVecUnal // handle unaligned operands
543	b 1f
544
545	.align 4 // align inner loops
546	1: // loop over 64-byte chunks
547	dcbt cm97,rs
548	dcbt cm129,rs
549	lvx v1,cm1,rs
550	lvx v2,cm17,rs
551	lvx v3,cm33,rs
552	lvx v4,cm49,rs
553	subi rs,rs,64
554	stvx v1,cm1,rd
555	stvx v2,cm17,rd
556	stvx v3,cm33,rd
557	stvx v4,cm49,rd
558	subi rd,rd,64
559	bdnz 1b
560
561	beq 4f // no leftover quadwords
562	mtctr r0
563	3: // loop over remaining quadwords (1-7)
564	lvx v1,cm1,rs
565	subi rs,rs,16
566	stvx v1,cm1,rd
567	subi rd,rd,16
568	bdnz 3b
569	4:
570	mtspr vrsave,rv // restore bitmap of live vr's
571	bne cr6,LShortReverse16 // handle last 0-15 bytes if any
572	blr
573
574
575	// Long, reverse, unaligned vector loop.
576
577	LReverseVecUnal:
578	lvsl vp,0,rs // get permute vector to shift left
579	lvx v1,cm1,rs // v1 always looks ahead
580	b 1f
581
582	.align 4 // align the inner loops
583	1: // loop over 64-byte chunks
584	lvx v2,cm17,rs
585	dcbt cm97,rs
586	lvx v3,cm33,rs
587	dcbt cm129,rs
588	lvx v4,cm49,rs
589	subi rs,rs,64
590	vperm vw,v2,v1,vp
591	lvx v1,cm1,rs
592	vperm vx,v3,v2,vp
593	stvx vw,cm1,rd
594	vperm vy,v4,v3,vp
595	stvx vx,cm17,rd
596	vperm vw,v1,v4,vp
597	stvx vy,cm33,rd
598	stvx vw,cm49,rd
599	subi rd,rd,64
600	bdnz 1b
601
602	beq 3f // no leftover quadwords
603	mtctr r0
604	2: // loop over 1-3 quadwords
605	lvx v2,cm17,rs
606	subi rs,rs,16
607	vperm vx,v2,v1,vp
608	vor v1,v2,v2 // v1 <- v2
609	stvx vx,cm1,rd
610	subi rd,rd,16
611	bdnz 2b
612	3:
613	mtspr vrsave,rv // restore bitmap of live vr's
614	bne cr6,LShortReverse16 // handle last 0-15 bytes iff any
615	blr
616
91447636	617	COMMPAGE_DESCRIPTOR(bcopy_g4,_COMM_PAGE_BCOPY,kHasAltivec,k64Bit,kCommPageDCBA+kCommPage32)