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linux/arch/hexagon/lib/memcpy.S

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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
*/
/*
* Description
*
* library function for memcpy where length bytes are copied from
* ptr_in to ptr_out. ptr_out is returned unchanged.
* Allows any combination of alignment on input and output pointers
* and length from 0 to 2^32-1
*
* Restrictions
* The arrays should not overlap, the program will produce undefined output
* if they do.
* For blocks less than 16 bytes a byte by byte copy is performed. For
* 8byte alignments, and length multiples, a dword copy is performed up to
* 96bytes
* History
*
* DJH 5/15/09 Initial version 1.0
* DJH 6/ 1/09 Version 1.1 modified ABI to inlcude R16-R19
* DJH 7/12/09 Version 1.2 optimized codesize down to 760 was 840
* DJH 10/14/09 Version 1.3 added special loop for aligned case, was
* overreading bloated codesize back up to 892
* DJH 4/20/10 Version 1.4 fixed Ldword_loop_epilog loop to prevent loads
* occurring if only 1 left outstanding, fixes bug
* # 3888, corrected for all alignments. Peeled off
* 1 32byte chunk from kernel loop and extended 8byte
* loop at end to solve all combinations and prevent
* over read. Fixed Ldword_loop_prolog to prevent
* overread for blocks less than 48bytes. Reduced
* codesize to 752 bytes
* DJH 4/21/10 version 1.5 1.4 fix broke code for input block ends not
* aligned to dword boundaries,underwriting by 1
* byte, added detection for this and fixed. A
* little bloat.
* DJH 4/23/10 version 1.6 corrected stack error, R20 was not being restored
* always, fixed the error of R20 being modified
* before it was being saved
* Natural c model
* ===============
* void * memcpy(char * ptr_out, char * ptr_in, int length) {
* int i;
* if(length) for(i=0; i < length; i++) { ptr_out[i] = ptr_in[i]; }
* return(ptr_out);
* }
*
* Optimized memcpy function
* =========================
* void * memcpy(char * ptr_out, char * ptr_in, int len) {
* int i, prolog, kernel, epilog, mask;
* u8 offset;
* s64 data0, dataF8, data70;
*
* s64 * ptr8_in;
* s64 * ptr8_out;
* s32 * ptr4;
* s16 * ptr2;
*
* offset = ((int) ptr_in) & 7;
* ptr8_in = (s64 *) &ptr_in[-offset]; //read in the aligned pointers
*
* data70 = *ptr8_in++;
* dataF8 = *ptr8_in++;
*
* data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
*
* prolog = 32 - ((int) ptr_out);
* mask = 0x7fffffff >> HEXAGON_R_cl0_R(len);
* prolog = prolog & mask;
* kernel = len - prolog;
* epilog = kernel & 0x1F;
* kernel = kernel>>5;
*
* if (prolog & 1) { ptr_out[0] = (u8) data0; data0 >>= 8; ptr_out += 1;}
* ptr2 = (s16 *) &ptr_out[0];
* if (prolog & 2) { ptr2[0] = (u16) data0; data0 >>= 16; ptr_out += 2;}
* ptr4 = (s32 *) &ptr_out[0];
* if (prolog & 4) { ptr4[0] = (u32) data0; data0 >>= 32; ptr_out += 4;}
*
* offset = offset + (prolog & 7);
* if (offset >= 8) {
* data70 = dataF8;
* dataF8 = *ptr8_in++;
* }
* offset = offset & 0x7;
*
* prolog = prolog >> 3;
* if (prolog) for (i=0; i < prolog; i++) {
* data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
* ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
* data70 = dataF8;
* dataF8 = *ptr8_in++;
* }
* if(kernel) { kernel -= 1; epilog += 32; }
* if(kernel) for(i=0; i < kernel; i++) {
* data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
* ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
* data70 = *ptr8_in++;
*
* data0 = HEXAGON_P_valignb_PPp(data70, dataF8, offset);
* ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
* dataF8 = *ptr8_in++;
*
* data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
* ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
* data70 = *ptr8_in++;
*
* data0 = HEXAGON_P_valignb_PPp(data70, dataF8, offset);
* ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
* dataF8 = *ptr8_in++;
* }
* epilogdws = epilog >> 3;
* if (epilogdws) for (i=0; i < epilogdws; i++) {
* data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
* ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
* data70 = dataF8;
* dataF8 = *ptr8_in++;
* }
* data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
*
* ptr4 = (s32 *) &ptr_out[0];
* if (epilog & 4) { ptr4[0] = (u32) data0; data0 >>= 32; ptr_out += 4;}
* ptr2 = (s16 *) &ptr_out[0];
* if (epilog & 2) { ptr2[0] = (u16) data0; data0 >>= 16; ptr_out += 2;}
* if (epilog & 1) { *ptr_out++ = (u8) data0; }
*
* return(ptr_out - length);
* }
*
* Codesize : 784 bytes
*/
#define ptr_out R0 /* destination pounter */
#define ptr_in R1 /* source pointer */
#define len R2 /* length of copy in bytes */
#define data70 R13:12 /* lo 8 bytes of non-aligned transfer */
#define dataF8 R11:10 /* hi 8 bytes of non-aligned transfer */
#define ldata0 R7:6 /* even 8 bytes chunks */
#define ldata1 R25:24 /* odd 8 bytes chunks */
#define data1 R7 /* lower 8 bytes of ldata1 */
#define data0 R6 /* lower 8 bytes of ldata0 */
#define ifbyte p0 /* if transfer has bytes in epilog/prolog */
#define ifhword p0 /* if transfer has shorts in epilog/prolog */
#define ifword p0 /* if transfer has words in epilog/prolog */
#define noprolog p0 /* no prolog, xfer starts at 32byte */
#define nokernel p1 /* no 32byte multiple block in the transfer */
#define noepilog p0 /* no epilog, xfer ends on 32byte boundary */
#define align p2 /* alignment of input rel to 8byte boundary */
#define kernel1 p0 /* kernel count == 1 */
#define dalign R25 /* rel alignment of input to output data */
#define star3 R16 /* number bytes in prolog - dwords */
#define rest R8 /* length - prolog bytes */
#define back R7 /* nr bytes > dword boundary in src block */
#define epilog R3 /* bytes in epilog */
#define inc R15:14 /* inc kernel by -1 and defetch ptr by 32 */
#define kernel R4 /* number of 32byte chunks in kernel */
#define ptr_in_p_128 R5 /* pointer for prefetch of input data */
#define mask R8 /* mask used to determine prolog size */
#define shift R8 /* used to work a shifter to extract bytes */
#define shift2 R5 /* in epilog to workshifter to extract bytes */
#define prolog R15 /* bytes in prolog */
#define epilogdws R15 /* number dwords in epilog */
#define shiftb R14 /* used to extract bytes */
#define offset R9 /* same as align in reg */
#define ptr_out_p_32 R17 /* pointer to output dczero */
#define align888 R14 /* if simple dword loop can be used */
#define len8 R9 /* number of dwords in length */
#define over R20 /* nr of bytes > last inp buf dword boundary */
#define ptr_in_p_128kernel R5:4 /* packed fetch pointer & kernel cnt */
.section .text
.p2align 4
.global memcpy
.type memcpy, @function
memcpy:
{
p2 = cmp.eq(len, #0); /* =0 */
align888 = or(ptr_in, ptr_out); /* %8 < 97 */
p0 = cmp.gtu(len, #23); /* %1, <24 */
p1 = cmp.eq(ptr_in, ptr_out); /* attempt to overwrite self */
}
{
p1 = or(p2, p1);
p3 = cmp.gtu(len, #95); /* %8 < 97 */
align888 = or(align888, len); /* %8 < 97 */
len8 = lsr(len, #3); /* %8 < 97 */
}
{
dcfetch(ptr_in); /* zero/ptrin=ptrout causes fetch */
p2 = bitsclr(align888, #7); /* %8 < 97 */
if(p1) jumpr r31; /* =0 */
}
{
p2 = and(p2,!p3); /* %8 < 97 */
if (p2.new) len = add(len, #-8); /* %8 < 97 */
if (p2.new) jump:NT .Ldwordaligned; /* %8 < 97 */
}
{
if(!p0) jump .Lbytes23orless; /* %1, <24 */
mask.l = #LO(0x7fffffff);
/* all bytes before line multiples of data */
prolog = sub(#0, ptr_out);
}
{
/* save r31 on stack, decrement sp by 16 */
allocframe(#24);
mask.h = #HI(0x7fffffff);
ptr_in_p_128 = add(ptr_in, #32);
back = cl0(len);
}
{
memd(sp+#0) = R17:16; /* save r16,r17 on stack6 */
r31.l = #LO(.Lmemcpy_return); /* set up final return pointer */
prolog &= lsr(mask, back);
offset = and(ptr_in, #7);
}
{
memd(sp+#8) = R25:24; /* save r25,r24 on stack */
dalign = sub(ptr_out, ptr_in);
r31.h = #HI(.Lmemcpy_return); /* set up final return pointer */
}
{
/* see if there if input buffer end if aligned */
over = add(len, ptr_in);
back = add(len, offset);
memd(sp+#16) = R21:20; /* save r20,r21 on stack */
}
{
noprolog = bitsclr(prolog, #7);
prolog = and(prolog, #31);
dcfetch(ptr_in_p_128);
ptr_in_p_128 = add(ptr_in_p_128, #32);
}
{
kernel = sub(len, prolog);
shift = asl(prolog, #3);
star3 = and(prolog, #7);
ptr_in = and(ptr_in, #-8);
}
{
prolog = lsr(prolog, #3);
epilog = and(kernel, #31);
ptr_out_p_32 = add(ptr_out, prolog);
over = and(over, #7);
}
{
p3 = cmp.gtu(back, #8);
kernel = lsr(kernel, #5);
dcfetch(ptr_in_p_128);
ptr_in_p_128 = add(ptr_in_p_128, #32);
}
{
p1 = cmp.eq(prolog, #0);
if(!p1.new) prolog = add(prolog, #1);
dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
ptr_in_p_128 = add(ptr_in_p_128, #32);
}
{
nokernel = cmp.eq(kernel,#0);
dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
ptr_in_p_128 = add(ptr_in_p_128, #32);
shiftb = and(shift, #8);
}
{
dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
ptr_in_p_128 = add(ptr_in_p_128, #32);
if(nokernel) jump .Lskip64;
p2 = cmp.eq(kernel, #1); /* skip ovr if kernel == 0 */
}
{
dczeroa(ptr_out_p_32);
/* don't advance pointer */
if(!p2) ptr_out_p_32 = add(ptr_out_p_32, #32);
}
{
dalign = and(dalign, #31);
dczeroa(ptr_out_p_32);
}
.Lskip64:
{
data70 = memd(ptr_in++#16);
if(p3) dataF8 = memd(ptr_in+#8);
if(noprolog) jump .Lnoprolog32;
align = offset;
}
/* upto initial 7 bytes */
{
ldata0 = valignb(dataF8, data70, align);
ifbyte = tstbit(shift,#3);
offset = add(offset, star3);
}
{
if(ifbyte) memb(ptr_out++#1) = data0;
ldata0 = lsr(ldata0, shiftb);
shiftb = and(shift, #16);
ifhword = tstbit(shift,#4);
}
{
if(ifhword) memh(ptr_out++#2) = data0;
ldata0 = lsr(ldata0, shiftb);
ifword = tstbit(shift,#5);
p2 = cmp.gtu(offset, #7);
}
{
if(ifword) memw(ptr_out++#4) = data0;
if(p2) data70 = dataF8;
if(p2) dataF8 = memd(ptr_in++#8); /* another 8 bytes */
align = offset;
}
.Lnoprolog32:
{
p3 = sp1loop0(.Ldword_loop_prolog, prolog)
rest = sub(len, star3); /* whats left after the loop */
p0 = cmp.gt(over, #0);
}
if(p0) rest = add(rest, #16);
.Ldword_loop_prolog:
{
if(p3) memd(ptr_out++#8) = ldata0;
ldata0 = valignb(dataF8, data70, align);
p0 = cmp.gt(rest, #16);
}
{
data70 = dataF8;
if(p0) dataF8 = memd(ptr_in++#8);
rest = add(rest, #-8);
}:endloop0
.Lkernel:
{
/* kernel is at least 32bytes */
p3 = cmp.gtu(kernel, #0);
/* last itn. remove edge effects */
if(p3.new) kernel = add(kernel, #-1);
/* dealt with in last dword loop */
if(p3.new) epilog = add(epilog, #32);
}
{
nokernel = cmp.eq(kernel, #0); /* after adjustment, recheck */
if(nokernel.new) jump:NT .Lepilog; /* likely not taken */
inc = combine(#32, #-1);
p3 = cmp.gtu(dalign, #24);
}
{
if(p3) jump .Lodd_alignment;
}
{
loop0(.Loword_loop_25to31, kernel);
kernel1 = cmp.gtu(kernel, #1);
rest = kernel;
}
.falign
.Loword_loop_25to31:
{
dcfetch(ptr_in_p_128); /* prefetch 4 lines ahead */
if(kernel1) ptr_out_p_32 = add(ptr_out_p_32, #32);
}
{
dczeroa(ptr_out_p_32); /* reserve the next 32bytes in cache */
p3 = cmp.eq(kernel, rest);
}
{
/* kernel -= 1 */
ptr_in_p_128kernel = vaddw(ptr_in_p_128kernel, inc);
/* kill write on first iteration */
if(!p3) memd(ptr_out++#8) = ldata1;
ldata1 = valignb(dataF8, data70, align);
data70 = memd(ptr_in++#8);
}
{
memd(ptr_out++#8) = ldata0;
ldata0 = valignb(data70, dataF8, align);
dataF8 = memd(ptr_in++#8);
}
{
memd(ptr_out++#8) = ldata1;
ldata1 = valignb(dataF8, data70, align);
data70 = memd(ptr_in++#8);
}
{
memd(ptr_out++#8) = ldata0;
ldata0 = valignb(data70, dataF8, align);
dataF8 = memd(ptr_in++#8);
kernel1 = cmp.gtu(kernel, #1);
}:endloop0
{
memd(ptr_out++#8) = ldata1;
jump .Lepilog;
}
.Lodd_alignment:
{
loop0(.Loword_loop_00to24, kernel);
kernel1 = cmp.gtu(kernel, #1);
rest = add(kernel, #-1);
}
.falign
.Loword_loop_00to24:
{
dcfetch(ptr_in_p_128); /* prefetch 4 lines ahead */
ptr_in_p_128kernel = vaddw(ptr_in_p_128kernel, inc);
if(kernel1) ptr_out_p_32 = add(ptr_out_p_32, #32);
}
{
dczeroa(ptr_out_p_32); /* reserve the next 32bytes in cache */
}
{
memd(ptr_out++#8) = ldata0;
ldata0 = valignb(dataF8, data70, align);
data70 = memd(ptr_in++#8);
}
{
memd(ptr_out++#8) = ldata0;
ldata0 = valignb(data70, dataF8, align);
dataF8 = memd(ptr_in++#8);
}
{
memd(ptr_out++#8) = ldata0;
ldata0 = valignb(dataF8, data70, align);
data70 = memd(ptr_in++#8);
}
{
memd(ptr_out++#8) = ldata0;
ldata0 = valignb(data70, dataF8, align);
dataF8 = memd(ptr_in++#8);
kernel1 = cmp.gtu(kernel, #1);
}:endloop0
.Lepilog:
{
noepilog = cmp.eq(epilog,#0);
epilogdws = lsr(epilog, #3);
kernel = and(epilog, #7);
}
{
if(noepilog) jumpr r31;
if(noepilog) ptr_out = sub(ptr_out, len);
p3 = cmp.eq(epilogdws, #0);
shift2 = asl(epilog, #3);
}
{
shiftb = and(shift2, #32);
ifword = tstbit(epilog,#2);
if(p3) jump .Lepilog60;
if(!p3) epilog = add(epilog, #-16);
}
{
loop0(.Ldword_loop_epilog, epilogdws);
/* stop criteria is lsbs unless = 0 then its 8 */
p3 = cmp.eq(kernel, #0);
if(p3.new) kernel= #8;
p1 = cmp.gt(over, #0);
}
/* if not aligned to end of buffer execute 1 more iteration */
if(p1) kernel= #0;
.Ldword_loop_epilog:
{
memd(ptr_out++#8) = ldata0;
ldata0 = valignb(dataF8, data70, align);
p3 = cmp.gt(epilog, kernel);
}
{
data70 = dataF8;
if(p3) dataF8 = memd(ptr_in++#8);
epilog = add(epilog, #-8);
}:endloop0
/* copy last 7 bytes */
.Lepilog60:
{
if(ifword) memw(ptr_out++#4) = data0;
ldata0 = lsr(ldata0, shiftb);
ifhword = tstbit(epilog,#1);
shiftb = and(shift2, #16);
}
{
if(ifhword) memh(ptr_out++#2) = data0;
ldata0 = lsr(ldata0, shiftb);
ifbyte = tstbit(epilog,#0);
if(ifbyte.new) len = add(len, #-1);
}
{
if(ifbyte) memb(ptr_out) = data0;
ptr_out = sub(ptr_out, len); /* return dest pointer */
jumpr r31;
}
/* do byte copy for small n */
.Lbytes23orless:
{
p3 = sp1loop0(.Lbyte_copy, len);
len = add(len, #-1);
}
.Lbyte_copy:
{
data0 = memb(ptr_in++#1);
if(p3) memb(ptr_out++#1) = data0;
}:endloop0
{
memb(ptr_out) = data0;
ptr_out = sub(ptr_out, len);
jumpr r31;
}
/* do dword copies for aligned in, out and length */
.Ldwordaligned:
{
p3 = sp1loop0(.Ldword_copy, len8);
}
.Ldword_copy:
{
if(p3) memd(ptr_out++#8) = ldata0;
ldata0 = memd(ptr_in++#8);
}:endloop0
{
memd(ptr_out) = ldata0;
ptr_out = sub(ptr_out, len);
jumpr r31; /* return to function caller */
}
.Lmemcpy_return:
r21:20 = memd(sp+#16); /* restore r20+r21 */
{
r25:24 = memd(sp+#8); /* restore r24+r25 */
r17:16 = memd(sp+#0); /* restore r16+r17 */
}
deallocframe; /* restore r31 and incrment stack by 16 */
jumpr r31
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