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Diffstat (limited to 'newlib/libc/machine/hppa/memcpy.S')
| -rw-r--r-- | newlib/libc/machine/hppa/memcpy.S | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/newlib/libc/machine/hppa/memcpy.S b/newlib/libc/machine/hppa/memcpy.S new file mode 100644 index 0000000..1fdc4ba --- /dev/null +++ b/newlib/libc/machine/hppa/memcpy.S @@ -0,0 +1,146 @@ +/* + * (c) Copyright 1986 HEWLETT-PACKARD COMPANY + * + * To anyone who acknowledges that this file is provided "AS IS" + * without any express or implied warranty: + * permission to use, copy, modify, and distribute this file + * for any purpose is hereby granted without fee, provided that + * the above copyright notice and this notice appears in all + * copies, and that the name of Hewlett-Packard Company not be + * used in advertising or publicity pertaining to distribution + * of the software without specific, written prior permission. + * Hewlett-Packard Company makes no representations about the + * suitability of this software for any purpose. + */ + +/* HPUX_ID: @(#) $Revision: 1.1 $ */ +/* + * memcpy(s1, s2, n) + * + * Copy n characters from s2 to s1; returns s1. + */ + +#define d_addr arg0 +#define s_addr arg1 +#define count arg2 +#define tmp5 arg3 +#define tmp1 r19 +#define tmp2 r20 +#define tmp3 r21 +#define tmp4 r22 +#define tmp6 r31 + +#include "DEFS.h" + +ENTRY(memcpy) + comib,>= 5,count,byteloop /* If count is <= 6 don't get fancy.*/ + movb,=,n d_addr,ret0,done /* The return value is defined to be the value of d_addr. DELAY SLOT */ + /* if d_addr is null then exit */ + extru s_addr,31,2,tmp1 /* Extract the low two bits of the source address. */ + extru d_addr,31,2,tmp2 /* Extract the low two bits of the destination address. */ + add count,tmp2,count /* pre increment the count to adjust for alignment of s1 */ + comb,<> tmp2,tmp1,not_aligned /* see if s1 is aligned w.r.t. s2. */ + dep 0,31,2,s_addr /* Compute the word address of the source. DELAY SLOT. */ + +/* aligned */ + +/* We will now begin the 16 byte at a time word move if count >= 16 ! */ +/* Else we will branch to the 4 byte-at-a time word move ! */ + + addibt,<,n -16,count,chekchunk /* If count < 16 then we can't move 16 byte chunks ! */ + /* actually we can legally move 13 or more bytes on the first loop. */ + /* These loads and stores are done so as to prevent processor interlock. */ +chunks: + ldwm 16(0,s_addr),tmp1 /* tmp1 = *s_addr s_addr += 16 */ + ldw -12(0,s_addr),tmp2 /* tmp2 = 2nd word */ + ldw -8(0,s_addr),tmp3 /* tmp3 = 3rd word */ + ldw -4(0,s_addr),tmp4 /* tmp4 = 4th word */ + /* Now store the results ! */ + stbys,b,m tmp1,4(0,d_addr) /* tmp1 = 1st word stored d_addr += 16 also take care of front porch. */ + stwm tmp2,4(0,d_addr) /* tmp2 = 2nd word stored. */ + stwm tmp3,4(0,d_addr) /* tmp3 = 3rd word stored. */ + addibf,< -16,count,chunks /* If count is still >= 16 do another loop. */ + stwm tmp4,4(0,d_addr) /* tmp4 = 4th word stored. DELAY SLOT */ + +chekchunk: + addibt,<,n 12,count,back_porch /* since the count is already decremented by -16 we're testing */ + /* to see if there are at least 4 bytes left ? */ +subchunk: + ldws,ma 4(s_addr),tmp1 /* tmp1 = *s_addr++ */ + addibf,< -4,count,subchunk /* count -= 4 */ + stbys,b,m tmp1,4(d_addr) /* *d_addr++ = tmp1 */ + + +back_porch: + addibt,=,n 4,count,done /* if count = 0 we're, of course, done ! */ + ldws 0(s_addr),tmp1 /* load up the back_porch */ + add d_addr,count,d_addr/* final store address is +1 too high ! */ + bv 0(r2) /* return--were done. */ + stbys,e tmp1,0(d_addr) /* kerplunk! whew ! */ + +/* Begin non_aligned code. (no refrence to politics) */ +not_aligned: + sub,>= tmp2,tmp1,tmp3 /* compute the shift quantity again and skip the load if tmp2 > tmp1. */ + ldwm 4(0,s_addr),tmp1 /* load up the first word from the source. tmp1 = *s_addr++ */ + zdep tmp3,28,29,tmp4 /* compute the number of bits to shift based on the number of bytes above. */ + mtctl tmp4,11 /* load the shift count into cr11 = shift count register. */ + + addibt,<,n -16,count,chkchnk2 /* first step in pre adjustment of count for looping. */ + +chunk2: + ldwm 16(0,s_addr),tmp2 /* get either first or second word . tmp2 = *s_addr++ */ + ldw -12(s_addr),tmp3 + ldw -8(s_addr),tmp4 + ldw -4(s_addr),tmp5 + vshd tmp1,tmp2,tmp6 /* position data ! */ + stbys,b,m tmp6,4(0,d_addr) /* store ! */ + + vshd tmp2,tmp3,tmp6 /* position data ! */ + stwm tmp6,4(0,d_addr) /* store ! */ + + vshd tmp3,tmp4,tmp6 /* position data ! */ + stwm tmp6,4(0,d_addr) /* store ! */ + + vshd tmp4,tmp5,tmp6 /* position data ! */ + stwm tmp6,4(0,d_addr) /* store the data ! */ + addibf,< -16,count,chunk2 /* If count is still >= 16 do another loop. */ + copy tmp5,tmp1 + + +chkchnk2: + addibt,<,n 12,count,bp_0 /* if we don't have 4 bytes left then do the back porch (bp_0) */ + +subchnk2: + ldwm 4(0,s_addr),tmp2 /* get next word ! */ + vshd tmp1,tmp2,tmp3 /* position data ! */ + addibt,< -4,count,bp_1 /* decrement count and when count < 4 goto back_porch (bp_1) */ + stbys,b,m tmp3,4(0,d_addr) /* store ! */ + + ldwm 4(0,s_addr),tmp1 /* get 4th word ! */ + vshd tmp2,tmp1,tmp3 /* position data ! */ + addib,>= -4,count,subchnk2 /* decrement count and when count <= 4 go to back porch (bp_2) */ + stbys,b,m tmp3,4(0,d_addr) /* store the data ! */ + +bp_0: copy tmp1,tmp2 /* switch registers used in the shift process. */ +bp_1: addibt,<=,n 4,count,done /* if count = -4 this implies that count = 0 -> done */ + add d_addr,count,d_addr /* bump destination address to be +1 too high ! */ + mfctl sar,tmp3 /* suppress final ldwm unless result used */ + extru tmp3,28,2,tmp3 /* convert bitshift to byteshift */ + sub,<= count,tmp3,r0 /* bytes unused if (count-byteshift <= 0*/ + + ldwm 4(0,s_addr),tmp1 /* get final word ! */ + vshd tmp2,tmp1,tmp3 /* position data ! */ + bv 0(r2) /* return */ + stbys,e tmp3,0(0,d_addr) /* store the data ! */ + +/* here we do ye old byte-at-a-time moves. */ +byteloop: + comb,>=,n 0,count,done + +encore: + ldbs,ma 1(s_addr),tmp1 + addibf,= -1,count,encore + stbs,ma tmp1,1(d_addr) + +done: +EXIT(memcpy) |