| /* |
| * memmove routine for Z8000 |
| * Copyright (C) 2004 Christian Groessler <chris@groessler.org> |
| * |
| * 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. |
| * |
| * This file is distributed WITHOUT ANY WARRANTY; without even the implied |
| * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| */ |
| |
| /* void *memmove(void *dest, const void *src, size_t length); |
| */ |
| |
| name "memmove.S" |
| |
| .text |
| even |
| global _memmove |
| |
| _memmove: |
| |
| #ifdef __Z8001__ |
| segm |
| |
| #ifdef __STD_CALL__ |
| ldl rr6,rr14(#4) |
| ldl rr4,rr14(#8) |
| ldl rr2,rr14(#12) |
| #else |
| pushl @rr14,rr6 |
| #endif |
| |
| /* rr2 - length (high word ignored) |
| * rr4 - src |
| * rr6 - dest |
| */ |
| |
| testl rr2 |
| jr z,finish |
| |
| /* check for destructive overlap (src < dest && dest < src + length) */ |
| |
| cpl rr6,rr4 |
| jp ule,memmove_entry /* non-destructive, let memcpy do the work */ |
| ldl rr0,rr2 |
| addl rr0,rr4 /* rr0 = src + length */ |
| cpl rr0,rr6 |
| jp ult,memmove_entry /* non-destructive, let memcpy do the work */ |
| |
| /* set-up pointers to copy backwards, add (length - 1) */ |
| addl rr4,rr2 /* src + length */ |
| addl rr6,rr2 /* dest + length */ |
| subl rr4,#1 |
| subl rr6,#1 |
| |
| /* check alignment */ |
| bitb rl7,#0 /* odd destination address? */ |
| jr z,testsrc |
| bitb rl5,#0 /* odd source address? */ |
| jr z,odd_copy |
| jr even_copy |
| |
| testsrc: |
| bitb rl5,#0 |
| jr nz,odd_copy /* src even, dest odd */ |
| lddb @rr6,@rr4,r3 |
| jr ov,finish /* jump if r5 is zero now */ |
| |
| /* copy words */ |
| even_copy: |
| ld r2,r3 /* remember length */ |
| srl r3,#1 |
| /* jr z,no_words it cannot be zero here */ |
| |
| dec r5,#1 |
| dec r7,#1 |
| lddr @rr6,@rr4,r3 |
| |
| no_words: |
| bitb rl2,#0 /* odd length? */ |
| jr z,finish |
| inc r5,#1 |
| inc r7,#1 |
| lddb @rr6,@rr4,r2 /* yes, copy last byte */ |
| jr finish |
| |
| /* copy bytes */ |
| odd_copy: |
| lddrb @rr6,@rr4,r3 |
| |
| finish: |
| #ifdef __STD_CALL__ |
| ldl rr6,rr14(#4) |
| #else |
| popl rr2,@rr14 |
| #endif |
| |
| |
| #else /* above Z8001, below Z8002 */ |
| |
| |
| unsegm |
| |
| #ifdef __STD_CALL__ |
| ld r7,r15(#2) |
| ld r6,r15(#4) |
| ld r5,r15(#6) |
| #else |
| ld r2,r7 /* buffer pointer return value */ |
| #endif |
| |
| /* r5 - length |
| * r6 - src |
| * r7 - dest |
| */ |
| test r5 |
| jr z,finish |
| |
| /* check for destructive overlap (src < dest && dest < src + length) */ |
| |
| cp r7,r6 |
| jp ule,memmove_entry /* non-destructive, let memcpy do the work */ |
| ld r0,r5 |
| add r0,r6 /* r0 = src + length */ |
| cp r0,r7 |
| jp ult,memmove_entry /* non-destructive, let memcpy do the work */ |
| |
| /* set-up pointers to copy backwards, add (length - 1) */ |
| add r6,r5 /* src + length */ |
| add r7,r5 /* dest + length */ |
| dec r6,#1 |
| dec r7,#1 |
| |
| /* check alignment */ |
| bitb rl7,#0 /* odd destination address? */ |
| jr z,testsrc |
| bitb rl6,#0 /* odd source address? */ |
| jr z,odd_copy |
| jr even_copy |
| |
| testsrc: |
| bitb rl6,#0 |
| jr nz,odd_copy /* src even, dest odd */ |
| lddb @r7,@r6,r5 |
| jr ov,finish /* jump if r5 is zero now */ |
| |
| /* copy words */ |
| even_copy: |
| ld r4,r5 /* remember length */ |
| srl r5,#1 |
| /* jr z,no_words it cannot be zero here */ |
| |
| dec r6,#1 |
| dec r7,#1 |
| lddr @r7,@r6,r5 |
| |
| no_words: |
| bitb rl4,#0 /* odd length? */ |
| jr z,finish |
| inc r6,#1 |
| inc r7,#1 |
| lddb @r7,@r6,r4 /* yes, copy last byte */ |
| jr finish |
| |
| /* copy bytes */ |
| odd_copy: |
| lddrb @r7,@r6,r5 |
| |
| finish: |
| #ifdef __STD_CALL__ |
| ld r7,r15(#2) |
| #endif |
| |
| #endif /* Z8002 */ |
| |
| ret |
| .end |
