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Diffstat (limited to 'sysdeps/powerpc/powerpc32/power4/memcopy.h')
| -rw-r--r-- | sysdeps/powerpc/powerpc32/power4/memcopy.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/power4/memcopy.h b/sysdeps/powerpc/powerpc32/power4/memcopy.h new file mode 100644 index 0000000000..c05208da55 --- /dev/null +++ b/sysdeps/powerpc/powerpc32/power4/memcopy.h @@ -0,0 +1,113 @@ +/* memcopy.h -- definitions for memory copy functions. Generic C version. + Copyright (C) 1991, 1992, 1993, 1997, 2004, 2006 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Torbjorn Granlund (tege@sics.se). + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +/* The strategy of the memory functions is: + + 1. Copy bytes until the destination pointer is aligned. + + 2. Copy words in unrolled loops. If the source and destination + are not aligned in the same way, use word memory operations, + but shift and merge two read words before writing. + + 3. Copy the few remaining bytes. + + This is fast on processors that have at least 10 registers for + allocation by GCC, and that can access memory at reg+const in one + instruction. + + I made an "exhaustive" test of this memmove when I wrote it, + exhaustive in the sense that I tried all alignment and length + combinations, with and without overlap. */ + +#include <sysdeps/generic/memcopy.h> + +/* The macros defined in this file are: + + BYTE_COPY_FWD(dst_beg_ptr, src_beg_ptr, nbytes_to_copy) + + BYTE_COPY_BWD(dst_end_ptr, src_end_ptr, nbytes_to_copy) + + WORD_COPY_FWD(dst_beg_ptr, src_beg_ptr, nbytes_remaining, nbytes_to_copy) + + WORD_COPY_BWD(dst_end_ptr, src_end_ptr, nbytes_remaining, nbytes_to_copy) + + MERGE(old_word, sh_1, new_word, sh_2) + [I fail to understand. I feel stupid. --roland] +*/ + + +/* Threshold value for when to enter the unrolled loops. */ +#undef OP_T_THRES +#define OP_T_THRES 16 + +/* Copy exactly NBYTES bytes from SRC_BP to DST_BP, + without any assumptions about alignment of the pointers. */ +#undef BYTE_COPY_FWD +#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes) \ + do \ + { \ + size_t __nbytes = (nbytes); \ + if (__nbytes & 1) \ + { \ + ((byte *) dst_bp)[0] = ((byte *) src_bp)[0]; \ + src_bp += 1; \ + dst_bp += 1; \ + __nbytes -= 1; \ + } \ + while (__nbytes > 0) \ + { \ + byte __x = ((byte *) src_bp)[0]; \ + byte __y = ((byte *) src_bp)[1]; \ + src_bp += 2; \ + __nbytes -= 2; \ + ((byte *) dst_bp)[0] = __x; \ + ((byte *) dst_bp)[1] = __y; \ + dst_bp += 2; \ + } \ + } while (0) + +/* Copy exactly NBYTES_TO_COPY bytes from SRC_END_PTR to DST_END_PTR, + beginning at the bytes right before the pointers and continuing towards + smaller addresses. Don't assume anything about alignment of the + pointers. */ +#undef BYTE_COPY_BWD +#define BYTE_COPY_BWD(dst_ep, src_ep, nbytes) \ + do \ + { \ + size_t __nbytes = (nbytes); \ + if (__nbytes & 1) \ + { \ + src_ep -= 1; \ + dst_ep -= 1; \ + ((byte *) dst_ep)[0] = ((byte *) src_ep)[0]; \ + __nbytes -= 1; \ + } \ + while (__nbytes > 0) \ + { \ + byte __x, __y; \ + src_ep -= 2; \ + __y = ((byte *) src_ep)[1]; \ + __x = ((byte *) src_ep)[0]; \ + dst_ep -= 2; \ + __nbytes -= 2; \ + ((byte *) dst_ep)[1] = __y; \ + ((byte *) dst_ep)[0] = __x; \ + } \ + } while (0) |