c53c70a90f
This change cleans up the string code in a number of ways: - For memcpy(), fix bug in prefetch and increase distance to 3 lines; optimize for unaligned data; do all loads before wh64 to make memcpy safe for forward-overlapping calls; etc. Performance is improved. - Use new copy_byte() function on tilegx to spread a single byte value out into a full word using the shufflebytes instruction. - Clean up header include ordering to be more canonical, and remove spurious #undefs of function names. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
45 lines
1.5 KiB
C
45 lines
1.5 KiB
C
/*
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* Copyright 2013 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*
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* Provide a mask based on the pointer alignment that
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* sets up non-zero bytes before the beginning of the string.
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* The MASK expression works because shift counts are taken mod 64.
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* Also, specify how to count "first" and "last" bits
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* when the bits have been read as a word.
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*/
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#include <asm/byteorder.h>
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#ifdef __LITTLE_ENDIAN
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#define MASK(x) (__insn_shl(1ULL, (x << 3)) - 1)
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#define NULMASK(x) ((2ULL << x) - 1)
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#define CFZ(x) __insn_ctz(x)
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#define REVCZ(x) __insn_clz(x)
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#else
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#define MASK(x) (__insn_shl(-2LL, ((-x << 3) - 1)))
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#define NULMASK(x) (-2LL << (63 - x))
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#define CFZ(x) __insn_clz(x)
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#define REVCZ(x) __insn_ctz(x)
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#endif
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/*
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* Create eight copies of the byte in a uint64_t. Byte Shuffle uses
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* the bytes of srcB as the index into the dest vector to select a
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* byte. With all indices of zero, the first byte is copied into all
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* the other bytes.
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*/
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static inline uint64_t copy_byte(uint8_t byte)
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{
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return __insn_shufflebytes(byte, 0, 0);
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}
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