From 385a199fef78912fcc134fbfd4240a02d8d07c3a Mon Sep 17 00:00:00 2001 From: Alexandre Julliard Date: Fri, 22 Jul 2005 09:23:16 +0000 Subject: [PATCH] Faster implementation of wcstombs that handles overlapping buffers properly (based on a patch by Dmitry Timoshkov). --- libs/unicode/wctomb.c | 77 +++++++++++++++++++++++-------------------- 1 file changed, 42 insertions(+), 35 deletions(-) diff --git a/libs/unicode/wctomb.c b/libs/unicode/wctomb.c index 68be134e7ae..088f10d4dcc 100644 --- a/libs/unicode/wctomb.c +++ b/libs/unicode/wctomb.c @@ -142,45 +142,52 @@ static inline int wcstombs_sbcs( const struct sbcs_table *table, ret = -1; } - if (dst <= (const char *)src && dst + 16 > (const char *)src) + while (srclen >= 16) { - /* overlapping buffers, do it char by char */ - while (srclen--) - { - *dst++ = uni2cp_low[uni2cp_high[*src >> 8] + (*src & 0xff)]; - src++; - } - return ret; - } - - for (;;) - { - switch(srclen) - { - default: - case 16: dst[15] = uni2cp_low[uni2cp_high[src[15] >> 8] + (src[15] & 0xff)]; - case 15: dst[14] = uni2cp_low[uni2cp_high[src[14] >> 8] + (src[14] & 0xff)]; - case 14: dst[13] = uni2cp_low[uni2cp_high[src[13] >> 8] + (src[13] & 0xff)]; - case 13: dst[12] = uni2cp_low[uni2cp_high[src[12] >> 8] + (src[12] & 0xff)]; - case 12: dst[11] = uni2cp_low[uni2cp_high[src[11] >> 8] + (src[11] & 0xff)]; - case 11: dst[10] = uni2cp_low[uni2cp_high[src[10] >> 8] + (src[10] & 0xff)]; - case 10: dst[9] = uni2cp_low[uni2cp_high[src[9] >> 8] + (src[9] & 0xff)]; - case 9: dst[8] = uni2cp_low[uni2cp_high[src[8] >> 8] + (src[8] & 0xff)]; - case 8: dst[7] = uni2cp_low[uni2cp_high[src[7] >> 8] + (src[7] & 0xff)]; - case 7: dst[6] = uni2cp_low[uni2cp_high[src[6] >> 8] + (src[6] & 0xff)]; - case 6: dst[5] = uni2cp_low[uni2cp_high[src[5] >> 8] + (src[5] & 0xff)]; - case 5: dst[4] = uni2cp_low[uni2cp_high[src[4] >> 8] + (src[4] & 0xff)]; - case 4: dst[3] = uni2cp_low[uni2cp_high[src[3] >> 8] + (src[3] & 0xff)]; - case 3: dst[2] = uni2cp_low[uni2cp_high[src[2] >> 8] + (src[2] & 0xff)]; - case 2: dst[1] = uni2cp_low[uni2cp_high[src[1] >> 8] + (src[1] & 0xff)]; - case 1: dst[0] = uni2cp_low[uni2cp_high[src[0] >> 8] + (src[0] & 0xff)]; - case 0: break; - } - if (srclen < 16) return ret; - dst += 16; + dst[0] = uni2cp_low[uni2cp_high[src[0] >> 8] + (src[0] & 0xff)]; + dst[1] = uni2cp_low[uni2cp_high[src[1] >> 8] + (src[1] & 0xff)]; + dst[2] = uni2cp_low[uni2cp_high[src[2] >> 8] + (src[2] & 0xff)]; + dst[3] = uni2cp_low[uni2cp_high[src[3] >> 8] + (src[3] & 0xff)]; + dst[4] = uni2cp_low[uni2cp_high[src[4] >> 8] + (src[4] & 0xff)]; + dst[5] = uni2cp_low[uni2cp_high[src[5] >> 8] + (src[5] & 0xff)]; + dst[6] = uni2cp_low[uni2cp_high[src[6] >> 8] + (src[6] & 0xff)]; + dst[7] = uni2cp_low[uni2cp_high[src[7] >> 8] + (src[7] & 0xff)]; + dst[8] = uni2cp_low[uni2cp_high[src[8] >> 8] + (src[8] & 0xff)]; + dst[9] = uni2cp_low[uni2cp_high[src[9] >> 8] + (src[9] & 0xff)]; + dst[10] = uni2cp_low[uni2cp_high[src[10] >> 8] + (src[10] & 0xff)]; + dst[11] = uni2cp_low[uni2cp_high[src[11] >> 8] + (src[11] & 0xff)]; + dst[12] = uni2cp_low[uni2cp_high[src[12] >> 8] + (src[12] & 0xff)]; + dst[13] = uni2cp_low[uni2cp_high[src[13] >> 8] + (src[13] & 0xff)]; + dst[14] = uni2cp_low[uni2cp_high[src[14] >> 8] + (src[14] & 0xff)]; + dst[15] = uni2cp_low[uni2cp_high[src[15] >> 8] + (src[15] & 0xff)]; src += 16; + dst += 16; srclen -= 16; } + + /* now handle remaining characters */ + src += srclen; + dst += srclen; + switch(srclen) + { + case 15: dst[-15] = uni2cp_low[uni2cp_high[src[-15] >> 8] + (src[-15] & 0xff)]; + case 14: dst[-14] = uni2cp_low[uni2cp_high[src[-14] >> 8] + (src[-14] & 0xff)]; + case 13: dst[-13] = uni2cp_low[uni2cp_high[src[-13] >> 8] + (src[-13] & 0xff)]; + case 12: dst[-12] = uni2cp_low[uni2cp_high[src[-12] >> 8] + (src[-12] & 0xff)]; + case 11: dst[-11] = uni2cp_low[uni2cp_high[src[-11] >> 8] + (src[-11] & 0xff)]; + case 10: dst[-10] = uni2cp_low[uni2cp_high[src[-10] >> 8] + (src[-10] & 0xff)]; + case 9: dst[-9] = uni2cp_low[uni2cp_high[src[-9] >> 8] + (src[-9] & 0xff)]; + case 8: dst[-8] = uni2cp_low[uni2cp_high[src[-8] >> 8] + (src[-8] & 0xff)]; + case 7: dst[-7] = uni2cp_low[uni2cp_high[src[-7] >> 8] + (src[-7] & 0xff)]; + case 6: dst[-6] = uni2cp_low[uni2cp_high[src[-6] >> 8] + (src[-6] & 0xff)]; + case 5: dst[-5] = uni2cp_low[uni2cp_high[src[-5] >> 8] + (src[-5] & 0xff)]; + case 4: dst[-4] = uni2cp_low[uni2cp_high[src[-4] >> 8] + (src[-4] & 0xff)]; + case 3: dst[-3] = uni2cp_low[uni2cp_high[src[-3] >> 8] + (src[-3] & 0xff)]; + case 2: dst[-2] = uni2cp_low[uni2cp_high[src[-2] >> 8] + (src[-2] & 0xff)]; + case 1: dst[-1] = uni2cp_low[uni2cp_high[src[-1] >> 8] + (src[-1] & 0xff)]; + case 0: break; + } + return ret; } /* slow version of wcstombs_sbcs that handles the various flags */