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1.ÄÚ´æ¶ÔÆë:¼ÆËã»úϵͳ¶Ô»ù±¾ÀàÐÍÊý¾ÝÔÚÄÚ´æÖдæ·ÅµÄλÖÃÓÐÏÞÖÆ£¬ËüÃÇ»áÒªÇóÕâЩÊý¾ÝµÄÊ×µØÖ·µÄÖµÊÇij¸öÊýk(ͨ³£ËüΪ4»ò8)µÄ±¶ÊýkÔò±»³ÆΪ¸ÃÊý¾ÝÀàÐ͵ĶÔÆëÄ£Êý(alignment modulus)
2.²»Í¬±àÒëÆ÷ĬÈϵÄ×î´ó¶ÔÆë×Ö½ÚÊýÊDz»Ò»ÑùµÄ,±ÈÈçvc==8,gcc==4,¿ÉÒÔͨ¹ý#progma pack (n)À´ÐÞ¸Ä,·ÖÎö³ÌÐòµÄʱºòҪעÒâ±àÒëÆ÷µÄÇø±ð
3.Ò»¸ö½á¹¹ÌåÀïÃæ,°´ÕÕalignment modulus×î´óµÄÊý¾Ý³ÉÔ±À´½øÐжÔÆë,³¬¹ý±àÒëÆ÷¹æ¶¨×î´óµÄ¶ÔÆë×Ö½Ú¸öÊý,°´±àÒëÆ÷×î´ó¶ÔÆë×Ö½Ú¸öÀ´
4.doubleÀàÐÍÔÚvcÀïÃæalignment modulus == 8,¶øÔÚgccÀïÃæÓÉÓÚĬÈÏ×î´ó¶ÔÆë¸öÊýÊÇ4,²»ÉèÖõĻ°,alignment modulus == 4
5.ÒòΪÊý×é¸÷ÔªËØÖ®¼ä²»ÄÜÓпÕ϶,ËùÒÔ{int a;char b;}
ÕâÖÖÇé¿ö,ĬÈÏÔÚVCÀïÃæÒ²ÐèÒªÕ¼8¸ö×Ö½Ú.
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µ±ÔÚCÖж¨ÒåÁËÒ»¸ö½á¹¹ÀàÐÍʱ£¬ËüµÄ´óСÊÇ·ñµÈÓÚ¸÷×Ö¶Î(field)´óС֮ºÍ£¿±àÒëÆ÷½«ÈçºÎÔÚÄÚ´æÖзÅÖÃÕâЩ×ֶΣ¿ANSI C¶Ô½á¹¹ÌåµÄÄÚ´æ²¼¾ÖÓÐʲôҪÇ󣿶øÎÒÃǵijÌÐòÓÖÄÜ·ñÒÀÀµÕâÖÖ²¼¾Ö£¿ÕâЩÎÊÌâ»òÐí¶Ô²»ÉÙÅóÓÑÀ´Ëµ»¹ÓеãÄ£ºý£¬ÄÇô±¾ÎľÍÊÔ×Å̽¾¿ËüÃDZ³ºóµÄÃØÃÜ¡£
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struct vector{int x,y,z;} s;
int *p,*q,*r;
struct vector *ps;
p = &s.x;
q = &s.y;
r = &s.z;
ps = &s;
assert(p < q);
assert(p < r);
assert(q < r);
assert((int*)ps == p);
// ÉÏÊö¶ÏÑÔÒ»¶¨²»»áʧ°Ü
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