绋嬪簭14-9 linux/include/string.h

  1 #ifndef _STRING_H_

  2 #define _STRING_H_

  3

  4 #ifndef NULL

  5 #define NULL ((void *) 0)

  6 #endif

  7

  8 #ifndef _SIZE_T

  9 #define _SIZE_T

 10 typedef unsigned int size_t;

 11 #endif

 12

 13 extern char * strerror(int errno);

 14

 15 /*

 16  * This string-include defines all string functions as inline

 17  * functions. Use gcc. It also assumes ds=es=data space, this should be

 18  * normal. Most of the string-functions are rather heavily hand-optimized,

 19  * see especially strtok,strstr,str[c]spn. They should work, but are not

 20  * very easy to understand. Everything is done entirely within the register

 21  * set, making the functions fast and clean. String instructions have been

 22  * used through-out, making for "slightly" unclear code :-)

 23  *

 24  *              (C) 1991 Linus Torvalds

 25  */

    /*

     * 杩欎釜瀛楃�︿覆澶存枃浠朵互鍐呭祵鍑芥暟鐨勫舰寮忓畾涔変簡鎵�鏈夊瓧绗︿覆鎿嶄綔鍑芥暟銆備娇鐢�gcc鏃讹紝鍚屾椂

     * 鍋囧畾浜�ds=es=鏁版嵁绌洪棿锛岃繖搴旇�ユ槸甯歌�勭殑銆傜粷澶у�氭暟瀛楃�︿覆鍑芥暟閮芥槸缁忔墜宸ヨ繘琛屽ぇ閲�

     * 浼樺寲鐨勶紝灏ゅ叾鏄�鍑芥��strtok銆�strstr銆�str[c]spn銆傚畠浠�搴旇�ヨ兘姝ｅ父宸ヤ綔锛屼絾鍗翠笉鏄�閭�

     * 涔堝�规槗鐞嗚В銆傛墍鏈夌殑鎿嶄綔鍩烘湰涓婇兘鏄�浣跨敤瀵勫瓨鍣ㄩ泦鏉ュ畬鎴愮殑锛岃繖浣垮緱鍑芥暟鍗冲揩鍙堟暣娲併��

     * 鎵�鏈夊湴鏂归兘浣跨敤浜嗗瓧绗︿覆鎸囦护锛岃繖鍙堜娇寰椾唬鐮佲�滅◢寰�鈥濋毦浠ョ悊瑙�J

     *

     *              (C) 1991 Linus Torvalds

     */

 26 

    //// 灏嗕竴涓�瀛楃�︿覆(src)鎷疯礉鍒板彟涓�涓�瀛楃�︿覆(dest)锛岀洿鍒伴亣鍒�NULL瀛楃�﹀悗鍋滄瓈��

    // 鍙傛暟锛�dest - 鐩�鐨勫瓧绗︿覆鎸囬拡锛�src - 婧愬瓧绗︿覆鎸囬拡銆�

    // %0 - esi(src)锛�%1 - edi(dest)銆�

 27 extern inline char * strcpy(char * dest,const char *src)

 28 {

 29 __asm__("cld\n"                      // 娓呮柟鍚戜綅銆�

 30         "1:\tlodsb\n\t"              // 鍔犺浇DS:[esi]澶�1瀛楄妭猫al锛屽苟鏇存柊esi銆�

 31         "stosb\n\t"                  // 瀛樺偍瀛楄妭al猫ES:[edi]锛屽苟鏇存柊edi銆�

 32         "testb %%al,%%al\n\t"        // 鍒氬瓨鍌ㄧ殑瀛楄妭鏄�0锛�

 33         "jne 1b"                     // 涓嶆槸鍒欏悜鍚庤烦杞�鍒版爣鍙�1澶勶紝鍚﹀垯缁撴潫銆�

 34         ::"S" (src),"D" (dest):"si","di","ax");

 35 return dest;                         // 杩斿洖鐩�鐨勫瓧绗︿覆鎸囬拡銆�

 36 }

 37

    //// 鎷疯礉婧愬瓧绗︿覆count涓�瀛楄妭鍒扮洰鐨勫瓧绗︿覆銆�

    // 濡傛灉婧愪覆闀垮害灏忎簬count涓�瀛楄妭锛屽氨闄勫姞绌哄瓧绗�(NULL)鍒扮洰鐨勫瓧绗︿覆銆�

    // 鍙傛暟锛�dest - 鐩�鐨勫瓧绗︿覆鎸囬拡锛�src - 婧愬瓧绗︿覆鎸囬拡锛�count - 鎷疯礉瀛楄妭鏁般��

    // %0 - esi(src)锛�%1 - edi(dest)锛�%2 - ecx(count)銆�

 38 extern inline char * strncpy(char * dest,const char *src,int count)

 39 {

 40 __asm__("cld\n"                      // 娓呮柟鍚戜綅銆�

 41         "1:\tdecl %2\n\t"            // 瀵勫瓨鍣�ecx--锛�count--锛夈��

 42         "js 2f\n\t"                  // 濡傛灉count<0鍒欏悜鍓嶈烦杞�鍒版爣鍙�2锛岀粨鏉熴��

 43         "lodsb\n\t"                  // 鍙�ds:[esi]澶�1瀛楄妭猫al锛屽苟涓�esi++銆�

 44         "stosb\n\t"                  // 瀛樺偍璇ュ瓧鑺�猫es:[edi]锛屽苟涓�edi++銆�

 45         "testb %%al,%%al\n\t"        // 璇ュ瓧鑺傛槸0锛�

 46         "jne 1b\n\t"                 // 涓嶆槸锛屽垯鍚戝墠璺宠浆鍒版爣鍙�1澶勭户缁�鎷疯礉銆�

 47         "rep\n\t"                    // 鍚﹀垯锛屽湪鐩�鐨勪覆涓�瀛樻斁鍓╀綑涓�鏁扮殑绌哄瓧绗︺��

 48         "stosb\n"

 49         "2:"

 50         ::"S" (src),"D" (dest),"c" (count):"si","di","ax","cx");

 51 return dest;                         // 杩斿洖鐩�鐨勫瓧绗︿覆鎸囬拡銆�

 52 }

 53

    //// 灏嗘簮瀛楃�︿覆鎷疯礉鍒扮洰鐨勫瓧绗︿覆鐨勬湯灏惧�勩��

    // 鍙傛暟锛�dest - 鐩�鐨勫瓧绗︿覆鎸囬拡锛�src - 婧愬瓧绗︿覆鎸囬拡銆�

    // %0 - esi(src)锛�%1 - edi(dest)锛�%2 - eax(0)锛�%3 - ecx(-1)銆�

 54 extern inline char * strcat(char * dest,const char * src)

 55 {

 56 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

 57         "repne\n\t"                  // 姣旇緝al涓�es:[edi]瀛楄妭锛屽苟鏇存柊edi++锛�

 58         "scasb\n\t"                  // 鐩村埌鎵惧埌鐩�鐨勪覆涓�鏄�0鐨勫瓧鑺傦紝姝ゆ椂edi宸叉寚鍚戝悗1瀛楄妭銆�

 59         "decl %1\n"                  // 璁�es:[edi]鎸囧悜0鍊煎瓧鑺傘��

 60         "1:\tlodsb\n\t"              // 鍙栨簮瀛楃�︿覆瀛楄��ds:[esi]猫al锛屽苟esi++銆�

 61         "stosb\n\t"                  // 灏嗚�ュ瓧鑺傚瓨鍒�es:[edi]锛屽苟edi++銆�

 62         "testb %%al,%%al\n\t"        // 璇ュ瓧鑺傛槸0锛�

 63         "jne 1b"                     // 涓嶆槸锛屽垯鍚戝悗璺宠浆鍒版爣鍙�1澶勭户缁�鎷疯礉锛屽惁鍒欑粨鏉熴��

 64         ::"S" (src),"D" (dest),"a" (0),"c" (0xffffffff):"si","di","ax","cx");

 65 return dest;                         // 杩斿洖鐩�鐨勫瓧绗︿覆鎸囬拡銆�

 66 }

 67

    //// 灏嗘簮瀛楃�︿覆鐨�count涓�瀛楄妭澶嶅埗鍒扮洰鐨勫瓧绗︿覆鐨勬湯灏惧�勶紝鏈�鍚庢坊涓�绌哄瓧绗︺��

    // 鍙傛暟锛�dest - 鐩�鐨勫瓧绗︿覆锛�src - 婧愬瓧绗︿覆锛�count - 娆插�嶅埗鐨勫瓧鑺傛暟銆�

    // %0 - esi(src)锛�%1 - edi(dest)锛�%2 - eax(0)锛�%3 - ecx(-1)锛�%4 - (count)銆�

 68 extern inline char * strncat(char * dest,const char * src,int count)

 69 {

 70 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

 71         "repne\n\t"                  // 姣旇緝al涓�es:[edi]瀛楄妭锛�edi++銆�

 72         "scasb\n\t"                  // 鐩村埌鎵惧埌鐩�鐨勪覆鐨勬湯绔�0鍊煎瓧鑺傘��

 73         "decl %1\n\t"                // edi鎸囧悜璇�0鍊煎瓧鑺傘��

 74         "movl %4,%3\n"               // 娆插�嶅埗瀛楄妭鏁�猫ecx銆�

 75         "1:\tdecl %3\n\t"            // ecx--锛堜粠0寮�濮嬭�℃暟锛夈��

 76         "js 2f\n\t"                  // ecx <0 ?锛屾槸鍒欏悜鍓嶈烦杞�鍒版爣鍙�2澶勩��

 77         "lodsb\n\t"                  // 鍚﹀垯鍙�ds:[esi]澶勭殑瀛楄妭猫al锛�esi++銆�

 78         "stosb\n\t"                  // 瀛樺偍鍒�es:[edi]澶勶紝edi++銆�

 79         "testb %%al,%%al\n\t"        // 璇ュ瓧鑺傚�间负0锛�

 80         "jne 1b\n"                   // 涓嶆槸鍒欏悜鍚庤烦杞�鍒版爣鍙�1澶勶紝缁х画澶嶅埗銆�

 81         "2:\txorl %2,%2\n\t"         // 灏�al娓呴浂銆�

 82         "stosb"                      // 瀛樺埌es:[edi]澶勩��

 83         ::"S" (src),"D" (dest),"a" (0),"c" (0xffffffff),"g" (count)

 84         :"si","di","ax","cx");

 85 return dest;                         // 杩斿洖鐩�鐨勫瓧绗︿覆鎸囬拡銆�

 86 }

 87

    //// 灏嗕竴涓�瀛楃�︿覆涓庡彟涓�涓�瀛楃�︿覆杩涜�屾瘮杈冦��

    // 鍙傛暟锛�cs - 瀛楃�︿��1锛�ct - 瀛楃�︿��2銆�

    // %0 - eax(__res)杩斿洖鍊硷紝%1 - edi(cs)瀛楃�︿��1鎸囬拡锛�%2 - esi(ct)瀛楃�︿��2鎸囬拡銆�

    // 杩斿洖锛氬�傛灉涓�1 > 涓�2锛屽垯杩斿洖1锛涗覆1 = 涓�2锛屽垯杩斿洖0锛涗覆1 < 涓�2锛屽垯杩斿洖-1銆�

    // 绗�90琛屽畾涔変簡涓�涓�灞�閮ㄥ瘎瀛樺櫒鍙橀噺銆傝�ュ彉閲忓皢琚�淇濆瓨鍦�eax瀵勫瓨鍣ㄤ腑锛屼互渚夸簬楂樻晥璁块棶鍜屾搷浣溿��

    // 杩欑�嶅畾涔夊彉閲忕殑鏂规硶涓昏�佺敤浜庡唴宓屾眹缂栫▼搴忎腑銆傝�︾粏璇存槑鍙傝��gcc鎵嬪唽鈥�鎸囧畾瀵勫瓨鍣ㄤ腑鐨勫彉閲�鈥�銆�

 88 extern inline int strcmp(const char * cs,const char * ct)

 89 {

 90 register int __res __asm__("ax");    // __res鏄�瀵勫瓨鍣ㄥ彉閲�(eax)銆�

 91 __asm__("cld\n"                      // 娓呮柟鍚戜綅銆�

 92         "1:\tlodsb\n\t"              // 鍙栧瓧绗︿覆2鐨勫瓧鑺�ds:[esi]猫al锛屽苟涓�esi++銆�

 93         "scasb\n\t"                  // al涓庡瓧绗︿覆1鐨勫瓧鑺�es:[edi]浣滄瘮杈冿紝骞朵笖edi++銆�

 94         "jne 2f\n\t"                 // 濡傛灉涓嶇浉绛夛紝鍒欏悜鍓嶈烦杞�鍒版爣鍙�2銆�

 95         "testb %%al,%%al\n\t"        // 璇ュ瓧鑺傛槸0鍊煎瓧鑺傚悧锛堝瓧绗︿覆缁撳熬锛夛紵

 96         "jne 1b\n\t"                 // 涓嶆槸锛屽垯鍚戝悗璺宠浆鍒版爣鍙�1锛岀户缁�姣旇緝銆�

 97         "xorl %%eax,%%eax\n\t"       // 鏄�锛屽垯杩斿洖鍊�eax娓呴浂锛�

 98         "jmp 3f\n"                   // 鍚戝墠璺宠浆鍒版爣鍙�3锛岀粨鏉熴��

 99         "2:\tmovl $1,%%eax\n\t"      // eax涓�缃�1銆�

100         "jl 3f\n\t"                  // 鑻ュ墠闈㈡瘮杈冧腑涓�2瀛楃��<涓�1瀛楃�︼紝鍒欒繑鍥炴�ｅ�肩粨鏉熴��

101         "negl %%eax\n"               // 鍚﹀垯eax = -eax锛岃繑鍥炶礋鍊硷紝缁撴潫銆�

102         "3:"

103         :"=a" (__res):"D" (cs),"S" (ct):"si","di");

104 return __res;                        // 杩斿洖姣旇緝缁撴灉銆�

105 }

106

    //// 瀛楃�︿��1涓庡瓧绗︿覆2鐨勫墠count涓�瀛楃�﹁繘琛屾瘮杈冦��

    // 鍙傛暟锛�cs - 瀛楃�︿��1锛�ct - 瀛楃�︿��2锛�count - 姣旇緝鐨勫瓧绗︽暟銆�

    // %0 - eax(__res)杩斿洖鍊硷紝%1 - edi(cs)涓�1鎸囬拡锛�%2 - esi(ct)涓�2鎸囬拡锛�%3 - ecx(count)銆�

    // 杩斿洖锛氬�傛灉涓�1 > 涓�2锛屽垯杩斿洖1锛涗覆1 = 涓�2锛屽垯杩斿洖0锛涗覆1 < 涓�2锛屽垯杩斿洖-1銆�

107 extern inline int strncmp(const char * cs,const char * ct,int count)

108 {

109 register int __res __asm__("ax");    // __res鏄�瀵勫瓨鍣ㄥ彉閲�(eax)銆�

110 __asm__("cld\n"                      // 娓呮柟鍚戜綅銆�

111         "1:\tdecl %3\n\t"            // count--銆�

112         "js 2f\n\t"                  // 濡傛灉count<0锛屽垯鍚戝墠璺宠浆鍒版爣鍙�2銆�

113         "lodsb\n\t"                  // 鍙栦覆2鐨勫瓧绗�ds:[esi]猫al锛屽苟涓�esi++銆�

114         "scasb\n\t"                  // 姣旇緝al涓庝覆1鐨勫瓧绗�es:[edi]锛屽苟涓�edi++銆�

115         "jne 3f\n\t"                 // 濡傛灉涓嶇浉绛夛紝鍒欏悜鍓嶈烦杞�鍒版爣鍙�3銆�

116         "testb %%al,%%al\n\t"        // 璇ュ瓧绗︽槸NULL瀛楃�﹀悧锛�

117         "jne 1b\n"                   // 涓嶆槸锛屽垯鍚戝悗璺宠浆鍒版爣鍙�1锛岀户缁�姣旇緝銆�

118         "2:\txorl %%eax,%%eax\n\t"   // 鏄�NULL瀛楃�︼紝鍒�eax娓呴浂锛堣繑鍥炲�硷級銆�

119         "jmp 4f\n"                   // 鍚戝墠璺宠浆鍒版爣鍙�4锛岀粨鏉熴��

120         "3:\tmovl $1,%%eax\n\t"      // eax涓�缃�1銆�

121         "jl 4f\n\t"                  // 濡傛灉鍓嶉潰姣旇緝涓�涓�2瀛楃��<涓�1瀛楃�︼紝鍒欒繑鍥�1缁撴潫銆�

122         "negl %%eax\n"               // 鍚﹀垯eax = -eax锛岃繑鍥炶礋鍊硷紝缁撴潫銆�

123         "4:"

124         :"=a" (__res):"D" (cs),"S" (ct),"c" (count):"si","di","cx");

125 return __res;                        // 杩斿洖姣旇緝缁撴灉銆�

126 }

127

    //// 鍦ㄥ瓧绗︿覆涓�瀵绘壘绗�涓�涓�鍖归厤鐨勫瓧绗︺��

    // 鍙傛暟锛�s - 瀛楃�︿覆锛�c - 娆插�绘壘鐨勫瓧绗︺��

    // %0 - eax(__res)锛�%1 - esi(瀛楃�︿覆鎸囬��s)锛�%2 - eax(瀛楃��c)銆�

    // 杩斿洖锛氳繑鍥炲瓧绗︿覆涓�绗�涓�娆″嚭鐜板尮閰嶅瓧绗︾殑鎸囬拡銆傝嫢娌℃湁鎵惧埌鍖归厤鐨勫瓧绗︼紝鍒欒繑鍥炵┖鎸囬拡銆�

128 extern inline char * strchr(const char * s,char c)

129 {

130 register char * __res __asm__("ax"); // __res鏄�瀵勫瓨鍣ㄥ彉閲�(eax)銆�

131 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

132         "movb %%al,%%ah\n"           // 灏嗘�叉瘮杈冨瓧绗︾Щ鍒�ah銆�

133         "1:\tlodsb\n\t"              // 鍙栧瓧绗︿覆涓�瀛楃��ds:[esi]猫al锛屽苟涓�esi++銆�

134         "cmpb %%ah,%%al\n\t"         // 瀛楃�︿覆涓�瀛楃��al涓庢寚瀹氬瓧绗�ah鐩告瘮杈冦��

135         "je 2f\n\t"                  // 鑻ョ浉绛夛紝鍒欏悜鍓嶈烦杞�鍒版爣鍙�2澶勩��

136         "testb %%al,%%al\n\t"        // al涓�瀛楃�︽槸NULL瀛楃�﹀悧锛燂紙瀛楃�︿覆缁撳熬锛燂級

137         "jne 1b\n\t"                 // 鑻ヤ笉鏄�锛屽垯鍚戝悗璺宠浆鍒版爣鍙�1锛岀户缁�姣旇緝銆�

138         "movl $1,%1\n"               // 鏄�锛屽垯璇存槑娌℃湁鎵惧埌鍖归厤瀛楃�︼紝esi缃�1銆�

139         "2:\tmovl %1,%0\n\t"         // 灏嗘寚鍚戝尮閰嶅瓧绗﹀悗涓�涓�瀛楄妭澶勭殑鎸囬拡鍊兼斁鍏�eax

140         "decl %0"                    // 灏嗘寚閽堣皟鏁翠负鎸囧悜鍖归厤鐨勫瓧绗︺��

141         :"=a" (__res):"S" (s),"0" (c):"si");

142 return __res;                        // 杩斿洖鎸囬拡銆�

143 }

144

    //// 瀵绘壘瀛楃�︿覆涓�鎸囧畾瀛楃�︽渶鍚庝竴娆″嚭鐜扮殑鍦版柟銆傦紙鍙嶅悜鎼滅储瀛楃�︿覆锛�

    // 鍙傛暟锛�s - 瀛楃�︿覆锛�c - 娆插�绘壘鐨勫瓧绗︺��

    // %0 - edx(__res)锛�%1 - edx(0)锛�%2 - esi(瀛楃�︿覆鎸囬��s)锛�%3 - eax(瀛楃��c)銆�

    // 杩斿洖锛氳繑鍥炲瓧绗︿覆涓�鏈�鍚庝竴娆″嚭鐜板尮閰嶅瓧绗︾殑鎸囬拡銆傝嫢娌℃湁鎵惧埌鍖归厤鐨勫瓧绗︼紝鍒欒繑鍥炵┖鎸囬拡銆�

145 extern inline char * strrchr(const char * s,char c)

146 {

147 register char * __res __asm__("dx"); // __res鏄�瀵勫瓨鍣ㄥ彉閲�(edx)銆�

148 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

149         "movb %%al,%%ah\n"           // 灏嗘�插�绘壘鐨勫瓧绗︾Щ鍒�ah銆�

150         "1:\tlodsb\n\t"              // 鍙栧瓧绗︿覆涓�瀛楃��ds:[esi]猫al锛屽苟涓�esi++銆�

151         "cmpb %%ah,%%al\n\t"         // 瀛楃�︿覆涓�瀛楃��al涓庢寚瀹氬瓧绗�ah浣滄瘮杈冦��

152         "jne 2f\n\t"                 // 鑻ヤ笉鐩哥瓑锛屽垯鍚戝墠璺宠浆鍒版爣鍙�2澶勩��

153         "movl %%esi,%0\n\t"          // 灏嗗瓧绗︽寚閽堜繚瀛樺埌edx涓�銆�

154         "decl %0\n"                  // 鎸囬拡鍚庨��涓�浣嶏紝鎸囧悜瀛楃�︿覆涓�鍖归厤瀛楃�﹀�勩��

155         "2:\ttestb %%al,%%al\n\t"    // 姣旇緝鐨勫瓧绗︽槸0鍚楋紙鍒板瓧绗︿覆灏撅級锛�

156         "jne 1b"                     // 涓嶆槸鍒欏悜鍚庤烦杞�鍒版爣鍙�1澶勶紝缁х画姣旇緝銆�

157         :"=d" (__res):"0" (0),"S" (s),"a" (c):"ax","si");

158 return __res;                        // 杩斿洖鎸囬拡銆�

159 }

160

    //// 鍦ㄥ瓧绗︿覆1涓�瀵绘壘绗�1涓�瀛楃�﹀簭鍒楋紝璇ュ瓧绗﹀簭鍒椾腑鐨勪换浣曞瓧绗﹂兘鍖呭惈鍦ㄥ瓧绗︿覆2涓�銆�

    // 鍙傛暟锛�cs - 瀛楃�︿��1鎸囬拡锛�ct - 瀛楃�︿��2鎸囬拡銆�

    // %0 - esi(__res)锛�%1 - eax(0)锛�%2 - ecx(-1)锛�%3 - esi(涓�1鎸囬拡cs)锛�%4 - (涓�2鎸囬拡ct)銆�

    // 杩斿洖瀛楃�︿��1涓�鍖呭惈瀛楃�︿覆2涓�浠讳綍瀛楃�︾殑棣栦釜瀛楃�﹀簭鍒楃殑闀垮害鍊笺��

161 extern inline int strspn(const char * cs, const char * ct)

162 {

163 register char * __res __asm__("si"); // __res鏄�瀵勫瓨鍣ㄥ彉閲�(esi)銆�

164 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

165         "movl %4,%%edi\n\t"          // 棣栧厛璁＄畻涓�2鐨勯暱搴︺�備覆2鎸囬拡鏀惧叆edi涓�銆�

166         "repne\n\t"                  // 姣旇緝al(0)涓庝覆2涓�鐨勫瓧绗︼��es:[edi]锛夛紝骞�edi++銆�

167         "scasb\n\t"                  // 濡傛灉涓嶇浉绛夊氨缁х画姣旇緝(ecx閫愭�ラ�掑噺)銆�

168         "notl %%ecx\n\t"             // ecx涓�姣忎綅鍙栧弽銆�

169         "decl %%ecx\n\t"             // ecx--锛屽緱涓�2鐨勯暱搴﹀�笺��

170         "movl %%ecx,%%edx\n"         // 灏嗕覆2鐨勯暱搴﹀�兼殏鏀惧叆edx涓�銆�

171         "1:\tlodsb\n\t"              // 鍙栦覆1瀛楃��ds:[esi]猫al锛屽苟涓�esi++銆�

172         "testb %%al,%%al\n\t"        // 璇ュ瓧绗︾瓑浜�0鍊煎悧锛堜覆1缁撳熬锛夛紵

173         "je 2f\n\t"                  // 濡傛灉鏄�锛屽垯鍚戝墠璺宠浆鍒版爣鍙�2澶勩��

174         "movl %4,%%edi\n\t"          // 鍙栦覆2澶存寚閽堟斁鍏�edi涓�銆�

175         "movl %%edx,%%ecx\n\t"       // 鍐嶅皢涓�2鐨勯暱搴﹀�兼斁鍏�ecx涓�銆�

176         "repne\n\t"                  // 姣旇緝al涓庝覆2涓�瀛楃��es:[edi]锛屽苟涓�edi++銆�

177         "scasb\n\t"                  // 濡傛灉涓嶇浉绛夊氨缁х画姣旇緝銆�

178         "je 1b\n"                    // 濡傛灉鐩哥瓑锛屽垯鍚戝悗璺宠浆鍒版爣鍙�1澶勩��

179         "2:\tdecl %0"                // esi--锛屾寚鍚戞渶鍚庝竴涓�鍖呭惈鍦ㄤ��2涓�鐨勫瓧绗︺��

180         :"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct)

181         :"ax","cx","dx","di");

182 return __res-cs;                     // 杩斿洖瀛楃�﹀簭鍒楃殑闀垮害鍊笺��

183 }

184

    //// 瀵绘壘瀛楃�︿��1涓�涓嶅寘鍚�瀛楃�︿��2涓�浠讳綍瀛楃�︾殑棣栦釜瀛楃�﹀簭鍒椼��

    // 鍙傛暟锛�cs - 瀛楃�︿��1鎸囬拡锛�ct - 瀛楃�︿��2鎸囬拡銆�

    // %0 - esi(__res)锛�%1 - eax(0)锛�%2 - ecx(-1)锛�%3 - esi(涓�1鎸囬拡cs)锛�%4 - (涓�2鎸囬拡ct)銆�

    // 杩斿洖瀛楃�︿��1涓�涓嶅寘鍚�瀛楃�︿��2涓�浠讳綍瀛楃�︾殑棣栦釜瀛楃�﹀簭鍒楃殑闀垮害鍊笺��

185 extern inline int strcspn(const char * cs, const char * ct)

186 {

187 register char * __res __asm__("si"); // __res鏄�瀵勫瓨鍣ㄥ彉閲�(esi)銆�

188 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

189         "movl %4,%%edi\n\t"          // 棣栧厛璁＄畻涓�2鐨勯暱搴︺�備覆2鎸囬拡鏀惧叆edi涓�銆�

190         "repne\n\t"                  // 姣旇緝al(0)涓庝覆2涓�鐨勫瓧绗︼��es:[edi]锛夛紝骞�edi++銆�

191         "scasb\n\t"                  // 濡傛灉涓嶇浉绛夊氨缁х画姣旇緝(ecx閫愭�ラ�掑噺)銆�

192         "notl %%ecx\n\t"             // ecx涓�姣忎綅鍙栧弽銆�

193         "decl %%ecx\n\t"             // ecx--锛屽緱涓�2鐨勯暱搴﹀�笺��

194         "movl %%ecx,%%edx\n"         // 灏嗕覆2鐨勯暱搴﹀�兼殏鏀惧叆edx涓�銆�

195         "1:\tlodsb\n\t"              // 鍙栦覆1瀛楃��ds:[esi]猫al锛屽苟涓�esi++銆�

196         "testb %%al,%%al\n\t"        // 璇ュ瓧绗︾瓑浜�0鍊煎悧锛堜覆1缁撳熬锛夛紵

197         "je 2f\n\t"                  // 濡傛灉鏄�锛屽垯鍚戝墠璺宠浆鍒版爣鍙�2澶勩��

198         "movl %4,%%edi\n\t"          // 鍙栦覆2澶存寚閽堟斁鍏�edi涓�銆�

199         "movl %%edx,%%ecx\n\t"       // 鍐嶅皢涓�2鐨勯暱搴﹀�兼斁鍏�ecx涓�銆�

200         "repne\n\t"                  // 姣旇緝al涓庝覆2涓�瀛楃��es:[edi]锛屽苟涓�edi++銆�

201         "scasb\n\t"                  // 濡傛灉涓嶇浉绛夊氨缁х画姣旇緝銆�

202         "jne 1b\n"                   // 濡傛灉涓嶇浉绛夛紝鍒欏悜鍚庤烦杞�鍒版爣鍙�1澶勩��

203         "2:\tdecl %0"                // esi--锛屾寚鍚戞渶鍚庝竴涓�鍖呭惈鍦ㄤ��2涓�鐨勫瓧绗︺��

204         :"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct)

205         :"ax","cx","dx","di");

206 return __res-cs;                     // 杩斿洖瀛楃�﹀簭鍒楃殑闀垮害鍊笺��

207 }

208

    //// 鍦ㄥ瓧绗︿覆1涓�瀵绘壘棣栦釜鍖呭惈鍦ㄥ瓧绗︿��2涓�鐨勪换浣曞瓧绗︺��

    // 鍙傛暟锛�cs - 瀛楃�︿��1鐨勬寚閽堬紝ct - 瀛楃�︿��2鐨勬寚閽堛��

    // %0 -esi(__res)锛�%1 -eax(0)锛�%2 -ecx(0xffffffff)锛�%3 -esi(涓�1鎸囬拡cs)锛�%4 -(涓�2鎸囬拡ct)銆�

    // 杩斿洖瀛楃�︿��1涓�棣栦釜鍖呭惈瀛楃�︿覆2涓�瀛楃�︾殑鎸囬拡銆�

209 extern inline char * strpbrk(const char * cs,const char * ct)

210 {

211 register char * __res __asm__("si"); // __res鏄�瀵勫瓨鍣ㄥ彉閲�(esi)銆�

212 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

213         "movl %4,%%edi\n\t"          // 棣栧厛璁＄畻涓�2鐨勯暱搴︺�備覆2鎸囬拡鏀惧叆edi涓�銆�

214         "repne\n\t"                  // 姣旇緝al(0)涓庝覆2涓�鐨勫瓧绗︼��es:[edi]锛夛紝骞�edi++銆�

215         "scasb\n\t"                  // 濡傛灉涓嶇浉绛夊氨缁х画姣旇緝(ecx閫愭�ラ�掑噺)銆�

216         "notl %%ecx\n\t"             // ecx涓�姣忎綅鍙栧弽銆�

217         "decl %%ecx\n\t"             // ecx--锛屽緱涓�2鐨勯暱搴﹀�笺��

218         "movl %%ecx,%%edx\n"         // 灏嗕覆2鐨勯暱搴﹀�兼殏鏀惧叆edx涓�銆�

219         "1:\tlodsb\n\t"              // 鍙栦覆1瀛楃��ds:[esi]猫al锛屽苟涓�esi++銆�

220         "testb %%al,%%al\n\t"        // 璇ュ瓧绗︾瓑浜�0鍊煎悧锛堜覆1缁撳熬锛夛紵

221         "je 2f\n\t"                  // 濡傛灉鏄�锛屽垯鍚戝墠璺宠浆鍒版爣鍙�2澶勩��

222         "movl %4,%%edi\n\t"          // 鍙栦覆2澶存寚閽堟斁鍏�edi涓�銆�

223         "movl %%edx,%%ecx\n\t"       // 鍐嶅皢涓�2鐨勯暱搴﹀�兼斁鍏�ecx涓�銆�

224         "repne\n\t"                  // 姣旇緝al涓庝覆2涓�瀛楃��es:[edi]锛屽苟涓�edi++銆�

225         "scasb\n\t"                  // 濡傛灉涓嶇浉绛夊氨缁х画姣旇緝銆�

226         "jne 1b\n\t"                 // 濡傛灉涓嶇浉绛夛紝鍒欏悜鍚庤烦杞�鍒版爣鍙�1澶勩��

227         "decl %0\n\t"                // esi--锛屾寚鍚戜竴涓�鍖呭惈鍦ㄤ��2涓�鐨勫瓧绗︺��

228         "jmp 3f\n"                   // 鍚戝墠璺宠浆鍒版爣鍙�3澶勩��

229         "2:\txorl %0,%0\n"           // 娌℃湁鎵惧埌绗﹀悎鏉′欢鐨勶紝灏嗚繑鍥炲�间负NULL銆�

230         "3:"

231         :"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct)

232         :"ax","cx","dx","di");

233 return __res;                        // 杩斿洖鎸囬拡鍊笺��

234 }

235

    //// 鍦ㄥ瓧绗︿覆1涓�瀵绘壘棣栦釜鍖归厤鏁翠釜瀛楃�︿覆2鐨勫瓧绗︿覆銆�

    // 鍙傛暟锛�cs - 瀛楃�︿��1鐨勬寚閽堬紝ct - 瀛楃�︿��2鐨勬寚閽堛��

    // %0 -eax(__res)锛�%1 -eax(0)锛�%2 -ecx(0xffffffff)锛�%3 -esi(涓�1鎸囬拡cs)锛�%4 -(涓�2鎸囬拡ct)銆�

    // 杩斿洖锛氳繑鍥炲瓧绗︿覆1涓�棣栦釜鍖归厤瀛楃�︿覆2鐨勫瓧绗︿覆鎸囬拡銆�

236 extern inline char * strstr(const char * cs,const char * ct)

237 {

238 register char * __res __asm__("ax"); // __res鏄�瀵勫瓨鍣ㄥ彉閲�(eax)銆�

239 __asm__("cld\n\t" \                  // 娓呮柟鍚戜綅銆�

240         "movl %4,%%edi\n\t"          // 棣栧厛璁＄畻涓�2鐨勯暱搴︺�備覆2鎸囬拡鏀惧叆edi涓�銆�

241         "repne\n\t"                  // 姣旇緝al(0)涓庝覆2涓�鐨勫瓧绗︼��es:[edi]锛夛紝骞�edi++銆�

242         "scasb\n\t"                  // 濡傛灉涓嶇浉绛夊氨缁х画姣旇緝(ecx閫愭�ラ�掑噺)銆�

243         "notl %%ecx\n\t"             // ecx涓�姣忎綅鍙栧弽銆�

244         "decl %%ecx\n\t"    /* NOTE! This also sets Z if searchstring='' */

                                /* 娉ㄦ剰锛佸�傛灉鎼滅储涓蹭负绌猴紝灏嗚�剧疆Z鏍囧織 */ // 寰椾覆2鐨勯暱搴﹀�笺��

245         "movl %%ecx,%%edx\n"         // 灏嗕覆2鐨勯暱搴﹀�兼殏鏀惧叆edx涓�銆�

246         "1:\tmovl %4,%%edi\n\t"      // 鍙栦覆2澶存寚閽堟斁鍏�edi涓�銆�

247         "movl %%esi,%%eax\n\t"       // 灏嗕覆1鐨勬寚閽堝�嶅埗鍒�eax涓�銆�

248         "movl %%edx,%%ecx\n\t"       // 鍐嶅皢涓�2鐨勯暱搴﹀�兼斁鍏�ecx涓�銆�

249         "repe\n\t"                   // 姣旇緝涓�1鍜屼覆2瀛楃��(ds:[esi],es:[edi])锛�esi++,edi++銆�

250         "cmpsb\n\t"                  // 鑻ュ�瑰簲瀛楃�︾浉绛夊氨涓�鐩存瘮杈冧笅鍘汇��

251         "je 2f\n\t"         /* also works for empty string, see above */

                                /* 瀵圭┖涓插悓鏍锋湁鏁堬紝瑙佷笂闈� */ // 鑻ュ叏鐩哥瓑锛屽垯杞�鍒版爣鍙�2銆�

252         "xchgl %%eax,%%esi\n\t"      // 涓�1澶存寚閽�猫esi锛屾瘮杈冪粨鏋滅殑涓�1鎸囬拡猫eax銆�

253         "incl %%esi\n\t"             // 涓�1澶存寚閽堟寚鍚戜笅涓�涓�瀛楃�︺��

254         "cmpb $0,-1(%%eax)\n\t"      // 涓�1鎸囬拡(eax-1)鎵�鎸囧瓧鑺傛槸0鍚楋紵

255         "jne 1b\n\t"                 // 涓嶆槸鍒欒浆鍒版爣鍙�1锛岀户缁�浠庝��1鐨勭��2涓�瀛楃�﹀紑濮嬫瘮杈冦��

256         "xorl %%eax,%%eax\n\t"       // 娓�eax锛岃〃绀烘病鏈夋壘鍒板尮閰嶃��

257         "2:"

258         :"=a" (__res):"0" (0),"c" (0xffffffff),"S" (cs),"g" (ct)

259         :"cx","dx","di","si");

260 return __res;                        // 杩斿洖姣旇緝缁撴灉銆�

261 }

262

    //// 璁＄畻瀛楃�︿覆闀垮害銆�

    // 鍙傛暟锛�s - 瀛楃�︿覆銆�

    // %0 - ecx(__res)锛�%1 - edi(瀛楃�︿覆鎸囬��s)锛�%2 - eax(0)锛�%3 - ecx(0xffffffff)銆�

    // 杩斿洖锛氳繑鍥炲瓧绗︿覆鐨勯暱搴︺��

263 extern inline int strlen(const char * s)

264 {

265 register int __res __asm__("cx");    // __res鏄�瀵勫瓨鍣ㄥ彉閲�(ecx)銆�

266 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

267         "repne\n\t"                  // al(0)涓庡瓧绗︿覆涓�瀛楃��es:[edi]姣旇緝锛�

268         "scasb\n\t"                  // 鑻ヤ笉鐩哥瓑灏变竴鐩存瘮杈冦��

269         "notl %0\n\t"                // ecx鍙栧弽銆�

270         "decl %0"                    // ecx--锛屽緱瀛楃�︿覆寰楅暱搴﹀�笺��

271         :"=c" (__res):"D" (s),"a" (0),"0" (0xffffffff):"di");

272 return __res;                        // 杩斿洖瀛楃�︿覆闀垮害鍊笺��

273 }

274

275 extern char * ___strtok;     // 鐢ㄤ簬涓存椂瀛樻斁鎸囧悜涓嬮潰琚�鍒嗘瀽瀛楃�︿覆1(s)鐨勬寚閽堛��

276

    //// 鍒╃敤瀛楃�︿��2涓�鐨勫瓧绗﹀皢瀛楃�︿覆1鍒嗗壊鎴愭爣璁�(tokern)搴忓垪銆�

    // 灏嗕覆1鐪嬩綔鏄�鍖呭惈闆朵釜鎴栧�氫釜鍗曡瘝(token)鐨勫簭鍒楋紝骞剁敱鍒嗗壊绗﹀瓧绗︿覆2涓�鐨勪竴涓�鎴栧�氫釜瀛楃��

    // 鍒嗗紑銆傜��涓�娆¤皟鐢� strtok()鏃讹紝灏嗚繑鍥炴寚鍚戝瓧绗︿覆1涓�绗�1涓�token棣栧瓧绗︾殑鎸囬拡锛屽苟鍦ㄨ繑

    // 鍥�token鏃跺皢涓� null瀛楃�﹀啓鍒板垎鍓茬�﹀�勩�傚悗缁�浣跨�� null 浣滀负瀛楃�︿��1鐨勮皟鐢�锛屽皢鐢ㄨ繖绉嶆��

    // 娉曠户缁�鎵�鎻忓瓧绗︿覆1锛岀洿鍒版病鏈�token 涓烘��銆傚湪涓嶅悓鐨勮皟鐢ㄨ繃绋嬩腑锛屽垎鍓茬�︿��2鍙�浠ヤ笉鍚屻��

    // 鍙傛暟锛�s - 寰呭�勭悊鐨勫瓧绗︿��1锛�ct - 鍖呭惈鍚勪釜鍒嗗壊绗︾殑瀛楃�︿��2銆�

    // 姹囩紪杈撳嚭锛�%0 - ebx(__res)锛�%1 - esi(__strtok)锛�

    // 姹囩紪杈撳叆锛�%2 - ebx(__strtok)锛�%3 - esi(瀛楃�︿��1鎸囬拡s)锛�%4 - (瀛楃�︿��2鎸囬拡ct)銆�

    // 杩斿洖锛氳繑鍥炲瓧绗︿覆s涓�绗�1涓�token锛屽�傛灉娌℃湁鎵惧��token锛屽垯杩斿洖涓�涓�null鎸囬拡銆�

    // 鍚庣画浣跨敤瀛楃�︿��s鎸囬拡涓�null鐨勮皟鐢�锛屽皢鍦ㄥ師瀛楃�︿覆s涓�鎼滅储涓嬩竴涓�token銆�

277 extern inline char * strtok(char * s,const char * ct)

278 {

279 register char * __res __asm__("si");

280 __asm__("testl %1,%1\n\t"            // 棣栧厛娴嬭瘯esi(瀛楃�︿��1鎸囬拡s)鏄�鍚︽��NULL銆�

281         "jne 1f\n\t"                 // 濡傛灉涓嶆槸锛屽垯琛ㄦ槑鏄�棣栨�¤皟鐢ㄦ湰鍑芥暟锛岃烦杞�鏍囧��1銆�

282         "testl %0,%0\n\t"            // 鑻ユ槸NULL锛岃〃绀烘�ゆ�℃槸鍚庣画璋冪敤锛屾祴ebx(__strtok)銆�

283         "je 8f\n\t"                  // 濡傛灉ebx鎸囬拡鏄�NULL锛屽垯涓嶈兘澶勭悊锛岃烦杞�缁撴潫銆�

284         "movl %0,%1\n"               // 灏�ebx鎸囬拡澶嶅埗鍒�esi銆�

285         "1:\txorl %0,%0\n\t"         // 娓�ebx鎸囬拡銆�

286         "movl $-1,%%ecx\n\t"         // 缃�ecx = 0xffffffff銆�

287         "xorl %%eax,%%eax\n\t"       // 娓呴浂eax銆�

288         "cld\n\t"                    // 娓呮柟鍚戜綅銆�

289         "movl %4,%%edi\n\t"          // 涓嬮潰姹傚瓧绗︿覆2鐨勯暱搴︺��edi鎸囧悜瀛楃�︿��2銆�

290         "repne\n\t"                  // 灏�al(0)涓�es:[edi]姣旇緝锛屽苟涓�edi++銆�

291         "scasb\n\t"                  // 鐩村埌鎵惧埌瀛楃�︿��2鐨勭粨鏉�null瀛楃�︼紝鎴栬�℃暟ecx==0銆�

292         "notl %%ecx\n\t"             // 灏�ecx鍙栧弽锛�

293         "decl %%ecx\n\t"             // ecx--锛屽緱鍒板瓧绗︿覆2鐨勯暱搴﹀�笺��

294         "je 7f\n\t"                  /* empty delimeter-string */

                                         /* 鍒嗗壊绗﹀瓧绗︿覆绌� */ // 鑻ヤ覆2闀垮害涓�0锛屽垯杞�鏍囧��7銆�

295         "movl %%ecx,%%edx\n"         // 灏嗕覆2闀垮害鏆傚瓨鍏�edx銆�

296         "2:\tlodsb\n\t"              // 鍙栦覆1鐨勫瓧绗�ds:[esi]猫al锛屽苟涓�esi++銆�

297         "testb %%al,%%al\n\t"        // 璇ュ瓧绗︿负0鍊煎悧(涓�1缁撴潫)锛�

298         "je 7f\n\t"                  // 濡傛灉鏄�锛屽垯璺宠浆鏍囧��7銆�

299         "movl %4,%%edi\n\t"          // edi鍐嶆�℃寚鍚戜��2棣栥��

300         "movl %%edx,%%ecx\n\t"       // 鍙栦覆2鐨勯暱搴﹀�肩疆鍏ヨ�℃暟鍣�ecx銆�

301         "repne\n\t"                  // 灏�al涓�涓�1鐨勫瓧绗︿笌涓�2涓�鎵�鏈夊瓧绗︽瘮杈冿紝

302         "scasb\n\t"                  // 鍒ゆ柇璇ュ瓧绗︽槸鍚︿负鍒嗗壊绗︺��

303         "je 2b\n\t"                  // 鑻ヨ兘鍦ㄤ覆2涓�鎵惧埌鐩稿悓瀛楃�︼紙鍒嗗壊绗︼級锛屽垯璺宠浆鏍囧彿2銆�

304         "decl %1\n\t"                // 鑻ヤ笉鏄�鍒嗗壊绗︼紝鍒欎��1鎸囬拡esi鎸囧悜姝ゆ椂鐨勮�ュ瓧绗︺��

305         "cmpb $0,(%1)\n\t"           // 璇ュ瓧绗︽槸NULL瀛楃�﹀悧锛�

306         "je 7f\n\t"                  // 鑻ユ槸锛屽垯璺宠浆鏍囧彿7澶勩��

307         "movl %1,%0\n"               // 灏嗚�ュ瓧绗︾殑鎸囬��esi瀛樻斁鍦�ebx銆�

308         "3:\tlodsb\n\t"              // 鍙栦覆1涓嬩竴涓�瀛楃��ds:[esi]猫al锛屽苟涓�esi++銆�

309         "testb %%al,%%al\n\t"        // 璇ュ瓧绗︽槸NULL瀛楃�﹀悧锛�

310         "je 5f\n\t"                  // 鑻ユ槸锛岃〃绀轰覆1缁撴潫锛岃烦杞�鍒版爣鍙�5銆�

311         "movl %4,%%edi\n\t"          // edi鍐嶆�℃寚鍚戜��2棣栥��

312         "movl %%edx,%%ecx\n\t"       // 涓�2闀垮害鍊肩疆鍏ヨ�℃暟鍣�ecx銆�

313         "repne\n\t"                  // 灏�al涓�涓�1鐨勫瓧绗︿笌涓�2涓�姣忎釜瀛楃�︽瘮杈冿紝

314         "scasb\n\t"                  // 娴嬭瘯al瀛楃�︽槸鍚︽槸鍒嗗壊绗︺��

315         "jne 3b\n\t"                 // 鑻ヤ笉鏄�鍒嗗壊绗﹀垯璺宠浆鏍囧��3锛屾��娴嬩覆1涓�涓嬩竴涓�瀛楃�︺��

316         "decl %1\n\t"                // 鑻ユ槸鍒嗗壊绗︼紝鍒�esi--锛屾寚鍚戣�ュ垎鍓茬�﹀瓧绗︺��

317         "cmpb $0,(%1)\n\t"           // 璇ュ垎鍓茬�︽��NULL瀛楃�﹀悧锛�

318         "je 5f\n\t"                  // 鑻ユ槸锛屽垯璺宠浆鍒版爣鍙�5銆�

319         "movb $0,(%1)\n\t"           // 鑻ヤ笉鏄�锛屽垯灏嗚�ュ垎鍓茬�︾��NULL瀛楃�︽浛鎹㈡帀銆�

320         "incl %1\n\t"                // esi鎸囧悜涓�1涓�涓嬩竴涓�瀛楃�︼紝涔熷嵆鍓╀綑涓查�栥��

321         "jmp 6f\n"                   // 璺宠浆鏍囧彿6澶勩��

322         "5:\txorl %1,%1\n"           // esi娓呴浂銆�

323         "6:\tcmpb $0,(%0)\n\t"       // ebx鎸囬拡鎸囧悜NULL瀛楃�﹀悧锛�

324         "jne 7f\n\t"                 // 鑻ヤ笉鏄�锛屽垯璺宠浆鏍囧��7銆�

325         "xorl %0,%0\n"               // 鑻ユ槸锛屽垯璁�ebx=NULL銆�

326         "7:\ttestl %0,%0\n\t"        // ebx鎸囬拡涓�NULL鍚楋紵

327         "jne 8f\n\t"                 // 鑻ヤ笉鏄�鍒欒烦杞�8锛岀粨鏉熸眹缂栦唬鐮併��

328         "movl %0,%1\n"               // 灏�esi缃�涓�NULL銆�

329         "8:"

330         :"=b" (__res),"=S" (___strtok)

331         :"0" (___strtok),"1" (s),"g" (ct)

332         :"ax","cx","dx","di");

333 return __res;                        // 杩斿洖鎸囧悜鏂�token鐨勬寚閽堛��

334 }

335

    //// 鍐呭瓨鍧楀�嶅埗銆備粠婧愬湴鍧�src澶勫紑濮嬪�嶅��n涓�瀛楄妭鍒扮洰鐨勫湴鍧�dest澶勩��

    // 鍙傛暟锛�dest - 澶嶅埗鐨勭洰鐨勫湴鍧�锛�src - 澶嶅埗鐨勬簮鍦板潃锛�n - 澶嶅埗瀛楄妭鏁般��

    // %0 - ecx(n)锛�%1 - esi(src)锛�%2 - edi(dest)銆�

336 extern inline void * memcpy(void * dest,const void * src, int n)

337 {

338 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

339         "rep\n\t"                    // 閲嶅�嶆墽琛屽�嶅埗ecx涓�瀛楄妭锛�

340         "movsb"                      // 浠�ds:[esi]鍒�es:[edi]锛�esi++锛�edi++銆�

341         ::"c" (n),"S" (src),"D" (dest)

342         :"cx","si","di");

343 return dest;                         // 杩斿洖鐩�鐨勫湴鍧�銆�

344 }

345

    //// 鍐呭瓨鍧楃Щ鍔ㄣ�傚悓鍐呭瓨鍧楀�嶅埗锛屼絾鑰冭檻绉诲姩鐨勬柟鍚戙��

    // 鍙傛暟锛�dest - 澶嶅埗鐨勭洰鐨勫湴鍧�锛�src - 澶嶅埗鐨勬簮鍦板潃锛�n - 澶嶅埗瀛楄妭鏁般��

    // 鑻�dest<src鍒欙細%0 - ecx(n)锛�%1 - esi(src)锛�%2 - edi(dest)銆�

    // 鍚﹀垯锛�%0 - ecx(n)锛�%1 - esi(src+n-1)锛�%2 - edi(dest+n-1)銆�

    // 杩欐牱鎿嶄綔鏄�涓轰簡闃叉�㈠湪澶嶅埗鏃堕敊璇�鍦伴噸鍙犺�嗙洊銆�

346 extern inline void * memmove(void * dest,const void * src, int n)

347 {

348 if (dest<src)

349 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

350         "rep\n\t"                    // 浠�ds:[esi]鍒�es:[edi]锛屽苟涓�esi++锛�edi++锛�

351         "movsb"                      // 閲嶅�嶆墽琛屽�嶅埗ecx瀛楄妭銆�

352         ::"c" (n),"S" (src),"D" (dest)

353         :"cx","si","di");

354 else

355 __asm__("std\n\t"                    // 缃�鏂瑰悜浣嶏紝浠庢湯绔�寮�濮嬪�嶅埗銆�

356         "rep\n\t"                    // 浠�ds:[esi]鍒�es:[edi]锛屽苟涓�esi--锛�edi--锛�

357         "movsb"                      // 澶嶅埗ecx涓�瀛楄妭銆�

358         ::"c" (n),"S" (src+n-1),"D" (dest+n-1)

359         :"cx","si","di");

360 return dest;

361 }

362

    //// 姣旇緝n涓�瀛楄妭鐨勪袱鍧楀唴瀛橈紙涓や釜瀛楃�︿覆锛夛紝鍗充娇閬囦笂NULL瀛楄妭涔熶笉鍋滄�㈡瘮杈冦��

    // 鍙傛暟锛�cs - 鍐呭瓨鍧�1鍦板潃锛�ct - 鍐呭瓨鍧�2鍦板潃锛�count - 姣旇緝鐨勫瓧鑺傛暟銆�

    // %0 - eax(__res)锛�%1 - eax(0)锛�%2 - edi(鍐呭瓨鍧�1)锛�%3 - esi(鍐呭瓨鍧�2)锛�%4 - ecx(count)銆�

    // 杩斿洖锛氳嫢鍧�1>鍧�2 杩斿洖1锛涘潡1<鍧�2锛岃繑鍥�-1锛涘潡1==鍧�2锛屽垯杩斿洖0銆�

363 extern inline int memcmp(const void * cs,const void * ct,int count)

364 {

365 register int __res __asm__("ax");    // __res鏄�瀵勫瓨鍣ㄥ彉閲忋��

366 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

367         "repe\n\t"                   // 濡傛灉鐩哥瓑鍒欓噸澶嶏紝

368         "cmpsb\n\t"                  // 姣旇緝ds:[esi]涓�es:[edi]鐨勫唴瀹癸紝骞朵笖esi++锛�edi++銆�

369         "je 1f\n\t"                  // 濡傛灉閮界浉鍚岋紝鍒欒烦杞�鍒版爣鍙�1锛岃繑鍥�0(eax)鍊�

370         "movl $1,%%eax\n\t"          // 鍚﹀垯eax缃�1锛�

371         "jl 1f\n\t"                  // 鑻ュ唴瀛樺潡2鍐呭�圭殑鍊�<鍐呭瓨鍧�1锛屽垯璺宠浆鏍囧彿1銆�

372         "negl %%eax\n"               // 鍚﹀垯eax = -eax銆�

373         "1:"

374         :"=a" (__res):"0" (0),"D" (cs),"S" (ct),"c" (count)

375         :"si","di","cx");

376 return __res;                        // 杩斿洖姣旇緝缁撴灉銆�

377 }

378

    //// 鍦�n瀛楄妭澶у皬鐨勫唴瀛樺潡(瀛楃�︿��)涓�瀵绘壘鎸囧畾瀛楃�︺��

    // 鍙傛暟锛�cs - 鎸囧畾鍐呭瓨鍧楀湴鍧�锛�c - 鎸囧畾鐨勫瓧绗︼紝count - 鍐呭瓨鍧楅暱搴︺��

    // %0 - edi(__res)锛�%1 - eax(瀛楃��c)锛�%2 - edi(鍐呭瓨鍧楀湴鍧�cs)锛�%3 - ecx(瀛楄妭鏁�count)銆�

    // 杩斿洖绗�涓�涓�鍖归厤瀛楃�︾殑鎸囬拡锛屽�傛灉娌℃湁鎵惧埌锛屽垯杩斿��NULL瀛楃�︺��

379 extern inline void * memchr(const void * cs,char c,int count)

380 {

381 register void * __res __asm__("di"); // __res鏄�瀵勫瓨鍣ㄥ彉閲忋��

382 if (!count)                          // 濡傛灉鍐呭瓨鍧楅暱搴�==0锛屽垯杩斿洖NULL锛屾病鏈夋壘鍒般��

383         return NULL;

384 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

385         "repne\n\t"                  // 濡傛灉涓嶇浉绛夊垯閲嶅�嶆墽琛屼笅闈㈣��鍙ワ��

386         "scasb\n\t"                  // al涓�瀛楃�︿笌es:[edi]瀛楃�︿綔姣旇緝锛屽苟涓�edi++锛�

387         "je 1f\n\t"                  // 濡傛灉鐩哥瓑鍒欏悜鍓嶈烦杞�鍒版爣鍙�1澶勩��

388         "movl $1,%0\n"               // 鍚﹀垯edi涓�缃�1銆�

389         "1:\tdecl %0"                // 璁�edi鎸囧悜鎵惧埌鐨勫瓧绗︼紙鎴栨槸NULL锛夈��

390         :"=D" (__res):"a" (c),"D" (cs),"c" (count)

391         :"cx");

392 return __res;                        // 杩斿洖瀛楃�︽寚閽堛��

393 }

394

    //// 鐢ㄥ瓧绗﹀～鍐欐寚瀹氶暱搴﹀唴瀛樺潡銆�

    // 鐢ㄥ瓧绗�c濉�鍐�s鎸囧悜鐨勫唴瀛樺尯鍩燂紝鍏卞～count瀛楄妭銆�

    // %0 - eax(瀛楃��c)锛�%1 - edi(鍐呭瓨鍦板潃)锛�%2 - ecx(瀛楄妭鏁�count)銆�

395 extern inline void * memset(void * s,char c,int count)

396 {

397 __asm__("cld\n\t"                    // 娓呮柟鍚戜綅銆�

398         "rep\n\t"                    // 閲嶅��ecx鎸囧畾鐨勬�℃暟锛屾墽琛�

399         "stosb"                      // 灏�al涓�瀛楃�﹀瓨鍏�es:[edi]涓�锛屽苟涓�edi++銆�

400         ::"a" (c),"D" (s),"c" (count)

401         :"cx","di");

402 return s;

403 }

404

405 #endif

406