\u4eca\u5929\u5199\u5185\u6838\u4ee3\u7801\u65f6\u8981\u5199\u4e00\u4e2a\u6bd4\u8f83\u4e24\u4e2a\u9875\u6846(Page Frame)\u7684\u51fd\u6570\uff0c\u60f3\u5230\u7528\u5185\u8054\u6c47\u7f16\u6765\u5199\u8fd9\u4e2a\u529f\u80fd\u3002\u4e0b\u9762\u662f\u4ee3\u7801\uff1a<\/p>\n
long cmp_x64(void *s1, void *s2, size_t n)
\n\t{
\n\t size_t num = n \/ 8;
\n\t register long res;<\/p>\n
__asm__ __volatile__ return res; \u4eca\u5929\u5199\u5185\u6838\u4ee3\u7801\u65f6\u8981\u5199\u4e00\u4e2a\u6bd4\u8f83\u4e24\u4e2a\u9875\u6846(Page Frame)\u7684\u51fd\u6570\uff0c\u60f3\u5230\u7528\u5185\u8054\u6c47\u7f16\u6765\u5199\u8fd9\u4e2a\u529f\u80fd\u3002\u4e0b\u9762\u662f\u4ee3\u7801\uff1a long cmp_x64(void *s1, void *s2, size_t n) { size_t num = n \/ 8; register long res; __asm__ __volatile__ ( "testq %3,%3\\n\\t" ; \u6d4b\u8bd5num\u662f\u4e0d\u662f0 "repe cmpsq\\n\\t" ; \u4e0d\u505c\u5730\u6bd4\u8f83\u76f4\u5230cx\u5bc4\u5b58\u5668\u4e3a0\u6216\u6bd4\u8f83\u5230\u5dee\u522b "je … Continue reading “GCC\u5185\u8054\u6c47\u7f16\u5199\u7684memcmp\u51fd\u6570 for x86-64”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,7],"tags":[51,105],"class_list":["post-933","post","type-post","status-publish","format-standard","hentry","category-tech_articles","category-unix_linux","tag-linux-2","tag-105"],"_links":{"self":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/posts\/933","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=933"}],"version-history":[{"count":0,"href":"https:\/\/ykyi.net\/index.php?rest_route=\/wp\/v2\/posts\/933\/revisions"}],"wp:attachment":[{"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=933"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=933"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ykyi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=933"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n\t (
\n\t "testq %3,%3\\n\\t" ; \u6d4b\u8bd5num\u662f\u4e0d\u662f0
\n\t "repe cmpsq\\n\\t" ; \u4e0d\u505c\u5730\u6bd4\u8f83\u76f4\u5230cx\u5bc4\u5b58\u5668\u4e3a0\u6216\u6bd4\u8f83\u5230\u5dee\u522b
\n\t "je 1f\\n\\t" ; \u4e24\u5757\u5185\u5b58\u76f8\u7b49\uff0c\u8df3\u51fa\uff0c\u8fd4\u56de0.
\n\t "sbbq %0,%0\\n\\t" ; sbb\u662fx86\u7684\u51cf\u6cd5\u6307\u4ee4\uff0c\u4f1a\u989d\u5916\u5730\u51cf\u53bbCF(\u501f\u4f4d)\u7684\u503c\uff0c\u8fd9\u6837%0\u5c31\u4f1a\u662f0\u6216\u8005-1
\n\t "orq $1,%0\\n" ; \u628a\u7acb\u5373\u65701\u6216\u5230%0\u4e0a\uff0c\u8fd9\u6837%0\u5c31\u4f1a\u662f1\u6216\u8005-1.
\n\t "1:"
\n\t : "=&a"(res) ; \u4f20\u5165\u53d8\u91cfres\u653e\u5165\u5bc4\u5b58\u5668ax\uff0c\u4e14\u8fd9\u4e2a\u53d8\u91cf\u662f\u8f93\u51fa\u503c(=)\uff0c\u4e0d\u8981\u4e0e\u5176\u5b83\u8f93\u5165\u8f93\u51fa\u5171\u7528\u5bc4\u5b58\u5668(&)
\n\t : "0"(res), "S"(s1), "D"(s2), "c"(num) ; \u8f93\u5165\u5217\u8868
\n\t : "cc"); \/\/ clobber list \u544a\u8bc9gcc\u5728\u8fd9\u6bb5\u5185\u8054\u6c47\u7f16\u4e2d\u54ea\u4e9b\u5bc4\u5b58\u5668\u88ab\u663e\u5f0f\/\u9690\u5f0f\u4fee\u6539.If our instruction can alter the condition code register, we have to add "cc" to the list of clobbered registers.<\/span><\/p>\n
\n\t}<\/p>\n","protected":false},"excerpt":{"rendered":"