{"id":23700,"date":"2022-11-27T22:15:46","date_gmt":"2022-11-27T16:45:46","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-i-need-help-understanding-what-some-instructions-mean\/"},"modified":"2022-11-27T22:15:46","modified_gmt":"2022-11-27T16:45:46","slug":"solved-i-need-help-understanding-what-some-instructions-mean","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-i-need-help-understanding-what-some-instructions-mean\/","title":{"rendered":"[Solved] I need help understanding what some instructions mean"},"content":{"rendered":"

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sub $0x10,%rsp<\/code> allocates space on the stack, it’s the same as doing pushq 0<\/code> twice except that the value in the allocated stack space will not necessarily be zero, but this is ok since the mov<\/code> instructions used later replace the garbage with real data. <\/p>\n

As Michael rightly stated the mov $0x0,%eax<\/code> is because printf<\/code> (as well as any other varargs function) takes the number of arguments in rax<\/code>.<\/p>\n<\/p><\/div>\n

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solved I need help understanding what some instructions mean <\/p>\n","protected":false},"excerpt":{"rendered":"

[ad_1] sub $0x10,%rsp allocates space on the stack, it’s the same as doing pushq 0 twice except that the value in the allocated stack space will not necessarily be zero, but this is ok since the mov instructions used later replace the garbage with real data. As Michael rightly stated the mov $0x0,%eax is because … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[320],"tags":[465,4600,1034],"class_list":["post-23700","post","type-post","status-publish","format-standard","hentry","category-solved","tag-assembly","tag-att","tag-x86-64"],"yoast_head":"\n[Solved] I need help understanding what some instructions mean - JassWeb<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/jassweb.com\/solved\/solved-i-need-help-understanding-what-some-instructions-mean\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] I need help understanding what some instructions mean - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] sub $0x10,%rsp allocates space on the stack, it’s the same as doing pushq 0 twice except that the value in the allocated stack space will not necessarily be zero, but this is ok since the mov instructions used later replace the garbage with real data. 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