{"id":49107,"date":"2026-11-01T09:49:37","date_gmt":"2026-11-01T00:49:37","guid":{"rendered":"https:\/\/jore2.com\/?p=49107"},"modified":"2026-11-01T09:49:37","modified_gmt":"2026-11-01T00:49:37","slug":"tips-22796-switch-lowering-in-gcc","status":"publish","type":"post","link":"https:\/\/jore2.com\/?p=49107","title":{"rendered":"GCC \ucef4\ud30c\uc77c\ub7ec\uac00 switch \ubb38 \uad6c\ubb38 \ubd84\uc11d \uc2dc \uc810\ud504 \ud14c\uc774\ube14\uacfc \ube44\uad50 \ud2b8\ub9ac \uc911 \ud558\ub098\ub97c \uc120\ud0dd\ud558\ub294 \uae30\uc900 \uacf5\uac1c"},"content":{"rendered":"<div class=\"jore2-editor-byline\">\n<p><strong>\uc774\uac00\uc740<\/strong><\/p>\n<\/div>\n<p>2024\ub144 1\uc6d4 14\uc77c \uacf5\uac1c\ub41c \uae30\uc220 \ube14\ub85c\uadf8 \ud3ec\uc2a4\ud2b8\uc5d0\uc11c GCC \ucef4\ud30c\uc77c\ub7ec\uac00 switch \ubb38\uc744 \uae30\uacc4\uc5b4\ub85c \ubcc0\ud658\ud558\ub294 \ub0b4\ubd80 \ub85c\uc9c1\uc774 \uc0c1\uc138\ud788 \uc124\uba85\ub418\uc5c8\uc2b5\ub2c8\ub2e4. \uac1c\ubc1c\uc790\ub4e4\uc740 \uc774 \uc790\ub8cc\ub97c \ud1b5\ud574 \ucef4\ud30c\uc77c\ub7ec\uac00 \ub2e8\uc21c\ud788 \uc870\uac74\ubb38\uc744 \ub098\uc5f4\ud558\ub294 \uac83\uc774 \uc544\ub2c8\ub77c, \uc131\ub2a5\uacfc \ucf54\ub4dc \ud06c\uae30\uc5d0 \ub530\ub77c \uc138 \uac00\uc9c0 \uc804\ub7b5 \uc911 \ud558\ub098\ub97c \uc120\ud0dd\ud55c\ub2e4\ub294 \uc0ac\uc2e4\uc744 \ud655\uc778\ud588\uc2b5\ub2c8\ub2e4.<\/p>\n<p>\uc8fc\uc694 \uc804\ub7b5\uc740 \uc810\ud504 \ud14c\uc774\ube14, \ube44\ud2b8\uc14b \ud14c\uc2a4\ud2b8, \uadf8\ub9ac\uace0 \uc774\uc9c4 \ube44\uad50 \ud2b8\ub9ac\uc785\ub2c8\ub2e4. GCC\ub294 \uc18d\ub3c4 \ucd5c\uc801\ud654 \ubaa8\ub4dc\uc778 -O1, -O2, -O3, -Ofast\uc5d0\uc11c\ub294 \uc810\ud504 \ud14c\uc774\ube14 \ud56d\ubaa9 \uc218\uc640 \ud544\uc694\ud55c \ube44\uad50 \uc5f0\uc0b0 \uc218\uc758 \ube44\uc728\uc774 \uc57d 8 \uc774\ud558\uc77c \ub54c\ub9cc \uc810\ud504 \ud14c\uc774\ube14\uc744 \uc0dd\uc131\ud569\ub2c8\ub2e4. \ubc18\uba74 \ud06c\uae30 \ucd5c\uc801\ud654 \ubaa8\ub4dc\uc778 -Os\uc5d0\uc11c\ub294 \uc774 \ube44\uc728\uc774 2\ub85c \ub354 \uc5c4\uaca9\ud558\uac8c \uc801\uc6a9\ub429\ub2c8\ub2e4.<\/p>\n<p>\ud604\ub300\uc758 x64 \ubc0f Arm64 \uc544\ud0a4\ud14d\ucc98\uc5d0\uc11c\ub294 case_values_threshold \ud568\uc218\uac00 \uae30\ubcf8\uac12\uc73c\ub85c 5\ub97c \uc124\uc815\ud558\uace0 \uc788\uc2b5\ub2c8\ub2e4. \uc774\ub294 switch \ubb38 \uc548\uc5d0 \ucd5c\uc18c 5\uac1c \uc774\uc0c1\uc758 \ucf00\uc774\uc2a4 \ub77c\ubca8\uc774 \uc874\uc7ac\ud574\uc57c \ube44\ub85c\uc18c \uc810\ud504 \ud14c\uc774\ube14 \uc0dd\uc131\uc744 \uac80\ud1a0\ud55c\ub2e4\ub294 \uc758\ubbf8\uc785\ub2c8\ub2e4. \uac04\uc811 \ubd84\uae30\uc640 \uacbd\uacc4 \uac80\uc0ac \uc790\uccb4\uac00 \uc624\ubc84\ud5e4\ub4dc\ub97c \ubc1c\uc0dd\uc2dc\ud0a4\uae30 \ub54c\ubb38\uc5d0, \ub108\ubb34 \uc801\uc740 \uc218\uc758 \ucf00\uc774\uc2a4\uc5d0\ub294 \ub2e8\uc21c\ud55c \ubd84\uae30\ubb38\uc774 \ub354 \ud6a8\uc728\uc801\uc774\ub77c\uace0 \ud310\ub2e8\ud558\uae30 \ub54c\ubb38\uc785\ub2c8\ub2e4.<\/p>\n<p>\uc5f0\uc18d\ub418\uc9c0 \uc54a\uc740 \uc791\uc740 \ubc94\uc704\uc758 \uac12\ub4e4\uc774 \ub4f1\uc7a5\ud560 \uacbd\uc6b0, GCC\ub294 \ubd84\uae30 \ub300\uc2e0 x86\uc758 bt \uba85\ub839\uc5b4\ub97c \uc0ac\uc6a9\ud558\uc5ec \uc0ac\uc804 \uacc4\uc0b0\ub41c \ube44\ud2b8 \ub9c8\uc2a4\ud06c \uc0c1\uc218\uc640 \ub2e8\uc77c \ube44\ud2b8 \ud14c\uc2a4\ud2b8\ub97c \uc218\ud589\ud558\uae30\ub3c4 \ud569\ub2c8\ub2e4. \ub9cc\uc57d \uc810\ud504 \ud14c\uc774\ube14\ub3c4, \ube44\ud2b8\uc14b\ub3c4 \uc720\ub9ac\ud558\uc9c0 \uc54a\uc740 \uc0c1\ud669\uc774\ub77c\uba74 GCC\ub294 \ud655\ub960 \uac00\uc911\uce58\ub97c \uc801\uc6a9\ud55c \uc774\uc9c4 \uc758\uc0ac\uacb0\uc815 \ud2b8\ub9ac\ub97c \uad6c\ucd95\ud558\uc5ec \ucd5c\uc885\uc801\uc73c\ub85c \ucf54\ub4dc\ub97c \uc0dd\uc131\ud569\ub2c8\ub2e4.<\/p>\n<p>\ucee4\ubba4\ub2c8\ud2f0 \ubc18\uc751\uc5d0\uc11c\ub294 \uc774\ub7ec\ud55c \ucd5c\uc801\ud654 \ub85c\uc9c1\uc5d0 \ub300\ud55c \ud765\ubbf8\ub85c\uc6b4 \ub17c\uc758\uac00 \uc774\uc5b4\uc84c\uc2b5\ub2c8\ub2e4. \ud2b9\ud788 \ub300\uaddc\ubaa8 \ud76c\uc18c switch \ubb38\uc5d0 \ub300\ud574 GCC\uc640 LLVM \ubaa8\ub450 \uc644\ubcbd\ud55c \ud574\uc2f1\uc744 \uad6c\ud604\ud558\uc9c0 \uc54a\ub294\ub2e4\ub294 \uc810\uc774 \uc9c0\uc801\ub418\uc5c8\uc2b5\ub2c8\ub2e4. \ud55c \uac1c\ubc1c\uc790\ub294 \uc720\ub2c8\ucf54\ub4dc \uc791\uc5c5 \ub4f1\uc5d0\uc11c \uc644\ubcbd\ud55c \ud574\uc2f1\uc744 \uc9c1\uc811 \uad6c\ud604\ud558\uba74 \ucef4\ud30c\uc77c \uc2dc\uac04\uc744 \ud06c\uac8c \ub2e8\ucd95\ud560 \uc218 \uc788\ub2e4\uace0 \uc5b8\uae09\ud588\uc73c\ub098, \uacf5\uc2dd \ucef4\ud30c\uc77c\ub7ec\uc5d0\ub294 \uc544\uc9c1 \ud574\ub2f9 \uae30\ub2a5\uc774 \ud3ec\ud568\ub418\uc5b4 \uc788\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/p>\n<p>\ub610 \ub2e4\ub978 \uc0ac\ub840\ub85c\ub294 .NET\uc758 System.HashCode \uac1c\ubc1c \ub2f9\uc2dc, \ud2b9\uc815 \uc0c1\ud669\uc5d0\uc11c \uc758\uc0ac\uacb0\uc815 \ud2b8\ub9ac\uac00 \uc810\ud504 \ud14c\uc774\ube14\ubcf4\ub2e4 \ud6e8\uc52c \ube60\ub978 \uc131\ub2a5\uc744 \ubcf4\uc600\ub2e4\ub294 \uacbd\ud5d8\ub2f4\uc774 \uacf5\uc720\ub418\uae30\ub3c4 \ud588\uc2b5\ub2c8\ub2e4. \uc774\ub294 \ucef4\ud30c\uc77c\ub7ec\uc758 \uc77c\ubc18\uc801\uc778 \ud734\ub9ac\uc2a4\ud2f1\uc774 \ubaa8\ub4e0 \ud558\ub4dc\uc6e8\uc5b4 \ud658\uacbd\uc774\ub098 \ub370\uc774\ud130 \ud328\ud134\uc5d0\uc11c \ucd5c\uc801\uc774 \uc544\ub2d0 \uc218 \uc788\uc74c\uc744 \uc2dc\uc0ac\ud569\ub2c8\ub2e4.<\/p>\n<p>\ud604\uc7ac\ub85c\uc11c\ub294 GCC\uc758 tree-switch-conversion.cc \uc18c\uc2a4 \ucf54\ub4dc\uc5d0\uc11c \ub3d9\uc801 \ud504\ub85c\uadf8\ub798\ubc0d\uc744 \ud65c\uc6a9\ud574 \ucd5c\uc801\uc758 \ud074\ub7ec\uc2a4\ud130 \ubd84\ud560\uc744 \uacb0\uc815\ud558\ub294 \uacfc\uc815\uae4c\uc9c0 \ucd94\uc801\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ub2e4\ub9cc, sparse_8 \uc608\uc81c\ucc98\ub7fc \uac12\uc744 \ub098\ub204\uc5b4 \uc810\ud504 \ud14c\uc774\ube14\uc744 \ub2e8\uc21c\ud654\ud558\ub294 \ubcc0\ud615\uc740 GCC\uac00 \uc790\ub3d9\uc73c\ub85c \ucc3e\uc544\ub0b4\uc9c0 \ubabb\ud558\ub294 \uac83\uc73c\ub85c \ub098\ud0c0\ub0ac\uc2b5\ub2c8\ub2e4.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>2024\ub144 1\uc6d4 \uacf5\uac1c\ub41c \uae30\uc220 \ubd84\uc11d \uc790\ub8cc\uc5d0 \ub530\ub974\uba74 GCC\ub294 \ucd5c\uc801\ud654 \ubaa8\ub4dc\uc5d0 \ub530\ub77c \uc810\ud504 \ud14c\uc774\ube14 \uc0ac\uc6a9 \ube44\uc728\uc744 8\ubc30 \ub610\ub294 2\ubc30\ub85c \uc81c\ud55c\ud558\uba70, \ucd5c\uc18c 5\uac1c\uc758 \ucf00\uc774\uc2a4 \ub77c\ubca8\uc774 \uc788\uc5b4\uc57c \uac04\uc811 \ubd84\uae30\ub97c \uace0\ub824\ud55c\ub2e4.<\/p>\n","protected":false},"author":4,"featured_media":49106,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jore2_quality_policy":"people-first-v2","footnotes":""},"categories":[387],"tags":[32434,32435,32436,3095,3055],"class_list":["post-49107","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-it","tag-gcc","tag-switch","tag-32436","tag-3095","tag-3055"],"featured_image_urls":{"full":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx.png",2400,1260,false],"thumbnail":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-150x150.png",150,150,true],"medium":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-300x158.png",300,158,true],"medium_large":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-768x403.png",640,336,true],"large":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-1024x538.png",640,336,true],"1536x1536":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-1536x806.png",1536,806,true],"2048x2048":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-2048x1075.png",2048,1075,true],"morenews-large":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-825x575.png",825,575,true],"morenews-medium":["https:\/\/jore2.com\/wp-content\/uploads\/2026\/11\/cg4bme6jx-590x410.png",590,410,true]},"author_info":{"info":["\uc774\uac00\uc740"]},"category_info":"<a 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