Update: Compiler Optimization

Author: wdv4758h

compiler/optimization.rst

@@ -2,7 +2,8 @@
 Optimizations
 ========================================
 
-========================================
+
+.. contents:: 目錄
 
 
 PGO (Profile-Guided Optimizations)
@@ -14,7 +15,27 @@ PGO (Profile-Guided Optimizations)
     - ``-fprofile-generate``
     - ``-fprofile-use``
 
+
+
 IPO (Interprocedural Optimization)
 ========================================
 
 * `Wikipedia - Interprocedural optimization <https://en.wikipedia.org/wiki/Interprocedural_optimization>`_
+
+
+
+Misc
+========================================
+
+* ``-O3`` 就正常 general 的優化盡量開
+* ``-Ofast`` 除了 ``-O3`` 的參數外，還會加一些更 aggressive 的參數（通常跟數學運算有關
+* ``-march=native`` 是以目前在編譯的 CPU 為目標對象做優化，可能會利用到一些特定 CPU 才有的指令（例如 SSE、AVX）
+* ``-flto`` 是開 link time 的優化
+
+
+
+參考
+========================================
+
+* `Gentoo Wiki - GCC Optimization <https://wiki.gentoo.org/wiki/GCC_optimization>`_
+* `Stack Overflow - Clang optimization levels <http://stackoverflow.com/questions/15548023/clang-optimization-levels>`_