Local and global common subexpression elimination 局部和全局公共子表达式消除
In this optimization , the value of a common subexpression is calculated once 在此优化中,计算一次公共子表达式的值。
For global common subexpression optimization , the compiler searches entire functions for common subexpressions 对于全局公共子表达式优化,编译器搜索全部函数中的公共子表达式。
For local common subexpression optimization , the compiler examines short sections of code for common subexpressions 对于局部公共子表达式优化,编译器检查公共子表达式的一小部分代码。
Renaming parameters , translating pattern , generating code of pattern , extracting common sub expression , constructing and optimizing pattern - matching tree , are finished during program translation 翻译过程中,将进行参数一致化、模式分量翻译、模式的编码、公共子表达式的提取、模式匹配树的构造及优化工作。
Because a fiber may get swapped out and restarted later on a different thread , the address of the tls array must not be cached or optimized as a common subexpression across a function call see the 因为纤程可能会交换出去并且稍后在不同的线程上重新启动,所以tls数组的地址不得缓存或优化为函数调用中的公共子表达式(有关详细信息,请参见