例:
if (almost_always_false_condition) { // do something }
有没有办法建议编译器在99%的条件下将是假的.条件计算需要大约60个周期进行检查,编译器本身无法在编译时计算.
(gcc 4.3)
performance gcc branch if-statement prediction
branch ×1
gcc ×1
if-statement ×1
performance ×1
prediction ×1