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Branch prediction technology can optimize C function performance by predicting branch jump directions. Branch prediction techniques in C include: Static branch prediction: Prediction based on branch patterns and history. Dynamic branch prediction: updates the prediction table based on runtime results. Optimization tip: Use likely() and unlikely() hints to the compiler. Optimize branch conditions using simple comparisons. Reduce the number of branches, merge branches or use the ternary operator. Use loop unrolling to eliminate branches. Use inline functions to eliminate function call overhead. Benchmarking helps evaluate optimization effectiveness and determine the best strategy.
Branch prediction technology in C function performance optimization
Branch prediction is an optimization technology that can predict branches at runtime Jump direction, thereby improving program execution efficiency. Branch prediction technology in C mainly includes:
Practical case:
Consider the following code example:
int foo(int x) { if (x < 0) { return -1; } else { return 1; } }
For this code, the compiler can use static branch prediction to speculate on large In most cases x
is non-negative and optimized to:
int foo(int x) { return x >= 0 ? 1 : -1; }
Optimization suggestions:
instead of
x != 0).
Special Note:
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