How Much Faster Are Release Builds Compared to Debug Builds?

Debug and the Release version of the performance differences

Performance impact

Debug and Release configuration in the programming environment are mainly the difference in compile code. In the debug mode, the compiler focuses on providing debugging information; and in the Release mode, it gives priority to performance optimization.

Optimized version of the release version

The JIT compiler used in the release version performs various optimizations, including:

Inner United: Use an embedded code replacement method to avoid calling expenses.

Register allocation: store local variables and parameters in the CPU register to minimize memory access.
Index check and elimination: The index check of the array can be skipped during the verification of the border to improve the performance.
Cycle expansion: Repeat cycles to reduce branches and enhance the execution of over -the -scale.
Dead code elimination: Delete sentences that have no side effects or effects.
Code improvement: Move the cycle constant code to the cycle to reduce the cost of execution.
Public sub -expression elimination: Use a single value to replace the repeated expression.
Constant folding: Use the calculation value to replace the constant expression.
Copy and dissemination: Use the previously allocated value allocation variable to improve the register allocation.
• Reliability

Although the optimization of the release mode has significantly improved performance, they rarely affect the reliability of the code. The JIT optimizer has been widely tested and is usually reliable. However, due to the difference in subtle implementation, a specific code mode involving a structure or floating -point computing may sometimes occur in the Release version. Conclusion

The performance differences between

Debug and the Release version may be very large, especially for code that repeatedly executed on the key execution path. However, the reliability of the Release version is usually very high, and most of the code running in the debug mode can also work normally in the release mode.

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