内存使用量
通过生成的代码优化 RAM、ROM 和栈空间的使用
可以通过以下方法控制内存消耗：指定代码生成器将变量定义为局部变量或全局变量，以及指定数据如何传递给子系统函数。修改配置设置以减少用于存储数据的内存量。
代码生成器通过合并控制流构造、删除不影响计算结果的模块的无效代码路径和代码来减少 ROM 消耗。您可以通过删除可能不需要的代码（如初始化代码、重置和禁用函数以及防御性代码）来进一步减少 ROM 消耗。
模型设置
主题
内存使用量优化基础知识
- Design Techniques to Optimize Models for Efficient Code Generation
Apply design tools and techniques to optimize a model for code generation. - Optimize Generated Code Using Code Efficiency Tools and Techniques
When generating production code from your model to deploy into a real-time embedded system, code efficiency is an important consideration. - Configure Model for Code Generation Objectives by Using Code Generation Advisor
Use the Code Generation Advisor to check your model against code generation objectives. - Generate Efficient Code by Setting Model Configuration Parameters
Choose the efficiency level and priorities for your generated code.
定义局部变量或全局变量
- Customize Stack Space Allocation
Control the maximum allowable stack size to provide some control over whether data is defined locally or globally in the generated code. - Enable and Reuse Local Block Outputs in Generated Code
Where possible, the code generator declares block outputs as local variables, so that it can potentially reuse these variables. - 在生成的代码中重用全局模块输出
代码生成器尝试重用全局变量。 - 优化全局变量使用
选择全局变量引用优化来满足您的内存使用量和执行速度要求。 - Optimize Generated Code by Passing Reusable Subsystem Outputs as Individual Arguments
The code generator eliminates data copies from local variables back to global block I/O structures by passing reusable subsystem outputs as individual arguments instead of as a pointer to a structure stored in global memory. - 减少不可重用的子系统函数中的全局变量
为了减少不可重用子系统的全局 RAM，请生成一个通过参量而不是全局变量传递数据的函数接口。 - Reduce Memory Usage for Models Containing Referenced Models
Reduce RAM usage for a referenced model by generating optimized code that reuses buffers or generates reusable temporary buffers to hold referenced model outputs.
减小代码大小
- 删除零初始化代码
控制是否在生成的代码中初始化内部数据（模块状态和模块输出）和外部数据（值为零的根输入端口和输出端口）。 - Remove Reset and Disable Functions from the Generated Code
Remove unreachable (dead-code) instances of the reset and disable functions from the generated code for ERT-based systems that include model referencing hierarchies. - Inline Numeric Values of Block Parameters
Reduce global RAM usage by inlining the literal numeric values of block parameters. - Optimize Generated Code by Consolidating Redundant If-Else Statements
The code generator optimizes the generated code by combiningif-elsestatements that share the same condition. - 控制设置为零的局部变量的初始化代码的生成
默认情况下，代码生成器不会将局部变量显式初始化为零。这会生成更高效的代码，但会违反某些编码标准，例如MISRA C++:2008 Rule 0-1-4(Polyspace Bug Finder)。此示例说明如何禁用此优化，以从设置为零的局部变量中删除初始化代码。
减少用于存储数据的内存量
- 重用不同大小和维度的缓冲区
对具有不同大小和形状的矩阵重用缓冲区。 - 优化时间计数器的内存使用量
优化代码生成器为经过时间计数器分配的内存。 - 使用布尔数据优化逻辑信号生成的代码
代码生成器通过将逻辑信号存储为Boolean数据类型来优化生成的代码。 - 通过将布尔数据打包到位字段中对生成的代码进行优化
代码生成器通过将布尔数据打包到 1 位位字段中来减少 RAM 消耗量。 - Represent Integer and Fixed-Point Data Using Bit Field Storage Class
Optimize memory by representing integer and fixed-point data using bit field storage classes in the Embedded Coder Dictionary. - Specify Single-Precision Data Type for Embedded Application
Generate code whose floating-point data types are only single precision, for example, for targeting a single-precision processor. - Generate Efficient Code by Specifying Data Types for Block Parameters
To generate more efficient code, match parameter data types with signal data types or store parameters in smaller data types. - Control Operator Type in Generated Code
Generate code with Logical or Bitwise Operators or a combination of both operators. - Generate Efficient Code Using Unified Analysis
Reduce RAM usage and data copies performing unified analysis at model-level.
