homeparams-copy-register-parameters-to-stack.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: /homeparams (Copy Register Parameters to Stack)	/homeparams (Copy Register Parameters to Stack)	12/17/2018	/homeparams	/homeparams compiler option [C++] -homeparams compiler option [C++]	51067de4-24f7-436b-b8d9-bc867a7d53aa

/homeparams (Copy Register Parameters to Stack)

Forces parameters passed in registers to also be written to their locations on the stack upon function entry.

Syntax

/homeparams

Remarks

This compiler option is only available in the native and cross-compilers that target x64.

The x64 calling convention requires stack space to be allocated for all parameters, even for parameters passed in registers. For more information, see Parameter Passing. By default, the register parameters aren't copied into the stack space allocated for them in release builds. This makes it difficult to debug an optimized release build of your program.

For release builds, you can use the /homeparams option to force the compiler to copy register parameters to the stack, to ensure that you can debug your application. /homeparams does imply a performance disadvantage, because it requires an extra cycle to load the register parameters onto the stack.

In debug builds, the stack is always populated with parameters passed in registers.

To set this compiler option in the Visual Studio development environment

1. Open the project's Property Pages dialog box. For details, see Set C++ compiler and build properties in Visual Studio.

2. Select the Configuration Properties > C/C++ > Command Line property page.

3. Enter the compiler option in the Additional Options box.

To set this compiler option programmatically

• See xref:Microsoft.VisualStudio.VCProjectEngine.VCCLCompilerTool.AdditionalOptions%2A.

See also

MSVC Compiler Options
MSVC Compiler Command-Line Syntax