---
title: "optimize pragma"
ms.date: "08/29/2019"
f1_keywords: ["vc-pragma.optimize", "optimize_CPP"]
helpviewer_keywords: ["pragmas, optimize", "optimize pragma"]
ms.assetid: cb13c1cc-186a-45bc-bee7-95a8de7381cc
---
# optimize pragma

Specifies optimizations on a function-by-function basis.

## Syntax

> **#pragma optimize( "** [ *optimization-list* ] **",** { **on** | **off** } **)**

## Remarks

The **optimize** pragma must appear outside a function. It takes effect at the first function defined after the pragma is seen. The **on** and **off** arguments turn options specified in the *optimization-list* on or off.

The *optimization-list* can be zero or more of the parameters shown in the following table.

### Parameters of the optimize Pragma

| Parameter(s) | Type of optimization |
|--------------------|--------------------------|
| **g** | Enable global optimizations. |
| **s** or **t** | Specify short or fast sequences of machine code. |
| **y** | Generate frame pointers on the program stack. |

These parameters are the same letters used with the [/O](../build/reference/o-options-optimize-code.md) compiler options. For example, the following pragma is equivalent to the `/Os` compiler option:

```cpp
#pragma optimize( "s", on )
```

Using the **optimize** pragma with the empty string (**""**) is a special form of the directive:

When you use the **off** parameter, it turns all the optimizations, **g**, **s**, **t**, and **y**, off.

When you use the **on** parameter, it resets the optimizations to the ones that you specified using the [/O](../build/reference/o-options-optimize-code.md) compiler option.

```cpp
#pragma optimize( "", off )
/* unoptimized code section */
#pragma optimize( "", on )
```

## See also

[Pragma directives and the __pragma keyword](../preprocessor/pragma-directives-and-the-pragma-keyword.md)