IAR #pragma optimize 指令

#pragma optimize= none //one of none, low, medium, high, size, or speed放在被优化函数前
#pragma optimize 指令
格式：
#pragma optimize=token token token
where token is one or more of the following:
s Optimizes for speed
z Optimizes for size
2|3|6|9 Specifies level of optimization
no_cse Turns off common sub-expression elimination
no_inline Turns off function inlining
no_unroll Turns off loop unrolling
no_code_motion Turns off code motion.

The #pragma optimize directive is used for decreasing the optimization level or for
turning off some specific optimizations. This #pragma directive only affects the
function that follows immediately after the directive.
Notice that it is not possible to optimize for speed and size at the same time. Only one
of the s and z tokens can be used.
Note: If you use the #pragma optimize directive to specify an optimization level that
is higher than the optimization level you specify using a compiler option, the #pragma
directive is ignored.
Example
#pragma optimize=s 9
int small_and_used_often()
{
...
}
#pragma optimize=z 9
int big_and_seldom_used()
{
...
}
/*======================================================================================
速度优化选项：
-s[2|3|6|9]
Use this option to make the compiler optimize the code for maximum execution speed.
If no optimization option is specified, the compiler will use the size optimization -z2
by default. If the -s option is used without specifying the optimization level, speed
optimization at level 2 is used by default.

*The most important difference between -s2 and -s3 is that at level 2, all non-static
variables will live during their entire scope.

大小优化选项
-z[2|3|6|9]
Use this option to make the compiler optimize the code for minimum size. If no
optimization option is specified, -z2 is used by default

*The most important difference between -z2 and -z3 is that at level 2, all non-static
variables will live during their entire scope.

2 None*
3 Low
6 Medium
9 High

IAR #pragma optimize 指令相关推荐

编译指令 #pragma optimize
MSDN: https://docs.microsoft.com/en-us/cpp/preprocessor/optimize?redirectedfrom=MSDN&view=vs-201 ...
pragma comment的使用 pragma预处理指令详解
pragma comment的使用 pragma预处理指令详解 #pragma comment( comment-type [,"commentstring"] ) 该宏放置一个注 ...
#pragma comment和#pragma 预处理指令详解
该宏放置一个注释到对象文件或者可执行文件. 例如,#pragma comment(lib,"Ws2_32.lib")表示链接Ws2_32.lib这个库. 和在工程设置里写上链入 ...
#pragma预处理指令详解
#pragma预处理指令详解在所有的预处理指令中,#Pragma指令可能是最复杂的了,它的作用是设定编译器的状态或者是指示编译器完成一些特定的动作.#pragma指令对每个编译器给出了一个方法,在保 ...
iar c语言指令,IAR中工程相关配置及c语言易忘知识点
使用K60单片机时,往往使用IAR的比较多.但是我之前一直使用KEIL来进行stm32的开发,所以就有一种先入为主的观念,总觉得KEIL比IAR要好一些.随着和IAR打交道越来越多,渐渐地发现IAR也 ...
IAR之IAR EWARM软件软件配置
IAR之IAR EWARM软件软件配置转自:http://www.360doc.com/content/16/0415/10/32464717_550770606.shtml IAR EWARM软件 ...
pragma指令简介
在编写程序的时候,我们经常要用到#pragma指令来设定编译器的状态或者是指示编译器完成一些特定的动作. 下面介绍了一下该指令的一些常用参数,希望对大家有所帮助! 一. message 参数. mes ...
#pragma指令与#ifndef指令
#pragma指令与#ifndef指令在C/C++中,在使用预编译指令#include的时候,为了防止重复引用造成二义性,通常有两种方式-- 第一种是#ifndef指令防止代码块重复引用,比如说 # ...
解析#pragma指令
#pragma指令对每个编译器给出了一个方法,在保持与 C和C++语言完全兼容的情况下,给出主机或操作系统专有的特征.依据定义,编译指示是机器或操作系统专有的,且对于每个编译器都是不同的. 其格式一 ...

IAR #pragma optimize 指令

IAR #pragma optimize 指令相关推荐

最新文章

热门文章