Turn off rt_roundd inserted function

Question

Matthew 2013-7-22

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/82808-turn-off-rt_roundd-inserted-function

编辑： Stephen23 2017-4-25

Hi,

During generating my C code I constantly get preparing to casting function. It's definition is:

static real_T rt_roundd(real_T u)
{
  real_T y;
    if (fabs(u) < 4.503599627370496E+15) {
      if (u >= 0.5) {
        y = floor(u + 0.5);
      } else if (u > -0.5) {
        y = 0.0;
      } else {
        y = ceil(u - 0.5);
      }
    } else {
      y = u;
    }
    return y;
  }

No matter what it does, it works horribly for my audio processing algorithm so I don't want it. How can I achieve it?

Removing it's calls works fine for my algorithm but I don't want to do it manually every time I get that code.

2 个评论
显示无隐藏无

Ryan Livingston 2013-7-23

编辑：Stephen23 2017-4-25

When you say it works horribly, do you mean it gives unexpected answers, it seems inefficient or something else?

Matthew 2013-7-23

I don't care. Audio samples become distorted after calculations in floating point and casting to C code and I'm not sure what causes that. Maybe it's Keil's compiler issue, maybe some optimalization I don't know.

What really works is removing all rt_roundd calls or putting "return y;" as first instruction in this function.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Ryan Livingston 2013-7-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/82808-turn-off-rt_roundd-inserted-function#answer_92564

编辑：Ryan Livingston 2017-4-25

You can use a Code Replacement library and define a function replacement for the round function. The library says map function foo to function bar in the generated code and math functions like ROUND are generally replaceable.

Here's a demo for using these libraries:

https://www.mathworks.com/examples/matlab-coder/mw/coder_product-coderdemo_crl-replacing-math-functions-and-operators?s_tid=srchtitle

and general doc for creating them:

http://www.mathworks.com/help/ecoder/ug/create-code-replacement-tables.html