Disabling integer overflow capping for uint8 datatypes

11 次查看（过去 30 天）
JMB
JMB 2024-6-20
编辑： Voss 2024-6-20
Hello!
I am currently in the middle of optimizing some high-performance code, and have run into a weird situation where I need integer overflow to occur on some uint8 variables. Unfortunately, it seems like MATLAB features datatype capping, meaning that when I perform the operation
uint8(100) * uint8(30)
I get a value of 255, where I would expect something like 184.
The same occurs when I perform addition:
uint8(100) + uint8(200)
Here, I also expect to get 44, but instead get 255.
Is there a way to turn this capping off, so that I can have the overflow occur? I understand that this could potentially be a "dangerous" operation to perform, but I really would benefit from having a way to test some code with integer overflow in MATLAB before I do any form of compilation or other code optimization work.

请先登录，再回答此问题。

回答（1 个）

Voss
Voss 2024-6-20
编辑：Voss 2024-6-20
Ran in:
I don't think you can disable integer overflow capping, but you could of course perform the operations on corresponding floating-point variables and then take the results mod 256.
x = uint8(100);
y = uint8(30);
z = uint8(200);
% original integer arithmetic
x * y
ans = uint8 255
x + z
ans = uint8 255
% with capping "disabled"
uint8( mod( double(x) * double(y) , 256) )
ans = uint8 184
uint8( mod( double(x) + double(z) , 256) )
ans = uint8 44

类别

在 Help Center 和 File Exchange 中查找有关 Logical 的更多信息

标签

产品


版本

R2024a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by