some bug on Polyspace ,the variable imask never has value of 3。

the variable imask never has value of this simple program.

[ElectronicABC]

[0..4] mean 0 1 2 3 4 ,but the program never has value 3.

Answer 1

[ElectronicABC]

this is a bug in this verion polyspace ,I run the same on my friends computer,get the right answer [0 ..2] or 4 or 8 ...

Answer 2

[Shubham]

Hi Chen,

I understand you could not figure out when the value of the variable "imask" reaches "3" as shown in the variable access panel.

The value of 3 in the "Reads" and "Writes" columns in the variable access denotes the frequency of reading or writing operations performed on the variable. It does not indicate the specific value of the variable "imask" during program execution.

For more info, read here:

https://www.mathworks.com/help/codeprover/ug/variable-access.html

[ElectronicABC]

not variable acess,but left yelllow tool tips show range[0..4] contains value 3 during program exectution.

[Shubham]

Hi Chen,

Could you please tell me which version of Polyspace are you using?

[ElectronicABC]

version 2021A

[Shubham]

Hi Chen, Polyspace does not execute source code but does approximation. It looks like it is an over approximation in Polyspace R2021. Polyspace provided an over approximation of the possible values of imask. This issue has been fixed in the latest release. Thanks