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+---- Thread: -32768 on 16-bit targets (/showthread.php?tid=1311)
-32768 on 16-bit targets - grunwald - 14-02-2017
Just to make sure since several of our customers brought this up lately:
Is the following code compliant on a target where 'int' is 16 bits?
Code:
int16_t x = -32768;Since the standard C type of '-32768' is 'long' on 16-bit targets, the essential type is the same.
Thus, I believe the code is not compliant.
This seems unfortunate given that the value does fit in the target type; especially since the same code is compliant on targets with 32-bit int.
Re: -32768 on 16-bit targets - misra-c - 30-03-2017
You are correct to say that the code is not-compliant.
The C standard type is "signed long", since it is the result of a unary negation on a literal whose type is "signed long".
The essential type and C standard type of an expression may only differ if the C standard type is "int" or "unsigned int". This is not the situation, so the essential type is also "signed long".
Using INT_MIN from the limits.h will return an expression with the correct value and "signed int" type.