To find the original price \( p \) of the shirt, we know that the current sale price is half of the original price. This can be expressed with the equation:
\[ \frac{p}{2} = 7.98 \]
To solve for \( p \), we can multiply both sides of the equation by 2:
\[ p = 7.98 \times 2 \]
Calculating that gives:
\[ p = 15.96 \]
Therefore, the original price of the shirt is:
\[ \text{p = } 15.96 \text{ dollars} \]