Synthesis Result : RTL vs Technology Map Viewer
They are equivalent. The code/rtl-viewer give the equation as (B xor p_b) and B and the technology map view shows it as B and !p_b. The former can be simplified to the latter as follows

\$(A \oplus B)A \$

\$(A\bar{B} + \bar{A}B)B\$

\$AA\bar{B} + A\bar{A}B\$

\$A\bar{B} + 0\$ (\$A\bar{A}\$ is 0, so the right side is 0)

\$A\bar{B}\$