I founf 2 cases where macro STD_LP_sbrk used.
if STD_LP_sbrk and STD_TP_sbrk, so call sbrk(0)
if STD_TP_sbrk, so call sbrk(STD_TP_sbrk)
If STD_LP_sbrk and Debug so call sbrk(STD_LP_sbrk)
Both triggered by env variavle USC_TP_SBRK and USC_LP_SBRK.
What is the idea for that?