cc -O2 -pipe -pthread -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations float/FLT_HAS_SUBNORM.c -o float/FLT_HAS_SUBNORM -D_POSIX_C_SOURCE=202405L -lm -lpthread float/FLT_HAS_SUBNORM.c:3:2: error: "FLT_HAS_SUBNORM is not defined" #error "FLT_HAS_SUBNORM is not defined" ^ 1 error generated.