These -m options are defined for the LatticeMico32 architecture:
-mbarrel-shift-enabled
Enable barrel-shift instructions.
-mdivide-enabled
Enable divide and modulus instructions.
-mmultiply-enabled
Enable multiply instructions.
-msign-extend-enabled
Enable sign extend instructions.
-muser-enabled
Enable user-defined instructions.
© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-7.3.0/gcc/LM32-Options.html