I eventually settled for plain aliases:
alias nim-gen='nim c -r -d:release --passC:-mcpu=cortex-a5
--passC:-mfpu=neon --passC:- ftree-vectorize --passC:-fprofile-generate
--passL:-lgcov'
alias nim-use='nim c -d:release --passC:-mcpu=cortex-a5 --passC:-mfpu=neon
--passC:-ftree-vectorize --passC:-fprofile-use'
so that building a profiled binary is as simple as, e.g.: $ nim-gen matmul.nim 1500 && nim-use matmul.nim
