What does compile-option -oldcg do?


In the makefiles of my legacy-code I found compile-flag -oldcg.
When I type

“pgf90 -help -oldgc”

I get

“-oldcg Test new CG”

Still I have no clue. Can you please tell me what this switch/flag does?



Hi Arjan,

In 32-bits, PGI has two separate compilers. One is for systems that support SSE (internally called the “New” Code Generator (CG)) and one for systems that support x87 (internally called the “Old” CG). The drivers (pgcc, pgf90, etc) automaticly determine the correct CG for your system. You can override the default via the “-tp” option or “-Mscalarsse” (Use SSE) and “-Mnoscalarsse” (Use x87).

The flag “-oldcg” has been deprecated and is no longer functional. Please use “-Mnoscalarsse” instead.

  • Mat