PDP-11 Options - Using the GNU Compiler Collection (GCC)

These options are defined for the PDP-11:

-mfpu: Use hardware FPP floating point. This is the default. (FIS floating point on the PDP-11/40 is not supported.) Implies -m45.
-msoft-float: Do not use hardware floating point.
-mac0: Return floating-point results in ac0 (fr0 in Unix assembler syntax).
-mno-ac0: Return floating-point results in memory. This is the default.
-m40: Generate code for a PDP-11/40. Implies -msoft-float -mno-split.
-m45: Generate code for a PDP-11/45. This is the default.
-m10: Generate code for a PDP-11/10. Implies -msoft-float -mno-split.
-mint16
-mno-int32: Use 16-bit int. This is the default.
-mint32
-mno-int16: Use 32-bit int.
-msplit: Target has split instruction and data space. Implies -m45.
-munix-asm: Use Unix assembler syntax.
-mdec-asm: Use DEC assembler syntax.
-mgnu-asm: Use GNU assembler syntax. This is the default.
-mlra: Use the new LRA register allocator. By default, the old “reload” allocator is used.