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-int32Use 16-bit int. This is the default.
-mint32 ¶-mno-int16Use 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.