3.17.25 PDP-11 Options
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.)
-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.
-m45- Generate code for a PDP-11/45. This is the default.
-m10- Generate code for a PDP-11/10.
-mbcopy-builtin- Use inline
movmemhi patterns for copying memory. This is the
default.
-mbcopy- Do not use inline
movmemhi patterns for copying memory.
-mint16-mno-int32- Use 16-bit
int. This is the default.
-mint32-mno-int16- Use 32-bit
int.
-mfloat64-mno-float32- Use 64-bit
float. This is the default.
-mfloat32-mno-float64- Use 32-bit
float.
-mabshi- Use
abshi2 pattern. This is the default.
-mno-abshi- Do not use
abshi2 pattern.
-mbranch-expensive- Pretend that branches are expensive. This is for experimenting with
code generation only.
-mbranch-cheap- Do not pretend that branches are expensive. This is the default.
-msplit- Generate code for a system with split I&D.
-mno-split- Generate code for a system without split I&D. This is the default.
-munix-asm- Use Unix assembler syntax. This is the default when configured for
pdp11-*-bsd.
-mdec-asm- Use DEC assembler syntax. This is the default when configured for any
PDP-11 target other than pdp11-*-bsd.