3.17.33 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.
-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’.

© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-5.4.0/gcc/PDP_002d11-Options.html