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

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3.18.34 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’.

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