3.19.38 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.) 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.
 
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Licensed under the GNU Free Documentation License, Version 1.3.
    https://gcc.gnu.org/onlinedocs/gcc-11.1.0/gcc/PDP_002d11-Options.html