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IBM RT Options

The following ‘-m’ options are defined for the IBM RT PC.

-min-line-mul   
Use an in-line code sequence for integer multiplies. This is the default.
-mcall-lib-mul   
Call lmul$$ for integer multiples.
-mfull-fp-blocks   
Generate full-size floating point data blocks, including the minimum amount of scratch space recommended by IBM. This is the default.
-mminimum-fp-blocks   
Do not include extra scratch space in floating point data blocks. This results in smaller code, but slower execution, since scratch space must be allocated dynamically.
-mfp-arg-in-fpregs   
Use a calling sequence incompatible with the IBM calling convention in which floating point arguments are passed in floating point registers.
-mfp-arg-in-gregs   
Use the normal calling convention for floating point arguments. This is the default.
-mhc-struct-return   
Return structures of more than one word in memory, rather than in a register. This provides compatibility with the MetaWare HighC (hc) compiler. Use the option ‘-fpcc-struct-return’ for compatibility with the Portable C Compiler (pcc).
-mnohc-struct-return   
Return some structures of more than one word in registers, when convenient. This is the default. For compatibility with the IBM-supplied compilers, use the option ‘-fpcc-struct-return’ or the option ‘-mhc-struct-return’.