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3.17.12 IBM RT Options

These `-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. Note that stdarg.h will not work with floating point operands if this option is specified.
-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.