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Re: PowerPC FPU support


David Edelsohn wrote:
Michael Eager writes:

Michael> I'm adding support to GCC for a different PPC floating point unit. Michael> It's similar to the standard PPC FPU in that it supports most of Michael> the same instructions and all operation are in FP registers. Michael> The FPU comes in a single-precision and double-precision variant. Michael> There's also an option of having no FPU.

Michael> Rather than creating yet another configuration with another
Michael> TARGET_<whatever> definition and creating ever more cluttered
Michael> condition expression, I've thought to replace TARGET_FPRS with
Michael> TARGET_FPRS_SINGLE and TARGET_FPRS_DOUBLE.  These would both have
Michael> the value 1 for standard PPC, and 1 or 0 depending on whether the
Michael> single-or double-precision FPU was available, as specified by a new
Michael> option -mfpu=.  There would be some added instruction patterns
Michael> for the single-precision operations.

	I think you want to look at TARGET_HARD_FLOAT, not TARGET_FPRS.
TARGET_FPRS was added for Motorola e500 that has FP in GPRs.

TARGET_HARD_FLOAT means that you have hardware floating point of some kind. I guess I could split this into TARGET_HARD_FLOAT_SINGLE and TARGET_HARD_FLOAT_DOUBLE.

--
Michael Eager	 eager@eagercon.com
1960 Park Blvd., Palo Alto, CA 94306  650-325-8077


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