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Re: standard runtime for (possible/hopeful) 64bit kernels



no 64-bit CPUs that only implement the old R3K style 32 x 32-bit
FPU.

That said, there's some MIPS32 CPUs with a "64-bit" FPU that have the
full 32 64-bit FP regs, but that's a different answer to a question you
didn't ask :-)

Um, just out of curiousities, how 64bit FP math load/store is implemented
in that case?  In orginal MIPS design FP circuit was physically
independent piece of HW from main ALU unit, and special insn encoding
space was assigned.  Beginning from? R4300i, integer circuit started
snacking FP unit and GP can optionally used for FP arith, partly because
MUL/DIV by FP circuit was faster than standard MULhi/MULlo function
block.  It seems e500 core follows the similar rationle.

Toru Nishimura / ALKYL Technology


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