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Annotation of OpenXM_contrib/gmp/mpn/mips3/README, Revision 1.1

1.1     ! maekawa     1: This directory contains mpn functions optimized for MIPS3.  Example of
        !             2: processors that implement MIPS3 are R4000, R4400, R4600, R4700, and R8000.
        !             3:
        !             4: RELEVANT OPTIMIZATION ISSUES
        !             5:
        !             6: 1. On the R4000 and R4400, branches, both the plain and the "likely" ones,
        !             7:    take 3 cycles to execute.  (The fastest possible loop will take 4 cycles,
        !             8:    because of the delay insn.)
        !             9:
        !            10:    On the R4600, branches takes a single cycle
        !            11:
        !            12:    On the R8000, branches often take no noticable cycles, as they are
        !            13:    executed in a separate function unit..
        !            14:
        !            15: 2. The R4000 and R4400 have a load latency of 4 cycles.
        !            16:
        !            17: 3. On the R4000 and R4400, multiplies take a data-dependent number of
        !            18:    cycles, contrary to the SGI documentation.  There seem to be 3 or 4
        !            19:    possible latencies.
        !            20:
        !            21: STATUS
        !            22:
        !            23: Good...