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Annotation of OpenXM_contrib/gmp/mpn/mips3/README, Revision 1.1.1.1

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...