README
1This directory contains mpn functions optimized for MIPS3. Example of
2processors that implement MIPS3 are R4000, R4400, R4600, R4700, and R8000.
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4RELEVANT OPTIMIZATION ISSUES
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61. 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.)
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10 On the R4600, branches takes a single cycle
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12 On the R8000, branches often take no noticeable cycles, as they are
13 executed in a separate function unit..
14
152. The R4000 and R4400 have a load latency of 4 cycles.
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173. 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.
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21STATUS
22
23Good...
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