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author | Werner Koch <wk@gnupg.org> | 1999-01-21 05:25:25 +0000 |
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committer | Werner Koch <wk@gnupg.org> | 1999-01-21 05:25:25 +0000 |
commit | a67389adbd43ea27910535819dd62ef16236f0d1 (patch) | |
tree | d877c8e0f8fa94473f95e43d5ef6c60a55dc596d /mpi/mips3 | |
parent | 90fb92ebefa6ca9d0a61f7a0137512b21959309e (diff) | |
download | libgcrypt-a67389adbd43ea27910535819dd62ef16236f0d1.tar.gz |
See ChangeLog: Thu Jan 21 06:22:10 CET 1999 Werner Koch
Diffstat (limited to 'mpi/mips3')
-rw-r--r-- | mpi/mips3/README | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/mpi/mips3/README b/mpi/mips3/README new file mode 100644 index 00000000..e94b2c74 --- /dev/null +++ b/mpi/mips3/README @@ -0,0 +1,23 @@ +This directory contains mpn functions optimized for MIPS3. Example of +processors that implement MIPS3 are R4000, R4400, R4600, R4700, and R8000. + +RELEVANT OPTIMIZATION ISSUES + +1. On the R4000 and R4400, branches, both the plain and the "likely" ones, + take 3 cycles to execute. (The fastest possible loop will take 4 cycles, + because of the delay insn.) + + On the R4600, branches takes a single cycle + + On the R8000, branches often take no noticable cycles, as they are + executed in a separate function unit.. + +2. The R4000 and R4400 have a load latency of 4 cycles. + +3. On the R4000 and R4400, multiplies take a data-dependent number of + cycles, contrary to the SGI documentation. There seem to be 3 or 4 + possible latencies. + +STATUS + +Good... |