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Diffstat (limited to 'plugins/MirOTR/libgcrypt-1.4.6/mpi/i586/README')
| -rw-r--r-- | plugins/MirOTR/libgcrypt-1.4.6/mpi/i586/README | 26 |
1 files changed, 0 insertions, 26 deletions
diff --git a/plugins/MirOTR/libgcrypt-1.4.6/mpi/i586/README b/plugins/MirOTR/libgcrypt-1.4.6/mpi/i586/README deleted file mode 100644 index d73b082684..0000000000 --- a/plugins/MirOTR/libgcrypt-1.4.6/mpi/i586/README +++ /dev/null @@ -1,26 +0,0 @@ -This directory contains mpn functions optimized for Intel Pentium -processors. - -RELEVANT OPTIMIZATION ISSUES - -1. Pentium doesn't allocate cache lines on writes, unlike most other modern -processors. Since the functions in the mpn class do array writes, we have to -handle allocating the destination cache lines by reading a word from it in the -loops, to achieve the best performance. - -2. Pairing of memory operations requires that the two issued operations refer -to different cache banks. The simplest way to insure this is to read/write -two words from the same object. If we make operations on different objects, -they might or might not be to the same cache bank. - -STATUS - -1. mpn_lshift and mpn_rshift run at about 6 cycles/limb, but the Pentium -documentation indicates that they should take only 43/8 = 5.375 cycles/limb, -or 5 cycles/limb asymptotically. - -2. mpn_add_n and mpn_sub_n run at asymptotically 2 cycles/limb. Due to loop -overhead and other delays (cache refill?), they run at or near 2.5 cycles/limb. - -3. mpn_mul_1, mpn_addmul_1, mpn_submul_1 all run 1 cycle faster than they -should... |