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+Copyright 1996 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+The GNU MP Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
+
+
+
+
+
+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.
+
+4. The R1x000 processors can issue one floating-point operation, two integer
+ operations, and one memory operation per cycle. The FPU has very short
+ latencies, while the integer multiply unit is non-pipelined. We should
+ therefore write fp based mpn_Xmul_1.
+
+STATUS
+
+Good...
projects / msp430-gcc.git / blobdiff