From a33e5716f56ac0e54bf6051df6b0889247455209 Mon Sep 17 00:00:00 2001 From: imp Date: Mon, 1 Mar 1999 06:27:31 +0000 Subject: Import mips2 and mips3 files from the 2.0.2 gmp distribution. Approved by: markm --- contrib/libgmp/mpn/mips3/README | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 contrib/libgmp/mpn/mips3/README (limited to 'contrib/libgmp/mpn/mips3/README') diff --git a/contrib/libgmp/mpn/mips3/README b/contrib/libgmp/mpn/mips3/README new file mode 100644 index 0000000..e94b2c7 --- /dev/null +++ b/contrib/libgmp/mpn/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... -- cgit v1.1