67 lines
1.9 KiB
Plaintext
67 lines
1.9 KiB
Plaintext
Some assembly routines for AMD64 architecture (Opteron, Athlon64)
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Author: P. Gaudry
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Date: April 2005 -- March 2006
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Copyright: LGPL
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Purpose:
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========
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This is a patch to gmp-4.2 for AMD64 architecture. The 4.2 version comes
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with basic assembly support. This patch gives substantial speed-up.
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Only a few functions have been written:
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add_n
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sub_n
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addmul_1
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submul_1
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mul_basecase
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sqr_basecase
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The assembly code is mostly a 64 bit translation of the k7 assembly code
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that is available in GMP. The main modifications are:
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* The ABI for function calls is not the same: up to 6 parameters
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are passed in registers, not on the stack.
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* Change movl to movq, eax to rax, etc... That's the easy part.
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* In an unrolled loop, the size of the unrolled code is not the same, so
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the computation of the jump is different.
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Changes:
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========
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There is almost no change compared to the patch for 4.1.4. The
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multiplication has been slighlty improved (around 3.15 cyc/limb) but most
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of the improvement in the gmpbench score comes from modifications in the
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C code of GMP between the 2 versions.
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Disclaimer:
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===========
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The code has been reasonnably well tested. I used the program tests/devel/try
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that tests quite a few bug possibilities. Nonetheless, there is no
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warranty whatsoever.
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Bugs:
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=====
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Please send comments and bugs to gaudry@lix.polytechnique.fr and *not* to
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the official GMP developpers: they have nothing to do with this code.
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Performance:
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============
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I've got a multiply bench of around 55000 on a 2.4 GHz Opteron (was 41500
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with the plain 4.2). The whole gmpbench score is about 10000 (was
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8200 before patch).
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Install:
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========
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1) Get the gmp-4.2 archive and unpack it, thus creating a
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directory /path_to_gmp/gmp-4.2/
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2) In the directory of mpn_amd64.42, run
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./install /path_to_gmp/gmp-4.2
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3) cd /path_to_gmp/gmp-4.2
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4) ./configure with your favorite options
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5) make && make check && make install
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