From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001
From: Duncan Wilkie <antigravityd@gmail.com>
Date: Sat, 18 Nov 2023 06:11:09 -0600
Subject: Initial commit.

---
 gmp-6.3.0/mpn/x86/copyi.asm | 99 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 gmp-6.3.0/mpn/x86/copyi.asm

(limited to 'gmp-6.3.0/mpn/x86/copyi.asm')

diff --git a/gmp-6.3.0/mpn/x86/copyi.asm b/gmp-6.3.0/mpn/x86/copyi.asm
new file mode 100644
index 0000000..f6b0354
--- /dev/null
+++ b/gmp-6.3.0/mpn/x86/copyi.asm
@@ -0,0 +1,99 @@
+dnl  x86 mpn_copyi -- copy limb vector, incrementing.
+
+dnl  Copyright 1999-2002 Free Software Foundation, Inc.
+
+dnl  This file is part of the GNU MP Library.
+dnl
+dnl  The GNU MP Library is free software; you can redistribute it and/or modify
+dnl  it under the terms of either:
+dnl
+dnl    * the GNU Lesser General Public License as published by the Free
+dnl      Software Foundation; either version 3 of the License, or (at your
+dnl      option) any later version.
+dnl
+dnl  or
+dnl
+dnl    * the GNU General Public License as published by the Free Software
+dnl      Foundation; either version 2 of the License, or (at your option) any
+dnl      later version.
+dnl
+dnl  or both in parallel, as here.
+dnl
+dnl  The GNU MP Library is distributed in the hope that it will be useful, but
+dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+dnl  for more details.
+dnl
+dnl  You should have received copies of the GNU General Public License and the
+dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
+dnl  see https://www.gnu.org/licenses/.
+
+include(`../config.m4')
+
+
+C     cycles/limb  startup (approx)
+C P5	  1.0	      35
+C P6	  0.75	      45
+C K6	  1.0	      30
+C K7	  1.3	      65
+C P4	  1.0	     120
+C
+C (Startup time includes some function call overheads.)
+
+
+C void mpn_copyi (mp_ptr dst, mp_srcptr src, mp_size_t size);
+C
+C Copy src,size to dst,size, working from low to high addresses.
+C
+C The code here is very generic and can be expected to be reasonable on all
+C the x86 family.
+C
+C P6 -  An MMX based copy was tried, but was found to be slower than a rep
+C       movs in all cases.  The fastest MMX found was 0.8 cycles/limb (when
+C       fully aligned).  A rep movs seems to have a startup time of about 15
+C       cycles, but doing something special for small sizes could lead to a
+C       branch misprediction that would destroy any saving.  For now a plain
+C       rep movs seems ok.
+C
+C K62 - We used to have a big chunk of code doing an MMX copy at 0.56 c/l if
+C       aligned or a 1.0 rep movs if not.  But that seemed excessive since
+C       it only got an advantage half the time, and even then only showed it
+C       above 50 limbs or so.
+
+defframe(PARAM_SIZE,12)
+defframe(PARAM_SRC, 8)
+defframe(PARAM_DST, 4)
+deflit(`FRAME',0)
+
+	TEXT
+	ALIGN(32)
+
+	C eax	saved esi
+	C ebx
+	C ecx	counter
+	C edx	saved edi
+	C esi	src
+	C edi	dst
+	C ebp
+
+PROLOGUE(mpn_copyi)
+
+	movl	PARAM_SIZE, %ecx
+	movl	%esi, %eax
+
+	movl	PARAM_SRC, %esi
+	movl	%edi, %edx
+
+	movl	PARAM_DST, %edi
+
+	cld	C better safe than sorry, see mpn/x86/README
+
+	rep
+	movsl
+
+	movl	%eax, %esi
+	movl	%edx, %edi
+
+	ret
+
+EPILOGUE()
-- 
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