diff options
Diffstat (limited to 'gmp-6.3.0/mpn/x86/pentium4/sse2/submul_1.asm')
| -rw-r--r-- | gmp-6.3.0/mpn/x86/pentium4/sse2/submul_1.asm | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/gmp-6.3.0/mpn/x86/pentium4/sse2/submul_1.asm b/gmp-6.3.0/mpn/x86/pentium4/sse2/submul_1.asm new file mode 100644 index 0000000..020675b --- /dev/null +++ b/gmp-6.3.0/mpn/x86/pentium4/sse2/submul_1.asm @@ -0,0 +1,182 @@ +dnl Intel Pentium-4 mpn_submul_1 -- Multiply a limb vector with a limb and +dnl subtract the result from a second limb vector. + +dnl Copyright 2001, 2002, 2008, 2010 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 +C P6 model 0-8,10-12 - +C P6 model 9 (Banias) 6.8 +C P6 model 13 (Dothan) 6.9 +C P4 model 0-1 (Willamette) ? +C P4 model 2 (Northwood) 5.87 +C P4 model 3-4 (Prescott) 6.5 + +C This code represents a step forwards compared to the code available before +C GMP 5.1, but it is not carefully tuned for either P6 or P4. In fact, it is +C not good for P6. For P4 it saved a bit over 1 c/l for both Northwood and +C Prescott compared to the old code. +C +C The arrangements made here to get a two instruction dependent chain are +C slightly subtle. In the loop the carry (or borrow rather) is a negative so +C that a paddq can be used to give a low limb ready to store, and a high limb +C ready to become the new carry after a psrlq. +C +C If the carry was a simple twos complement negative then the psrlq shift would +C need to bring in 0 bits or 1 bits according to whether the high was zero or +C non-zero, since a non-zero value would represent a negative needing sign +C extension. That wouldn't be particularly easy to arrange and certainly would +C add an instruction to the dependent chain, so instead an offset is applied so +C that the high limb will be 0xFFFFFFFF+c. With c in the range -0xFFFFFFFF to +C 0, the value 0xFFFFFFFF+c is in the range 0 to 0xFFFFFFFF and is therefore +C always positive and can always have 0 bits shifted in, which is what psrlq +C does. +C +C The extra 0xFFFFFFFF must be subtracted before c is used, but that can be +C done off the dependent chain. The total adjustment then is to add +C 0xFFFFFFFF00000000 to offset the new carry, and subtract 0x00000000FFFFFFFF +C to remove the offset from the current carry, for a net add of +C 0xFFFFFFFE00000001. In the code this is applied to the destination limb when +C fetched. +C +C It's also possible to view the 0xFFFFFFFF adjustment as a ones-complement +C negative, which is how it's undone for the return value, but that doesn't +C seem as clear. + +defframe(PARAM_CARRY, 20) +defframe(PARAM_MULTIPLIER,16) +defframe(PARAM_SIZE, 12) +defframe(PARAM_SRC, 8) +defframe(PARAM_DST, 4) + + TEXT + ALIGN(16) + +PROLOGUE(mpn_submul_1c) +deflit(`FRAME',0) + movd PARAM_CARRY, %mm1 + jmp L(start_1c) +EPILOGUE() + +PROLOGUE(mpn_submul_1) +deflit(`FRAME',0) + pxor %mm1, %mm1 C initial borrow + +L(start_1c): + mov PARAM_SRC, %eax + pcmpeqd %mm0, %mm0 + + movd PARAM_MULTIPLIER, %mm7 + pcmpeqd %mm6, %mm6 + + mov PARAM_DST, %edx + psrlq $32, %mm0 C 0x00000000FFFFFFFF + + mov PARAM_SIZE, %ecx + psllq $32, %mm6 C 0xFFFFFFFF00000000 + + psubq %mm0, %mm6 C 0xFFFFFFFE00000001 + + psubq %mm1, %mm0 C 0xFFFFFFFF - borrow + + + movd (%eax), %mm3 C up + movd (%edx), %mm4 C rp + + add $-1, %ecx + paddq %mm6, %mm4 C add 0xFFFFFFFE00000001 + pmuludq %mm7, %mm3 + jnz L(gt1) + psubq %mm3, %mm4 C prod + paddq %mm4, %mm0 C borrow + movd %mm0, (%edx) C result + jmp L(rt) + +L(gt1): movd 4(%eax), %mm1 C up + movd 4(%edx), %mm2 C rp + + add $-1, %ecx + jz L(eev) + + ALIGN(16) +L(top): paddq %mm6, %mm2 C add 0xFFFFFFFE00000001 + pmuludq %mm7, %mm1 + psubq %mm3, %mm4 C prod + movd 8(%eax), %mm3 C up + paddq %mm4, %mm0 C borrow + movd 8(%edx), %mm4 C rp + movd %mm0, (%edx) C result + psrlq $32, %mm0 + + add $-1, %ecx + jz L(eod) + + paddq %mm6, %mm4 C add 0xFFFFFFFE00000001 + pmuludq %mm7, %mm3 + psubq %mm1, %mm2 C prod + movd 12(%eax), %mm1 C up + paddq %mm2, %mm0 C borrow + movd 12(%edx), %mm2 C rp + movd %mm0, 4(%edx) C result + psrlq $32, %mm0 + + lea 8(%eax), %eax + lea 8(%edx), %edx + add $-1, %ecx + jnz L(top) + + +L(eev): paddq %mm6, %mm2 C add 0xFFFFFFFE00000001 + pmuludq %mm7, %mm1 + psubq %mm3, %mm4 C prod + paddq %mm4, %mm0 C borrow + movd %mm0, (%edx) C result + psrlq $32, %mm0 + psubq %mm1, %mm2 C prod + paddq %mm2, %mm0 C borrow + movd %mm0, 4(%edx) C result +L(rt): psrlq $32, %mm0 + movd %mm0, %eax + not %eax + emms + ret + +L(eod): paddq %mm6, %mm4 C add 0xFFFFFFFE00000001 + pmuludq %mm7, %mm3 + psubq %mm1, %mm2 C prod + paddq %mm2, %mm0 C borrow + movd %mm0, 4(%edx) C result + psrlq $32, %mm0 + psubq %mm3, %mm4 C prod + paddq %mm4, %mm0 C borrow + movd %mm0, 8(%edx) C result + jmp L(rt) +EPILOGUE() |