| /* IBM POWER submul_1 -- Multiply a limb vector with a limb and subtract |
| * the result from a second limb vector. |
| * |
| * Copyright (C) 1992, 1994, 1999, 2002 Free Software Foundation, Inc. |
| * |
| * This file is part of Libgcrypt. |
| * |
| * Libgcrypt 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 2.1 of |
| * the License, or (at your option) any later version. |
| * |
| * Libgcrypt 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 this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA |
| */ |
| |
| #include "sysdep.h" |
| #include "asm-syntax.h" |
| |
| |
| /* |
| |
| # INPUT PARAMETERS |
| # res_ptr r3 |
| # s1_ptr r4 |
| # size r5 |
| # s2_limb r6 |
| |
| # The RS/6000 has no unsigned 32x32->64 bit multiplication instruction. To |
| # obtain that operation, we have to use the 32x32->64 signed multiplication |
| # instruction, and add the appropriate compensation to the high limb of the |
| # result. We add the multiplicand if the multiplier has its most significant |
| # bit set, and we add the multiplier if the multiplicand has its most |
| # significant bit set. We need to preserve the carry flag between each |
| # iteration, so we have to compute the compensation carefully (the natural, |
| # srai+and doesn't work). Since the POWER architecture has a branch unit |
| # we can branch in zero cycles, so that's how we perform the additions. |
| */ |
| |
| .toc |
| .csect ._gcry_mpih_submul_1[PR] |
| .align 2 |
| .globl _gcry_mpih_submul_1 |
| .globl ._gcry_mpih_submul_1 |
| .csect _gcry_mpih_submul_1[DS] |
| _gcry_mpih_submul_1: |
| .long ._gcry_mpih_submul_1[PR], TOC[tc0], 0 |
| .csect ._gcry_mpih_submul_1[PR] |
| ._gcry_mpih_submul_1: |
| |
| cal 3,-4(3) |
| l 0,0(4) |
| cmpi 0,6,0 |
| mtctr 5 |
| mul 9,0,6 |
| srai 7,0,31 |
| and 7,7,6 |
| mfmq 11 |
| cax 9,9,7 |
| l 7,4(3) |
| sf 8,11,7 # add res_limb |
| a 11,8,11 # invert cy (r11 is junk) |
| blt Lneg |
| Lpos: bdz Lend |
| |
| Lploop: lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 10,0,6 |
| mfmq 0 |
| ae 11,0,9 # low limb + old_cy_limb + old cy |
| l 7,4(3) |
| aze 10,10 # propagate cy to new cy_limb |
| sf 8,11,7 # add res_limb |
| a 11,8,11 # invert cy (r11 is junk) |
| bge Lp0 |
| cax 10,10,6 # adjust high limb for negative limb from s1 |
| Lp0: bdz Lend0 |
| lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 9,0,6 |
| mfmq 0 |
| ae 11,0,10 |
| l 7,4(3) |
| aze 9,9 |
| sf 8,11,7 |
| a 11,8,11 # invert cy (r11 is junk) |
| bge Lp1 |
| cax 9,9,6 # adjust high limb for negative limb from s1 |
| Lp1: bdn Lploop |
| |
| b Lend |
| |
| Lneg: cax 9,9,0 |
| bdz Lend |
| Lnloop: lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 10,0,6 |
| mfmq 7 |
| ae 11,7,9 |
| l 7,4(3) |
| ae 10,10,0 # propagate cy to new cy_limb |
| sf 8,11,7 # add res_limb |
| a 11,8,11 # invert cy (r11 is junk) |
| bge Ln0 |
| cax 10,10,6 # adjust high limb for negative limb from s1 |
| Ln0: bdz Lend0 |
| lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 9,0,6 |
| mfmq 7 |
| ae 11,7,10 |
| l 7,4(3) |
| ae 9,9,0 # propagate cy to new cy_limb |
| sf 8,11,7 # add res_limb |
| a 11,8,11 # invert cy (r11 is junk) |
| bge Ln1 |
| cax 9,9,6 # adjust high limb for negative limb from s1 |
| Ln1: bdn Lnloop |
| b Lend |
| |
| Lend0: cal 9,0(10) |
| Lend: st 8,4(3) |
| aze 3,9 |
| br |
| |
