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authoradmin@progandy.co.cc <admin@progandy.co.cc@eced67a3-f377-a0ae-92ae-d6de1850b05a>2010-08-19 20:12:06 +0000
committeradmin@progandy.co.cc <admin@progandy.co.cc@eced67a3-f377-a0ae-92ae-d6de1850b05a>2010-08-19 20:12:06 +0000
commit11e5e8749eb7d4d3cfebfa49bbb7ea4624608647 (patch)
treec773fee94a63a078e5cb59bdbfd3165f1830b7ea /libgcrypt-1.4.6/mpi/alpha/mpih-mul1.S
parentc7e64af067562167b6941f3ad8383e3ceb817633 (diff)
initial commit with v0.8.6.1
git-svn-id: http://mirotr.googlecode.com/svn/trunk@2 eced67a3-f377-a0ae-92ae-d6de1850b05a
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+/* Alpha 21064 mpih-mul1.S -- Multiply a limb vector with a limb and store
+ * the result in a second limb vector.
+ *
+ * Copyright (C) 1992, 1994, 1995, 1998,
+ * 2001, 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
+ */
+
+
+/*******************
+ * mpi_limb_t
+ * _gcry_mpih_mul_1( mpi_ptr_t res_ptr, (r16)
+ * mpi_ptr_t s1_ptr, (r17)
+ * mpi_size_t s1_size, (r18)
+ * mpi_limb_t s2_limb) (r19)
+ *
+ * This code runs at 42 cycles/limb on the EV4 and 18 cycles/limb on the EV5.
+ *
+ * To improve performance for long multiplications, we would use
+ * 'fetch' for S1 and 'fetch_m' for RES. It's not obvious how to use
+ * these instructions without slowing down the general code: 1. We can
+ * only have two prefetches in operation at any time in the Alpha
+ * architecture. 2. There will seldom be any special alignment
+ * between RES_PTR and S1_PTR. Maybe we can simply divide the current
+ * loop into an inner and outer loop, having the inner loop handle
+ * exactly one prefetch block?
+ */
+
+ .set noreorder
+ .set noat
+.text
+ .align 3
+ .globl _gcry_mpih_mul_1
+ .ent _gcry_mpih_mul_1 2
+_gcry_mpih_mul_1:
+ .frame $30,0,$26
+
+ ldq $2,0($17) # $2 = s1_limb
+ subq $18,1,$18 # size--
+ mulq $2,$19,$3 # $3 = prod_low
+ bic $31,$31,$4 # clear cy_limb
+ umulh $2,$19,$0 # $0 = prod_high
+ beq $18,Lend1 # jump if size was == 1
+ ldq $2,8($17) # $2 = s1_limb
+ subq $18,1,$18 # size--
+ stq $3,0($16)
+ beq $18,Lend2 # jump if size was == 2
+
+ .align 3
+Loop: mulq $2,$19,$3 # $3 = prod_low
+ addq $4,$0,$0 # cy_limb = cy_limb + 'cy'
+ subq $18,1,$18 # size--
+ umulh $2,$19,$4 # $4 = cy_limb
+ ldq $2,16($17) # $2 = s1_limb
+ addq $17,8,$17 # s1_ptr++
+ addq $3,$0,$3 # $3 = cy_limb + prod_low
+ stq $3,8($16)
+ cmpult $3,$0,$0 # $0 = carry from (cy_limb + prod_low)
+ addq $16,8,$16 # res_ptr++
+ bne $18,Loop
+
+Lend2: mulq $2,$19,$3 # $3 = prod_low
+ addq $4,$0,$0 # cy_limb = cy_limb + 'cy'
+ umulh $2,$19,$4 # $4 = cy_limb
+ addq $3,$0,$3 # $3 = cy_limb + prod_low
+ cmpult $3,$0,$0 # $0 = carry from (cy_limb + prod_low)
+ stq $3,8($16)
+ addq $4,$0,$0 # cy_limb = prod_high + cy
+ ret $31,($26),1
+Lend1: stq $3,0($16)
+ ret $31,($26),1
+
+ .end _gcry_mpih_mul_1
+
+