diff options
Diffstat (limited to 'grub-core/lib/libgcrypt/mpi/alpha/mpih-mul1.S')
| -rw-r--r-- | grub-core/lib/libgcrypt/mpi/alpha/mpih-mul1.S | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/grub-core/lib/libgcrypt/mpi/alpha/mpih-mul1.S b/grub-core/lib/libgcrypt/mpi/alpha/mpih-mul1.S new file mode 100644 index 0000000..cd91b10 --- /dev/null +++ b/grub-core/lib/libgcrypt/mpi/alpha/mpih-mul1.S @@ -0,0 +1,90 @@ +/* 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 + + |