diff options
Diffstat (limited to 'comm/third_party/libgcrypt/mpi/alpha/mpih-rshift.S')
-rw-r--r-- | comm/third_party/libgcrypt/mpi/alpha/mpih-rshift.S | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/comm/third_party/libgcrypt/mpi/alpha/mpih-rshift.S b/comm/third_party/libgcrypt/mpi/alpha/mpih-rshift.S new file mode 100644 index 0000000000..f0c9814388 --- /dev/null +++ b/comm/third_party/libgcrypt/mpi/alpha/mpih-rshift.S @@ -0,0 +1,118 @@ +/* alpha rshift + * Copyright (C) 1994, 1995, 1998, 1999, + * 2000, 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 + * + * Note: This code is heavily based on the GNU MP Library. + * Actually it's the same code with only minor changes in the + * way the data is stored; this is to support the abstraction + * of an optional secure memory allocation which may be used + * to avoid revealing of sensitive data due to paging etc. + */ + + + + +/******************* + * mpi_limb_t + * _gcry_mpih_rshift( mpi_ptr_t wp, (r16) + * mpi_ptr_t up, (r17) + * mpi_size_t usize, (r18) + * unsigned cnt) (r19) + * + * This code runs at 4.8 cycles/limb on the 21064. With infinite unrolling, + * it would take 4 cycles/limb. It should be possible to get down to 3 + * cycles/limb since both ldq and stq can be paired with the other used + * instructions. But there are many restrictions in the 21064 pipeline that + * makes it hard, if not impossible, to get down to 3 cycles/limb: + * + * 1. ldq has a 3 cycle delay, srl and sll have a 2 cycle delay. + * 2. Only aligned instruction pairs can be paired. + * 3. The store buffer or silo might not be able to deal with the bandwidth. + */ + + .set noreorder + .set noat +.text + .align 3 + .globl _gcry_mpih_rshift + .ent _gcry_mpih_rshift +_gcry_mpih_rshift: + .frame $30,0,$26,0 + + ldq $4,0($17) # load first limb + addq $17,8,$17 + subq $31,$19,$7 + subq $18,1,$18 + and $18,4-1,$20 # number of limbs in first loop + sll $4,$7,$0 # compute function result + + beq $20,.R0 + subq $18,$20,$18 + + .align 3 +.Roop0: + ldq $3,0($17) + addq $16,8,$16 + addq $17,8,$17 + subq $20,1,$20 + srl $4,$19,$5 + sll $3,$7,$6 + bis $3,$3,$4 + bis $5,$6,$8 + stq $8,-8($16) + bne $20,.Roop0 + +.R0: beq $18,.Rend + + .align 3 +.Roop: ldq $3,0($17) + addq $16,32,$16 + subq $18,4,$18 + srl $4,$19,$5 + sll $3,$7,$6 + + ldq $4,8($17) + srl $3,$19,$1 + bis $5,$6,$8 + stq $8,-32($16) + sll $4,$7,$2 + + ldq $3,16($17) + srl $4,$19,$5 + bis $1,$2,$8 + stq $8,-24($16) + sll $3,$7,$6 + + ldq $4,24($17) + srl $3,$19,$1 + bis $5,$6,$8 + stq $8,-16($16) + sll $4,$7,$2 + + addq $17,32,$17 + bis $1,$2,$8 + stq $8,-8($16) + + bgt $18,.Roop + +.Rend: srl $4,$19,$8 + stq $8,0($16) + ret $31,($26),1 + .end _gcry_mpih_rshift + |