mpir/mpn/alpha/cntlz.asm

47 lines
1.4 KiB
NASM

dnl Alpha auxiliary for longlong.h's count_leading_zeros
dnl Copyright 1997, 2000, 2002 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of the GNU Lesser General Public License as published
dnl by the Free Software Foundation; either version 2.1 of the License, or (at
dnl your option) any later version.
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 Lesser General Public
dnl License for more details.
dnl You should have received a copy of the GNU Lesser General Public License
dnl along with the GNU MP Library; see the file COPYING.LIB. If not, write
dnl to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
dnl Boston, MA 02110-1301, USA.
include(`../config.m4')
ASM_START()
EXTERN(__clz_tab)
PROLOGUE(mpn_count_leading_zeros,gp)
cmpbge r31, r16, r1
LEA(r3,__clz_tab)
sra r1, 1, r1
xor r1, 127, r1
srl r16, 1, r16
addq r1, r3, r1
ldq_u r0, 0(r1)
lda r2, 64
extbl r0, r1, r0
s8subl r0, 8, r0
srl r16, r0, r16
addq r16, r3, r16
ldq_u r1, 0(r16)
extbl r1, r16, r1
subq r2, r1, r2
subq r2, r0, r0
ret r31, (r26),1
EPILOGUE(mpn_count_leading_zeros)
ASM_END()