dnl HP-PA 1.1 mpn_mul_1 -- Multiply a limb vector with a limb
and store the
dnl result in a second limb vector.
dnl Copyright 1992-1994, 2000-2002 Free Software Foundation,
Inc.
dnl
This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software
; you can redistribute it and/or modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General
Public License as published by the Free
dnl Software Foundation
; either version 3 of the License, or (at your
dnl
option) any later
version.
dnl
dnl
or
dnl
dnl * the GNU General
Public License as published by the Free Software
dnl Foundation
; either version 2 of the License, or (at your option) any
dnl later
version.
dnl
dnl
or both in parallel, as here.
dnl
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 General
Public License
dnl
for more details.
dnl
dnl You should have received copies of the GNU General
Public License
and the
dnl GNU Lesser General
Public License along with the GNU MP Library.
If not,
dnl see
https://www.gnu.org/licenses/.
include(`../config.m4
')
C INPUT PARAMETERS
C res_ptr r26
C s1_ptr r25
C size r24
C s2_limb r23
C
This runs at 9 cycles/limb on a PA7000. With the used instructions, it can
C not become faster due to
data cache contention after a store. On the PA7100
C it runs at 7 cycles/limb.
C We could use fldds to read two limbs at a
time from the S1 array,
and that
C could bring down the times to 8.5
and 6.5 cycles/limb
for the PA7000
and
C PA7100, respectively. We don
't do that since it does not seem worth the
C (alignment) troubles...
C At least the PA7100 is rumored to be able to deal with cache-misses without
C stalling instruction issue.
If this is true,
and the cache is actually also
C lockup-free, we should use a deeper software pipeline,
and load from S1 very
C early! (The loads
and stores to -12(sp) will surely be in the cache.)
ASM_START()
PROLOGUE(mpn_mul_1)
C .callinfo frame=64,no_calls
ldo 64(%r30),%r30
fldws,ma 4(%r25),%fr5
stw %r23,-16(%r30) C move s2_limb ...
addib,= -1,%r24,L(just_one_limb)
fldws -16(%r30),%fr4 C ... into fr4
add %r0,%r0,%r0 C clear
carry
xmpyu %fr4,%fr5,%fr6
fldws,ma 4(%r25),%fr7
fstds %fr6,-16(%r30)
xmpyu %fr4,%fr7,%fr8
ldw -12(%r30),%r19 C least significant limb in product
ldw -16(%r30),%r28
fstds %fr8,-16(%r30)
addib,= -1,%r24,L(
end)
ldw -12(%r30),%r1
C Main loop
LDEF(loop)
fldws,ma 4(%r25),%fr5
stws,ma %r19,4(%r26)
addc %r28,%r1,%r19
xmpyu %fr4,%fr5,%fr6
ldw -16(%r30),%r28
fstds %fr6,-16(%r30)
addib,<> -1,%r24,L(loop)
ldw -12(%r30),%r1
LDEF(
end)
stws,ma %r19,4(%r26)
addc %r28,%r1,%r19
ldw -16(%r30),%r28
stws,ma %r19,4(%r26)
addc %r0,%r28,%r28
bv 0(%r2)
ldo -64(%r30),%r30
LDEF(just_one_limb)
xmpyu %fr4,%fr5,%fr6
fstds %fr6,-16(%r30)
ldw -16(%r30),%r28
ldo -64(%r30),%r30
bv 0(%r2)
fstws %fr6R,0(%r26)
EPILOGUE()
