275 lines
7.7 KiB
NASM
275 lines
7.7 KiB
NASM
dnl Alpha ev6 mpn_sub_n -- Subtract two limb vectors of the same length > 0
|
|
dnl and store difference in a third limb vector.
|
|
|
|
dnl Copyright 2000, 2003, 2005 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')
|
|
|
|
C cycles/limb
|
|
C EV4: ?
|
|
C EV5: 5.4
|
|
C EV6: 2.125
|
|
|
|
C INPUT PARAMETERS
|
|
C rp r16
|
|
C up r17
|
|
C vp r18
|
|
C n r19
|
|
C cy r20 (for mpn_add_nc)
|
|
|
|
C TODO
|
|
C Finish cleaning up cy registers r22, r23 (make them use cy0/cy1)
|
|
C Use multi-pronged feed-in.
|
|
C Perform additional micro-tuning
|
|
|
|
C This code was written in cooperation with ev6 pipeline expert Steve Root.
|
|
|
|
C Pair loads and stores where possible
|
|
C Store pairs oct-aligned where possible (didn't need it here)
|
|
C Stores are delayed every third cycle
|
|
C Loads and stores are delayed by fills
|
|
C U stays still, put code there where possible (note alternation of U1 and U0)
|
|
C L moves because of loads and stores
|
|
C Note dampers in L to limit damage
|
|
|
|
C This odd-looking optimization expects that were having random bits in our
|
|
C data, so that a pure zero result is unlikely. so we penalize the unlikely
|
|
C case to help the common case.
|
|
|
|
define(`u0', `r0') define(`u1', `r3')
|
|
define(`v0', `r1') define(`v1', `r4')
|
|
|
|
define(`cy0', `r20') define(`cy1', `r21')
|
|
|
|
MULFUNC_PROLOGUE(mpn_sub_n mpn_sub_nc)
|
|
|
|
ASM_START()
|
|
PROLOGUE(mpn_sub_nc)
|
|
br r31, $entry
|
|
EPILOGUE()
|
|
PROLOGUE(mpn_sub_n)
|
|
bis r31, r31, cy0 C clear carry in
|
|
$entry: cmpult r19, 5, r22 C L1 move counter
|
|
ldq u1, 0(r17) C L0 get next ones
|
|
ldq v1, 0(r18) C L1
|
|
bne r22, $Lsmall
|
|
|
|
ldq u0, 8(r17) C L0 get next ones
|
|
ldq v0, 8(r18) C L1
|
|
subq u1, v1, r5 C U0 sub two data
|
|
|
|
cmpult u1, v1, r23 C U0 did it borrow
|
|
ldq u1, 16(r17) C L0 get next ones
|
|
ldq v1, 16(r18) C L1
|
|
|
|
subq u0, v0, r8 C U1 sub two data
|
|
subq r5, cy0, r24 C U0 borrow in
|
|
|
|
cmpult u0, v0, r22 C U1 did it borrow
|
|
beq r5, $fix5f C U0 fix exact zero
|
|
$ret5f: ldq u0, 24(r17) C L0 get next ones
|
|
ldq v0, 24(r18) C L1
|
|
|
|
subq r8, r23, r25 C U1 borrow from last
|
|
subq u1, v1, r7 C U0 sub two data
|
|
|
|
beq r8, $fix6f C U1 fix exact zero
|
|
$ret6f: cmpult u1, v1, r23 C U0 did it borrow
|
|
ldq u1, 32(r17) C L0 get next ones
|
|
ldq v1, 32(r18) C L1
|
|
|
|
lda r17, 40(r17) C L0 move pointer
|
|
lda r18, 40(r18) C L1 move pointer
|
|
|
|
lda r16, -8(r16)
|
|
lda r19, -13(r19) C L1 move counter
|
|
blt r19, $Lend C U1 loop control
|
|
|
|
|
|
C Main loop. 8-way unrolled.
|
|
ALIGN(16)
|
|
$Loop: subq u0, v0, r2 C U1 sub two data
|
|
stq r24, 8(r16) C L0 put an answer
|
|
subq r7, r22, r24 C U0 borrow from last
|
|
stq r25, 16(r16) C L1 pair
|
|
|
|
cmpult u0, v0, cy1 C U1 did it borrow
|
|
beq r7, $fix7 C U0 fix exact 0
|
|
$ret7: ldq u0, 0(r17) C L0 get next ones
|
|
ldq v0, 0(r18) C L1
|
|
|
|
bis r31, r31, r31 C L damp out
|
|
subq r2, r23, r25 C U1 borrow from last
|
|
bis r31, r31, r31 C L moves in L !
|
|
subq u1, v1, r5 C U0 sub two data
|
|
|
|
beq r2, $fix0 C U1 fix exact zero
|
|
$ret0: cmpult u1, v1, cy0 C U0 did it borrow
|
|
ldq u1, 8(r17) C L0 get next ones
|
|
ldq v1, 8(r18) C L1
|
|
|
|
subq u0, v0, r8 C U1 sub two data
|
|
stq r24, 24(r16) C L0 store pair
|
|
subq r5, cy1, r24 C U0 borrow from last
|
|
stq r25, 32(r16) C L1
|
|
|
|
cmpult u0, v0, r22 C U1 did it borrow
|
|
beq r5, $fix1 C U0 fix exact zero
|
|
$ret1: ldq u0, 16(r17) C L0 get next ones
|
|
ldq v0, 16(r18) C L1
|
|
|
|
lda r16, 64(r16) C L0 move pointer
|
|
subq r8, cy0, r25 C U1 borrow from last
|
|
lda r19, -8(r19) C L1 move counter
|
|
subq u1, v1, r7 C U0 sub two data
|
|
|
|
beq r8, $fix2 C U1 fix exact zero
|
|
$ret2: cmpult u1, v1, r23 C U0 did it borrow
|
|
ldq u1, 24(r17) C L0 get next ones
|
|
ldq v1, 24(r18) C L1
|
|
|
|
subq u0, v0, r2 C U1 sub two data
|
|
stq r24, -24(r16) C L0 put an answer
|
|
subq r7, r22, r24 C U0 borrow from last
|
|
stq r25, -16(r16) C L1 pair
|
|
|
|
cmpult u0, v0, cy1 C U1 did it borrow
|
|
beq r7, $fix3 C U0 fix exact 0
|
|
$ret3: ldq u0, 32(r17) C L0 get next ones
|
|
ldq v0, 32(r18) C L1
|
|
|
|
bis r31, r31, r31 C L damp out
|
|
subq r2, r23, r25 C U1 borrow from last
|
|
bis r31, r31, r31 C L moves in L !
|
|
subq u1, v1, r5 C U0 sub two data
|
|
|
|
beq r2, $fix4 C U1 fix exact zero
|
|
$ret4: cmpult u1, v1, cy0 C U0 did it borrow
|
|
ldq u1, 40(r17) C L0 get next ones
|
|
ldq v1, 40(r18) C L1
|
|
|
|
subq u0, v0, r8 C U1 sub two data
|
|
stq r24, -8(r16) C L0 store pair
|
|
subq r5, cy1, r24 C U0 borrow from last
|
|
stq r25, 0(r16) C L1
|
|
|
|
cmpult u0, v0, r22 C U1 did it borrow
|
|
beq r5, $fix5 C U0 fix exact zero
|
|
$ret5: ldq u0, 48(r17) C L0 get next ones
|
|
ldq v0, 48(r18) C L1
|
|
|
|
ldl r31, 256(r17) C L0 prefetch
|
|
subq r8, cy0, r25 C U1 borrow from last
|
|
ldl r31, 256(r18) C L1 prefetch
|
|
subq u1, v1, r7 C U0 sub two data
|
|
|
|
beq r8, $fix6 C U1 fix exact zero
|
|
$ret6: cmpult u1, v1, r23 C U0 did it borrow
|
|
ldq u1, 56(r17) C L0 get next ones
|
|
ldq v1, 56(r18) C L1
|
|
|
|
lda r17, 64(r17) C L0 move pointer
|
|
bis r31, r31, r31 C U
|
|
lda r18, 64(r18) C L1 move pointer
|
|
bge r19, $Loop C U1 loop control
|
|
C ==== main loop end
|
|
|
|
$Lend: subq u0, v0, r2 C U1 sub two data
|
|
stq r24, 8(r16) C L0 put an answer
|
|
subq r7, r22, r24 C U0 borrow from last
|
|
stq r25, 16(r16) C L1 pair
|
|
cmpult u0, v0, cy1 C U1 did it borrow
|
|
beq r7, $fix7c C U0 fix exact 0
|
|
$ret7c: subq r2, r23, r25 C U1 borrow from last
|
|
subq u1, v1, r5 C U0 sub two data
|
|
beq r2, $fix0c C U1 fix exact zero
|
|
$ret0c: cmpult u1, v1, cy0 C U0 did it borrow
|
|
stq r24, 24(r16) C L0 store pair
|
|
subq r5, cy1, r24 C U0 borrow from last
|
|
stq r25, 32(r16) C L1
|
|
beq r5, $fix1c C U0 fix exact zero
|
|
$ret1c: stq r24, 40(r16) C L0 put an answer
|
|
lda r16, 48(r16) C L0 move pointer
|
|
|
|
lda r19, 8(r19)
|
|
beq r19, $Lret
|
|
|
|
ldq u1, 0(r17)
|
|
ldq v1, 0(r18)
|
|
$Lsmall:
|
|
lda r19, -1(r19)
|
|
beq r19, $Lend0
|
|
|
|
ALIGN(8)
|
|
$Loop0: subq u1, v1, r2 C main sub
|
|
cmpult u1, v1, r8 C compute bw from last sub
|
|
ldq u1, 8(r17)
|
|
ldq v1, 8(r18)
|
|
subq r2, cy0, r5 C borrow sub
|
|
lda r17, 8(r17)
|
|
lda r18, 8(r18)
|
|
stq r5, 0(r16)
|
|
cmpult r2, cy0, cy0 C compute bw from last sub
|
|
lda r19, -1(r19) C decr loop cnt
|
|
bis r8, cy0, cy0 C combine bw from the two subs
|
|
lda r16, 8(r16)
|
|
bne r19, $Loop0
|
|
$Lend0: subq u1, v1, r2 C main sub
|
|
subq r2, cy0, r5 C borrow sub
|
|
cmpult u1, v1, r8 C compute bw from last sub
|
|
cmpult r2, cy0, cy0 C compute bw from last sub
|
|
stq r5, 0(r16)
|
|
bis r8, cy0, r0 C combine bw from the two subs
|
|
ret r31,(r26),1
|
|
|
|
ALIGN(8)
|
|
$Lret: lda r0, 0(cy0) C copy borrow into return register
|
|
ret r31,(r26),1
|
|
|
|
$fix5f: bis r23, cy0, r23 C bring forward borrow
|
|
br r31, $ret5f
|
|
$fix6f: bis r22, r23, r22 C bring forward borrow
|
|
br r31, $ret6f
|
|
$fix0: bis cy1, r23, cy1 C bring forward borrow
|
|
br r31, $ret0
|
|
$fix1: bis cy0, cy1, cy0 C bring forward borrow
|
|
br r31, $ret1
|
|
$fix2: bis r22, cy0, r22 C bring forward borrow
|
|
br r31, $ret2
|
|
$fix3: bis r23, r22, r23 C bring forward borrow
|
|
br r31, $ret3
|
|
$fix4: bis cy1, r23, cy1 C bring forward borrow
|
|
br r31, $ret4
|
|
$fix5: bis cy1, cy0, cy0 C bring forward borrow
|
|
br r31, $ret5
|
|
$fix6: bis r22, cy0, r22 C bring forward borrow
|
|
br r31, $ret6
|
|
$fix7: bis r23, r22, r23 C bring forward borrow
|
|
br r31, $ret7
|
|
$fix0c: bis cy1, r23, cy1 C bring forward borrow
|
|
br r31, $ret0c
|
|
$fix1c: bis cy0, cy1, cy0 C bring forward borrow
|
|
br r31, $ret1c
|
|
$fix7c: bis r23, r22, r23 C bring forward borrow
|
|
br r31, $ret7c
|
|
|
|
EPILOGUE()
|
|
ASM_END()
|