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dnl Alpha ev6 mpn_add_n -- Add two limb vectors of the same length > 0 and
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dnl store sum in a third limb vector.
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dnl Copyright 2000 Free Software Foundation, Inc.
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dnl This file is part of the GNU MP Library.
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dnl The GNU MP Library is free software; you can redistribute it and/or modify
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dnl it under the terms of the GNU Lesser General Public License as published
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dnl by the Free Software Foundation; either version 2.1 of the License, or (at
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dnl your option) any later version.
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dnl The GNU MP Library is distributed in the hope that it will be useful, but
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dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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dnl License for more details.
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dnl You should have received a copy of the GNU Lesser General Public License
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dnl along with the GNU MP Library; see the file COPYING.LIB. If not, write to
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dnl the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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dnl MA 02111-1307, USA.
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include(`../config.m4')
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dnl This code runs at 5.4 cycles/limb on EV5, and 2.1 cycles/limb on EV6.
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dnl This code was written in close cooperation with ev6 pipeline expert
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dnl Steve Root. Any errors are tege's fault, though.
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dnl sustains 8 adds in 17 cycles !
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dnl (from the d_cache)
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dnl pair loads and stores where possible
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dnl store pairs oct-aligned where possible
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dnl (didn't need it here)
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dnl stores are delayed every third cycle
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dnl loads and stores are delayed by fills
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dnl U stays still, put code there where possible
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dnl (note alternation of U1 and U0)
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dnl L moves because of loads and stores
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dnl note dampers in L to limit damage
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dnl note, load ahead of time where possible
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dnl this odd-looking optimization expects
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dnl that were having random bits in our data, so
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dnl that a pure zero result is unlikely. so we
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dnl penalize the unlikely case to help the
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lda r19, -8(r19) C L1 move counter
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ldq r0, 0(r17) C L0 get next ones
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ldq r3, 8(r17) C L0 get next ones
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ldq r6, 16(r17) C L0 get next ones
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ldq r9, 24(r17) C L0 get next ones
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addq r0, r1, r2 C U1 add two data
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cmpult r2, r1, r20 C U1 did it carry
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ldq r0, 32(r17) C L0 get next ones
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addq r3, r4, r5 C U0 add two data
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cmpult r5, r4, r21 C U0 did it carry
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ldq r3, 40(r17) C L0 get next ones
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addq r6, r7, r8 C U1 add two data
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addq r5, r20, r5 C U0 carry from last
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cmpult r8, r7, r22 C U1 did it carry
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beq r5, $fix5w C U0 fix exact zero
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$ret5w: ldq r6, 48(r17) C L0 get next ones
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bis r31, r31, r31 C L damp out
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addq r8, r21, r8 C U1 carry from last
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bis r31, r31, r31 C L moves in L !
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addq r9, r10, r11 C U0 add two data
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beq r8, $fix6w C U1 fix exact zero
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$ret6w: cmpult r11, r10, r23 C U0 did it carry
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ldq r9, 56(r17) C L0 get next ones
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ldq r10, 56(r18) C L1
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lda r17, 64(r17) C L0 move pointer
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bis r31, r31, r31 C U
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lda r18, 64(r18) C L1 move pointer
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lda r19, -8(r19) C L1 move counter
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C Main loop. 8-way unrolled.
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addq r0, r1, r2 C U1 add two data
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addq r11, r22, r11 C U0 add in carry
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stq r5, 8(r16) C L0 put an answer
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stq r8, 16(r16) C L1 pair
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cmpult r2, r1, r20 C U1 did it carry
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beq r11, $fix7 C U0 fix exact 0
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$ret7: ldq r0, 0(r17) C L0 get next ones
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bis r31, r31, r31 C L damp out
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addq r2, r23, r2 C U1 carry from last
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bis r31, r31, r31 C L moves in L !
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addq r3, r4, r5 C U0 add two data
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beq r2, $fix0 C U1 fix exact zero
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$ret0: cmpult r5, r4, r21 C U0 did it carry
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ldq r3, 8(r17) C L0 get next ones
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addq r6, r7, r8 C U1 add two data
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addq r5, r20, r5 C U0 carry from last
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stq r11, 24(r16) C L0 store pair
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cmpult r8, r7, r22 C U1 did it carry
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beq r5, $fix1 C U0 fix exact zero
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$ret1: ldq r6, 16(r17) C L0 get next ones
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lda r16, 64(r16) C L0 move pointer
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addq r8, r21, r8 C U1 carry from last
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lda r19, -8(r19) C L1 move counter
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addq r9, r10, r11 C U0 add two data
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beq r8, $fix2 C U1 fix exact zero
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$ret2: cmpult r11, r10, r23 C U0 did it carry
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ldq r9, 24(r17) C L0 get next ones
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ldq r10, 24(r18) C L1
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addq r0, r1, r2 C U1 add two data
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addq r11, r22, r11 C U0 add in carry
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stq r5, -24(r16) C L0 put an answer
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stq r8, -16(r16) C L1 pair
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cmpult r2, r1, r20 C U1 did it carry
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beq r11, $fix3 C U0 fix exact 0
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$ret3: ldq r0, 32(r17) C L0 get next ones
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bis r31, r31, r31 C L damp out
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addq r2, r23, r2 C U1 carry from last
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bis r31, r31, r31 C L moves in L !
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addq r3, r4, r5 C U0 add two data
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beq r2, $fix4 C U1 fix exact zero
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$ret4: cmpult r5, r4, r21 C U0 did it carry
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ldq r3, 40(r17) C L0 get next ones
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addq r6, r7, r8 C U1 add two data
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addq r5, r20, r5 C U0 carry from last
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stq r11, -8(r16) C L0 store pair
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cmpult r8, r7, r22 C U1 did it carry
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beq r5, $fix5 C U0 fix exact zero
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$ret5: ldq r6, 48(r17) C L0 get next ones
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bis r31, r31, r31 C L damp out
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addq r8, r21, r8 C U1 carry from last
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bis r31, r31, r31 C L moves in L !
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addq r9, r10, r11 C U0 add two data
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beq r8, $fix6 C U1 fix exact zero
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$ret6: cmpult r11, r10, r23 C U0 did it carry
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ldq r9, 56(r17) C L0 get next ones
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ldq r10, 56(r18) C L1
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lda r17, 64(r17) C L0 move pointer
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bis r31, r31, r31 C U
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lda r18, 64(r18) C L1 move pointer
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bge r19, $Loop C U1 loop control
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addq r0, r1, r2 C U1 add two data
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addq r11, r22, r11 C U0 add in carry
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stq r5, 8(r16) C L0 put an answer
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stq r8, 16(r16) C L1 pair
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cmpult r2, r1, r20 C U1 did it carry
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beq r11, $fix7c C U0 fix exact 0
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addq r2, r23, r2 C U1 carry from last
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addq r3, r4, r5 C U0 add two data
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beq r2, $fix0c C U1 fix exact zero
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$ret0c: cmpult r5, r4, r21 C U0 did it carry
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addq r6, r7, r8 C U1 add two data
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addq r5, r20, r5 C U0 carry from last
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stq r11, 24(r16) C L0 store pair
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cmpult r8, r7, r22 C U1 did it carry
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beq r5, $fix1c C U0 fix exact zero
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lda r16, 64(r16) C L0 move pointer
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addq r8, r21, r8 C U1 carry from last
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addq r9, r10, r11 C U0 add two data
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beq r8, $fix2c C U1 fix exact zero
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$ret2c: cmpult r11, r10, r23 C U0 did it carry
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addq r11, r22, r11 C U0 add in carry
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stq r5, -24(r16) C L0 put an answer
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stq r8, -16(r16) C L1 pair
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beq r11, $fix3c C U0 fix exact 0
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stq r11, -8(r16) C L0 store pair
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$Loop0: addq r0, r1, r2 C main add
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cmpult r2, r1, r8 C compute cy from last add
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addq r2, r23, r20 C carry add
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cmpult r20, r2, r23 C compute cy from last add
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lda r19, -1(r19) C decr loop cnt
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bis r8, r23, r23 C combine cy from the two adds
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$Lend0: addq r0, r1, r2 C main add
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addq r2, r23, r20 C carry add
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cmpult r2, r1, r8 C compute cy from last add
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cmpult r20, r2, r23 C compute cy from last add
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bis r8, r23, r23 C combine cy from the two adds
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lda r0, 0(r23) C copy carry into return register
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$fix5w: bis r21, r20, r21 C bring forward carry
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$fix6w: bis r22, r21, r22 C bring forward carry
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$fix0: bis r20, r23, r20 C bring forward carry
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$fix1: bis r21, r20, r21 C bring forward carry
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$fix2: bis r22, r21, r22 C bring forward carry
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$fix3: bis r23, r22, r23 C bring forward carry
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$fix4: bis r20, r23, r20 C bring forward carry
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$fix5: bis r20, r21, r21 C bring forward carry
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$fix6: bis r22, r21, r22 C bring forward carry
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$fix7: bis r23, r22, r23 C bring forward carry
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$fix0c: bis r20, r23, r20 C bring forward carry
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$fix1c: bis r21, r20, r21 C bring forward carry
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$fix2c: bis r22, r21, r22 C bring forward carry
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$fix3c: bis r23, r22, r23 C bring forward carry
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$fix7c: bis r23, r22, r23 C bring forward carry
added
removed
gmp3/mpn/alpha/ev6/add_n.asm
