dnl PowerPC-64 mpn_addlshC_n, mpn_sublshC_n, mpn_rsblshC_n.
dnl Copyright 2003, 2005, 2009, 2010, 2013 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
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dnl Software Foundation; either version 3 of the License, or (at your
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dnl or
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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.
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dnl or both in parallel, as here.
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C cycles/limb
C POWER3/PPC630 1.83 (1.5 c/l should be possible)
C POWER4/PPC970 3 (2.0 c/l should be possible)
C POWER5 3
C POWER6 3.5-47
C POWER7 3
C STATUS
C * Try combining upx+up, and vpx+vp.
C * The worst case 47 c/l for POWER6 happens if the 3rd operand for ldx is
C greater than the 2nd operand. Yes, this addition is non-commutative wrt
C performance.
C INPUT PARAMETERS
define(`rp', `r3')
define(`up', `r4')
define(`vp', `r5')
define(`n', `r6')
ifdef(`DO_add', `
define(`ADDSUBC', `addc $1, $2, $3')
define(`ADDSUBE', `adde $1, $2, $3')
define(INITCY, `addic $1, r1, 0')
define(RETVAL, `addze r3, $1')
define(`func', mpn_addlsh`'LSH`'_n)')
ifdef(`DO_sub', `
define(`ADDSUBC', `subfc $1, $2, $3')
define(`ADDSUBE', `subfe $1, $2, $3')
define(INITCY, `addic $1, r1, -1')
define(RETVAL, `subfze r3, $1
neg r3, r3')
define(`func', mpn_sublsh`'LSH`'_n)')
ifdef(`DO_rsb', `
define(`ADDSUBC', `subfc $1, $3, $2')
define(`ADDSUBE', `subfe $1, $3, $2')
define(INITCY, `addic $1, r1, -1')
define(RETVAL, `addme r3, $1')
define(`func', mpn_rsblsh`'LSH`'_n)')
define(`rpx', `r6')
define(`upx', `r7')
define(`vpx', `r12')
define(`s0', `r0') define(`s1', `r9')
define(`u0', `r8')
define(`v0', `r10') define(`v1', `r11')
ASM_START()
PROLOGUE(func)
cmpldi cr0, n, 13
bgt L(big)
mtctr n C copy n in ctr
INITCY( r0) C clear cy
ld v0, 0(vp) C load v limb
ld u0, 0(up) C load u limb
addi up, up, -8 C update up
addi rp, rp, -8 C update rp
sldi s1, v0, LSH
bdz L(ex1) C If done, skip loop
ALIGN(16)
L(lo0): ld v1, 8(vp) C load v limb
ADDSUBE(s1, s1, u0) C add limbs with cy, set cy
ldu u0, 16(up) C load u limb and update up
srdi s0, v0, RSH C shift down previous v limb
std s1, 8(rp) C store result limb
rldimi s0, v1, LSH, 0 C left shift v limb and merge with prev v limb
bdz L(ex0) C decrement ctr and exit if done
ldu v0, 16(vp) C load v limb and update vp
ADDSUBE(s0, s0, u0) C add limbs with cy, set cy
ld u0, 8(up) C load u limb
srdi s1, v1, RSH C shift down previous v limb
stdu s0, 16(rp) C store result limb and update rp
rldimi s1, v0, LSH, 0 C left shift v limb and merge with prev v limb
bdnz L(lo0) C decrement ctr and loop back
L(ex1): ADDSUBE(r7, s1, u0)
std r7, 8(rp) C store last result limb
srdi r0, v0, RSH
RETVAL( r0)
blr
L(ex0): ADDSUBE(r7, s0, u0)
std r7, 16(rp) C store last result limb
srdi r0, v1, RSH
RETVAL( r0)
blr
L(big): rldicl. r0, n, 0,63 C r0 = n & 1, set cr0
addi r6, n, -1 C ...for ctr
srdi r6, r6, 1 C ...for ctr
mtctr r6 C copy count into ctr
beq cr0, L(b0)
L(b1): ld v1, 0(vp)
ld u0, 0(up)
sldi s1, v1, LSH
srdi s0, v1, RSH
ld v0, 8(vp)
ADDSUBC(s1, s1, u0) C add limbs without cy, set cy
addi rpx, rp, -16
addi rp, rp, -8
sub upx, up, rp
sub vpx, vp, rp
sub up, up, rpx
sub vp, vp, rpx
addi up, up, 8
addi upx, upx, 16
addi vp, vp, 16
addi vpx, vpx, 24
b L(mid)
L(b0): ld v0, 0(vp)
ld u0, 0(up)
sldi s0, v0, LSH
srdi s1, v0, RSH
ld v1, 8(vp)
ADDSUBC(s0, s0, u0) C add limbs without cy, set cy
addi rpx, rp, -8
addi rp, rp, -16
sub upx, up, rpx
sub vpx, vp, rpx
sub up, up, rp
sub vp, vp, rp
addi up, up, 8
addi upx, upx, 16
addi vp, vp, 16
addi vpx, vpx, 24
ALIGN(32)
L(top): ldx u0, rp, up
ldx v0, rp, vp
rldimi s1, v1, LSH, 0
stdu s0, 16(rp)
srdi s0, v1, RSH
ADDSUBE(s1, s1, u0) C add limbs with cy, set cy
L(mid): ldx u0, rpx, upx
ldx v1, rpx, vpx
rldimi s0, v0, LSH, 0
stdu s1, 16(rpx)
srdi s1, v0, RSH
ADDSUBE(s0, s0, u0) C add limbs with cy, set cy
bdnz L(top) C decrement CTR and loop back
ldx u0, rp, up
rldimi s1, v1, LSH, 0
std s0, 16(rp)
srdi s0, v1, RSH
ADDSUBE(s1, s1, u0) C add limbs with cy, set cy
std s1, 24(rp)
RETVAL( s0)
blr
EPILOGUE()