dnl PowerPC-32/VMX and PowerPC-64/VMX mpn_copyd.
dnl Copyright 2006 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 16-byte coaligned unaligned
C cycles/limb cycles/limb
C 7400,7410 (G4): 0.5 0.64
C 744x,745x (G4+): 0.75 0.82
C 970 (G5): 0.78 1.02 (64-bit limbs)
C STATUS
C * Works for all sizes and alignments.
C TODO
C * Optimize unaligned case. Some basic tests with 2-way and 4-way unrolling
C indicate that we can reach 0.56 c/l for 7400, 0.75 c/l for 745x, and 0.80
C c/l for 970.
C * Consider using VMX instructions also for head and tail, by using some
C read-modify-write tricks.
C * The VMX code is used from the smallest sizes it handles, but measurements
C show a large speed bump at the cutoff points. Small copying (perhaps
C using some read-modify-write technique) should be optimized.
C * Make an mpn_com based on this code.
define(`GMP_LIMB_BYTES', eval(GMP_LIMB_BITS/8))
define(`LIMBS_PER_VR', eval(16/GMP_LIMB_BYTES))
define(`LIMBS_PER_2VR', eval(32/GMP_LIMB_BYTES))
ifelse(GMP_LIMB_BITS,32,`
define(`LIMB32',` $1')
define(`LIMB64',`')
',`
define(`LIMB32',`')
define(`LIMB64',` $1')
')
C INPUT PARAMETERS
define(`rp', `r3')
define(`up', `r4')
define(`n', `r5')
define(`us', `v4')
ASM_START()
PROLOGUE(mpn_copyd)
LIMB32(`slwi. r0, n, 2 ')
LIMB64(`sldi. r0, n, 3 ')
add rp, rp, r0
add up, up, r0
LIMB32(`cmpi cr7, n, 11 ')
LIMB64(`cmpdi cr7, n, 5 ')
bge cr7, L(big)
beqlr cr0
C Handle small cases with plain operations
mtctr n
L(topS):
LIMB32(`lwz r0, -4(up) ')
LIMB64(`ld r0, -8(up) ')
addi up, up, -GMP_LIMB_BYTES
LIMB32(`stw r0, -4(rp) ')
LIMB64(`std r0, -8(rp) ')
addi rp, rp, -GMP_LIMB_BYTES
bdnz L(topS)
blr
C Handle large cases with VMX operations
L(big):
addi rp, rp, -16
addi up, up, -16
mfspr r12, 256
oris r0, r12, 0xf800 C Set VRSAVE bit 0-4
mtspr 256, r0
LIMB32(`rlwinm. r7, rp, 30,30,31') C (rp >> 2) mod 4
LIMB64(`rlwinm. r7, rp, 29,31,31') C (rp >> 3) mod 2
beq L(rp_aligned)
subf n, r7, n
L(top0):
LIMB32(`lwz r0, 12(up) ')
LIMB64(`ld r0, 8(up) ')
addi up, up, -GMP_LIMB_BYTES
LIMB32(`addic. r7, r7, -1 ')
LIMB32(`stw r0, 12(rp) ')
LIMB64(`std r0, 8(rp) ')
addi rp, rp, -GMP_LIMB_BYTES
LIMB32(`bne L(top0) ')
L(rp_aligned):
LIMB32(`rlwinm. r0, up, 30,30,31') C (up >> 2) mod 4
LIMB64(`rlwinm. r0, up, 29,31,31') C (up >> 3) mod 2
LIMB64(`srdi r7, n, 2 ') C loop count corresponding to n
LIMB32(`srwi r7, n, 3 ') C loop count corresponding to n
mtctr r7 C copy n to count register
li r10, -16
beq L(up_aligned)
lvsl us, 0, up
addi up, up, 16
LIMB32(`andi. r0, n, 0x4 ')
LIMB64(`andi. r0, n, 0x2 ')
beq L(1)
lvx v0, 0, up
lvx v2, r10, up
vperm v3, v2, v0, us
stvx v3, 0, rp
addi up, up, -32
addi rp, rp, -16
b L(lpu)
L(1): lvx v2, 0, up
addi up, up, -16
b L(lpu)
ALIGN(32)
L(lpu): lvx v0, 0, up
vperm v3, v0, v2, us
stvx v3, 0, rp
lvx v2, r10, up
addi up, up, -32
vperm v3, v2, v0, us
stvx v3, r10, rp
addi rp, rp, -32
bdnz L(lpu)
b L(tail)
L(up_aligned):
LIMB32(`andi. r0, n, 0x4 ')
LIMB64(`andi. r0, n, 0x2 ')
beq L(lpa)
lvx v0, 0, up
stvx v0, 0, rp
addi up, up, -16
addi rp, rp, -16
b L(lpa)
ALIGN(32)
L(lpa): lvx v0, 0, up
lvx v1, r10, up
addi up, up, -32
nop
stvx v0, 0, rp
stvx v1, r10, rp
addi rp, rp, -32
bdnz L(lpa)
L(tail):
LIMB32(`rlwinm. r7, n, 0,30,31 ') C r7 = n mod 4
LIMB64(`rlwinm. r7, n, 0,31,31 ') C r7 = n mod 2
beq L(ret)
LIMB32(`li r10, 12 ')
L(top2):
LIMB32(`lwzx r0, r10, up ')
LIMB64(`ld r0, 8(up) ')
LIMB32(`addic. r7, r7, -1 ')
LIMB32(`stwx r0, r10, rp ')
LIMB64(`std r0, 8(rp) ')
LIMB32(`addi r10, r10, -GMP_LIMB_BYTES')
LIMB32(`bne L(top2) ')
L(ret): mtspr 256, r12
blr
EPILOGUE()