github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/powerpc64/p6/rshift.asm (about)

     1  dnl  PowerPC-64 mpn_rshift -- rp[] = up[] << cnt
     2  
     3  dnl  Copyright 2003, 2005, 2010, 2013 Free Software Foundation, Inc.
     4  
     5  dnl  This file is part of the GNU MP Library.
     6  dnl
     7  dnl  The GNU MP Library is free software; you can redistribute it and/or modify
     8  dnl  it under the terms of either:
     9  dnl
    10  dnl    * the GNU Lesser General Public License as published by the Free
    11  dnl      Software Foundation; either version 3 of the License, or (at your
    12  dnl      option) any later version.
    13  dnl
    14  dnl  or
    15  dnl
    16  dnl    * the GNU General Public License as published by the Free Software
    17  dnl      Foundation; either version 2 of the License, or (at your option) any
    18  dnl      later version.
    19  dnl
    20  dnl  or both in parallel, as here.
    21  dnl
    22  dnl  The GNU MP Library is distributed in the hope that it will be useful, but
    23  dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    24  dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    25  dnl  for more details.
    26  dnl
    27  dnl  You should have received copies of the GNU General Public License and the
    28  dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
    29  dnl  see https://www.gnu.org/licenses/.
    30  
    31  include(`../config.m4')
    32  
    33  C		    cycles/limb
    34  C POWER3/PPC630		 ?
    35  C POWER4/PPC970		 ?
    36  C POWER5		 2
    37  C POWER6		 3.5  (mysteriously 3.0 for cnt=1)
    38  
    39  C TODO
    40  C  * Micro-optimise header code
    41  C  * Perhaps do 4-way unrolling, for 2.5 c/l on POWER6.  The code is 4248
    42  C    bytes, 4-way code would become about 50% larger.
    43  
    44  C INPUT PARAMETERS
    45  define(`rp_param',  `r3')
    46  define(`up',  `r4')
    47  define(`n',   `r5')
    48  define(`cnt', `r6')
    49  
    50  define(`tnc',`r0')
    51  define(`retval',`r3')
    52  define(`rp',  `r7')
    53  
    54  ASM_START()
    55  PROLOGUE(mpn_rshift,toc)
    56  
    57  ifdef(`HAVE_ABI_mode32',`
    58  	rldicl	n, n, 0,32		C FIXME: avoid this zero extend
    59  ')
    60  	mflr	r12
    61  	LEAL(	r11, L(e1))		C address of L(e1) label in SHIFT(1)
    62  	sldi	r10, cnt, 6		C multiply cnt by size of a SHIFT block
    63  	add	r11, r11, r10		C address of L(oN) for N = cnt
    64  	srdi	r10, n, 1
    65  	mr	rp, rp_param
    66  	subfic	tnc, cnt, 64
    67  	rlwinm.	r8, n, 0,31,31		C extract bit 0
    68  	mtctr	r10
    69  	beq	L(evn)
    70  
    71  L(odd):	ld	r9, 0(up)
    72  	cmpdi	cr0, n, 1		C n = 1?
    73  	beq	L(1)
    74  	ld	r8, 8(up)
    75  	addi	r11, r11, -84		C L(o1) - L(e1) - 64
    76  	mtlr	r11
    77  	sld	r3, r9, tnc		C retval
    78  	addi	up, up, 8
    79  	addi	rp, rp, 8
    80  	blr				C branch to L(oN)
    81  
    82  L(evn):	ld	r8, 0(up)
    83  	ld	r9, 8(up)
    84  	addi	r11, r11, -64
    85  	mtlr	r11
    86  	sld	r3, r8, tnc		C retval
    87  	addi	up, up, 16
    88  	blr				C branch to L(eN)
    89  
    90  L(1):	sld	r3, r9, tnc		C retval
    91  	srd	r8, r9, cnt
    92  	std	r8, 0(rp)
    93  	mtlr	r12
    94  ifdef(`HAVE_ABI_mode32',
    95  `	mr	r4, r3
    96  	srdi	r3, r3, 32
    97  ')
    98  	blr
    99  
   100  
   101  define(SHIFT,`
   102  L(lo$1):ld	r8, 0(up)
   103  	std	r11, 0(rp)
   104  	addi	rp, rp, 16
   105  L(o$1):	srdi	r10, r9, $1
   106  	rldimi	r10, r8, eval(64-$1), 0
   107  	ld	r9, 8(up)
   108  	addi	up, up, 16
   109  	std	r10, -8(rp)
   110  L(e$1):	srdi	r11, r8, $1
   111  	rldimi	r11, r9, eval(64-$1), 0
   112  	bdnz	L(lo$1)
   113  	std	r11, 0(rp)
   114  	srdi	r10, r9, $1
   115  	b	L(com)
   116  	nop
   117  	nop
   118  ')
   119  
   120  	ALIGN(64)
   121  forloop(`i',1,63,`SHIFT(i)')
   122  
   123  L(com):	std	r10, 8(rp)
   124  	mtlr	r12
   125  ifdef(`HAVE_ABI_mode32',
   126  `	mr	r4, r3
   127  	srdi	r3, r3, 32
   128  ')
   129  	blr
   130  EPILOGUE()
   131  ASM_END()