github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/arm/v6t2/divrem_1.asm (about)

     1  dnl  ARM v6t2 mpn_divrem_1 and mpn_preinv_divrem_1.
     2  
     3  dnl  Contributed to the GNU project by Torbjörn Granlund.
     4  
     5  dnl  Copyright 2012 Free Software Foundation, Inc.
     6  
     7  dnl  This file is part of the GNU MP Library.
     8  dnl
     9  dnl  The GNU MP Library is free software; you can redistribute it and/or modify
    10  dnl  it under the terms of either:
    11  dnl
    12  dnl    * the GNU Lesser General Public License as published by the Free
    13  dnl      Software Foundation; either version 3 of the License, or (at your
    14  dnl      option) any later version.
    15  dnl
    16  dnl  or
    17  dnl
    18  dnl    * the GNU General Public License as published by the Free Software
    19  dnl      Foundation; either version 2 of the License, or (at your option) any
    20  dnl      later version.
    21  dnl
    22  dnl  or both in parallel, as here.
    23  dnl
    24  dnl  The GNU MP Library is distributed in the hope that it will be useful, but
    25  dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    26  dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    27  dnl  for more details.
    28  dnl
    29  dnl  You should have received copies of the GNU General Public License and the
    30  dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
    31  dnl  see https://www.gnu.org/licenses/.
    32  
    33  include(`../config.m4')
    34  
    35  C		norm	unorm	frac
    36  C StrongARM	 -	 -	 -
    37  C XScale	 -	 -	 -
    38  C Cortex-A7	 ?	 ?	 ?
    39  C Cortex-A8	 ?	 ?	 ?
    40  C Cortex-A9	13	14	13
    41  C Cortex-A15	11.4	11.8	11.1
    42  
    43  C TODO
    44  C  * Optimise inner-loops better, they could likely run a cycle or two faster.
    45  C  * Decrease register usage, streamline non-loop code.
    46  
    47  define(`qp_arg',  `r0')
    48  define(`fn',      `r1')
    49  define(`up_arg',  `r2')
    50  define(`n_arg',   `r3')
    51  define(`d_arg',   `0')
    52  define(`dinv_arg',`4')
    53  define(`cnt_arg', `8')
    54  
    55  define(`n',       `r9')
    56  define(`qp',      `r5')
    57  define(`up',      `r6')
    58  define(`cnt',     `r7')
    59  define(`tnc',     `r10')
    60  define(`dinv',    `r0')
    61  define(`d',       `r4')
    62  
    63  ASM_START()
    64  PROLOGUE(mpn_preinv_divrem_1)
    65  	stmfd	sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr}
    66  	ldr	d,    [sp, #9*4+d_arg]
    67  	ldr	cnt,  [sp, #9*4+cnt_arg]
    68  	str	r1, [sp, #9*4+d_arg]	C reuse d stack slot for fn
    69  	sub	n, r3, #1
    70  	add	r3, r1, n
    71  	cmp	d, #0
    72  	add	qp, qp_arg, r3, lsl #2	C put qp at Q[] end
    73  	add	up, up_arg, n, lsl #2	C put up at U[] end
    74  	ldr	dinv, [sp, #9*4+dinv_arg]
    75  	blt	L(nent)
    76  	b	L(uent)
    77  EPILOGUE()
    78  
    79  PROLOGUE(mpn_divrem_1)
    80  	stmfd	sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr}
    81  	sub	n, r3, #1
    82  	ldr	d, [sp, #9*4+d_arg]	C d
    83  	str	r1, [sp, #9*4+d_arg]	C reuse d stack slot for fn
    84  	add	r3, r1, n
    85  	cmp	d, #0
    86  	add	qp, qp_arg, r3, lsl #2	C put qp at Q[] end
    87  	add	up, up_arg, n, lsl #2	C put up at U[] end
    88  	blt	L(normalised)
    89  
    90  L(unnorm):
    91  	clz	cnt, d
    92  	mov	r0, d, lsl cnt		C pass d << cnt
    93  	bl	mpn_invert_limb
    94  L(uent):
    95  	mov	d, d, lsl cnt		C d <<= cnt
    96  	cmp	n, #0
    97  	mov	r1, #0			C r
    98  	blt	L(frac)
    99  
   100  	ldr	r11, [up, #0]
   101  
   102  	rsb	tnc, cnt, #32
   103  	mov	r1, r11, lsr tnc
   104  	mov	r11, r11, lsl cnt
   105  	beq	L(uend)
   106  
   107  	ldr	r3, [up, #-4]!
   108  	orr	r2, r11, r3, lsr tnc
   109  	b	L(mid)
   110  
   111  L(utop):
   112  	mls	r1, d, r8, r11
   113  	mov	r11, r3, lsl cnt
   114  	ldr	r3, [up, #-4]!
   115  	cmp	r1, r2
   116  	addhi	r1, r1, d
   117  	subhi	r8, r8, #1
   118  	orr	r2, r11, r3, lsr tnc
   119  	cmp	r1, d
   120  	bcs	L(ufx)
   121  L(uok):	str	r8, [qp], #-4
   122  L(mid):	add	r8, r1, #1
   123  	mov	r11, r2
   124  	umlal	r2, r8, r1, dinv
   125  	subs	n, n, #1
   126  	bne	L(utop)
   127  
   128  	mls	r1, d, r8, r11
   129  	mov	r11, r3, lsl cnt
   130  	cmp	r1, r2
   131  	addhi	r1, r1, d
   132  	subhi	r8, r8, #1
   133  	cmp	r1, d
   134  	rsbcs	r1, d, r1
   135  	addcs	r8, r8, #1
   136  	str	r8, [qp], #-4
   137  
   138  L(uend):add	r8, r1, #1
   139  	mov	r2, r11
   140  	umlal	r2, r8, r1, dinv
   141  	mls	r1, d, r8, r11
   142  	cmp	r1, r2
   143  	addhi	r1, r1, d
   144  	subhi	r8, r8, #1
   145  	cmp	r1, d
   146  	rsbcs	r1, d, r1
   147  	addcs	r8, r8, #1
   148  	str	r8, [qp], #-4
   149  L(frac):
   150  	ldr	r2, [sp, #9*4+d_arg]	C fn
   151  	cmp	r2, #0
   152  	beq	L(fend)
   153  
   154  L(ftop):mov	r6, #0
   155  	add	r3, r1, #1
   156  	umlal	r6, r3, r1, dinv
   157  	mov	r8, #0
   158  	mls	r1, d, r3, r8
   159  	cmp	r1, r6
   160  	addhi	r1, r1, d
   161  	subhi	r3, r3, #1
   162  	subs	r2, r2, #1
   163  	str	r3, [qp], #-4
   164  	bne	L(ftop)
   165  
   166  L(fend):mov	r11, r1, lsr cnt
   167  L(rtn):	mov	r0, r11
   168  	ldmfd	sp!, {r4, r5, r6, r7, r8, r9, r10, r11, pc}
   169  
   170  L(normalised):
   171  	mov	r0, d
   172  	bl	mpn_invert_limb
   173  L(nent):
   174  	cmp	n, #0
   175  	mov	r11, #0			C r
   176  	blt	L(nend)
   177  
   178  	ldr	r11, [up, #0]
   179  	cmp	r11, d
   180  	movlo	r2, #0			C hi q limb
   181  	movhs	r2, #1			C hi q limb
   182  	subhs	r11, r11, d
   183  
   184  	str	r2, [qp], #-4
   185  	cmp	n, #0
   186  	beq	L(nend)
   187  
   188  L(ntop):ldr	r1, [up, #-4]!
   189  	add	r12, r11, #1
   190  	umlal	r1, r12, r11, dinv
   191  	ldr	r3, [up, #0]
   192  	mls	r11, d, r12, r3
   193  	cmp	r11, r1
   194  	addhi	r11, r11, d
   195  	subhi	r12, r12, #1
   196  	cmp	d, r11
   197  	bls	L(nfx)
   198  L(nok):	str	r12, [qp], #-4
   199  	subs	n, n, #1
   200  	bne	L(ntop)
   201  
   202  L(nend):mov	r1, r11			C r
   203  	mov	cnt, #0			C shift cnt
   204  	b	L(frac)
   205  
   206  L(nfx):	add	r12, r12, #1
   207  	rsb	r11, d, r11
   208  	b	L(nok)
   209  L(ufx):	rsb	r1, d, r1
   210  	add	r8, r8, #1
   211  	b	L(uok)
   212  EPILOGUE()