dnl  Intel P6 mpn_addmul_1/mpn_submul_1 -- add or subtract mpn multiple.

dnl  Copyright 1999-2002, 2005 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			    cycles/limb

C P5

C P6 model 0-8,10-12		 6.44

C P6 model 9  (Banias)		 6.15

C P6 model 13 (Dothan)		 6.11

C P4 model 0  (Willamette)

C P4 model 1  (?)

C P4 model 2  (Northwood)

C P4 model 3  (Prescott)

C P4 model 4  (Nocona)

C AMD K6

C AMD K7

C AMD K8

dnl  P6 UNROLL_COUNT cycles/limb

dnl          8           6.7

dnl         16           6.35

dnl         32           6.3

dnl         64           6.3

dnl  Maximum possible with the current code is 64.

deflit(UNROLL_COUNT, 16)

ifdef(`OPERATION_addmul_1', `

	define(M4_inst,        addl)

	define(M4_function_1,  mpn_addmul_1)

	define(M4_function_1c, mpn_addmul_1c)

	define(M4_description, add it to)

	define(M4_desc_retval, carry)

',`ifdef(`OPERATION_submul_1', `

	define(M4_inst,        subl)

	define(M4_function_1,  mpn_submul_1)

	define(M4_function_1c, mpn_submul_1c)

	define(M4_description, subtract it from)

	define(M4_desc_retval, borrow)

',`m4_error(`Need OPERATION_addmul_1 or OPERATION_submul_1

')')')

MULFUNC_PROLOGUE(mpn_addmul_1 mpn_addmul_1c mpn_submul_1 mpn_submul_1c)

C mp_limb_t M4_function_1 (mp_ptr dst, mp_srcptr src, mp_size_t size,

C                            mp_limb_t mult);

C mp_limb_t M4_function_1c (mp_ptr dst, mp_srcptr src, mp_size_t size,

C                             mp_limb_t mult, mp_limb_t carry);

C

C Calculate src,size multiplied by mult and M4_description dst,size.

C Return the M4_desc_retval limb from the top of the result.

C

C This code is pretty much the same as the K6 code.  The unrolled loop is

C the same, but there's just a few scheduling tweaks in the setups and the

C simple loop.

C

C A number of variations have been tried for the unrolled loop, with one or

C two carries, and with loads scheduled earlier, but nothing faster than 6

C cycles/limb has been found.

ifdef(`PIC',`

deflit(UNROLL_THRESHOLD, 5)

',`

deflit(UNROLL_THRESHOLD, 5)

')

defframe(PARAM_CARRY,     20)

defframe(PARAM_MULTIPLIER,16)

defframe(PARAM_SIZE,      12)

defframe(PARAM_SRC,       8)

defframe(PARAM_DST,       4)

	TEXT

	ALIGN(32)

PROLOGUE(M4_function_1c)

	pushl	%ebx

deflit(`FRAME',4)

	movl	PARAM_CARRY, %ebx

	jmp	L(start_nc)

EPILOGUE()

PROLOGUE(M4_function_1)

	push	%ebx

deflit(`FRAME',4)

	xorl	%ebx, %ebx	C initial carry

L(start_nc):

	movl	PARAM_SIZE, %ecx

	pushl	%esi

deflit(`FRAME',8)

	movl	PARAM_SRC, %esi

	pushl	%edi

deflit(`FRAME',12)

	movl	PARAM_DST, %edi

	pushl	%ebp

deflit(`FRAME',16)

	cmpl	$UNROLL_THRESHOLD, %ecx

	movl	PARAM_MULTIPLIER, %ebp

	jae	L(unroll)

	C simple loop

	C this is offset 0x22, so close enough to aligned

L(simple):

	C eax	scratch

	C ebx	carry

	C ecx	counter

	C edx	scratch

	C esi	src

	C edi	dst

	C ebp	multiplier

	movl	(%esi), %eax

	addl	$4, %edi

	mull	%ebp

	addl	%ebx, %eax

	adcl	$0, %edx

	M4_inst	%eax, -4(%edi)

	movl	%edx, %ebx

	adcl	$0, %ebx

	decl	%ecx

	leal	4(%esi), %esi

	jnz	L(simple)

	popl	%ebp

	popl	%edi

	popl	%esi

	movl	%ebx, %eax

	popl	%ebx

	ret

C------------------------------------------------------------------------------

C VAR_JUMP holds the computed jump temporarily because there's not enough

C registers when doing the mul for the initial two carry limbs.

C

C The add/adc for the initial carry in %ebx is necessary only for the

C mpn_add/submul_1c entry points.  Duplicating the startup code to

C eliminate this for the plain mpn_add/submul_1 doesn't seem like a good

C idea.

dnl  overlapping with parameters already fetched

define(VAR_COUNTER,`PARAM_SIZE')

define(VAR_JUMP,   `PARAM_DST')

	C this is offset 0x43, so close enough to aligned

L(unroll):

	C eax

	C ebx	initial carry

	C ecx	size

	C edx

	C esi	src

	C edi	dst

	C ebp

	movl	%ecx, %edx

	decl	%ecx

	subl	$2, %edx

	negl	%ecx

	shrl	$UNROLL_LOG2, %edx

	andl	$UNROLL_MASK, %ecx

	movl	%edx, VAR_COUNTER

	movl	%ecx, %edx

	C 15 code bytes per limb

ifdef(`PIC',`

	call	L(pic_calc)

L(here):

',`

	shll	$4, %edx

	negl	%ecx

	leal	L(entry) (%edx,%ecx,1), %edx

')

	movl	(%esi), %eax		C src low limb

	movl	%edx, VAR_JUMP

	leal	ifelse(UNROLL_BYTES,256,128+) 4(%esi,%ecx,4), %esi

	mull	%ebp

	addl	%ebx, %eax	C initial carry (from _1c)

	adcl	$0, %edx

	movl	%edx, %ebx	C high carry

	leal	ifelse(UNROLL_BYTES,256,128) (%edi,%ecx,4), %edi

	movl	VAR_JUMP, %edx

	testl	$1, %ecx

	movl	%eax, %ecx	C low carry

	cmovnz(	%ebx, %ecx)	C high,low carry other way around

	cmovnz(	%eax, %ebx)

	jmp	*%edx

ifdef(`PIC',`

L(pic_calc):

	shll	$4, %edx

	negl	%ecx

	C See mpn/x86/README about old gas bugs

	leal	(%edx,%ecx,1), %edx

	addl	$L(entry)-L(here), %edx

	addl	(%esp), %edx

	ret_internal

')

C -----------------------------------------------------------

	ALIGN(32)

L(top):

deflit(`FRAME',16)

	C eax	scratch

	C ebx	carry hi

	C ecx	carry lo

	C edx	scratch

	C esi	src

	C edi	dst

	C ebp	multiplier

	C

	C VAR_COUNTER	loop counter

	C

	C 15 code bytes per limb

	addl	$UNROLL_BYTES, %edi

L(entry):

deflit(CHUNK_COUNT,2)

forloop(`i', 0, UNROLL_COUNT/CHUNK_COUNT-1, `

	deflit(`disp0', eval(i*4*CHUNK_COUNT ifelse(UNROLL_BYTES,256,-128)))

	deflit(`disp1', eval(disp0 + 4))

Zdisp(	movl,	disp0,(%esi), %eax)

	mull	%ebp

Zdisp(	M4_inst,%ecx, disp0,(%edi))

	adcl	%eax, %ebx

	movl	%edx, %ecx

	adcl	$0, %ecx

	movl	disp1(%esi), %eax

	mull	%ebp

	M4_inst	%ebx, disp1(%edi)

	adcl	%eax, %ecx

	movl	%edx, %ebx

	adcl	$0, %ebx

')

	decl	VAR_COUNTER

	leal	UNROLL_BYTES(%esi), %esi

	jns	L(top)

deflit(`disp0',	eval(UNROLL_BYTES ifelse(UNROLL_BYTES,256,-128)))

	M4_inst	%ecx, disp0(%edi)

	movl	%ebx, %eax

	popl	%ebp

	popl	%edi

	popl	%esi

	popl	%ebx

	adcl	$0, %eax

	ret

EPILOGUE()