dnl  S/390-64 mpn_sublsh1_n

dnl  Copyright 2011 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 z900		10

C z990		 5

C z9		 ?

C z10		12

C z196		 ?

C TODO

C  * Optimise for small n

C  * Compute RETVAL for sublsh1_n less stupidly

C INPUT PARAMETERS

define(`rp',	`%r2')

define(`up',	`%r3')

define(`vp',	`%r4')

define(`n',	`%r5')

ifdef(`OPERATION_addlsh1_n',`

  define(ADSBR,		algr)

  define(ADSBCR,	alcgr)

  define(INITCY,	`lghi	%r13, -1')

  define(RETVAL,	`la	%r2, 2(%r1,%r13)')

  define(func, mpn_addlsh1_n)

')

ifdef(`OPERATION_sublsh1_n',`

  define(ADSBR,		slgr)

  define(ADSBCR,	slbgr)

  define(INITCY,	`lghi	%r13, 0')

  define(RETVAL,`dnl

	slgr	%r1, %r13

	lghi	%r2, 1

	algr	%r2, %r1')

  define(func, mpn_sublsh1_n)

')

ASM_START()

PROLOGUE(mpn_sublsh1_n)

	stmg	%r6, %r13, 48(%r15)

	aghi	n, 3

	lghi	%r7, 3

	srlg	%r0, n, 2

	ngr	%r7, n			C n mod 4

	je	L(b1)

	cghi	%r7, 2

	jl	L(b2)

	jne	L(b0)

L(b3):	lmg	%r5, %r7, 0(up)

	la	up, 24(up)

	lmg	%r9, %r11, 0(vp)

	la	vp, 24(vp)

	algr	%r9, %r9

	alcgr	%r10, %r10

	alcgr	%r11, %r11

	slbgr	%r1, %r1

	ADSBR	%r5, %r9

	ADSBCR	%r6, %r10

	ADSBCR	%r7, %r11

	slbgr	%r13, %r13

	stmg	%r5, %r7, 0(rp)

	la	rp, 24(rp)

	brctg	%r0, L(top)

	j	L(end)

L(b0):	lghi	%r1, -1

	INITCY

	j	L(top)

L(b1):	lg	%r5, 0(up)

	la	up, 8(up)

	lg	%r9, 0(vp)

	la	vp, 8(vp)

	algr	%r9, %r9

	slbgr	%r1, %r1

	ADSBR	%r5, %r9

	slbgr	%r13, %r13

	stg	%r5, 0(rp)

	la	rp, 8(rp)

	brctg	%r0, L(top)

	j	L(end)

L(b2):	lmg	%r5, %r6, 0(up)

	la	up, 16(up)

	lmg	%r9, %r10, 0(vp)

	la	vp, 16(vp)

	algr	%r9, %r9

	alcgr	%r10, %r10

	slbgr	%r1, %r1

	ADSBR	%r5, %r9

	ADSBCR	%r6, %r10

	slbgr	%r13, %r13

	stmg	%r5, %r6, 0(rp)

	la	rp, 16(rp)

	brctg	%r0, L(top)

	j	L(end)

L(top):	lmg	%r9, %r12, 0(vp)

	la	vp, 32(vp)

	aghi	%r1, 1			C restore carry

	alcgr	%r9, %r9

	alcgr	%r10, %r10

	alcgr	%r11, %r11

	alcgr	%r12, %r12

	slbgr	%r1, %r1		C save carry

	lmg	%r5, %r8, 0(up)

	la	up, 32(up)

	aghi	%r13, 1			C restore carry

	ADSBCR	%r5, %r9

	ADSBCR	%r6, %r10

	ADSBCR	%r7, %r11

	ADSBCR	%r8, %r12

	slbgr	%r13, %r13		C save carry

	stmg	%r5, %r8, 0(rp)

	la	rp, 32(rp)

	brctg	%r0, L(top)

L(end):	RETVAL

	lmg	%r6, %r13, 48(%r15)

	br	%r14

EPILOGUE()