usr/src/lib/libc/sparc/gen/lshiftl.s

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30         .file   "lshiftl.s"
  31
  32 /*
  33  * Shift a double long value. Ported from m32 version to sparc.
  34  *
  35  *      dl_t
  36  *      lshiftl (op, cnt)
  37  *              dl_t    op;
  38  *              int     cnt;
  39  */
  40
  41 #include "SYS.h"
  42
  43         ENTRY(lshiftl)
  44
  45         ld      [%o7+8],%o4             ! Instruction at ret-addr should be a
  46         cmp     %o4,8                   ! 'unimp 8' indicating a valid call.
  47         be      1f                      ! if OK, go forward.
  48         nop                             ! delay instruction.
  49         jmp     %o7+8                   ! return
  50         nop                             ! delay instruction.
  51
  52 1:
  53         ld      [%o0+0],%o2             ! fetch op.dl_hop
  54         ld      [%o0+4],%o3             ! fetch op.dl_lop
  55         subcc   %g0,%o1,%o4             ! test cnt < 0 and save reciprocol
  56         bz      .done
  57         ld      [%sp+(16*4)],%o0        ! address to store result into
  58         bg      .right                  !
  59         nop
  60                                         ! Positive (or null) shift (left)
  61         and     %o1,0x3f,%o1            ! Reduce range to 0..63
  62         subcc   %o1,32,%o5              ! cnt - 32 (also test cnt >= 32)
  63         bneg,a  .leftsmall              !
  64         add     %o4,32,%o4              ! 32 - cnt (actually ((-cnt) + 32)
  65         sll     %o3,%o5,%o2             ! R.h = R.l << (cnt - 32)
  66         ba      .done                   !
  67         or      %g0,%g0,%o3             ! R.l = 0
  68
  69 .leftsmall:
  70         srl     %o3,%o4,%o5             ! temp = R.l >> (31 - cnt)
  71         sll     %o3,%o1,%o3             ! R.l = R.l << cnt
  72         sll     %o2,%o1,%o2             ! R.h = R.h << cnt
  73         ba      .done                   !
  74         or      %o2,%o5,%o2             ! R.h = R.h | temp
  75
  76 .right:                                 ! Negative shift (right)
  77         and     %o4,0x3f,%o4            ! Reduce range to 0..63
  78         subcc   %o4,32,%o5              ! cnt - 32 (also test cnt >= 32)
  79         bneg,a  .rightsmall             !
  80         add     %o1,32,%o1              ! 32 - cnt (actually ((-cnt) + 32)
  81         srl     %o2,%o5,%o3             ! R.l = R.h >> (cnt - 32)
  82         ba      .done                   !
  83         or      %g0,%g0,%o2             ! R.h = 0
  84
  85 .rightsmall:
  86         sll     %o2,%o1,%o5             ! temp = R.h << (31 - cnt)
  87         srl     %o3,%o4,%o3             ! R.l = R.l >> cnt
  88         srl     %o2,%o4,%o2             ! R.h = R.h >> cnt
  89         ba      .done                   !
  90         or      %o3,%o5,%o3             ! R.l = R.l | temp
  91
  92 .done:
  93         st      %o2,[%o0+0]             ! store result, dl_hop
  94         jmp     %o7+12                  ! return
  95         st      %o3,[%o0+4]             ! store result, dl_lop
  96
  97         SET_SIZE(lshiftl)