1dnl  S/390 mpn_submul_1 -- Multiply a limb vector with a limb and subtract the
2dnl  result from a second limb vector.
3
4dnl  Copyright 2001 Free Software Foundation, Inc.
5
6dnl  This file is part of the GNU MP Library.
7dnl
8dnl  The GNU MP Library is free software; you can redistribute it and/or modify
9dnl  it under the terms of either:
10dnl
11dnl    * the GNU Lesser General Public License as published by the Free
12dnl      Software Foundation; either version 3 of the License, or (at your
13dnl      option) any later version.
14dnl
15dnl  or
16dnl
17dnl    * the GNU General Public License as published by the Free Software
18dnl      Foundation; either version 2 of the License, or (at your option) any
19dnl      later version.
20dnl
21dnl  or both in parallel, as here.
22dnl
23dnl  The GNU MP Library is distributed in the hope that it will be useful, but
24dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
25dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
26dnl  for more details.
27dnl
28dnl  You should have received copies of the GNU General Public License and the
29dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
30dnl  see https://www.gnu.org/licenses/.
31
32include(`../config.m4')
33
34define(`rp',2)
35define(`up',3)
36define(`n',4)
37define(`vlimb',5)
38define(`cylimb',7)
39
40ASM_START()
41PROLOGUE(mpn_submul_1)
42          stm       6,7,24(15)
43          slr       cylimb,cylimb       # clear cylimb
44          ltr       vlimb,vlimb
45          jnl       .Loopp
46
47.Loopn:   l         1,0(up)             # load from u
48          lr        6,1                 #
49          mr        0,vlimb             # multiply signed
50          alr       0,6                 # add vlimb to phi
51          sra       6,31                # make mask
52          nr        6,vlimb             # 0 or vlimb
53          alr       0,6                 # conditionally add vlimb to phi
54          alr       1,cylimb  # add carry limb to plo
55          brc       8+4,+8              # branch if not carry
56          ahi       0,1                 # increment phi
57          l         6,0(rp)             # load r limb
58          slr       6,1                 # add u limb to plo
59          brc       2+1,+8              # branch if not carry
60          ahi       0,1                 # increment phi
61          lr        cylimb,0  # new cylimb
62          st        6,0(rp)             # store
63          la        up,4(,up)
64          la        rp,4(,rp)
65          brct      n,.Loopn
66
67          lr        2,cylimb
68          lm        6,7,24(15)
69          br        14
70
71.Loopp:   l         1,0(up)             # load from u
72          lr        6,1                 #
73          mr        0,vlimb             # multiply signed
74          sra       6,31                # make mask
75          nr        6,vlimb             # 0 or vlimb
76          alr       0,6                 # conditionally add vlimb to phi
77          alr       1,cylimb  # add carry limb to plo
78          brc       8+4,+8              # branch if not carry
79          ahi       0,1                 # increment phi
80          l         6,0(rp)             # load r limb
81          slr       6,1                 # add u limb to plo
82          brc       2+1,+8              # branch if not carry
83          ahi       0,1                 # increment phi
84          lr        cylimb,0  # new cylimb
85          st        6,0(rp)             # store
86          la        up,4(,up)
87          la        rp,4(,rp)
88          brct      n,.Loopp
89
90          lr        2,cylimb
91          lm        6,7,24(15)
92          br        14
93EPILOGUE(mpn_submul_1)
94