| 1 | /* __mpn_sub_n -- Add two limb vectors of the same length > 0 and store |
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| 2 | sum in a third limb vector. |
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| 3 | Copyright (C) 2000-2024 Free Software Foundation, Inc. |
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| 4 | This file is part of the GNU MP Library. |
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| 5 | |
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| 6 | The GNU MP Library is free software; you can redistribute it and/or modify |
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| 7 | it under the terms of the GNU Lesser General Public License as published by |
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| 8 | the Free Software Foundation; either version 2.1 of the License, or (at your |
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| 9 | option) any later version. |
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| 10 | |
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| 11 | The GNU MP Library is distributed in the hope that it will be useful, but |
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| 12 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
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| 13 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
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| 14 | License for more details. |
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| 15 | |
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| 16 | You should have received a copy of the GNU Lesser General Public License |
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| 17 | along with the GNU MP Library; see the file COPYING.LIB. If not, |
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| 18 | see <https://www.gnu.org/licenses/>. */ |
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| 19 | |
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| 20 | /* |
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| 21 | INPUT PARAMETERS |
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| 22 | res_ptr %r2 |
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| 23 | s1_ptr %r3 |
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| 24 | s2_ptr %r4 |
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| 25 | size %r5 |
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| 26 | */ |
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| 27 | |
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| 28 | #include "sysdep.h" |
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| 29 | #include "asm-syntax.h" |
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| 30 | |
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| 31 | ENTRY(__mpn_sub_n) |
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| 32 | st %r6,24(%r15) # save register 6 |
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| 33 | cfi_offset (%r6, -72) |
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| 34 | sr %r1,%r1 |
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| 35 | lhi %r0,1 # cannot use ahi to add carry, use slr |
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| 36 | .L0: l %r6,0(%r1,%r3) # .L0 -> no carry from last sub |
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| 37 | sl %r6,0(%r1,%r4) |
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| 38 | st %r6,0(%r1,%r2) |
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| 39 | la %r1,4(0,%r1) |
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| 40 | brc 4,.L3 |
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| 41 | .L1: brct %r5,.L0 |
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| 42 | slr %r2,%r2 # no last carry to return |
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| 43 | j .Lexit |
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| 44 | .L2: l %r6,0(%r1,%r3) # .L2 -> carry from last sub |
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| 45 | sl %r6,0(%r1,%r4) |
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| 46 | brc 4,.L4 |
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| 47 | slr %r6,%r0 # no carry yet, add carry from last sub |
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| 48 | st %r6,0(%r1,%r2) |
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| 49 | la %r1,4(0,%r1) |
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| 50 | brc 11,.L1 # new carry ? |
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| 51 | .L3: brct %r5,.L2 |
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| 52 | lr %r2,%r0 # return last carry |
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| 53 | j .Lexit |
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| 54 | .L4: slr %r6,%r0 # already a carry, add carry from last sub |
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| 55 | st %r6,0(%r1,%r2) |
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| 56 | la %r1,4(0,%r1) |
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| 57 | brct %r5,.L2 |
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| 58 | lr %r2,%r0 # return last carry |
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| 59 | .Lexit: l %r6,24(%r15) # restore register 6 |
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| 60 | br %r14 |
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| 61 | END(__mpn_sub_n) |
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| 62 | |
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