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59 lines
1.8 KiB
ArmAsm
59 lines
1.8 KiB
ArmAsm
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; Copyright (C) 2017-2018 Free Software Foundation, Inc.
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; Contributed by Sebastian Perta.
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;
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; This file is free software; you can redistribute it and/or modify it
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; under the terms of the GNU General Public License as published by the
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; Free Software Foundation; either version 3, or (at your option) any
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; later version.
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;
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; This file is distributed in the hope that it will be useful, but
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; WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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; General Public License for more details.
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;
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; Under Section 7 of GPL version 3, you are granted additional
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; permissions described in the GCC Runtime Library Exception, version
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; 3.1, as published by the Free Software Foundation.
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;
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; You should have received a copy of the GNU General Public License and
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; a copy of the GCC Runtime Library Exception along with this program;
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; see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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; <http://www.gnu.org/licenses/>.
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#include "vregs.h"
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.text
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START_FUNC ___subdi3
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movw hl, sp ; use HL-based addressing (allows for direct subw)
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movw ax, [hl+4]
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subw ax, [hl+12]
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movw r8, ax
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mov a, [hl+6] ; middle bytes of the result are determined using 8-bit
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subc a, [hl+14] ; SUBC insns which both account for and update the carry bit
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mov r10, a ; (no SUBWC instruction is available)
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mov a, [hl+7]
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subc a, [hl+15]
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mov r11, a
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mov a, [hl+8]
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subc a, [hl+16]
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mov r12, a
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mov a, [hl+9]
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subc a, [hl+17]
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mov r13, a
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movw ax, [hl+10]
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sknc ; account for the possible carry from the
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decw ax ; latest 8-bit operation
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subw ax, [hl+18]
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movw r14, ax
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ret
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END_FUNC ___subdi3
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