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82 lines
1.9 KiB
ArmAsm
82 lines
1.9 KiB
ArmAsm
/* Integer multiplication routines for RISC-V.
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Copyright (C) 2016-2017 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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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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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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.text
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.align 2
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#if __riscv_xlen == 32
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/* Our RV64 64-bit routines are equivalent to our RV32 32-bit routines. */
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# define __multi3 __muldi3
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#endif
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.globl __multi3
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__multi3:
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#if __riscv_xlen == 32
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/* Our RV64 64-bit routines are equivalent to our RV32 32-bit routines. */
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# define __muldi3 __mulsi3
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#endif
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/* We rely on the fact that __muldi3 doesn't clobber the t-registers. */
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mv t0, ra
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mv t5, a0
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mv a0, a1
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mv t6, a3
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mv a1, t5
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mv a4, a2
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li a5, 0
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li t2, 0
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li t4, 0
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.L1:
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add a6, t2, a1
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andi t3, a4, 1
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slli a7, a5, 1
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slti t1, a1, 0
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srli a4, a4, 1
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add a5, t4, a5
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beqz t3, .L2
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sltu t3, a6, t2
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mv t2, a6
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add t4, t3, a5
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.L2:
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slli a1, a1, 1
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or a5, t1, a7
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bnez a4, .L1
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beqz a0, .L3
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mv a1, a2
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call __muldi3
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add t4, t4, a0
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.L3:
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beqz t6, .L4
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mv a1, t6
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mv a0, t5
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call __muldi3
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add t4, t4, a0
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.L4:
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mv a0, t2
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mv a1, t4
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jr t0
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