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/* Integer multiplication routines for RISC-V.
Copyright (C) 2016-2017 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
.text
.align 2
#if __riscv_xlen == 32
/* Our RV64 64-bit routines are equivalent to our RV32 32-bit routines. */
# define __multi3 __muldi3
#endif
.globl __multi3
__multi3:
#if __riscv_xlen == 32
/* Our RV64 64-bit routines are equivalent to our RV32 32-bit routines. */
# define __muldi3 __mulsi3
#endif
/* We rely on the fact that __muldi3 doesn't clobber the t-registers. */
mv t0, ra
mv t5, a0
mv a0, a1
mv t6, a3
mv a1, t5
mv a4, a2
li a5, 0
li t2, 0
li t4, 0
.L1:
add a6, t2, a1
andi t3, a4, 1
slli a7, a5, 1
slti t1, a1, 0
srli a4, a4, 1
add a5, t4, a5
beqz t3, .L2
sltu t3, a6, t2
mv t2, a6
add t4, t3, a5
.L2:
slli a1, a1, 1
or a5, t1, a7
bnez a4, .L1
beqz a0, .L3
mv a1, a2
call __muldi3
add t4, t4, a0
.L3:
beqz t6, .L4
mv a1, t6
mv a0, t5
call __muldi3
add t4, t4, a0
.L4:
mv a0, t2
mv a1, t4
jr t0
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