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/* SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0 */
#include <linux/linkage.h>
#include <asm/asmmacro.h>
#include <asm/core.h>
ENTRY(__divsi3)
abi_entry_default
#if XCHAL_HAVE_DIV32
quos a2, a2, a3
#else
xor a7, a2, a3 /* sign = dividend ^ divisor */
do_abs a6, a2, a4 /* udividend = abs (dividend) */
do_abs a3, a3, a4 /* udivisor = abs (divisor) */
bltui a3, 2, .Lle_one /* check if udivisor <= 1 */
do_nsau a5, a6, a2, a8 /* udividend_shift = nsau (udividend) */
do_nsau a4, a3, a2, a8 /* udivisor_shift = nsau (udivisor) */
bgeu a5, a4, .Lspecial
sub a4, a4, a5 /* count = udivisor_shift - udividend_shift */
ssl a4
sll a3, a3 /* udivisor <<= count */
movi a2, 0 /* quotient = 0 */
/* test-subtract-and-shift loop; one quotient bit on each iteration */
#if XCHAL_HAVE_LOOPS
loopnez a4, .Lloopend
#endif /* XCHAL_HAVE_LOOPS */
.Lloop:
bltu a6, a3, .Lzerobit
sub a6, a6, a3
addi a2, a2, 1
.Lzerobit:
slli a2, a2, 1
srli a3, a3, 1
#if !XCHAL_HAVE_LOOPS
addi a4, a4, -1
bnez a4, .Lloop
#endif /* !XCHAL_HAVE_LOOPS */
.Lloopend:
bltu a6, a3, .Lreturn
addi a2, a2, 1 /* increment if udividend >= udivisor */
.Lreturn:
neg a5, a2
movltz a2, a5, a7 /* return (sign < 0) ? -quotient : quotient */
abi_ret_default
.Lle_one:
beqz a3, .Lerror
neg a2, a6 /* if udivisor == 1, then return... */
movgez a2, a6, a7 /* (sign < 0) ? -udividend : udividend */
abi_ret_default
.Lspecial:
bltu a6, a3, .Lreturn0 /* if dividend < divisor, return 0 */
movi a2, 1
movi a4, -1
movltz a2, a4, a7 /* else return (sign < 0) ? -1 : 1 */
abi_ret_default
.Lerror:
/* Divide by zero: Use an illegal instruction to force an exception.
The subsequent "DIV0" string can be recognized by the exception
handler to identify the real cause of the exception. */
ill
.ascii "DIV0"
.Lreturn0:
movi a2, 0
#endif /* XCHAL_HAVE_DIV32 */
abi_ret_default
ENDPROC(__divsi3)
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