tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0 */
2#include <linux/linkage.h>
3#include <asm/asmmacro.h>
4#include <asm/core.h>
5
6ENTRY(__umodsi3)
7
8 abi_entry_default
9#if XCHAL_HAVE_DIV32
10 remu a2, a2, a3
11#else
12 bltui a3, 2, .Lle_one /* check if the divisor is <= 1 */
13
14 do_nsau a5, a2, a6, a7 /* dividend_shift = nsau (dividend) */
15 do_nsau a4, a3, a6, a7 /* divisor_shift = nsau (divisor) */
16 bgeu a5, a4, .Lspecial
17
18 sub a4, a4, a5 /* count = divisor_shift - dividend_shift */
19 ssl a4
20 sll a3, a3 /* divisor <<= count */
21
22 /* test-subtract-and-shift loop */
23#if XCHAL_HAVE_LOOPS
24 loopnez a4, .Lloopend
25#endif /* XCHAL_HAVE_LOOPS */
26.Lloop:
27 bltu a2, a3, .Lzerobit
28 sub a2, a2, a3
29.Lzerobit:
30 srli a3, a3, 1
31#if !XCHAL_HAVE_LOOPS
32 addi a4, a4, -1
33 bnez a4, .Lloop
34#endif /* !XCHAL_HAVE_LOOPS */
35.Lloopend:
36
37.Lspecial:
38 bltu a2, a3, .Lreturn
39 sub a2, a2, a3 /* subtract once more if dividend >= divisor */
40.Lreturn:
41 abi_ret_default
42
43.Lle_one:
44 bnez a3, .Lreturn0
45
46 /* Divide by zero: Use an illegal instruction to force an exception.
47 The subsequent "DIV0" string can be recognized by the exception
48 handler to identify the real cause of the exception. */
49 ill
50 .ascii "DIV0"
51
52.Lreturn0:
53 movi a2, 0
54#endif /* XCHAL_HAVE_DIV32 */
55 abi_ret_default
56
57ENDPROC(__umodsi3)
58EXPORT_SYMBOL(__umodsi3)