| /* 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) |
