1dbf4ed89SMax Filippov/* SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0 */ 2dbf4ed89SMax Filippov#include <linux/linkage.h> 3dbf4ed89SMax Filippov#include <asm/asmmacro.h> 4dbf4ed89SMax Filippov#include <asm/core.h> 5dbf4ed89SMax Filippov 6dbf4ed89SMax FilippovENTRY(__divsi3) 7dbf4ed89SMax Filippov 8dbf4ed89SMax Filippov abi_entry_default 9dbf4ed89SMax Filippov#if XCHAL_HAVE_DIV32 10dbf4ed89SMax Filippov quos a2, a2, a3 11dbf4ed89SMax Filippov#else 12dbf4ed89SMax Filippov xor a7, a2, a3 /* sign = dividend ^ divisor */ 13dbf4ed89SMax Filippov do_abs a6, a2, a4 /* udividend = abs (dividend) */ 14dbf4ed89SMax Filippov do_abs a3, a3, a4 /* udivisor = abs (divisor) */ 15dbf4ed89SMax Filippov bltui a3, 2, .Lle_one /* check if udivisor <= 1 */ 16dbf4ed89SMax Filippov do_nsau a5, a6, a2, a8 /* udividend_shift = nsau (udividend) */ 17dbf4ed89SMax Filippov do_nsau a4, a3, a2, a8 /* udivisor_shift = nsau (udivisor) */ 18dbf4ed89SMax Filippov bgeu a5, a4, .Lspecial 19dbf4ed89SMax Filippov 20dbf4ed89SMax Filippov sub a4, a4, a5 /* count = udivisor_shift - udividend_shift */ 21dbf4ed89SMax Filippov ssl a4 22dbf4ed89SMax Filippov sll a3, a3 /* udivisor <<= count */ 23dbf4ed89SMax Filippov movi a2, 0 /* quotient = 0 */ 24dbf4ed89SMax Filippov 25dbf4ed89SMax Filippov /* test-subtract-and-shift loop; one quotient bit on each iteration */ 26dbf4ed89SMax Filippov#if XCHAL_HAVE_LOOPS 27dbf4ed89SMax Filippov loopnez a4, .Lloopend 28dbf4ed89SMax Filippov#endif /* XCHAL_HAVE_LOOPS */ 29dbf4ed89SMax Filippov.Lloop: 30dbf4ed89SMax Filippov bltu a6, a3, .Lzerobit 31dbf4ed89SMax Filippov sub a6, a6, a3 32dbf4ed89SMax Filippov addi a2, a2, 1 33dbf4ed89SMax Filippov.Lzerobit: 34dbf4ed89SMax Filippov slli a2, a2, 1 35dbf4ed89SMax Filippov srli a3, a3, 1 36dbf4ed89SMax Filippov#if !XCHAL_HAVE_LOOPS 37dbf4ed89SMax Filippov addi a4, a4, -1 38dbf4ed89SMax Filippov bnez a4, .Lloop 39dbf4ed89SMax Filippov#endif /* !XCHAL_HAVE_LOOPS */ 40dbf4ed89SMax Filippov.Lloopend: 41dbf4ed89SMax Filippov 42dbf4ed89SMax Filippov bltu a6, a3, .Lreturn 43dbf4ed89SMax Filippov addi a2, a2, 1 /* increment if udividend >= udivisor */ 44dbf4ed89SMax Filippov.Lreturn: 45dbf4ed89SMax Filippov neg a5, a2 46dbf4ed89SMax Filippov movltz a2, a5, a7 /* return (sign < 0) ? -quotient : quotient */ 47dbf4ed89SMax Filippov abi_ret_default 48dbf4ed89SMax Filippov 49dbf4ed89SMax Filippov.Lle_one: 50dbf4ed89SMax Filippov beqz a3, .Lerror 51dbf4ed89SMax Filippov neg a2, a6 /* if udivisor == 1, then return... */ 52dbf4ed89SMax Filippov movgez a2, a6, a7 /* (sign < 0) ? -udividend : udividend */ 53dbf4ed89SMax Filippov abi_ret_default 54dbf4ed89SMax Filippov 55dbf4ed89SMax Filippov.Lspecial: 56dbf4ed89SMax Filippov bltu a6, a3, .Lreturn0 /* if dividend < divisor, return 0 */ 57dbf4ed89SMax Filippov movi a2, 1 58dbf4ed89SMax Filippov movi a4, -1 59dbf4ed89SMax Filippov movltz a2, a4, a7 /* else return (sign < 0) ? -1 : 1 */ 60dbf4ed89SMax Filippov abi_ret_default 61dbf4ed89SMax Filippov 62dbf4ed89SMax Filippov.Lerror: 63dbf4ed89SMax Filippov /* Divide by zero: Use an illegal instruction to force an exception. 64dbf4ed89SMax Filippov The subsequent "DIV0" string can be recognized by the exception 65dbf4ed89SMax Filippov handler to identify the real cause of the exception. */ 66dbf4ed89SMax Filippov ill 67dbf4ed89SMax Filippov .ascii "DIV0" 68dbf4ed89SMax Filippov 69dbf4ed89SMax Filippov.Lreturn0: 70dbf4ed89SMax Filippov movi a2, 0 71dbf4ed89SMax Filippov#endif /* XCHAL_HAVE_DIV32 */ 72dbf4ed89SMax Filippov abi_ret_default 73dbf4ed89SMax Filippov 74dbf4ed89SMax FilippovENDPROC(__divsi3) 75*338d9150SMax FilippovEXPORT_SYMBOL(__divsi3) 76