162306a36Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0 */ 262306a36Sopenharmony_ci#include <linux/linkage.h> 362306a36Sopenharmony_ci#include <asm/asmmacro.h> 462306a36Sopenharmony_ci#include <asm/core.h> 562306a36Sopenharmony_ci 662306a36Sopenharmony_ciENTRY(__divsi3) 762306a36Sopenharmony_ci 862306a36Sopenharmony_ci abi_entry_default 962306a36Sopenharmony_ci#if XCHAL_HAVE_DIV32 1062306a36Sopenharmony_ci quos a2, a2, a3 1162306a36Sopenharmony_ci#else 1262306a36Sopenharmony_ci xor a7, a2, a3 /* sign = dividend ^ divisor */ 1362306a36Sopenharmony_ci do_abs a6, a2, a4 /* udividend = abs (dividend) */ 1462306a36Sopenharmony_ci do_abs a3, a3, a4 /* udivisor = abs (divisor) */ 1562306a36Sopenharmony_ci bltui a3, 2, .Lle_one /* check if udivisor <= 1 */ 1662306a36Sopenharmony_ci do_nsau a5, a6, a2, a8 /* udividend_shift = nsau (udividend) */ 1762306a36Sopenharmony_ci do_nsau a4, a3, a2, a8 /* udivisor_shift = nsau (udivisor) */ 1862306a36Sopenharmony_ci bgeu a5, a4, .Lspecial 1962306a36Sopenharmony_ci 2062306a36Sopenharmony_ci sub a4, a4, a5 /* count = udivisor_shift - udividend_shift */ 2162306a36Sopenharmony_ci ssl a4 2262306a36Sopenharmony_ci sll a3, a3 /* udivisor <<= count */ 2362306a36Sopenharmony_ci movi a2, 0 /* quotient = 0 */ 2462306a36Sopenharmony_ci 2562306a36Sopenharmony_ci /* test-subtract-and-shift loop; one quotient bit on each iteration */ 2662306a36Sopenharmony_ci#if XCHAL_HAVE_LOOPS 2762306a36Sopenharmony_ci loopnez a4, .Lloopend 2862306a36Sopenharmony_ci#endif /* XCHAL_HAVE_LOOPS */ 2962306a36Sopenharmony_ci.Lloop: 3062306a36Sopenharmony_ci bltu a6, a3, .Lzerobit 3162306a36Sopenharmony_ci sub a6, a6, a3 3262306a36Sopenharmony_ci addi a2, a2, 1 3362306a36Sopenharmony_ci.Lzerobit: 3462306a36Sopenharmony_ci slli a2, a2, 1 3562306a36Sopenharmony_ci srli a3, a3, 1 3662306a36Sopenharmony_ci#if !XCHAL_HAVE_LOOPS 3762306a36Sopenharmony_ci addi a4, a4, -1 3862306a36Sopenharmony_ci bnez a4, .Lloop 3962306a36Sopenharmony_ci#endif /* !XCHAL_HAVE_LOOPS */ 4062306a36Sopenharmony_ci.Lloopend: 4162306a36Sopenharmony_ci 4262306a36Sopenharmony_ci bltu a6, a3, .Lreturn 4362306a36Sopenharmony_ci addi a2, a2, 1 /* increment if udividend >= udivisor */ 4462306a36Sopenharmony_ci.Lreturn: 4562306a36Sopenharmony_ci neg a5, a2 4662306a36Sopenharmony_ci movltz a2, a5, a7 /* return (sign < 0) ? -quotient : quotient */ 4762306a36Sopenharmony_ci abi_ret_default 4862306a36Sopenharmony_ci 4962306a36Sopenharmony_ci.Lle_one: 5062306a36Sopenharmony_ci beqz a3, .Lerror 5162306a36Sopenharmony_ci neg a2, a6 /* if udivisor == 1, then return... */ 5262306a36Sopenharmony_ci movgez a2, a6, a7 /* (sign < 0) ? -udividend : udividend */ 5362306a36Sopenharmony_ci abi_ret_default 5462306a36Sopenharmony_ci 5562306a36Sopenharmony_ci.Lspecial: 5662306a36Sopenharmony_ci bltu a6, a3, .Lreturn0 /* if dividend < divisor, return 0 */ 5762306a36Sopenharmony_ci movi a2, 1 5862306a36Sopenharmony_ci movi a4, -1 5962306a36Sopenharmony_ci movltz a2, a4, a7 /* else return (sign < 0) ? -1 : 1 */ 6062306a36Sopenharmony_ci abi_ret_default 6162306a36Sopenharmony_ci 6262306a36Sopenharmony_ci.Lerror: 6362306a36Sopenharmony_ci /* Divide by zero: Use an illegal instruction to force an exception. 6462306a36Sopenharmony_ci The subsequent "DIV0" string can be recognized by the exception 6562306a36Sopenharmony_ci handler to identify the real cause of the exception. */ 6662306a36Sopenharmony_ci ill 6762306a36Sopenharmony_ci .ascii "DIV0" 6862306a36Sopenharmony_ci 6962306a36Sopenharmony_ci.Lreturn0: 7062306a36Sopenharmony_ci movi a2, 0 7162306a36Sopenharmony_ci#endif /* XCHAL_HAVE_DIV32 */ 7262306a36Sopenharmony_ci abi_ret_default 7362306a36Sopenharmony_ci 7462306a36Sopenharmony_ciENDPROC(__divsi3) 7562306a36Sopenharmony_ciEXPORT_SYMBOL(__divsi3) 76