llvm-project

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// ====-- ashldi3.c - Implement __ashldi3 ---------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements __ashldi3 for the compiler_rt library.
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//
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//===----------------------------------------------------------------------===//
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#include "int_lib.h"
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// Returns: a << b
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// Precondition:  0 <= b < bits_in_dword
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COMPILER_RT_ABI di_int __ashldi3(di_int a, int b) {
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  const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
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  dwords input;
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  dwords result;
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  input.all = a;
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  if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ {
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    result.s.low = 0;
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    result.s.high = input.s.low << (b - bits_in_word);
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  } else /* 0 <= b < bits_in_word */ {
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    if (b == 0)
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      return a;
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    result.s.low = input.s.low << b;
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    result.s.high =
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        ((su_int)input.s.high << b) | (input.s.low >> (bits_in_word - b));
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  }
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  return result.all;
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}
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#if defined(__ARM_EABI__)
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COMPILER_RT_ALIAS(__ashldi3, __aeabi_llsl)
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#endif
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