13cab2bb3Spatrick //===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------===//
23cab2bb3Spatrick //
33cab2bb3Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
43cab2bb3Spatrick // See https://llvm.org/LICENSE.txt for license information.
53cab2bb3Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
63cab2bb3Spatrick //
73cab2bb3Spatrick //===----------------------------------------------------------------------===//
83cab2bb3Spatrick //
93cab2bb3Spatrick // This file implements __ashrdi3 for the compiler_rt library.
103cab2bb3Spatrick //
113cab2bb3Spatrick //===----------------------------------------------------------------------===//
123cab2bb3Spatrick 
133cab2bb3Spatrick #include "int_lib.h"
143cab2bb3Spatrick 
153cab2bb3Spatrick // Returns: arithmetic a >> b
163cab2bb3Spatrick 
173cab2bb3Spatrick // Precondition:  0 <= b < bits_in_dword
183cab2bb3Spatrick 
__ashrdi3(di_int a,int b)19*1f9cb04fSpatrick COMPILER_RT_ABI di_int __ashrdi3(di_int a, int b) {
203cab2bb3Spatrick   const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
213cab2bb3Spatrick   dwords input;
223cab2bb3Spatrick   dwords result;
233cab2bb3Spatrick   input.all = a;
243cab2bb3Spatrick   if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ {
253cab2bb3Spatrick     // result.s.high = input.s.high < 0 ? -1 : 0
263cab2bb3Spatrick     result.s.high = input.s.high >> (bits_in_word - 1);
273cab2bb3Spatrick     result.s.low = input.s.high >> (b - bits_in_word);
283cab2bb3Spatrick   } else /* 0 <= b < bits_in_word */ {
293cab2bb3Spatrick     if (b == 0)
303cab2bb3Spatrick       return a;
313cab2bb3Spatrick     result.s.high = input.s.high >> b;
323cab2bb3Spatrick     result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b);
333cab2bb3Spatrick   }
343cab2bb3Spatrick   return result.all;
353cab2bb3Spatrick }
363cab2bb3Spatrick 
373cab2bb3Spatrick #if defined(__ARM_EABI__)
383cab2bb3Spatrick COMPILER_RT_ALIAS(__ashrdi3, __aeabi_lasr)
393cab2bb3Spatrick #endif
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