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Diffstat (limited to 'lib/libcompiler_rt/ashrdi3.c')
-rw-r--r-- | lib/libcompiler_rt/ashrdi3.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/lib/libcompiler_rt/ashrdi3.c b/lib/libcompiler_rt/ashrdi3.c new file mode 100644 index 00000000000..14c878bb779 --- /dev/null +++ b/lib/libcompiler_rt/ashrdi3.c @@ -0,0 +1,44 @@ +/*===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is dual licensed under the MIT and the University of Illinois Open + * Source Licenses. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __ashrdi3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +/* Returns: arithmetic a >> b */ + +/* Precondition: 0 <= b < bits_in_dword */ + +ARM_EABI_FNALIAS(lasr, ashrdi3) + +COMPILER_RT_ABI di_int +__ashrdi3(di_int a, si_int b) +{ + const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT); + dwords input; + dwords result; + input.all = a; + if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ + { + /* result.s.high = input.s.high < 0 ? -1 : 0 */ + result.s.high = input.s.high >> (bits_in_word - 1); + result.s.low = input.s.high >> (b - bits_in_word); + } + else /* 0 <= b < bits_in_word */ + { + if (b == 0) + return a; + result.s.high = input.s.high >> b; + result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b); + } + return result.all; +} |