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Diffstat (limited to 'lib/ashldi3.c')
-rw-r--r-- | lib/ashldi3.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/lib/ashldi3.c b/lib/ashldi3.c new file mode 100644 index 000000000000..993f71ca9724 --- /dev/null +++ b/lib/ashldi3.c @@ -0,0 +1,41 @@ +/* ====-- ashldi3.c - Implement __ashldi3 -----------------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is distributed under the University of Illinois Open Source + * License. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __ashldi3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +/* Returns: a << b */ + +/* Precondition: 0 <= b < bits_in_dword */ + +di_int +__ashldi3(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.low = 0; + result.s.high = input.s.low << (b - bits_in_word); + } + else /* 0 <= b < bits_in_word */ + { + if (b == 0) + return a; + result.s.low = input.s.low << b; + result.s.high = (input.s.high << b) | (input.s.low >> (bits_in_word - b)); + } + return result.all; +} |