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Diffstat (limited to 'lib/ashldi3.c')
-rw-r--r-- | lib/ashldi3.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/lib/ashldi3.c b/lib/ashldi3.c new file mode 100644 index 000000000..e9e24c31d --- /dev/null +++ b/lib/ashldi3.c @@ -0,0 +1,40 @@ +//===-- 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.low = 0; + result.high = input.low << (b - bits_in_word); + } + else // 0 <= b < bits_in_word + { + if (b == 0) + return a; + result.low = input.low << b; + result.high = (input.high << b) | (input.low >> (bits_in_word - b)); + } + return result.all; +} |