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author | Daniel Dunbar <daniel@zuster.org> | 2009-06-26 16:47:03 +0000 |
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committer | Daniel Dunbar <daniel@zuster.org> | 2009-06-26 16:47:03 +0000 |
commit | b3a6901e66f55b35aa9e01bcb24134e6a65ea004 (patch) | |
tree | 4d57d73575ea3f7e30bf430920d6e96fa2a369c1 /lib/muldi3.c | |
parent | 8cbe163cba77c772621f89ddb33793ac170b1fa2 (diff) | |
download | compiler-rt-b3a6901e66f55b35aa9e01bcb24134e6a65ea004.tar.gz |
Initial import of compiler-rt.
-
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@74292 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/muldi3.c')
-rw-r--r-- | lib/muldi3.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/lib/muldi3.c b/lib/muldi3.c new file mode 100644 index 000000000..98299e6f0 --- /dev/null +++ b/lib/muldi3.c @@ -0,0 +1,53 @@ +//===-- muldi3.c - Implement __muldi3 -------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements __muldi3 for the compiler_rt library. +// +//===----------------------------------------------------------------------===// + +#include "int_lib.h" + +// Returns: a * b + +static +di_int +__muldsi3(su_int a, su_int b) +{ + dwords r; + const int bits_in_word_2 = (int)(sizeof(si_int) * CHAR_BIT) / 2; + const su_int lower_mask = (su_int)~0 >> bits_in_word_2; + r.low = (a & lower_mask) * (b & lower_mask); + su_int t = r.low >> bits_in_word_2; + r.low &= lower_mask; + t += (a >> bits_in_word_2) * (b & lower_mask); + r.low += (t & lower_mask) << bits_in_word_2; + r.high = t >> bits_in_word_2; + t = r.low >> bits_in_word_2; + r.low &= lower_mask; + t += (b >> bits_in_word_2) * (a & lower_mask); + r.low += (t & lower_mask) << bits_in_word_2; + r.high += t >> bits_in_word_2; + r.high += (a >> bits_in_word_2) * (b >> bits_in_word_2); + return r.all; +} + +// Returns: a * b + +di_int +__muldi3(di_int a, di_int b) +{ + dwords x; + x.all = a; + dwords y; + y.all = b; + dwords r; + r.all = __muldsi3(x.low, y.low); + r.high += x.high * y.low + x.low * y.high; + return r.all; +} |