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author | dim <dim@FreeBSD.org> | 2015-01-08 19:47:10 +0000 |
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committer | dim <dim@FreeBSD.org> | 2015-01-08 19:47:10 +0000 |
commit | ab328f15cea04a45750ef56019d2b3d971e033f3 (patch) | |
tree | f47eabbd2a48be6d6fec3ddeeefae5b4aeb87dbc /contrib/compiler-rt/lib/builtins/mulvti3.c | |
parent | 8189659be8e499f37c87fdd05ef5ec9f88619d56 (diff) | |
parent | 2f1c5cc1039d86db0037cb086bd58f4b90dc6f66 (diff) | |
download | FreeBSD-src-ab328f15cea04a45750ef56019d2b3d971e033f3.zip FreeBSD-src-ab328f15cea04a45750ef56019d2b3d971e033f3.tar.gz |
Update compiler-rt to trunk r224034. This brings a number of new
builtins, and also the various sanitizers. Support for these will be
added in a later commit.
Diffstat (limited to 'contrib/compiler-rt/lib/builtins/mulvti3.c')
-rw-r--r-- | contrib/compiler-rt/lib/builtins/mulvti3.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/builtins/mulvti3.c b/contrib/compiler-rt/lib/builtins/mulvti3.c new file mode 100644 index 0000000..f4c7d16 --- /dev/null +++ b/contrib/compiler-rt/lib/builtins/mulvti3.c @@ -0,0 +1,60 @@ +/* ===-- mulvti3.c - Implement __mulvti3 -----------------------------------=== + * + * 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 __mulvti3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +#ifdef CRT_HAS_128BIT + +/* Returns: a * b */ + +/* Effects: aborts if a * b overflows */ + +COMPILER_RT_ABI ti_int +__mulvti3(ti_int a, ti_int b) +{ + const int N = (int)(sizeof(ti_int) * CHAR_BIT); + const ti_int MIN = (ti_int)1 << (N-1); + const ti_int MAX = ~MIN; + if (a == MIN) + { + if (b == 0 || b == 1) + return a * b; + compilerrt_abort(); + } + if (b == MIN) + { + if (a == 0 || a == 1) + return a * b; + compilerrt_abort(); + } + ti_int sa = a >> (N - 1); + ti_int abs_a = (a ^ sa) - sa; + ti_int sb = b >> (N - 1); + ti_int abs_b = (b ^ sb) - sb; + if (abs_a < 2 || abs_b < 2) + return a * b; + if (sa == sb) + { + if (abs_a > MAX / abs_b) + compilerrt_abort(); + } + else + { + if (abs_a > MIN / -abs_b) + compilerrt_abort(); + } + return a * b; +} + +#endif /* CRT_HAS_128BIT */ |