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author | Dimitry Andric <dim@FreeBSD.org> | 2015-01-07 19:55:37 +0000 |
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committer | Dimitry Andric <dim@FreeBSD.org> | 2015-01-07 19:55:37 +0000 |
commit | ca9211ecdede9bdedb812b2243a4abdb8dacd1b9 (patch) | |
tree | 9b19e801150082c33e9152275829a6ce90614b55 /lib/builtins/mulvdi3.c | |
parent | 8ef50bf3d1c287b5013c3168de77a462dfce3495 (diff) | |
download | src-ca9211ecdede9bdedb812b2243a4abdb8dacd1b9.tar.gz src-ca9211ecdede9bdedb812b2243a4abdb8dacd1b9.zip |
Import compiler-rt trunk r224034.vendor/compiler-rt/compiler-rt-r224034
Notes
Notes:
svn path=/vendor/compiler-rt/dist/; revision=276789
svn path=/vendor/compiler-rt/compiler-rt-r224034/; revision=276790; tag=vendor/compiler-rt/compiler-rt-r224034
Diffstat (limited to 'lib/builtins/mulvdi3.c')
-rw-r--r-- | lib/builtins/mulvdi3.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/lib/builtins/mulvdi3.c b/lib/builtins/mulvdi3.c new file mode 100644 index 000000000000..e63249e0a04c --- /dev/null +++ b/lib/builtins/mulvdi3.c @@ -0,0 +1,56 @@ +/*===-- mulvdi3.c - Implement __mulvdi3 -----------------------------------=== + * + * 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 __mulvdi3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +/* Returns: a * b */ + +/* Effects: aborts if a * b overflows */ + +COMPILER_RT_ABI di_int +__mulvdi3(di_int a, di_int b) +{ + const int N = (int)(sizeof(di_int) * CHAR_BIT); + const di_int MIN = (di_int)1 << (N-1); + const di_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(); + } + di_int sa = a >> (N - 1); + di_int abs_a = (a ^ sa) - sa; + di_int sb = b >> (N - 1); + di_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; +} |