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| author | Owen Anderson <resistor@mac.com> | 2012-08-15 18:28:45 +0000 |
|---|---|---|
| committer | Owen Anderson <resistor@mac.com> | 2012-08-15 18:28:45 +0000 |
| commit | c82cc587a468d44e5cfabfa8f8a639667127845d (patch) | |
| tree | 05e458aa3ea8daf0d4dcdadcdabc918473cc38df /lib | |
| parent | c97eda2c9e34f4c491f59bbac81af2fd63fef49d (diff) | |
| download | external_llvm-c82cc587a468d44e5cfabfa8f8a639667127845d.zip external_llvm-c82cc587a468d44e5cfabfa8f8a639667127845d.tar.gz external_llvm-c82cc587a468d44e5cfabfa8f8a639667127845d.tar.bz2 | |
Fix another roundToIntegral bug where very large values could become infinity. Problem and solution identified by Steve Canon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161969 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Support/APFloat.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp index b42a168..ed261a4 100644 --- a/lib/Support/APFloat.cpp +++ b/lib/Support/APFloat.cpp @@ -1770,6 +1770,12 @@ APFloat::opStatus APFloat::roundToIntegral(roundingMode rounding_mode) { opStatus fs; assertArithmeticOK(*semantics); + // If the exponent is large enough, we know that this value is already + // integral, and the arithmetic below would potentially cause it to saturate + // to +/-Inf. Bail out early instead. + if (exponent+1 >= (int)semanticsPrecision(*semantics)) + return opOK; + // The algorithm here is quite simple: we add 2^(p-1), where p is the // precision of our format, and then subtract it back off again. The choice // of rounding modes for the addition/subtraction determines the rounding mode |