From c82cc587a468d44e5cfabfa8f8a639667127845d Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Wed, 15 Aug 2012 18:28:45 +0000 Subject: 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 --- lib/Support/APFloat.cpp | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'lib/Support/APFloat.cpp') diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp index b42a168bae..ed261a4194 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 -- cgit v1.2.3-70-g09d2