From 5889f66ebcfa8c3847d7e50d49ff0d9e260b2d97 Mon Sep 17 00:00:00 2001
From: graham <g.macpherson@opencfd.co.uk>
Date: Fri, 3 Jun 2011 16:04:37 +0100
Subject: [PATCH] ENH: Prevent overflow in weight field.
---
.../decompose/scotchDecomp/scotchDecomp.C | 23 ++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/src/parallel/decompose/scotchDecomp/scotchDecomp.C b/src/parallel/decompose/scotchDecomp/scotchDecomp.C
index 17ff685d49e..0851431b965 100644
--- a/src/parallel/decompose/scotchDecomp/scotchDecomp.C
+++ b/src/parallel/decompose/scotchDecomp/scotchDecomp.C
@@ -409,11 +409,32 @@ Foam::label Foam::scotchDecomp::decomposeOneProc
<< exit(FatalError);
}
+ scalar velotabSum = sum(cWeights)/minWeights;
+
+ scalar rangeScale(1.0);
+
+ if (velotabSum > scalar(INT_MAX - 1))
+ {
+ // 0.9 factor of safety to avoid floating point round-off in
+ // rangeScale tipping the subsequent sum over the integer limit.
+ rangeScale = 0.9*scalar(INT_MAX - 1)/velotabSum;
+
+ WarningIn
+ (
+ "scotchDecomp::decompose"
+ "(const pointField&, const scalarField&)"
+ ) << "Sum of weights has overflowed integer: " << velotabSum
+ << ", compressing weight scale by a factor of " << rangeScale
+ << endl;
+ }
+
// Convert to integers.
velotab.setSize(cWeights.size());
+
forAll(velotab, i)
{
- velotab[i] = int(cWeights[i]/minWeights);
+ velotab[i] =
+ int((cWeights[i]/minWeights - 1)*rangeScale) + 1;
}
}
--
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