From b63a6179d8489fecd9956d8ff434fc27f4217195 Mon Sep 17 00:00:00 2001
From: PBerger <philipp.berger@rwth-aachen.de>
Date: Thu, 13 Mar 2014 23:47:42 +0100
Subject: [PATCH] Fixed a possible bug in the equalModuloPrecision comparison
 of vectors. Same for the CUDA Kernel, but there all hell broke free.

Former-commit-id: 6cb21c391962fda161a51bff543877ef701317f8
---
 .../cudaForStorm/srcCuda/basicValueIteration.cu      | 12 +++++++-----
 src/utility/vector.h                                 |  5 ++++-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/resources/cudaForStorm/srcCuda/basicValueIteration.cu b/resources/cudaForStorm/srcCuda/basicValueIteration.cu
index e42f36eda..25541adbc 100644
--- a/resources/cudaForStorm/srcCuda/basicValueIteration.cu
+++ b/resources/cudaForStorm/srcCuda/basicValueIteration.cu
@@ -14,7 +14,7 @@
 #include <thrust/device_ptr.h>
 #include <thrust/functional.h>
 
-
+#ifdef DEBUG
 #define CUDA_CHECK_ALL_ERRORS() do { \
 	cudaError_t errSync  = cudaGetLastError(); \
 	cudaError_t errAsync = cudaDeviceSynchronize(); \
@@ -24,7 +24,9 @@
 	if (errAsync != cudaSuccess) { \
 		std::cout << "(DLL) Async kernel error: " << cudaGetErrorString(errAsync) << " (Code: " << errAsync << ")" << std::endl; \
 	} } while(false)
-
+#else
+#define CUDA_CHECK_ALL_ERRORS() do {} while (false)
+#endif
 
 template<typename T, bool Relative>
 struct equalModuloPrecision : public thrust::binary_function<T,T,T>
@@ -32,6 +34,9 @@ struct equalModuloPrecision : public thrust::binary_function<T,T,T>
 __host__ __device__ T operator()(const T &x, const T &y) const
 {
     if (Relative) {
+		if (y == 0) {
+			return x;
+		}
 		const T result = (x - y) / y;
 		return ((result >= 0) ? (result) : (-result));
     } else {
@@ -229,9 +234,6 @@ void basicValueIteration_mvReduce(uint_fast64_t const maxIterationCount, ValueTy
 		converged = (maxX < precision);
 		++iterationCount;
 
-		// If there are empty rows in the matrix we need to clear multiplyResult
-		thrust::fill(devicePtrThrust_multiplyResult, devicePtrThrust_multiplyResult + matrixRowCount, 0);
-
 		// Swap pointers, device_x always contains the most current result
 		std::swap(device_x, device_xSwap);
 	}
diff --git a/src/utility/vector.h b/src/utility/vector.h
index dd3bb2a1f..6527d7b19 100644
--- a/src/utility/vector.h
+++ b/src/utility/vector.h
@@ -330,7 +330,10 @@ namespace storm {
             template<class T>
             bool equalModuloPrecision(T const& val1, T const& val2, T precision, bool relativeError = true) {
                 if (relativeError) {
-                    if (std::abs(val1 - val2)/val2 > precision) return false;
+					if (val2 == 0) {
+						return (val1 > precision);
+					}
+                    if (std::abs((val1 - val2)/val2) > precision) return false;
                 } else {
                     if (std::abs(val1 - val2) > precision) return false;
                 }