Changeset 1055 for cpp

Timestamp:

12/27/20 19:39:44 (4 years ago)

Author:

Maciej Komosinski

Message:

Added a workaround (potentially incorrect) for numerical instability in SVD calculation and the embarcadero compiler

File:

• cpp/frams/model/similarity/SVD/lapack.cpp (modified) (2 diffs)

cpp/frams/model/similarity/SVD/lapack.cpp

@@ -59 +59 @@
 #include <stdint.h> //uint8_t
 #include "lapack.h"
+#include <common/log.h>
 
 
@@ -296 +297 @@
                         else
                         {
-                                c = (_Tp)std::sqrt((gamma + beta) / (gamma * 2));
-                                s = (_Tp)(p / (gamma * c * 2));
+                                if (gamma == 0) //MK 2020-12: workaround for embarcadero compiler
+                                {
+#ifndef __BORLANDC__ //It happens so often in embarcadero-produced executables that don't even bother the user with messages. Visual c++ and gcc/clang do not experience this problem.
+                                        logPrintf("Lapack", "JacobiSVD", LOG_ERROR, "Numerical instability in JacobiSVDImpl_(), likely 0.0/0.0, specific to floating point handling by this particular compiler. p=%.17g, gamma=%.17g, beta=%.17g. Recovering with bogus results.", p, gamma, beta);
+#endif
+                                        c = s = 0;
+                                }
+                                else
+                                {
+                                        c = (_Tp)std::sqrt((gamma + beta) / (gamma * 2));
+                                        s = (_Tp)(p / (gamma * c * 2));
+                                }
                         }