Warn about overflow

Author: filikat

highs/ipm/hipo/ipm/FactorHiGHSSolver.cpp

@@ -5,6 +5,7 @@
 #include "Status.h"
 #include "ipm/hipo/auxiliary/Auxiliary.h"
 #include "ipm/hipo/auxiliary/Log.h"
+#include "ipm/hipo/factorhighs/ReturnValues.h"
 
 namespace hipo {
 
@@ -33,7 +34,7 @@ static Int getASstructure(const HighsSparseMatrix& A, std::vector<Int>& ptr,
   Int mA = A.num_row_;
   Int nzA = A.numNz();
 
-  if (nA + nzA + mA > kHighsIInf) return kStatusOoM;
+  if (nA + nzA + mA > kHighsIInf) return kStatusOverflow;
 
   ptr.resize(nA + mA + 1);
   rows.resize(nA + nzA + mA);
@@ -195,6 +196,8 @@ Int FactorHiGHSSolver::buildNEstructure(const HighsSparseMatrix& A,
     // intersection of row with rows below finished.
 
     // if the total number of nonzeros exceeds the maximum, return error
+    if ((int64_t)ptrNE_[row] + (int64_t)nz_in_col >= kHighsIInf)
+      return kStatusOverflow;
     if ((int64_t)ptrNE_[row] + (int64_t)nz_in_col >= nz_limit)
       return kStatusOoM;
 
@@ -395,7 +398,14 @@ Int FactorHiGHSSolver::analyseAS(Symbolic& S) {
     S.print(log_, true);
   }
 
-  return status ? kStatusErrorAnalyse : kStatusOk;
+  if (status == kRetIntOverflow)
+    status = kStatusOverflow;
+  else if (status)
+    status = kStatusErrorAnalyse;
+  else
+    status = kStatusOk;
+
+  return status;
 }
 
 void FactorHiGHSSolver::freeNEmemory() {
@@ -434,7 +444,20 @@ Int FactorHiGHSSolver::analyseNE(Symbolic& S, int64_t nz_limit) {
     S.print(log_, true);
   }
 
-  return status ? kStatusErrorAnalyse : kStatusOk;
+  if (status == kRetIntOverflow)
+    status = kStatusOverflow;
+  else if (status)
+    status = kStatusErrorAnalyse;
+  else
+    status = kStatusOk;
+
+  return status;
+}
+
+static void warnOverflow(const LogHighs& log) {
+  log.printw(
+      "32-bit integer overflow occurred during the factorisation. Consider "
+      "compiling HiGHS with 64-bit integers.\n");
 }
 
 Int FactorHiGHSSolver::chooseNla() {
@@ -446,14 +469,22 @@ Int FactorHiGHSSolver::chooseNla() {
   Symbolic symb_AS{};
   bool failure_NE = false;
   bool failure_AS = false;
+  bool overflow_NE = false;
+  bool overflow_AS = false;
 
   symb_NE.setMetisNo2hop(options_.metis_no2hop);
   symb_AS.setMetisNo2hop(options_.metis_no2hop);
 
   Clock clock;
 
   // Perform analyse phase of augmented system
-  if (analyseAS(symb_AS)) failure_AS = true;
+  if (Int status_AS = analyseAS(symb_AS)) {
+    failure_AS = true;
+    if (status_AS == kStatusOverflow) {
+      log_.printDevInfo("AS overflow\n");
+      overflow_AS = true;
+    }
+  }
 
   // Perform analyse phase of normal equations
   if (model_.m() > kMinRowsForDensity &&
@@ -469,7 +500,11 @@ Int FactorHiGHSSolver::chooseNla() {
 
     Int NE_status = analyseNE(symb_NE, NE_nz_limit);
     if (NE_status) failure_NE = true;
-    if (NE_status == kStatusOoM) log_.printDevInfo("NE matrix is too large\n");
+    if (NE_status == kStatusOverflow) {
+      log_.printDevInfo("NE overflow\n");
+      overflow_NE = true;
+    } else if (NE_status == kStatusOoM)
+      log_.printDevInfo("NE matrix is too large\n");
   }
 
   Int status = kStatusOk;
@@ -491,6 +526,8 @@ Int FactorHiGHSSolver::chooseNla() {
       log_.print(
           "Large fill-in in factorisation. Consider setting the "
           "hipo_metis_no2hop option to true\n");
+
+    if (overflow_AS && overflow_NE) warnOverflow(log_);
   } else {
     // Total number of operations, given by dense flops and sparse indexing
     // operations, weighted with an empirical factor
@@ -539,21 +576,19 @@ Int FactorHiGHSSolver::setNla() {
 
   switch (options_.nla) {
     case kOptionNlaAugmented: {
-      if (analyseAS(S_)) {
+      if (Int status = analyseAS(S_)) {
         log_.printe("AS requested, failed analyse phase\n");
+        if (status == kStatusOverflow) warnOverflow(log_);
         return kStatusErrorAnalyse;
       }
       log_stream << textline("Newton system:") << "AS requested\n";
       break;
     }
 
     case kOptionNlaNormEq: {
-      Int status = analyseNE(S_);
-      if (status == kStatusOoM) {
-        log_.printe("NE requested, matrix is too large\n");
-        return kStatusOoM;
-      } else if (status) {
+      if (Int status = analyseNE(S_)) {
         log_.printe("NE requested, failed analyse phase\n");
+        if (status == kStatusOverflow) warnOverflow(log_);
         return kStatusErrorAnalyse;
       }
       log_stream << textline("Newton system:") << "NE requested\n";

highs/ipm/hipo/ipm/Status.h

@@ -26,6 +26,7 @@ enum Status {
   kStatusFailed,
   kStatusError,
   kStatusOoM,
+  kStatusOverflow,
   kStatusErrorAnalyse,
   kStatusErrorFactorise,
   kStatusErrorSolve,
@@ -67,6 +68,7 @@ inline std::string statusString(Status status) {
       {kStatusImprecise, "imprecise"},
       {kStatusError, "internal error"},
       {kStatusOoM, "out of memory"},
+      {kStatusOverflow, "Integer overflow"},
       {kStatusErrorAnalyse, "error in analyse phase"},
       {kStatusErrorFactorise, "error in factorise phase"},
       {kStatusErrorSolve, "error in solve phase"},