Merge changes Iee153445,Iee274471 am: 79df15ea88 am: 10f298fc41 am: 7cb5001398 am: bc0f5df265aml_uwb_331910010aml_uwb_331820070aml_uwb_331613010aml_uwb_331611010aml_uwb_331410010aml_uwb_331310030aml_uwb_331115000aml_uwb_331015040aml_uwb_330810010aml_tz4_332714070aml_tz4_332714050aml_tz4_332714010aml_tz4_331910000aml_tz4_331314030aml_tz4_331314020aml_tz4_331314010aml_tz4_331012050aml_tz4_331012040aml_tz4_331012000aml_ase_331311020aml_ase_331112000aml_ase_331011020android13-mainline-uwb-releaseandroid13-mainline-tzdata4-releaseandroid13-mainline-appsearch-releaseaml_tz4_332714010

Original change: https://android-review.googlesource.com/c/platform/external/eigen/+/1999079

Change-Id: Ife39d10c8b23d3eeb174cd52f462f9d20527ad03

1 files changed, 6 insertions, 4 deletions

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorCostModel.h b/unsupported/Eigen/CXX11/src/Tensor/TensorCostModel.h
index 83c449cf1..195267ce8 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorCostModel.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorCostModel.h
@@ -174,8 +174,11 @@ class TensorCostModel {
   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE int numThreads(
       double output_size, const TensorOpCost& cost_per_coeff, int max_threads) {
     double cost = totalCost(output_size, cost_per_coeff);
-    int threads = (cost - kStartupCycles) / kPerThreadCycles + 0.9;
-    return numext::mini(max_threads, numext::maxi(1, threads));
+    double threads = (cost - kStartupCycles) / kPerThreadCycles + 0.9;
+    // Make sure we don't invoke undefined behavior when we convert to an int.
+    threads = numext::mini<double>(threads, GenericNumTraits<int>::highest());
+    return numext::mini(max_threads,
+                        numext::maxi<int>(1, static_cast<int>(threads)));
   }
 
   // taskSize assesses parallel task size.
@@ -186,14 +189,13 @@ class TensorCostModel {
     return totalCost(output_size, cost_per_coeff) / kTaskSize;
   }
 
- private:
   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE double totalCost(
       double output_size, const TensorOpCost& cost_per_coeff) {
     // Cost of memory fetches from L2 cache. 64 is typical cache line size.
     // 11 is L2 cache latency on Haswell.
     // We don't know whether data is in L1, L2 or L3. But we are most interested
     // in single-threaded computational time around 100us-10ms (smaller time
-    // is too small for parallelization, larger time is not intersting
+    // is too small for parallelization, larger time is not interesting
     // either because we are probably using all available threads already).
     // And for the target time range, L2 seems to be what matters. Data set
     // fitting into L1 is too small to take noticeable time. Data set fitting