GPU: No need to store if Bz was constant as constant RTC param

Author: davidrohr

GPU/GPUTracking/Base/GPUParam.cxx

@@ -30,7 +30,7 @@ using namespace o2::gpu;
 
 #include "utils/qconfigrtc.h"
 
-void GPUParam::SetDefaults(float solenoidBz)
+void GPUParam::SetDefaults(float solenoidBz, bool assumeConstantBz)
 {
   memset((void*)this, 0, sizeof(*this));
   new (&rec) GPUSettingsRec;
@@ -84,7 +84,7 @@ void GPUParam::SetDefaults(float solenoidBz)
 #endif
 
   par.dAlpha = 0.349066f;
-  UpdateBzOnly(solenoidBz);
+  UpdateBzOnly(solenoidBz, assumeConstantBz);
   par.dodEdx = 0;
 
   constexpr float plusZmin = 0.0529937;
@@ -109,7 +109,6 @@ void GPUParam::SetDefaults(float solenoidBz)
     SectorParam[i].AngleMax = SectorParam[i].Alpha + par.dAlpha / 2.f;
   }
 
-  par.assumeConstantBz = false;
   par.toyMCEventsFlag = false;
   par.continuousTracking = false;
   continuousMaxTimeBin = 0;
@@ -120,8 +119,7 @@ void GPUParam::SetDefaults(float solenoidBz)
 void GPUParam::UpdateSettings(const GPUSettingsGRP* g, const GPUSettingsProcessing* p, const GPURecoStepConfiguration* w, const GPUSettingsRecDynamic* d)
 {
   if (g) {
-    UpdateBzOnly(g->solenoidBzNominalGPU);
-    par.assumeConstantBz = g->constBz;
+    UpdateBzOnly(g->solenoidBzNominalGPU, g->constBz);
     par.toyMCEventsFlag = g->homemadeEvents;
     par.continuousTracking = g->grpContinuousMaxTimeBin != 0;
     continuousMaxTimeBin = g->grpContinuousMaxTimeBin == -1 ? GPUSettings::TPC_MAX_TF_TIME_BIN : g->grpContinuousMaxTimeBin;
@@ -143,12 +141,12 @@ void GPUParam::UpdateSettings(const GPUSettingsGRP* g, const GPUSettingsProcessi
   }
 }
 
-void GPUParam::UpdateBzOnly(float newSolenoidBz)
+void GPUParam::UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz)
 {
   bzkG = newSolenoidBz;
   bzCLight = bzkG * o2::gpu::gpu_common_constants::kCLight;
   polynomialField.Reset();
-  if (par.assumeConstantBz) {
+  if (assumeConstantBz) {
     GPUTPCGMPolynomialFieldManager::GetPolynomialField(GPUTPCGMPolynomialFieldManager::kUniform, bzkG, polynomialField);
   } else {
     GPUTPCGMPolynomialFieldManager::GetPolynomialField(bzkG, polynomialField);
@@ -158,7 +156,7 @@ void GPUParam::UpdateBzOnly(float newSolenoidBz)
 
 void GPUParam::SetDefaults(const GPUSettingsGRP* g, const GPUSettingsRec* r, const GPUSettingsProcessing* p, const GPURecoStepConfiguration* w)
 {
-  SetDefaults(g->solenoidBzNominalGPU);
+  SetDefaults(g->solenoidBzNominalGPU, g->constBz);
   if (r) {
     rec = *r;
     if (rec.fitPropagateBzOnly == -1) {

GPU/GPUTracking/Base/GPUParam.h

@@ -77,10 +77,10 @@ struct GPUParam_t {
 struct GPUParam : public internal::GPUParam_t<GPUSettingsRec, GPUSettingsParam> {
 
 #ifndef GPUCA_GPUCODE
-  void SetDefaults(float solenoidBz);
+  void SetDefaults(float solenoidBz, bool assumeConstantBz);
   void SetDefaults(const GPUSettingsGRP* g, const GPUSettingsRec* r = nullptr, const GPUSettingsProcessing* p = nullptr, const GPURecoStepConfiguration* w = nullptr);
   void UpdateSettings(const GPUSettingsGRP* g, const GPUSettingsProcessing* p = nullptr, const GPURecoStepConfiguration* w = nullptr, const GPUSettingsRecDynamic* d = nullptr);
-  void UpdateBzOnly(float newSolenoidBz);
+  void UpdateBzOnly(float newSolenoidBz, bool assumeConstantBz);
   void UpdateRun3ClusterErrors(const float* yErrorParam, const float* zErrorParam);
 #endif
 

GPU/GPUTracking/Definitions/GPUSettingsList.h

@@ -652,7 +652,6 @@ EndConfig()
 // Derrived parameters used in GPUParam
 BeginHiddenConfig(GPUSettingsParam, param)
 AddVariableRTC(dAlpha, float, 0.f)            // angular size
-AddVariableRTC(assumeConstantBz, int8_t, 0)   // Assume a constant magnetic field
 AddVariableRTC(toyMCEventsFlag, int8_t, 0)    // events were build with home-made event generator
 AddVariableRTC(continuousTracking, int8_t, 0) // Continuous tracking, estimate bz and errors for abs(z) = 125cm during seeding
 AddVariableRTC(dodEdx, int8_t, 0)             // Do dEdx computation

GPU/GPUTracking/Interface/GPUO2InterfaceRefit.cxx

@@ -129,7 +129,7 @@ GPUO2InterfaceRefit::GPUO2InterfaceRefit(const ClusterNativeAccess* cl, const Co
 
 void GPUO2InterfaceRefit::updateCalib(const CorrectionMapsHelper* trans, float bzNominalGPU)
 {
-  mParam->UpdateBzOnly(bzNominalGPU);
+  mParam->UpdateBzOnly(bzNominalGPU, false);
   mRefit->SetFastTransformHelper(trans);
 }
 

GPU/GPUTracking/Interface/GPUO2InterfaceUtils.cxx

@@ -51,7 +51,7 @@ template <>
 void GPUO2InterfaceUtils::RunZSEncoder<DigitArray>(const DigitArray& in, std::unique_ptr<uint64_t[]>* outBuffer, uint32_t* outSizes, o2::raw::RawFileWriter* raw, const o2::InteractionRecord* ir, int32_t version, bool verify, float threshold, bool padding, std::function<void(std::vector<o2::tpc::Digit>&)> digitsFilter)
 {
   GPUParam param;
-  param.SetDefaults(5.00668);
+  param.SetDefaults(5.00668, false);
   o2::gpu::GPUReconstructionConvert::RunZSEncoder(in, outBuffer, outSizes, raw, ir, param, version, verify, threshold, padding, digitsFilter);
 }
 template <>