DataFormatsTPC: place shared constants in the constant address space

MSL requires every variable at program scope, class-scope statics included, to
name an address space. GPUglobalconstexpr() expands to constexpr everywhere
except Metal, so this is a no-op for host, CUDA, HIP, OpenCL and cling.

Author: ktf

DataFormats/Detectors/TPC/include/DataFormatsTPC/CalibdEdxCorrection.h

@@ -39,8 +39,8 @@ GPUconstexpr() float TglScale[4] = {1.9, 1.5, 1.22, 1.02}; ///< Max Tgl values f
 class CalibdEdxCorrection
 {
  public:
-  static constexpr int FitSize = 288; ///< Number of fitted corrections
-  static constexpr int ParamSize = 8; ///< Number of params per fit
+  static GPUglobalconstexpr() int FitSize = 288; ///< Number of fitted corrections
+  static GPUglobalconstexpr() int ParamSize = 8; ///< Number of params per fit
 
 #if !defined(GPUCA_GPUCODE)
   CalibdEdxCorrection()

DataFormats/Detectors/TPC/include/DataFormatsTPC/ClusterNative.h

@@ -59,13 +59,13 @@ struct ClusterNative {
                       flagEdge = 0x4,      // At edge of TPC sector
                       flagSingle = 0x8 };  // Single pad or single time-bin cluster
 
-  static constexpr int scaleTimePacked = 64;      //< ~50 is needed for 0.1mm precision, but leads to float rounding artifacts around 20ms
-  static constexpr int scalePadPacked = 64;       //< ~60 is needed for 0.1mm precision, but power of two avoids rounding
-  static constexpr int scaleSigmaTimePacked = 32; // 1/32nd of pad/timebin precision for cluster size
-  static constexpr int scaleSigmaPadPacked = 32;
-  static constexpr int scaleSaturatedQtot = 8;
-  static constexpr int maxRegularQtot = 25 * 1024;
-  static constexpr int maxSaturatedQtot = (USHRT_MAX - maxRegularQtot) * scaleSaturatedQtot;
+  static GPUglobalconstexpr() int scaleTimePacked = 64;      //< ~50 is needed for 0.1mm precision, but leads to float rounding artifacts around 20ms
+  static GPUglobalconstexpr() int scalePadPacked = 64;       //< ~60 is needed for 0.1mm precision, but power of two avoids rounding
+  static GPUglobalconstexpr() int scaleSigmaTimePacked = 32; // 1/32nd of pad/timebin precision for cluster size
+  static GPUglobalconstexpr() int scaleSigmaPadPacked = 32;
+  static GPUglobalconstexpr() int scaleSaturatedQtot = 8;
+  static GPUglobalconstexpr() int maxRegularQtot = 25 * 1024;
+  static GPUglobalconstexpr() int maxSaturatedQtot = (USHRT_MAX - maxRegularQtot) * scaleSaturatedQtot;
 
   uint32_t timeFlagsPacked; //< Contains the time in the lower 24 bits in a packed format, contains the flags in the
                             // upper 8 bits

DataFormats/Detectors/TPC/include/DataFormatsTPC/Defs.h

@@ -19,6 +19,8 @@
 #ifndef AliceO2_TPC_Defs_H
 #define AliceO2_TPC_Defs_H
 
+#include "GPUCommonDef.h"
+
 #ifndef GPUCA_GPUCODE_DEVICE
 #include <cmath>
 #endif
@@ -37,8 +39,8 @@ enum Side { A = 0,
             UNDEFINED = 2 };
 //   enum class Side {A=0, C=1};
 //  Problem with root cint. does not seem to support enum class ...
-constexpr unsigned char SECTORSPERSIDE = 18;
-constexpr unsigned char SIDES = 2;
+GPUglobalconstexpr() unsigned char SECTORSPERSIDE = 18;
+GPUglobalconstexpr() unsigned char SIDES = 2;
 
 constexpr double PI = 3.14159265358979323846;
 constexpr double TWOPI = 2. * PI;
@@ -54,10 +56,10 @@ enum GEMstack { IROCgem = 0,
                 OROC1gem = 1,
                 OROC2gem = 2,
                 OROC3gem = 3 };
-constexpr unsigned short GEMSTACKSPERSECTOR = 4;
-constexpr unsigned short GEMSPERSTACK = 4;
-constexpr unsigned short GEMSTACKSPERSIDE = GEMSTACKSPERSECTOR * SECTORSPERSIDE;
-constexpr unsigned short GEMSTACKS = GEMSTACKSPERSECTOR * SECTORSPERSIDE * SIDES;
+GPUglobalconstexpr() unsigned short GEMSTACKSPERSECTOR = 4;
+GPUglobalconstexpr() unsigned short GEMSPERSTACK = 4;
+GPUglobalconstexpr() unsigned short GEMSTACKSPERSIDE = GEMSTACKSPERSECTOR * SECTORSPERSIDE;
+GPUglobalconstexpr() unsigned short GEMSTACKS = GEMSTACKSPERSECTOR * SECTORSPERSIDE * SIDES;
 
 /// Definition of the different pad subsets
 enum class PadSubset : char {
@@ -71,7 +73,7 @@ enum ChargeType {
   Max = 0,
   Tot = 1
 };
-constexpr unsigned short CHARGETYPES = 2;
+GPUglobalconstexpr() unsigned short CHARGETYPES = 2;
 
 /// GEM stack identification
 struct StackID {