SiStripClusterizer, an Alpaka port of the CUDA ClustersFromRawProducerGPU

DataFormats/SiStripCluster/interface/SiStripCluster.h

@@ -30,6 +30,9 @@ class SiStripCluster {
     initQB();
   }
 
+  SiStripCluster(uint16_t firstStrip, std::vector<uint8_t>&& data, float barycenter, float charge)
+      : amplitudes_(std::move(data)), firstStrip_(firstStrip), barycenter_(barycenter), charge_(charge) {}
+
   template <typename Iter>
   SiStripCluster(const uint16_t& firstStrip, Iter begin, Iter end) : amplitudes_(begin, end), firstStrip_(firstStrip) {
     initQB();

DataFormats/SiStripClusterSoA/BuildFile.xml

@@ -0,0 +1,8 @@
+<use name="DataFormats/Common"/>
+<use name="DataFormats/Portable"/>
+<use name="DataFormats/SoATemplate"/>
+<use name="HeterogeneousCore/AlpakaInterface"/>
+<flags ALPAKA_BACKENDS="!serial"/>
+<export>
+  <lib name="1"/>
+</export>

DataFormats/SiStripClusterSoA/README.md

@@ -0,0 +1,26 @@
+# SiStripClusterSoA
+The `SiStripClusterHost`/`SiStripClusterDevice` is a portable collection based on the `SiStripClusterSoALayout` (`DataFormats/SiStripClusterSoA/interface/SiStripClusterSoA.h`).
+
+It is used to store the collection of SiStrip cluster candidates from the heterogeneous SiStripClusterizer module (`RecoLocalTracker/SiStripClusterizer`).
+
+## Data members
+The fields in the structure have the following meaning:
+
+| SoA type | C-type | Name | Description |
+| --- | --- | --- | --- |
+| column | uint32_t | clusterIndex | Index for the first strip amplitude in this cluster candidate, to be fetched by the Digi collection |
+| column | uint16_t | clusterSize | Cluster cand. strip count |
+| column | uint32_t | clusterDetId | Cluster cand. detector ID |
+| column | uint16_t | firstStrip | First strip ID of the cluster cand. |
+| column | bool | candidateAccepted | Is the cluster candidate a good one? [^ThreeThresholdAlgorithm.cc#L103-L107] |
+| column | float | barycenter | Cluster cand. barycenter [^SiStripCluster.h#L164] |
+| column | float | charge | Cluster cand. charge [^SiStripCluster.h#L152-L159] |
+| column | uint32_t | candidateAcceptedPrefix | Prefix sum of the candidateAccepted colum, used to index the good clusters |
+| scalar | uint32_t | nClusterCandidates | Number of cluster candidates in the collection [^noteCand] |
+| scalar | uint32_t | maxClusterSize | Max number of contiguous strips for clustering (setup) |
+
+<!--  -->
+[^ThreeThresholdAlgorithm.cc#L103-L107]: [RecoLocalTracker/SiStripClusterizer/src/ThreeThresholdAlgorithm.cc](https://github.com/cms-sw/cmssw/blob/CMSSW_16_0_X/RecoLocalTracker/SiStripClusterizer/src/ThreeThresholdAlgorithm.cc#L103-L107)
+[^SiStripCluster.h#L164]: [DataFormats/SiStripCluster/interface/SiStripCluster.h#L164](https://github.com/cms-sw/cmssw/blob/CMSSW_16_0_X/DataFormats/SiStripCluster/interface/SiStripCluster.h#L164)
+[^SiStripCluster.h#L152-L159]: [DataFormats/SiStripCluster/interface/SiStripCluster.h#L152-L159](https://github.com/cms-sw/cmssw/blob/CMSSW_16_0_X/DataFormats/SiStripCluster/interface/SiStripCluster.h#L152-L159)
+[^noteCand]: this is typically lower than the collection pre-allocated size (i.e., from `collection->metadata().size()`). It indicates the number of non-contiguous strip seeds over which the clustering is perfomed. It can be used while loop over the collection to break earlier than the collection size.

DataFormats/SiStripClusterSoA/interface/SiStripClusterHost.h

@@ -0,0 +1,12 @@
+#ifndef DataFormats_SiStripClusterSoA_interface_SiStripClusterHost_h
+#define DataFormats_SiStripClusterSoA_interface_SiStripClusterHost_h
+
+#include "DataFormats/Portable/interface/PortableHostCollection.h"
+#include "DataFormats/SiStripClusterSoA/interface/SiStripClusterSoA.h"
+
+namespace sistrip {
+  // SoA with SiStripCluster fields in host memory
+  using SiStripClusterHost = PortableHostCollection<SiStripClusterSoA>;
+}  // namespace sistrip
+
+#endif  // DataFormats_SiStripClusterSoA_interface_SiStripClusterHost_h

DataFormats/SiStripClusterSoA/interface/SiStripClusterSoA.h

@@ -0,0 +1,26 @@
+
+#ifndef DataFormats_SiStripClusterSoA_interface_SiStripClusterSoA_h
+#define DataFormats_SiStripClusterSoA_interface_SiStripClusterSoA_h
+
+#include "DataFormats/SoATemplate/interface/SoALayout.h"
+
+namespace sistrip {
+
+  GENERATE_SOA_LAYOUT(SiStripClusterSoALayout,
+                      SOA_COLUMN(uint32_t, clusterIndex),
+                      SOA_COLUMN(uint16_t, clusterSize),
+                      SOA_COLUMN(uint32_t, clusterDetId),
+                      SOA_COLUMN(uint16_t, firstStrip),
+                      SOA_COLUMN(bool, candidateAccepted),
+                      SOA_COLUMN(float, barycenter),
+                      SOA_COLUMN(float, charge),
+                      SOA_COLUMN(uint32_t, candidateAcceptedPrefix),
+                      SOA_SCALAR(uint32_t, nClusterCandidates),
+                      SOA_SCALAR(uint32_t, maxClusterSize))
+
+  using SiStripClusterSoA = SiStripClusterSoALayout<>;
+  using SiStripClusterView = SiStripClusterSoA::View;
+  using SiStripClusterConstView = SiStripClusterSoA::ConstView;
+}  // namespace sistrip
+
+#endif  // DataFormats_SiStripClusterSoA_interface_SiStripClustersSoA_h

DataFormats/SiStripClusterSoA/interface/alpaka/SiStripClusterDevice.h

@@ -0,0 +1,19 @@
+#ifndef DataFormats_SiStripClusterSoA_interface_alpaka_SiStripClustersDevice_h
+#define DataFormats_SiStripClusterSoA_interface_alpaka_SiStripClustersDevice_h
+
+#include "DataFormats/Portable/interface/alpaka/PortableCollection.h"
+#include "DataFormats/SiStripClusterSoA/interface/SiStripClusterHost.h"
+#include "DataFormats/SiStripClusterSoA/interface/SiStripClusterSoA.h"
+#include "HeterogeneousCore/AlpakaInterface/interface/config.h"
+
+namespace ALPAKA_ACCELERATOR_NAMESPACE::sistrip {
+  // make the names from the top-level sistrip namespace visible for unqualified lookup
+  // inside the ALPAKA_ACCELERATOR_NAMESPACE::sistrip namespace
+  using namespace ::sistrip;
+  using SiStripClusterDevice = PortableCollection<SiStripClusterSoA>;
+}  // namespace ALPAKA_ACCELERATOR_NAMESPACE::sistrip
+
+// check that the sistrip device collection for the host device is the same as the sistrip host collection
+ASSERT_DEVICE_MATCHES_HOST_COLLECTION(sistrip::SiStripClusterDevice, sistrip::SiStripClusterHost);
+
+#endif  // DataFormats_SiStripClusterSoA_interface_alpaka_SiStripClustersDevice_h

DataFormats/SiStripClusterSoA/src/alpaka/classes_cuda.h

@@ -0,0 +1,9 @@
+#ifndef DataFormats_SiStripClusterSoA_src_alpaka_classes_cuda_h
+#define DataFormats_SiStripClusterSoA_src_alpaka_classes_cuda_h
+
+#include "DataFormats/Common/interface/Wrapper.h"
+#include "DataFormats/Common/interface/DeviceProduct.h"
+#include "DataFormats/SiStripClusterSoA/interface/SiStripClusterSoA.h"
+#include "DataFormats/SiStripClusterSoA/interface/alpaka/SiStripClusterDevice.h"
+
+#endif

DataFormats/SiStripClusterSoA/src/alpaka/classes_cuda_def.xml

@@ -0,0 +1,5 @@
+<lcgdict>
+  <class name="alpaka_cuda_async::sistrip::SiStripClusterDevice" persistent="false"/>
+  <class name="edm::DeviceProduct<alpaka_cuda_async::sistrip::SiStripClusterDevice>" persistent="false"/>
+  <class name="edm::Wrapper<edm::DeviceProduct<alpaka_cuda_async::sistrip::SiStripClusterDevice>>" persistent="false"/>
+</lcgdict>

DataFormats/SiStripClusterSoA/src/alpaka/classes_rocm.h

@@ -0,0 +1,9 @@
+#ifndef DataFormats_SiStripClusterSoA_src_alpaka_classes_rocm_h
+#define DataFormats_SiStripClusterSoA_src_alpaka_classes_rocm_h
+
+#include "DataFormats/Common/interface/Wrapper.h"
+#include "DataFormats/Common/interface/DeviceProduct.h"
+#include "DataFormats/SiStripClusterSoA/interface/SiStripClusterSoA.h"
+#include "DataFormats/SiStripClusterSoA/interface/alpaka/SiStripClusterDevice.h"
+
+#endif

DataFormats/SiStripClusterSoA/src/alpaka/classes_rocm_def.xml

@@ -0,0 +1,5 @@
+<lcgdict>
+  <class name="alpaka_rocm_async::sistrip::SiStripClusterDevice" persistent="false"/>
+  <class name="edm::DeviceProduct<alpaka_rocm_async::sistrip::SiStripClusterDevice>" persistent="false"/>
+  <class name="edm::Wrapper<edm::DeviceProduct<alpaka_rocm_async::sistrip::SiStripClusterDevice>>" persistent="false"/>
+</lcgdict>

DataFormats/SiStripClusterSoA/src/classes.cc

@@ -0,0 +1,4 @@
+#include "DataFormats/Portable/interface/PortableHostCollectionReadRules.h"
+#include "DataFormats/SiStripClusterSoA/interface/SiStripClusterHost.h"
+
+SET_PORTABLEHOSTCOLLECTION_READ_RULES(sistrip::SiStripClusterHost);

DataFormats/SiStripClusterSoA/src/classes.h

@@ -0,0 +1,7 @@
+#ifndef DataFormats_SiStripClusterSoA_src_classes_h
+#define DataFormats_SiStripClusterSoA_src_classes_h
+
+#include "DataFormats/Common/interface/Wrapper.h"
+#include "DataFormats/SiStripClusterSoA/interface/SiStripClusterHost.h"
+
+#endif  // DataFormats_SiStripClusterSoA_src_classes_h

DataFormats/SiStripClusterSoA/src/classes_def.xml

@@ -0,0 +1,7 @@
+<lcgdict>
+  <!-- ::Layout alias must be listed before the aliased-to type -->
+  <class name="sistrip::SiStripClusterHost::Layout"/>
+  <class name="sistrip::SiStripClusterSoALayout<128,false>"/>
+  <class name="sistrip::SiStripClusterHost"/>
+  <class name="edm::Wrapper<sistrip::SiStripClusterHost>" splitLevel="0"/>
+</lcgdict>

DataFormats/SiStripDigiSoA/BuildFile.xml

@@ -0,0 +1,8 @@
+<use name="DataFormats/Common"/>
+<use name="DataFormats/Portable"/>
+<use name="DataFormats/SoATemplate"/>
+<use name="HeterogeneousCore/AlpakaInterface"/>
+<flags ALPAKA_BACKENDS="!serial"/>
+<export>
+  <lib name="1"/>
+</export>

DataFormats/SiStripDigiSoA/interface/SiStripDigiHost.h

@@ -0,0 +1,12 @@
+#ifndef DataFormats_SiStripDigiSoA_interface_SiStripDigiHost_h
+#define DataFormats_SiStripDigiSoA_interface_SiStripDigiHost_h
+
+#include "DataFormats/Portable/interface/PortableHostCollection.h"
+#include "DataFormats/SiStripDigiSoA/interface/SiStripDigiSoA.h"
+
+namespace sistrip {
+  // SoA with SiStripClusters fields in host memory
+  using SiStripDigiHost = PortableHostCollection<SiStripDigiSoA>;
+}  // namespace sistrip
+
+#endif

DataFormats/SiStripDigiSoA/interface/SiStripDigiSoA.h

@@ -0,0 +1,20 @@
+
+#ifndef DataFormats_SiStripDigiSoA_interface_SiStripDigiSoA_h
+#define DataFormats_SiStripDigiSoA_interface_SiStripDigiSoA_h
+
+#include "DataFormats/SoATemplate/interface/SoALayout.h"
+
+namespace sistrip {
+  GENERATE_SOA_LAYOUT(SiStripDigiSoALayout,
+                      SOA_COLUMN(uint8_t, adc),
+                      SOA_COLUMN(uint16_t, channel),
+                      SOA_COLUMN(uint16_t, stripId),
+                      SOA_SCALAR(uint32_t, nbGoodCandidates),
+                      SOA_SCALAR(uint32_t, nbCandidates))
+
+  using SiStripDigiSoA = SiStripDigiSoALayout<>;
+  using SiStripDigiView = SiStripDigiSoA::View;
+  using SiStripDigiConstView = SiStripDigiSoA::ConstView;
+}  // namespace sistrip
+
+#endif

DataFormats/SiStripDigiSoA/interface/alpaka/SiStripDigiDevice.h

@@ -0,0 +1,18 @@
+#ifndef DataFormats_SiStripDigiSoA_interface_alpaka_SiStripDigiDevice_h
+#define DataFormats_SiStripDigiSoA_interface_alpaka_SiStripDigiDevice_h
+
+#include "DataFormats/Portable/interface/alpaka/PortableCollection.h"
+#include "DataFormats/SiStripDigiSoA/interface/SiStripDigiHost.h"
+#include "DataFormats/SiStripDigiSoA/interface/SiStripDigiSoA.h"
+#include "HeterogeneousCore/AlpakaInterface/interface/config.h"
+
+namespace ALPAKA_ACCELERATOR_NAMESPACE::sistrip {
+  // make the names from the top-level sistrip namespace visible for unqualified lookup
+  // inside the ALPAKA_ACCELERATOR_NAMESPACE::sistrip namespace
+  using namespace ::sistrip;
+  using SiStripDigiDevice = PortableCollection<SiStripDigiSoA>;
+}  // namespace ALPAKA_ACCELERATOR_NAMESPACE::sistrip
+
+ASSERT_DEVICE_MATCHES_HOST_COLLECTION(sistrip::SiStripDigiDevice, sistrip::SiStripDigiHost);
+
+#endif

DataFormats/SiStripDigiSoA/src/alpaka/classes_cuda.h

@@ -0,0 +1,8 @@
+#ifndef DataFormats_SiStripDigiSoA_src_alpaka_classes_cuda_h
+#define DataFormats_SiStripDigiSoA_src_alpaka_classes_cuda_h
+
+#include "DataFormats/Common/interface/DeviceProduct.h"
+#include "DataFormats/Common/interface/Wrapper.h"
+#include "DataFormats/SiStripDigiSoA/interface/alpaka/SiStripDigiDevice.h"
+
+#endif

DataFormats/SiStripDigiSoA/src/alpaka/classes_cuda_def.xml

@@ -0,0 +1,5 @@
+<lcgdict>
+  <class name="alpaka_cuda_async::sistrip::SiStripDigiDevice" persistent="false"/>
+  <class name="edm::DeviceProduct<alpaka_cuda_async::sistrip::SiStripDigiDevice>" persistent="false"/>
+  <class name="edm::Wrapper<edm::DeviceProduct<alpaka_cuda_async::sistrip::SiStripDigiDevice>>" persistent="false"/>
+</lcgdict>

DataFormats/SiStripDigiSoA/src/alpaka/classes_rocm.h

@@ -0,0 +1,8 @@
+#ifndef DataFormats_SiStripDigiSoA_src_alpaka_classes_rocm_h
+#define DataFormats_SiStripDigiSoA_src_alpaka_classes_rocm_h
+
+#include "DataFormats/Common/interface/DeviceProduct.h"
+#include "DataFormats/Common/interface/Wrapper.h"
+#include "DataFormats/SiStripDigiSoA/interface/alpaka/SiStripDigiDevice.h"
+
+#endif

DataFormats/SiStripDigiSoA/src/alpaka/classes_rocm_def.xml

@@ -0,0 +1,5 @@
+<lcgdict>
+  <class name="alpaka_rocm_async::sistrip::SiStripDigiDevice" persistent="false"/>
+  <class name="edm::DeviceProduct<alpaka_rocm_async::sistrip::SiStripDigiDevice>" persistent="false"/>
+  <class name="edm::Wrapper<edm::DeviceProduct<alpaka_rocm_async::sistrip::SiStripDigiDevice>>" persistent="false"/>
+</lcgdict>

DataFormats/SiStripDigiSoA/src/classes.cc

@@ -0,0 +1,4 @@
+#include "DataFormats/Portable/interface/PortableHostCollectionReadRules.h"
+#include "DataFormats/SiStripDigiSoA/interface/SiStripDigiHost.h"
+
+SET_PORTABLEHOSTCOLLECTION_READ_RULES(sistrip::SiStripDigiHost);

DataFormats/SiStripDigiSoA/src/classes.h

@@ -0,0 +1,8 @@
+#ifndef DataFormats_SiStripDigiSoA_src_classes_h
+#define DataFormats_SiStripDigiSoA_src_classes_h
+
+#include "DataFormats/Common/interface/Wrapper.h"
+#include "DataFormats/SiStripDigiSoA/interface/SiStripDigiSoA.h"
+#include "DataFormats/SiStripDigiSoA/interface/SiStripDigiHost.h"
+
+#endif

DataFormats/SiStripDigiSoA/src/classes_def.xml

@@ -0,0 +1,7 @@
+<lcgdict>
+  <!-- ::Layout alias must be listed before the aliased-to type -->
+  <class name="sistrip::SiStripDigiHost::Layout"/>
+  <class name="sistrip::SiStripDigiSoALayout<128,false>"/>
+  <class name="sistrip::SiStripDigiHost"/>
+  <class name="edm::Wrapper<sistrip::SiStripDigiHost>" splitLevel="0"/>
+</lcgdict>

EventFilter/SiStripRawToDigi/interface/SiStripFEDBuffer.h

@@ -194,18 +194,18 @@ namespace sistrip {
     namespace detail {
 
       template <uint8_t num_words>
-      uint16_t getADC_W(const uint8_t* data, uint_fast16_t offset, uint8_t bits_shift) {
+      constexpr uint16_t getADC_W(const uint8_t* data, uint_fast16_t offset, uint8_t bits_shift) {
         // get ADC from one or two bytes (at most 10 bits), and shift if needed
         return (data[offset ^ 7] + (num_words == 2 ? ((data[(offset + 1) ^ 7] & 0x03) << 8) : 0)) << bits_shift;
       }
 
       template <uint16_t mask>
-      uint16_t getADC_B2(const uint8_t* data, uint_fast16_t wOffset, uint_fast8_t bOffset) {
+      constexpr uint16_t getADC_B2(const uint8_t* data, uint_fast16_t wOffset, uint_fast8_t bOffset) {
         // get ADC from two bytes, from wOffset until bOffset bits from the next byte (maximum decided by mask)
         return (((data[wOffset ^ 7]) << bOffset) + (data[(wOffset + 1) ^ 7] >> (BITS_PER_BYTE - bOffset))) & mask;
       }
       template <uint16_t mask>
-      uint16_t getADC_B1(const uint8_t* data, uint_fast16_t wOffset, uint_fast8_t bOffset) {
+      constexpr uint16_t getADC_B1(const uint8_t* data, uint_fast16_t wOffset, uint_fast8_t bOffset) {
         // get ADC from one byte, until bOffset into the byte at wOffset (maximum decided by mask)
         return (data[wOffset ^ 7] >> (BITS_PER_BYTE - bOffset)) & mask;
       }

EventFilter/SiStripRawToDigi/interface/SiStripFEDBufferComponents.h

@@ -615,28 +615,32 @@ namespace sistrip {
   //holds information about position of a channel in the buffer for use by unpacker
   class FEDChannel {
   public:
-    FEDChannel(const uint8_t* const data, const uint32_t offset, const uint16_t length);
+    enum class ZSROMode { nonLite = 7, lite = 2 };
+    constexpr FEDChannel(const uint8_t* const data, const uint32_t offset, const uint16_t length);
+    constexpr FEDChannel(const uint8_t* const data, const uint32_t offset, const ZSROMode zsRoMode);
     //gets length from first 2 bytes (assuming normal FED channel)
-    FEDChannel(const uint8_t* const data, const uint32_t offset);
-    uint16_t length() const;
-    const uint8_t* data() const;
-    uint32_t offset() const;
+    constexpr FEDChannel(const uint8_t* const data, const uint32_t offset);
+    constexpr uint16_t stripsInCh(uint8_t num_bits) const;
+    constexpr uint16_t length() const;
+    constexpr const uint8_t* data() const;
+    constexpr uint32_t offset() const;
     /**
      * Retrieve the APV CM median for a non-lite zero-suppressed channel
      *
      * apvIndex should be either 0 or 1 (there are, by construction, two APVs on every channel)
      * No additional checks are done here, so the caller should check
      * the readout mode and/or packet code.
      */
-    uint16_t cmMedian(const uint8_t apvIndex) const;
+    constexpr uint16_t cmMedian(const uint8_t apvIndex) const;
     //third byte of channel data for normal FED channels
-    uint8_t packetCode() const;
+    constexpr uint8_t packetCode() const;
 
   private:
     friend class FEDBuffer;
     const uint8_t* data_;
     uint32_t offset_;
     uint16_t length_;
+    uint8_t headerLen_ = 0;
   };
 
   //base class for sistrip FED buffers which have a DAQ header/trailer and tracker special header
@@ -1557,28 +1561,48 @@ namespace sistrip {
 
   //FEDChannel
 
-  inline FEDChannel::FEDChannel(const uint8_t* const data, const uint32_t offset) : data_(data), offset_(offset) {
+  constexpr FEDChannel::FEDChannel(const uint8_t* const data, const uint32_t offset, const ZSROMode zsRoMode)
+      : data_(data), offset_(offset), headerLen_(zsRoMode == ZSROMode::nonLite ? 7 : 2) {
+    length_ = (data_[(offset_) ^ 7] + (data_[(offset_ + 1) ^ 7] << 8));
+  }
+
+  constexpr FEDChannel::FEDChannel(const uint8_t* const data, const uint32_t offset) : data_(data), offset_(offset) {
     length_ = (data_[(offset_) ^ 7] + (data_[(offset_ + 1) ^ 7] << 8));
   }
 
-  inline FEDChannel::FEDChannel(const uint8_t* const data, const uint32_t offset, const uint16_t length)
+  constexpr FEDChannel::FEDChannel(const uint8_t* const data, const uint32_t offset, const uint16_t length)
       : data_(data), offset_(offset), length_(length) {}
 
-  inline uint16_t FEDChannel::length() const { return length_; }
+  constexpr uint16_t FEDChannel::stripsInCh(uint8_t num_bits) const {
+    const bool emptyCh = (headerLen_ + 2) >= (length_);
+    const uint16_t start = offset_ + headerLen_;
+    const uint16_t end = offset_ + length_;
+    uint16_t stripN = 0;
+    if (!emptyCh) {
+      for (uint16_t nStrip_wOfs = start + 1; nStrip_wOfs < end;) {
+        const uint8_t clustStripN = data_[(nStrip_wOfs) ^ 7];
+        nStrip_wOfs += ((uint32_t)clustStripN) * num_bits / 8 + 2;
+        stripN += clustStripN;
+      }
+    }
+    return stripN;
+  }
+
+  constexpr uint16_t FEDChannel::length() const { return length_; }
 
-  inline uint8_t FEDChannel::packetCode() const { return data_[(offset_ + 2) ^ 7]; }
+  constexpr uint8_t FEDChannel::packetCode() const { return data_[(offset_ + 2) ^ 7]; }
 
-  inline uint16_t FEDChannel::cmMedian(const uint8_t apvIndex) const {
+  constexpr uint16_t FEDChannel::cmMedian(const uint8_t apvIndex) const {
     uint16_t result = 0;
     //CM median is 10 bits with lowest order byte first. First APV CM median starts in 4th byte of channel data
     result |= data_[(offset_ + 3 + 2 * apvIndex) ^ 7];
     result |= (((data_[(offset_ + 4 + 2 * apvIndex) ^ 7]) << 8) & 0x300);
     return result;
   }
 
-  inline const uint8_t* FEDChannel::data() const { return data_; }
+  constexpr const uint8_t* FEDChannel::data() const { return data_; }
 
-  inline uint32_t FEDChannel::offset() const { return offset_; }
+  constexpr uint32_t FEDChannel::offset() const { return offset_; }
 }  // namespace sistrip
 
 #endif  //ndef EventFilter_SiStripRawToDigi_FEDBufferComponents_H