refactor(sysrap): remove experimental curand variants and dead test paths (#307)

This PR removes two experimental RNG branches that are no longer part of the supported runtime path
and add ongoing maintenance cost:

- curand-done-right integration was only used by standalone experimental tests and not by normal
  CMake/CTest targets.
- RNG_PHILITEOX and curandlite added conditional complexity across SysRap and QUDARap while default
  builds already use RNG_PHILOX.

Keeping these unused paths increases review surface, complicates compile-time branching, and risks
bit-rot in code that is not exercised in normal CI workflows. This change simplifies the RNG model
to the actively used options.

Author: plexoos

qudarap/QSim.cc

@@ -2051,12 +2051,6 @@ std::string QSim::Desc(char delim)  // static
        << "RNG_PHILOX"
 #else
        << "NOT-RNG_PHILOX"
-#endif
-       << delim
-#ifdef RNG_PHILITEOX
-       << "RNG_PHILITEOX"
-#else
-       << "NOT-RNG_PHILITEOX"
 #endif
        << delim
        ;

qudarap/qrng.h

@@ -146,35 +146,3 @@ struct qrng<Philox>
     void set_uploaded_states( void* ){}
 #endif
 };
-
-
-#ifdef RNG_PHILITEOX
-template<>
-struct qrng<PhiloxLite>
-{
-    ULL  seed ;
-    ULL  offset ;
-    ULL  skipahead_event_offset ;
-
-#if defined(__CUDACC__) || defined(__CUDABE__)
-    QRNG_METHOD void init(PhiloxLite& rng, unsigned long long event_idx, unsigned long long photon_idx )
-    {
-        ULL subsequence_ = photon_idx ;
-        curand_init( seed, subsequence_, offset, &rng ) ;
-        ULL skipahead_ = skipahead_event_offset*event_idx ;
-        skipahead( skipahead_, &rng );
-    }
-#else
-    qrng(ULL seed_, ULL offset_, ULL skipahead_event_offset_ )
-        :
-        seed(seed_),
-        offset(offset_),
-        skipahead_event_offset(skipahead_event_offset_)
-    {
-    }
-    void set_uploaded_states( void* ){}
-#endif
-};
-#endif
-
-

sysrap/CMakeLists.txt

@@ -111,11 +111,6 @@ set(SOURCES
     SFastSim_Debug.cc
     SFastSimOpticalModel.cc
 ) 
-    
-
-set(CURANDLITE_HEADERS
-    curandlite/curandStatePhilox4_32_10_OpticksLite.h
-) 
 
 
 set(HEADERS
@@ -646,7 +641,7 @@ PLOG_LOCAL
    integration with packages (like junosw) that do not hide 
    symbols by default  
 
-RNG_XORWOW/RNG_PHILOX/RNG_PHILITEOX
+RNG_XORWOW/RNG_PHILOX
    Use one of these to pick the curandState implementation, in srng.h
    picking RNG_XORWOW requires curandState files which slows
    down initialization greatly when simulating many millions 
@@ -685,7 +680,6 @@ target_compile_definitions( ${name} PUBLIC WITH_SLOG)
 endif()
 
 install(FILES ${HEADERS} DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}/sysrap/)
-install(FILES ${CURANDLITE_HEADERS} DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}/curandlite)
 
 install(TARGETS ${name}
         EXPORT ${PROJECT_NAME}Targets

sysrap/SEventConfig.cc

@@ -78,13 +78,13 @@ const char* SEventConfig::_HitMaskDefault = "SD" ;
 
 
 #if defined(RNG_XORWOW)
-const char* SEventConfig::_MaxSlotDefault =  ;
+const char* SEventConfig::_MaxSlotDefault = WITH_STATE_LIMIT ;
 const char* SEventConfig::_MaxGenstepDefault = WITH_STATE_LIMIT ;
 const char* SEventConfig::_MaxPhotonDefault = WITH_STATE_LIMIT ;
 const char* SEventConfig::_MaxSimtraceDefault = WITH_STATE_LIMIT ;
 const char* SEventConfig::_MaxCurandDefault = WITH_STATE_LIMIT ;
 
-#elif defined(RNG_PHILOX) || defined(RNG_PHILITEOX)
+#elif defined(RNG_PHILOX)
 const char* SEventConfig::_MaxSlotDefault = "0" ;     // see SEventConfig::SetDevice : set according to VRAM
 const char* SEventConfig::_MaxGenstepDefault = NO_STATE_LIMIT_GENSTEP ;  // adhoc
 const char* SEventConfig::_MaxPhotonDefault = NO_STATE_LIMIT ;
@@ -1973,4 +1973,3 @@ uint64_t SEventConfig::AllocEstimateTotal(int _max_slot)
     delete estimate ;
     return total ;
 }
-