GPU: Remove if constexpr for C++ < 17

davidrohr · davidrohr · commit 8727301fd5f1 · 2020-11-18T11:16:19.000+01:00
diff --git a/GPU/Common/GPUCommonDef.h b/GPU/Common/GPUCommonDef.h
@@ -56,17 +56,14 @@
   #define CONSTEXPR constexpr
   #define CONSTEXPRRET CONSTEXPR
   #if defined(__cplusplus) && __cplusplus >= 201703L
-    #define CONSTEXPRIF if constexpr
     #define CONSTEXPR17 constexpr
   #else
-    #define CONSTEXPRIF if
     #define CONSTEXPR17
   #endif
 #else
   #define CON_DELETE
   #define CON_DEFAULT
   #define CONSTEXPR const
-  #define CONSTEXPRIF if
   #define CONSTEXPR17
   #define CONSTEXPRRET
 #endif
diff --git a/GPU/Common/GPUCommonMath.h b/GPU/Common/GPUCommonMath.h
@@ -148,10 +148,15 @@ class GPUCommonMath
   GPUd() CONSTEXPR17 static T nextMultipleOf(T val);
 
 #ifdef GPUCA_NOCOMPAT
+  GPUdi() static float Sum2() // Needed for legacy C++, For >=17 the below if constexpr handles the case
+  {
+    return 0.f;
+  }
+
   template <typename... Args>
   GPUdi() static float Sum2(float w, Args... args)
   {
-    if constexpr (sizeof...(Args) == 0) {
+    if CONSTEXPR17 (sizeof...(Args) == 0) {
       return w * w;
     } else {
       return w * w + Sum2(args...);
@@ -185,16 +190,13 @@ typedef GPUCommonMath CAMath;
 template <int I, class T>
 GPUdi() CONSTEXPR17 T GPUCommonMath::nextMultipleOf(T val)
 {
-  CONSTEXPRIF(I & (I - 1))
-  {
+  if CONSTEXPR17 (I & (I - 1)) {
     T tmp = val % I;
     if (tmp) {
       val += I - tmp;
     }
     return val;
-  }
-  else
-  {
+  } else {
     return (val + I - 1) & ~(T)(I - 1);
   }
   return 0; // BUG: Cuda complains about missing return value with constexpr if
diff --git a/GPU/GPUTracking/DataCompression/GPUTPCCompressionKernels.cxx b/GPU/GPUTracking/DataCompression/GPUTPCCompressionKernels.cxx
@@ -339,13 +339,10 @@ GPUdi() GPUTPCCompressionGatherKernels::Vec128* GPUTPCCompressionGatherKernels::
 template <typename T, typename S>
 GPUdi() bool GPUTPCCompressionGatherKernels::isAlignedTo(const S* ptr)
 {
-  CONSTEXPRIF(alignof(S) >= alignof(T))
-  {
+  if CONSTEXPR17 (alignof(S) >= alignof(T)) {
     static_cast<void>(ptr);
     return true;
-  }
-  else
-  {
+  } else {
     return reinterpret_cast<size_t>(ptr) % alignof(T) == 0;
   }
   return false; // BUG: Cuda complains about missing return value with constexpr if
