[ser] Folded warn_hlsl_impcast_XYZ coherence diags into one

Author: simoll

tools/clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -7758,15 +7758,15 @@ def warn_hlsl_semantic_attribute_position_misuse_hint: Warning<
 def warn_hlsl_unary_negate_unsigned : Warning<
   "unary negate of unsigned value is still unsigned">,
   InGroup<Conversion>, DefaultWarn;
-def warn_hlsl_impcast_glc_mismatch : Warning<
-  "implicit conversion from %0 to %1 %select{loses|adds}2 globallycoherent annotation">,
-  InGroup<Conversion>, DefaultWarn;
-def warn_hlsl_impcast_rdc_mismatch : Warning<
-  "implicit conversion from %0 to %1 %select{loses|adds}2 reordercoherent annotation">,
-  InGroup<Conversion>, DefaultWarn;
-def warn_hlsl_impcast_rdc_glc_mismatch : Warning<
-  "implicit conversion from %0 to %1 %select{demotes globallycoherent to reordercoherent|promotes reordercoherent to globallycoherent}2 annotation">,
-  InGroup<Conversion>, DefaultWarn;
+def warn_hlsl_impcast_coherence_mismatch : Warning<
+  "implicit conversion from %0 to %1 %select{"
+  "demotes globallycoherent to reordercoherent|"
+  "promotes reordercoherent to globallycoherent|"
+  "loses reordercoherent|"
+  "loses globallycoherent|"
+  "adds reordercoherent|"
+  "adds globallycoherent}2 annotation">,
+  InGroup<Conversion>;
 def warn_hlsl_glc_implies_rdc : Warning<
   "attribute 'globallycoherent' implies 'reordercoherent'">, InGroup<IgnoredAttributes>;
 def warn_hlsl_narrowing : Warning<

tools/clang/lib/Sema/SemaHLSL.cpp

@@ -13716,18 +13716,35 @@ void Sema::DiagnoseCoherenceMismatch(const Expr *SrcExpr, QualType TargetType,
     // 'globallycoherent'
     bool SrcRD = hlsl::HasHLSLReorderCoherent(SrcTy);
     bool DstRD = hlsl::HasHLSLReorderCoherent(DstTy);
-    bool DemoteToRD = SrcGL && DstRD;
-    bool PromoteToGL = SrcRD && DstGL;
-    if (DemoteToRD || PromoteToGL)
-      Diag(Loc, diag::warn_hlsl_impcast_rdc_glc_mismatch)
-          << SrcExpr->getType() << TargetType
-          << /*demotes|promotes*/ PromoteToGL;
-    else if (SrcGL != DstGL)
-      Diag(Loc, diag::warn_hlsl_impcast_glc_mismatch)
-          << SrcExpr->getType() << TargetType << /*loses|adds*/ DstGL;
-    else if (SrcRD != DstRD)
-      Diag(Loc, diag::warn_hlsl_impcast_rdc_mismatch)
-          << SrcExpr->getType() << TargetType << /*loses|adds*/ DstRD;
+
+    enum {
+      NoMismatch = -1,
+      DemoteToRD = 0,
+      PromoteToGL = 1,
+      LosesRD = 2,
+      LosesGL = 3,
+      AddsRD = 4,
+      AddsGL = 5
+    } MismatchType = NoMismatch;
+
+    if (SrcGL && DstRD)
+      MismatchType = DemoteToRD;
+    else if (SrcRD && DstGL)
+      MismatchType = PromoteToGL;
+    else if (SrcRD && !DstRD)
+      MismatchType = LosesRD;
+    else if (SrcGL && !DstGL)
+      MismatchType = LosesGL;
+    else if (!SrcRD && DstRD)
+      MismatchType = AddsRD;
+    else if (!SrcGL && DstGL)
+      MismatchType = AddsGL;
+
+    if (MismatchType == NoMismatch)
+      return;
+
+    Diag(Loc, diag::warn_hlsl_impcast_coherence_mismatch)
+        << SrcExpr->getType() << TargetType << MismatchType;
   }
 }