refactor to copy frontend

Author: joaosaffran

llvm/include/llvm/Frontend/HLSL/RootSignatureValidations.h

@@ -41,8 +41,6 @@ LLVM_ABI bool verifyLOD(float LOD);
 LLVM_ABI bool verifyBoundOffset(uint32_t Offset);
 LLVM_ABI bool verifyNoOverflowedOffset(uint64_t Offset);
 LLVM_ABI uint64_t computeRangeBound(uint32_t Offset, uint32_t Size);
-LLVM_ABI uint64_t updateOngoingOffset(uint64_t CurOffset,
-                                      uint64_t NumDescriptors, uint64_t Offset);
 
 } // namespace rootsig
 } // namespace hlsl

llvm/lib/Frontend/HLSL/RootSignatureMetadata.cpp

@@ -561,34 +561,39 @@ static Error
 validateDescriptorTableRegisterOverflow(const mcdxbc::DescriptorTable &Table,
                                         uint32_t Location) {
   uint64_t Offset = 0;
-
+  bool IsPrevUnbound = false;
+  
   for (const mcdxbc::DescriptorRange &Range : Table.Ranges) {
     // Validation of NumDescriptors should have happened by this point.
     if (Range.NumDescriptors == 0)
       continue;
 
-    if (Range.OffsetInDescriptorsFromTableStart != DescriptorTableOffsetAppend)
-      Offset = Range.OffsetInDescriptorsFromTableStart;
-
-    if (!verifyNoOverflowedOffset(Offset))
-      return make_error<OffsetOverflowError>(
-          Range.RangeType, Range.BaseShaderRegister, Range.RegisterSpace);
-
     const uint64_t RangeBound = llvm::hlsl::rootsig::computeRangeBound(
         Range.BaseShaderRegister, Range.NumDescriptors);
 
     if (!verifyNoOverflowedOffset(RangeBound))
       return make_error<ShaderRegisterOverflowError>(
           Range.RangeType, Range.BaseShaderRegister, Range.RegisterSpace);
 
+    bool IsAppending =
+        Range.OffsetInDescriptorsFromTableStart == DescriptorTableOffsetAppend;
+    if (!IsAppending)
+      Offset = Range.OffsetInDescriptorsFromTableStart;
+
+    if (IsPrevUnbound && IsAppending)
+      return make_error<ShaderRegisterOverflowError>(
+          Range.RangeType, Range.BaseShaderRegister, Range.RegisterSpace);
+
     const uint64_t OffsetBound =
         llvm::hlsl::rootsig::computeRangeBound(Offset, Range.NumDescriptors);
 
     if (!verifyNoOverflowedOffset(OffsetBound))
       return make_error<DescriptorRangeOverflowError>(
           Range.RangeType, Range.BaseShaderRegister, Range.RegisterSpace);
-    Offset = updateOngoingOffset(Offset, Range.NumDescriptors,
-                                 Range.OffsetInDescriptorsFromTableStart);
+
+    Offset = OffsetBound + 1;
+    IsPrevUnbound =
+        Range.NumDescriptors == llvm::hlsl::rootsig::NumDescriptorsUnbounded;
   }
 
   return Error::success();

llvm/lib/Frontend/HLSL/RootSignatureValidations.cpp

@@ -140,15 +140,6 @@ uint64_t computeRangeBound(uint32_t Offset, uint32_t Size) {
 
   return uint64_t(Offset) + uint64_t(Size) - 1;
 }
-
-uint64_t updateOngoingOffset(uint64_t CurOffset, uint64_t NumDescriptors,
-                             uint64_t Offset) {
-  // Append to the current offset if DescriptorTableOffsetAppend is set,
-  // otherwise calculate the new Offset.
-  return Offset == DescriptorTableOffsetAppend ? CurOffset + NumDescriptors
-                                               : Offset + NumDescriptors;
-}
-
 } // namespace rootsig
 } // namespace hlsl
 } // namespace llvm