[DirectX] Overlapping binding detection - check register space first

llvm/include/llvm/Analysis/DXILResource.h

@@ -360,9 +360,11 @@ class ResourceInfo {
              std::tie(RHS.RecordID, RHS.Space, RHS.LowerBound, RHS.Size);
     }
     bool overlapsWith(const ResourceBinding &RHS) const {
+      if (Space != RHS.Space)
+        return false;
       if (Size == UINT32_MAX)
         return LowerBound < RHS.LowerBound;
-      return Space == RHS.Space && LowerBound + Size - 1 >= RHS.LowerBound;
+      return LowerBound + Size - 1 >= RHS.LowerBound;
     }
   };
 

llvm/test/CodeGen/DirectX/Binding/binding-overlap-7.ll

@@ -0,0 +1,35 @@
+; Use llc for this test so that we don't abort after the first error.
+; RUN: not llc %s -o /dev/null 2>&1 | FileCheck %s
+
+; Check that there is no overlap with unbounded array in different space
+
+  ; Buffer<double> A[2] : register(t2, space4);
+  ; Buffer<double> B : register(t20, space5);  // does not overlap
+  ; Buffer<double> C[] : register(t2, space4); // overlaps with A
+
+; CHECK: error: resource A at register 2 overlaps with resource C at register 2 in space 4
+; CHECK-NOT: error: resource C at register 2 overlaps with resource B at register 20 in space 5
+
+target triple = "dxil-pc-shadermodel6.3-library"
+
+@A.str = private unnamed_addr constant [2 x i8] c"A\00", align 1
+@B.str = private unnamed_addr constant [2 x i8] c"B\00", align 1
+@C.str = private unnamed_addr constant [2 x i8] c"C\00", align 1
+
+define void @test_not_overlapping_in_different_spaces() {
+entry:
+
+  ; Buffer<double> A[2] : register(t2, space4);
+  %h0 = call target("dx.TypedBuffer", double, 0, 0, 0)
+            @llvm.dx.resource.handlefrombinding(i32 4, i32 2, i32 2, i32 10, i1 false, ptr @A.str)
+
+  ; Buffer<double> B : register(t20, space5);
+  %h1 = call target("dx.TypedBuffer", i64, 0, 0, 0)
+            @llvm.dx.resource.handlefrombinding(i32 5, i32 20, i32 1, i32 0, i1 false, ptr @B.str)
+
+  ; Buffer<double> C[] : register(t2, space4);
+  %h2 = call target("dx.TypedBuffer", double, 0, 0, 0)
+            @llvm.dx.resource.handlefrombinding(i32 4, i32 2, i32 -1, i32 10, i1 false, ptr @C.str)
+
+  ret void
+}