[HLSL] Fix detection of overlapping binding with unbounded array

[hekota]

Fixes #150534

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

@llvm/pr-subscribers-backend-directx

Author: Helena Kotas (hekota)

Changes

Fixes #150534

---

Full diff: https://github.com/llvm/llvm-project/pull/150547.diff

3 Files Affected:

• (modified) llvm/include/llvm/Analysis/DXILResource.h (+2)
• (modified) llvm/lib/Analysis/DXILResource.cpp (+4-3)
• (added) llvm/test/CodeGen/DirectX/Binding/binding-overlap-6.ll (+24)

diff --git a/llvm/include/llvm/Analysis/DXILResource.h b/llvm/include/llvm/Analysis/DXILResource.h
index 9e2dc1ad771cf..956dcbcc33305 100644
--- a/llvm/include/llvm/Analysis/DXILResource.h
+++ b/llvm/include/llvm/Analysis/DXILResource.h
@@ -359,6 +359,8 @@ class ResourceInfo {
              std::tie(RHS.RecordID, RHS.Space, RHS.LowerBound, RHS.Size);
     }
     bool overlapsWith(const ResourceBinding &RHS) const {
+      if (Size == UINT32_MAX)
+        return LowerBound < RHS.LowerBound;
       return Space == RHS.Space && LowerBound + Size - 1 >= RHS.LowerBound;
     }
   };
diff --git a/llvm/lib/Analysis/DXILResource.cpp b/llvm/lib/Analysis/DXILResource.cpp
index 2da6468ec3dcf..179b7b4dc17f9 100644
--- a/llvm/lib/Analysis/DXILResource.cpp
+++ b/llvm/lib/Analysis/DXILResource.cpp
@@ -1079,15 +1079,16 @@ void DXILResourceBindingInfo::populate(Module &M, DXILResourceTypeMap &DRTM) {
       // add new space
       S = &BS->Spaces.emplace_back(B.Space);
 
-    // the space is full - set flag to report overlapping binding later
-    if (S->FreeRanges.empty()) {
+    // The space is full - there are no free slots left, or the rest of the
+    // slots are taken by an unbouded array. Set flag to report overlapping
+    // binding later.
+    if (S->FreeRanges.empty() || S->FreeRanges.back().UpperBound < UINT32_MAX) {
       OverlappingBinding = true;
       continue;
     }
 
     // adjust the last free range lower bound, split it in two, or remove it
     BindingRange &LastFreeRange = S->FreeRanges.back();
-    assert(LastFreeRange.UpperBound == UINT32_MAX);
     if (LastFreeRange.LowerBound == B.LowerBound) {
       if (B.UpperBound < UINT32_MAX)
         LastFreeRange.LowerBound = B.UpperBound + 1;
diff --git a/llvm/test/CodeGen/DirectX/Binding/binding-overlap-6.ll b/llvm/test/CodeGen/DirectX/Binding/binding-overlap-6.ll
new file mode 100644
index 0000000000000..3c37e639f0ede
--- /dev/null
+++ b/llvm/test/CodeGen/DirectX/Binding/binding-overlap-6.ll
@@ -0,0 +1,24 @@
+; RUN: not opt -S -passes='dxil-post-optimization-validation' -mtriple=dxil-pc-shadermodel6.3-library %s 2>&1 | FileCheck %s
+
+; Check overlap with unbounded array
+
+; A overlaps with B
+; RWBuffer<float> A[3] : register(u0);
+; RWBuffer<float> B[] : register(u4);
+; RWBuffer<float> C : register(u17);
+
+; CHECK: error: resource B at register 4 overlaps with resource C at register 17 in space 0
+
+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_overlapping() {
+entry:
+  %h1 = call target("dx.TypedBuffer", float, 1, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 0, i32 3, i32 0, i1 false, ptr @A.str)
+  %h2 = call target("dx.TypedBuffer", float, 1, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 4, i32 -1, i32 0, i1 false, ptr @B.str)
+  %h3 = call target("dx.TypedBuffer", float, 1, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 17, i32 1, i32 0, i1 false, ptr @C.str)
+  ret void
+}