[llvm-branch-commits] [llvm] [DirectX] Detect resources with identical overlapping binding (PR #140645)

[Helena Kotas via llvm-branch-commits]

https://github.com/hekota created https://github.com/llvm/llvm-project/pull/140645

This change uses resource name during DXIL resource binding analysis to detect when two (or more) resources have identical overlapping binding.

The DXIL resource analysis just detects that there is a problem with the binding and sets the `hasOverlappingBinding` flag. Full error reporting will happen later in DXILPostOptimizationValidation pass (llvm/llvm-project#110723).

Depends on #139991 

>From 8d55009a5ace1d8d9605668199622b3dd49cde29 Mon Sep 17 00:00:00 2001
From: Helena Kotas <hekotas at microsoft.com>
Date: Mon, 19 May 2025 16:16:52 -0700
Subject: [PATCH] [DirectX] Detect resources with identical overlapping binding

This change uses resource name during DXIL resource binding analysis to detect
when two (or more) resources have identical overlapping binding.

The DXIL resource analysis just detects that there is a problem with the binding
and sets the `hasOverlappingBinding` flag. Full error reporting will happen
later in DXILPostOptimizationValidation pass (llvm/llvm-project#110723).
---
 llvm/lib/Analysis/DXILResource.cpp              | 17 +++++++++--------
 .../DirectX/ResourceBindingAnalysisTests.cpp    | 12 +++++-------
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/llvm/lib/Analysis/DXILResource.cpp b/llvm/lib/Analysis/DXILResource.cpp
index 36b3901246285..d0c1e1e9ba2d3 100644
--- a/llvm/lib/Analysis/DXILResource.cpp
+++ b/llvm/lib/Analysis/DXILResource.cpp
@@ -892,10 +892,11 @@ void DXILResourceBindingInfo::populate(Module &M, DXILResourceTypeMap &DRTM) {
     uint32_t Space;
     uint32_t LowerBound;
     uint32_t UpperBound;
+    Value *Name;
     Binding(ResourceClass RC, uint32_t Space, uint32_t LowerBound,
-            uint32_t UpperBound)
-        : RC(RC), Space(Space), LowerBound(LowerBound), UpperBound(UpperBound) {
-    }
+            uint32_t UpperBound, Value *Name)
+        : RC(RC), Space(Space), LowerBound(LowerBound), UpperBound(UpperBound),
+          Name(Name) {}
   };
   SmallVector<Binding> Bindings;
 
@@ -920,6 +921,7 @@ void DXILResourceBindingInfo::populate(Module &M, DXILResourceTypeMap &DRTM) {
               cast<ConstantInt>(CI->getArgOperand(1))->getZExtValue();
           int32_t Size =
               cast<ConstantInt>(CI->getArgOperand(2))->getZExtValue();
+          Value *Name = CI->getArgOperand(5);
 
           // negative size means unbounded resource array;
           // upper bound register overflow should be detected in Sema
@@ -927,7 +929,7 @@ void DXILResourceBindingInfo::populate(Module &M, DXILResourceTypeMap &DRTM) {
                  "upper bound register overflow");
           uint32_t UpperBound = Size < 0 ? UINT32_MAX : LowerBound + Size - 1;
           Bindings.emplace_back(RTI.getResourceClass(), Space, LowerBound,
-                                UpperBound);
+                                UpperBound, Name);
         }
       break;
     }
@@ -946,8 +948,9 @@ void DXILResourceBindingInfo::populate(Module &M, DXILResourceTypeMap &DRTM) {
 
   // remove duplicates
   Binding *NewEnd = llvm::unique(Bindings, [](auto &LHS, auto &RHS) {
-    return std::tie(LHS.RC, LHS.Space, LHS.LowerBound, LHS.UpperBound) ==
-           std::tie(RHS.RC, RHS.Space, RHS.LowerBound, RHS.UpperBound);
+    return std::tie(LHS.RC, LHS.Space, LHS.LowerBound, LHS.UpperBound,
+                    LHS.Name) == std::tie(RHS.RC, RHS.Space, RHS.LowerBound,
+                                          RHS.UpperBound, RHS.Name);
   });
   if (NewEnd != Bindings.end())
     Bindings.erase(NewEnd);
@@ -987,8 +990,6 @@ void DXILResourceBindingInfo::populate(Module &M, DXILResourceTypeMap &DRTM) {
       if (B.UpperBound < UINT32_MAX)
         S->FreeRanges.emplace_back(B.UpperBound + 1, UINT32_MAX);
     } else {
-      // FIXME: This only detects overlapping bindings that are not an exact
-      // match (llvm/llvm-project#110723)
       OverlappingBinding = true;
       if (B.UpperBound < UINT32_MAX)
         LastFreeRange.LowerBound =
diff --git a/llvm/unittests/Target/DirectX/ResourceBindingAnalysisTests.cpp b/llvm/unittests/Target/DirectX/ResourceBindingAnalysisTests.cpp
index 6cd0d9f4fc5e7..6cd1a48d8d5fd 100644
--- a/llvm/unittests/Target/DirectX/ResourceBindingAnalysisTests.cpp
+++ b/llvm/unittests/Target/DirectX/ResourceBindingAnalysisTests.cpp
@@ -167,7 +167,6 @@ TEST_F(ResourceBindingAnalysisTest, TestUnboundedAndOverlap) {
   // StructuredBuffer<float> C[]  : register(t0, space2);
   // StructuredBuffer<float> D    : register(t4, space2); /* overlapping */
   StringRef Assembly = R"(
-%__cblayout_CB = type <{ i32 }>
 define void @main() {
 entry:
   %handleA = call target("dx.RawBuffer", float, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 -1, i32 10, i1 false, ptr null)
@@ -198,11 +197,12 @@ TEST_F(ResourceBindingAnalysisTest, TestExactOverlap) {
   // StructuredBuffer<float> A  : register(t5);
   // StructuredBuffer<float> B  : register(t5);
   StringRef Assembly = R"(
-%__cblayout_CB = type <{ i32 }>
+ at A.str = private unnamed_addr constant [2 x i8] c"A\00", align 1
+ at B.str = private unnamed_addr constant [2 x i8] c"B\00", align 1
 define void @main() {
 entry:
-  %handleA = call target("dx.RawBuffer", float, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 1, i32 0, i1 false, ptr null)
-  %handleB = call target("dx.RawBuffer", float, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 1, i32 0, i1 false, ptr null)
+  %handleA = call target("dx.RawBuffer", float, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 1, i32 0, i1 false, ptr @A.str)
+  %handleB = call target("dx.RawBuffer", float, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 1, i32 0, i1 false, ptr @B.str)
   ret void
 }
   )";
@@ -213,9 +213,7 @@ define void @main() {
       MAM->getResult<DXILResourceBindingAnalysis>(*M);
 
   EXPECT_EQ(false, DRBI.hasImplicitBinding());
-  // FIXME (XFAIL): detecting overlap of two resource with identical binding
-  // is not yet supported (llvm/llvm-project#110723).
-  EXPECT_EQ(false, DRBI.hasOverlappingBinding());
+  EXPECT_EQ(true, DRBI.hasOverlappingBinding());
 
   DXILResourceBindingInfo::BindingSpaces &SRVSpaces =
       DRBI.getBindingSpaces(ResourceClass::SRV);