[llvm] f9ae8aa - [DirectX] Detect resources with identical overlapping binding (#140645)

[via llvm-commits]

Author: Helena Kotas
Date: 2025-05-28T14:07:51-07:00
New Revision: f9ae8aaff2e5aaf8e1f7369a3da6952460414991

URL: https://github.com/llvm/llvm-project/commit/f9ae8aaff2e5aaf8e1f7369a3da6952460414991
DIFF: https://github.com/llvm/llvm-project/commit/f9ae8aaff2e5aaf8e1f7369a3da6952460414991.diff

LOG: [DirectX] Detect resources with identical overlapping binding (#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).

Added: 
    

Modified: 
    llvm/lib/Analysis/DXILResource.cpp
    llvm/unittests/Target/DirectX/ResourceBindingAnalysisTests.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/DXILResource.cpp b/llvm/lib/Analysis/DXILResource.cpp
index fd08d046fa9f7..44acb13cdee97 100644
--- a/llvm/lib/Analysis/DXILResource.cpp
+++ b/llvm/lib/Analysis/DXILResource.cpp
@@ -920,10 +920,11 @@ 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;
 
@@ -948,6 +949,7 @@ 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
@@ -955,7 +957,7 @@ 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;
     }
@@ -974,8 +976,9 @@ 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);
@@ -1015,8 +1018,6 @@ 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);