[llvm] f7c6c7c - [DirectX] Overlapping binding detection - check register space first (#152250)

[via llvm-commits]

Author: Helena Kotas
Date: 2025-08-07T10:48:47-07:00
New Revision: f7c6c7ce361b8664eee962f10803e92661582176

URL: https://github.com/llvm/llvm-project/commit/f7c6c7ce361b8664eee962f10803e92661582176
DIFF: https://github.com/llvm/llvm-project/commit/f7c6c7ce361b8664eee962f10803e92661582176.diff

LOG: [DirectX] Overlapping binding detection - check register space first (#152250)

The code that checks for overlapping binding did not compare register space when one of the bindings was for an unbounded resource array, leading to false errors. This change fixes it.

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

Modified: 
    llvm/include/llvm/Analysis/DXILResource.h

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Analysis/DXILResource.h b/llvm/include/llvm/Analysis/DXILResource.h
index 9d07bc0013ca7..88ac0a11fe5a2 100644
--- a/llvm/include/llvm/Analysis/DXILResource.h
+++ b/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;
     }
   };
 

diff  --git a/llvm/test/CodeGen/DirectX/Binding/binding-overlap-7.ll b/llvm/test/CodeGen/DirectX/Binding/binding-overlap-7.ll
new file mode 100644
index 0000000000000..25f81dd26b9db
--- /dev/null
+++ b/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 
diff erent 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"
+
+ 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
+ at C.str = private unnamed_addr constant [2 x i8] c"C\00", align 1
+
+define void @test_not_overlapping_in_
diff erent_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
+}