[llvm] b6b4262 - [DirectX] Fix DXIL container generating invalid PSV0 part for unbounded resources (#163287)

[via llvm-commits]

Author: Helena Kotas
Date: 2025-10-14T11:34:38-07:00
New Revision: b6b426257509c147c53a74c138eb87b48630579f

URL: https://github.com/llvm/llvm-project/commit/b6b426257509c147c53a74c138eb87b48630579f
DIFF: https://github.com/llvm/llvm-project/commit/b6b426257509c147c53a74c138eb87b48630579f.diff

LOG: [DirectX] Fix DXIL container generating invalid PSV0 part for unbounded resources (#163287)

When calculating the upper bound for resource binding to be stored in the PSV0 part of the DXIL container, the compiler needs to take into account that the resource range could be _unbounded_, which is indicated by the binding size being `UINT32_MAX`.

Fixes [#159679](https://github.com/llvm/llvm-project/issues/159679)

Added: 
    

Modified: 
    llvm/lib/Target/DirectX/DXContainerGlobals.cpp
    llvm/test/CodeGen/DirectX/ContainerData/PSVResources.ll

Removed: 
    


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diff  --git a/llvm/lib/Target/DirectX/DXContainerGlobals.cpp b/llvm/lib/Target/DirectX/DXContainerGlobals.cpp
index ca81d30473c03..8ace2d2777c74 100644
--- a/llvm/lib/Target/DirectX/DXContainerGlobals.cpp
+++ b/llvm/lib/Target/DirectX/DXContainerGlobals.cpp
@@ -28,6 +28,7 @@
 #include "llvm/Support/MD5.h"
 #include "llvm/TargetParser/Triple.h"
 #include "llvm/Transforms/Utils/ModuleUtils.h"
+#include <cstdint>
 #include <optional>
 
 using namespace llvm;
@@ -193,7 +194,12 @@ void DXContainerGlobals::addResourcesForPSV(Module &M, PSVRuntimeInfo &PSV) {
         dxbc::PSV::v2::ResourceBindInfo BindInfo;
         BindInfo.Type = Type;
         BindInfo.LowerBound = Binding.LowerBound;
-        BindInfo.UpperBound = Binding.LowerBound + Binding.Size - 1;
+        assert(Binding.Size == UINT32_MAX ||
+               (uint64_t)Binding.LowerBound + Binding.Size - 1 <= UINT32_MAX &&
+                   "Resource range is too large");
+        BindInfo.UpperBound = (Binding.Size == UINT32_MAX)
+                                  ? UINT32_MAX
+                                  : Binding.LowerBound + Binding.Size - 1;
         BindInfo.Space = Binding.Space;
         BindInfo.Kind = static_cast<dxbc::PSV::ResourceKind>(Kind);
         BindInfo.Flags = Flags;

diff  --git a/llvm/test/CodeGen/DirectX/ContainerData/PSVResources.ll b/llvm/test/CodeGen/DirectX/ContainerData/PSVResources.ll
index bea03102e4ccf..70224fce55407 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/PSVResources.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/PSVResources.ll
@@ -94,6 +94,18 @@ define void @main() #0 {
   %uav2_2 = call target("dx.TypedBuffer", <4 x float>, 1, 0, 0)
               @llvm.dx.resource.handlefrombinding.tdx.TypedBuffer_f32_1_0(
                   i32 4, i32 0, i32 10, i32 5, ptr null)
+
+  ; RWBuffer<float4> UnboundedArray[] : register(u10, space5)
+; CHECK:        - Type:            UAVTyped
+; CHECK:          Space:           5
+; CHECK:          LowerBound:      10
+; CHECK:          UpperBound:      4294967295
+; CHECK:          Kind:            TypedBuffer
+; CHECK:          Flags:
+; CHECK:            UsedByAtomic64:  false
+  ; RWBuffer<float4> Buf = BufferArray[100];
+  %uav3 = call target("dx.TypedBuffer", <4 x float>, 1, 0, 0)
+              @llvm.dx.resource.handlefrombinding(i32 5, i32 10, i32 -1, i32 100, ptr null)
   ret void
 }