Metal: `Interlocked` (atomic) member function support for buffers (#4655)

* Metal: `Interlocked` (atomic) member function support for buffers

fixes: #4654
fixes: #4481

1. Add `Interlocked` (atomic) member function support for buffers to Metal
2. Fix `__getEquivalentStructuredBuffer` so it works with CPP/Metal targets

* add `CompareStore` support

* legalize RWByteAddressBuffer to fully replace StructuredBuffer

* destroy replaced byte-addr buffer

* cleanup as per review and add comment to explain why certain code exists

* fix flow of byte-address-buffer replacement

* toggle on option to translate byteAddrBuffer to StructuredBuffer

* cleanup unused buffers

* add treatGetEquivalentStructuredBufferAsGetThis flag to treat getEquivStructuredBuffer as a byteAddressBuffer

* comment to explain `treatGetEquivalentStructuredBufferAsGetThis`

---------

Co-authored-by: Yong He <yonghe@outlook.com>

5 files changed, 161 insertions, 13 deletions

diff --git a/source/slang/hlsl.meta.slang b/source/slang/hlsl.meta.slang
index 2639c1e88..9760f974a 100644
--- a/source/slang/hlsl.meta.slang
+++ b/source/slang/hlsl.meta.slang
@@ -4193,13 +4193,19 @@ ${{{{
     __cuda_sm_version(2.0)
     [__requiresNVAPI]
     [ForceInline]
-    [require(cuda_glsl_hlsl_spirv, atomic_glsl_hlsl_nvapi_cuda_float1)]
+    [require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_nvapi_cuda_metal_float1)]
     void InterlockedAddF32(uint byteAddress, float valueToAdd, out float originalValue)
     {
         __target_switch
         {
         case hlsl: __intrinsic_asm "($3 = NvInterlockedAddFp32($0, $1, $2))";
         case cuda: __intrinsic_asm "(*$3 = atomicAdd($0._getPtrAt<float>($1), $2))";
+        case metal:
+            {
+                let buf = __getEquivalentStructuredBuffer<float>(this);
+                __metalInterlocked_add(__getMetalAtomicRef(buf[byteAddress / 4]), valueToAdd, originalValue);
+                return;
+            }
         case glsl:
         case spirv:
             {
@@ -4264,13 +4270,19 @@ ${{{{
     [__requiresNVAPI]
     [ForceInline]
     __cuda_sm_version(2.0)
-    [require(cuda_glsl_hlsl_spirv, atomic_glsl_hlsl_nvapi_cuda_float1)]
+    [require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_nvapi_cuda_metal_float1)]
     void InterlockedAddF32(uint byteAddress, float valueToAdd)
     {
         __target_switch
         {
         case hlsl: __intrinsic_asm "(NvInterlockedAddFp32($0, $1, $2))";
         case cuda: __intrinsic_asm "atomicAdd($0._getPtrAt<float>($1), $2)";
+        case metal:
+            {
+                let buf = __getEquivalentStructuredBuffer<float>(this);
+                __metalInterlocked_add(__getMetalAtomicRef(buf[byteAddress / 4]), valueToAdd);
+                return;
+            }
         case glsl:
         case spirv:
             {
@@ -4763,6 +4775,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$3 = atomicAdd($0._getPtrAt<uint32_t>($1), $2))";
         case hlsl: __intrinsic_asm ".InterlockedAdd";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_add(__getMetalAtomicRef(buf[dest / 4]), value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedAdd(buf[dest / 4], value, original_value);
@@ -4781,6 +4798,11 @@ ${{{{
         case cuda: __intrinsic_asm "atomicAdd($0._getPtrAt<uint32_t>($1), $2)";
         case hlsl: __intrinsic_asm ".InterlockedAdd";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_add(__getMetalAtomicRef(buf[dest / 4]), value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedAdd(buf[dest / 4], value);
@@ -4800,6 +4822,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$3 = atomicAnd($0._getPtrAt<uint32_t>($1), $2))";
         case hlsl: __intrinsic_asm ".InterlockedAnd";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_and(__getMetalAtomicRef(buf[dest / 4]), value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedAnd(buf[dest / 4], value, original_value);
@@ -4818,6 +4845,11 @@ ${{{{
         case cuda: __intrinsic_asm "atomicAnd($0._getPtrAt<uint32_t>($1), $2)";
         case hlsl: __intrinsic_asm ".InterlockedAnd";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_and(__getMetalAtomicRef(buf[dest / 4]), value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedAnd(buf[dest / 4], value);
@@ -4838,6 +4870,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$4 = atomicCAS($0._getPtrAt<uint32_t>($1), $2, $3))";
         case hlsl: __intrinsic_asm ".InterlockedCompareExchange";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_compare_exchange(__getMetalAtomicRef(buf[dest / 4]), compare_value, value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedCompareExchange(buf[dest / 4], compare_value, value, original_value);
@@ -4845,7 +4882,7 @@ ${{{{
     }
 
     [ForceInline]
-    [require(cuda_glsl_hlsl_spirv, byteaddressbuffer_rw)]
+    [require(cuda_glsl_hlsl_metal_spirv, byteaddressbuffer_rw)]
     void InterlockedCompareStore(
         UINT dest,
         UINT compare_value,
@@ -4856,6 +4893,12 @@ ${{{{
         case glsl: __intrinsic_asm "atomicCompSwap($0._data[$1/4], $2, $3)";
         case cuda: __intrinsic_asm "atomicCAS($0._getPtrAt<uint32_t>($1), $2, $3)";
         case hlsl: __intrinsic_asm ".InterlockedCompareStore";
+        case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_compare_exchange(__getMetalAtomicRef(buf[dest / 4]), compare_value, value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedCompareStore(buf[dest / 4], compare_value, value);
@@ -4875,6 +4918,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$3 = atomicExch($0._getPtrAt<uint32_t>($1), $2))";
         case hlsl: __intrinsic_asm ".InterlockedExchange";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_exchange(__getMetalAtomicRef(buf[dest / 4]), value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedExchange(buf[dest / 4], value, original_value);
@@ -4894,6 +4942,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$3 = atomicMax($0._getPtrAt<uint32_t>($1), $2))";
         case hlsl: __intrinsic_asm ".InterlockedMax";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_max(__getMetalAtomicRef(buf[dest / 4]), value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedMax(buf[dest / 4], value, original_value);
@@ -4912,6 +4965,11 @@ ${{{{
         case cuda: __intrinsic_asm "atomicMax($0._getPtrAt<uint32_t>($1), $2)";
         case hlsl: __intrinsic_asm ".InterlockedMax";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_max(__getMetalAtomicRef(buf[dest / 4]), value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedMax(buf[dest / 4], value);
@@ -4931,6 +4989,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$3 = atomicMin($0._getPtrAt<uint32_t>($1), $2))";
         case hlsl: __intrinsic_asm ".InterlockedMin";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_min(__getMetalAtomicRef(buf[dest / 4]), value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedMin(buf[dest / 4], value, original_value);
@@ -4949,6 +5012,11 @@ ${{{{
         case cuda: __intrinsic_asm "atomicMin($0._getPtrAt<uint32_t>($1), $2)";
         case hlsl: __intrinsic_asm ".InterlockedMin";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_min(__getMetalAtomicRef(buf[dest / 4]), value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedMin(buf[dest / 4], value);
@@ -4968,6 +5036,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$3 = atomicOr($0._getPtrAt<uint32_t>($1), $2))";
         case hlsl: __intrinsic_asm ".InterlockedOr";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_or(__getMetalAtomicRef(buf[dest / 4]), value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedOr(buf[dest / 4], value, original_value);
@@ -4986,6 +5059,11 @@ ${{{{
         case cuda: __intrinsic_asm "atomicOr($0._getPtrAt<uint32_t>($1), $2)";
         case hlsl: __intrinsic_asm ".InterlockedOr";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_or(__getMetalAtomicRef(buf[dest / 4]), value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedOr(buf[dest / 4], value);
@@ -5005,6 +5083,11 @@ ${{{{
         case cuda: __intrinsic_asm "(*$3 = atomicXor($0._getPtrAt<uint32_t>($1), $2))";
         case hlsl: __intrinsic_asm ".InterlockedXor";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_xor(__getMetalAtomicRef(buf[dest / 4]), value, original_value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedXor(buf[dest / 4], value, original_value);
@@ -5023,6 +5106,11 @@ ${{{{
         case cuda: __intrinsic_asm "atomicXor($0._getPtrAt<uint32_t>($1), $2)";
         case hlsl: __intrinsic_asm ".InterlockedXor";
         case metal:
+        {
+            let buf = __getEquivalentStructuredBuffer<uint>(this);
+            __metalInterlocked_xor(__getMetalAtomicRef(buf[dest / 4]), value);
+            return;
+        }
         case spirv:
             let buf = __getEquivalentStructuredBuffer<uint>(this);
             ::InterlockedXor(buf[dest / 4], value);
@@ -9254,7 +9342,7 @@ for (SlangAtomicOperationInfo atomicOp : slangAtomicOperationInfo)
 
 [ForceInline]
 __glsl_version(430)
-[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda)]
+[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda_metal)]
 void Interlocked$(atomicOp.slangCallSuffix)(__ref $(T) dest,  $(T) value)
 {
     static_assert(__isTextureScalarAccess(dest) || !__isTextureAccess(dest), "Atomic must be applied to scalar texture or non-texture");
@@ -9288,7 +9376,7 @@ void Interlocked$(atomicOp.slangCallSuffix)(__ref $(T) dest,  $(T) value)
 
 [ForceInline]
 __glsl_version(430)
-[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda)]
+[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda_metal)]
 void Interlocked$(atomicOp.slangCallSuffix)(__ref $(T) dest, $(T) value, out $(T) original_value)
 {
     static_assert(__isTextureScalarAccess(dest) || !__isTextureAccess(dest), "Atomic must be applied to a scalar texture or non-texture");
@@ -9335,7 +9423,7 @@ for(const char* T : {"int64_t", "uint64_t"})
 {
 }}}}
 [ForceInline]
-[require(cuda_glsl_hlsl_spirv, atomic_glsl_hlsl_cuda)]
+[require(cuda_glsl_hlsl_spirv, atomic_glsl_hlsl_cuda_metal)]
 void InterlockedAdd(__ref $(T) dest, $(T) value)
 {   
     __target_switch
@@ -9515,7 +9603,7 @@ ${{{{
 
 [ForceInline]
 __glsl_version(430)
-[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda)]
+[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda_metal)]
 void InterlockedCompareExchange(__ref int dest, int compare_value, int value, out int original_value)
 {
     static_assert(__isTextureScalarAccess(dest) || !__isTextureAccess(dest), "Atomic must be applied to scalar texture or non-texture");
@@ -9550,7 +9638,7 @@ void InterlockedCompareExchange(__ref int dest, int compare_value, int value, ou
 
 [ForceInline]
 __glsl_version(430)
-[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda)]
+[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda_metal)]
 void InterlockedCompareExchange(__ref uint dest, uint compare_value, uint value, out uint original_value)
 {
     static_assert(__isTextureScalarAccess(dest) || !__isTextureAccess(dest), "Atomic must be applied to scalar texture or non-texture");
@@ -9613,7 +9701,7 @@ void InterlockedCompareExchangeFloatBitwise(__ref  float dest, float compare_val
 
 [ForceInline]
 __glsl_version(430)
-[require(cuda_glsl_hlsl_spirv, atomic_glsl_hlsl_cuda)]
+[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda_metal)]
 void InterlockedCompareStore(__ref int dest,  int compare_value,  int value)
 {
     __target_switch
@@ -9622,16 +9710,41 @@ void InterlockedCompareStore(__ref int dest,  int compare_value,  int value)
     case glsl: __intrinsic_asm "$atomicCompSwap($A, $1, $2)";
     case cuda: __intrinsic_asm "atomicCAS($0, $1, $2)";
     case spirv:
+    {
         spirv_asm
         {
             result:$$int = OpAtomicCompareExchange &dest Device None None $value $compare_value;
         };
+        return;
+    }
+    case metal:
+    {
+        if (__isTextureAccess(dest))
+        {
+            vector<int, 4> vec_compare_value = vector<int, 4>(compare_value);
+            if(__isTextureArrayAccess(dest))
+            {
+                __metalImageInterlocked_compare_exchange(__extractTextureFromTextureAccess(dest), 
+                    __extractCoordFromTextureAccess(dest), __extractArrayCoordFromTextureAccess(dest), vec_compare_value, vector<int, 4>(value));
+            }
+            else
+            {
+                __metalImageInterlocked_compare_exchange(__extractTextureFromTextureAccess(dest), 
+                    __extractCoordFromTextureAccess(dest), vec_compare_value, vector<int, 4>(value));
+            }
+        }
+        else
+        {
+            __metalInterlocked_compare_exchange(__getMetalAtomicRef(dest), compare_value, value);
+        }
+        return;
+    }
     }
 }
 
 [ForceInline]
 __glsl_version(430)
-[require(cuda_glsl_hlsl_spirv, atomic_glsl_hlsl_cuda)]
+[require(cuda_glsl_hlsl_metal_spirv, atomic_glsl_hlsl_cuda_metal)]
 void InterlockedCompareStore(__ref uint dest, uint compare_value, uint value)
 {
     __target_switch
@@ -9644,6 +9757,26 @@ void InterlockedCompareStore(__ref uint dest, uint compare_value, uint value)
         {
             result:$$uint = OpAtomicCompareExchange &dest Device None None $value $compare_value;
         };
+    case metal:
+        if (__isTextureAccess(dest))
+        {
+            vector<uint, 4> vec_compare_value = vector<uint, 4>(compare_value);
+            if(__isTextureArrayAccess(dest))
+            {
+                __metalImageInterlocked_compare_exchange(__extractTextureFromTextureAccess(dest), 
+                    __extractCoordFromTextureAccess(dest), __extractArrayCoordFromTextureAccess(dest), vec_compare_value, vector<uint, 4>(value));
+            }
+            else
+            {
+                __metalImageInterlocked_compare_exchange(__extractTextureFromTextureAccess(dest), 
+                    __extractCoordFromTextureAccess(dest), vec_compare_value, vector<uint, 4>(value));
+            }
+        }
+        else
+        {
+            __metalInterlocked_compare_exchange(__getMetalAtomicRef(dest), compare_value, value);
+        }
+        return;
     }
 }
 
@@ -20006,7 +20139,7 @@ extension __TextureImpl<float, Shape, 0, 0, 0, $(kStdlibResourceAccessReadWrite)
     [__requiresNVAPI]
     [ForceInline]
     __glsl_extension(GL_EXT_shader_atomic_float)
-    [require(glsl_hlsl_spirv, atomic_glsl_hlsl_nvapi_cuda_float1)]
+    [require(glsl_hlsl_spirv, atomic_glsl_hlsl_nvapi_cuda_metal_float1)]
     void InterlockedAddF32(vector<uint, Shape.dimensions> coord, float value, out float originalValue)
     {
         __target_switch
diff --git a/source/slang/slang-capabilities.capdef b/source/slang/slang-capabilities.capdef
index a27146bf9..b13571d18 100644
--- a/source/slang/slang-capabilities.capdef
+++ b/source/slang/slang-capabilities.capdef
@@ -820,12 +820,12 @@ alias subgroup_clustered = GL_KHR_shader_subgroup_clustered | _sm_6_0 | _cuda_sm
 alias subgroup_quad = GL_KHR_shader_subgroup_quad | _sm_6_0 | _cuda_sm_7_0;
 alias subgroup_partitioned = GL_NV_shader_subgroup_partitioned + subgroup_ballot_activemask | _sm_6_5 | _cuda_sm_7_0;
 
-alias atomic_glsl_hlsl_nvapi_cuda_float1 = atomic_glsl_float1 | hlsl_nvapi + _sm_4_0 | _cuda_sm_2_0;
+alias atomic_glsl_hlsl_nvapi_cuda_metal_float1 = atomic_glsl_float1 | hlsl_nvapi + _sm_4_0 | _cuda_sm_2_0 | metal;
 alias atomic_glsl_hlsl_nvapi_cuda5_int64 = atomic_glsl_int64 | hlsl_nvapi + _sm_4_0 | _cuda_sm_6_0;
 alias atomic_glsl_hlsl_nvapi_cuda6_int64 = atomic_glsl_int64 | hlsl_nvapi + _sm_4_0 | _cuda_sm_6_0;
 alias atomic_glsl_hlsl_nvapi_cuda9_int64 = atomic_glsl_int64 | hlsl_nvapi + _sm_4_0 | _cuda_sm_9_0;
 
-alias atomic_glsl_hlsl_cuda = atomic_glsl | _sm_5_0 | _cuda_sm_2_0 | metal;
+alias atomic_glsl_hlsl_cuda_metal = atomic_glsl | _sm_5_0 | _cuda_sm_2_0 | metal;
 alias atomic_glsl_hlsl_cuda9_int64 = atomic_glsl_int64 | _sm_6_6 | _cuda_sm_9_0 | metal;
 
 alias helper_lane = _sm_6_0 + fragment
diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index 678b4137a..b690b7c38 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -1039,6 +1039,7 @@ Result linkAndOptimizeIR(
         case CodeGenTarget::MetalLib:
         case CodeGenTarget::MetalLibAssembly:
             byteAddressBufferOptions.scalarizeVectorLoadStore = true;
+            byteAddressBufferOptions.treatGetEquivalentStructuredBufferAsGetThis = true;
             byteAddressBufferOptions.translateToStructuredBufferOps = false;
             byteAddressBufferOptions.lowerBasicTypeOps = true;
             break;
@@ -1135,6 +1136,8 @@ Result linkAndOptimizeIR(
     }
     break;
     case CodeGenTarget::Metal:
+    case CodeGenTarget::MetalLib:
+    case CodeGenTarget::MetalLibAssembly:
     {
         legalizeIRForMetal(irModule, sink);
     }
diff --git a/source/slang/slang-ir-byte-address-legalize.cpp b/source/slang/slang-ir-byte-address-legalize.cpp
index dba3ab5f5..d5685bad6 100644
--- a/source/slang/slang-ir-byte-address-legalize.cpp
+++ b/source/slang/slang-ir-byte-address-legalize.cpp
@@ -38,6 +38,8 @@ struct ByteAddressBufferLegalizationContext
     IRModule* m_module;
     IRBuilder m_builder;
 
+    Dictionary<IRInst*, IRType*> byteAddrBufferToReplace;
+
     // Everything starts with a request to process a module,
     // which delegates to the central recrusive walk of the IR.
     //
@@ -787,10 +789,15 @@ struct ByteAddressBufferLegalizationContext
 
     IRInst* getEquivalentStructuredBuffer(IRType* elementType, IRInst* byteAddressBuffer)
     {
+        if (this->m_options.treatGetEquivalentStructuredBufferAsGetThis)
+            return byteAddressBuffer;
+
         if (!elementType)
         {
             return nullptr;
         }
+        if (as<IRHLSLStructuredBufferTypeBase>(byteAddressBuffer->getDataType()))
+            return byteAddressBuffer;
         // The simple case for replacement is when the byte-address buffer to
         // be replaced is a global shader parameter. That path will get its
         // own routine.
diff --git a/source/slang/slang-ir-byte-address-legalize.h b/source/slang/slang-ir-byte-address-legalize.h
index 1ae69070e..8a92bcf33 100644
--- a/source/slang/slang-ir-byte-address-legalize.h
+++ b/source/slang/slang-ir-byte-address-legalize.h
@@ -14,6 +14,11 @@ struct ByteAddressBufferLegalizationOptions
     bool useBitCastFromUInt = false;
     bool translateToStructuredBufferOps = false;
     bool lowerBasicTypeOps = false;
+
+    /// Causes all calls to `getEquivlentStructuredBuffer` to return a `ByteAddressBuffer` (this) instead of a `StructuredBuffer`.
+    /// This option is used for targets that do not distinctly define `ByteAddressBuffer`/`StructuredBuffer` and introduce
+    /// operations which prevent DCE from destroying old definitions of `ByteAddressBuffer` after variable replacement.
+    bool treatGetEquivalentStructuredBufferAsGetThis = false;
 };
 
     /// Legalize byte-address buffer `Load()` and `Store()` operations.