[llvm] 62f9115 - [SPIR-V] Add capability for non-uniform indexing for `StructuredBuffer` types. (#163424)

via llvm-commits llvm-commits at lists.llvm.org
Fri Oct 17 14:17:13 PDT 2025


Author: Lucie Choi
Date: 2025-10-17T17:17:09-04:00
New Revision: 62f91152fbb3b0a0f581e18a923ee0aec3f77ebd

URL: https://github.com/llvm/llvm-project/commit/62f91152fbb3b0a0f581e18a923ee0aec3f77ebd
DIFF: https://github.com/llvm/llvm-project/commit/62f91152fbb3b0a0f581e18a923ee0aec3f77ebd.diff

LOG: [SPIR-V] Add capability for non-uniform indexing for  `StructuredBuffer` types. (#163424)

- Capability `StorageBufferArrayNonUniformIndexing` is required if the
non-uniform index accesses "arrays in the StorageBuffer [storage
class](https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#Storage_Class)
or
BufferBlock-[decorated](https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#Decoration)
arrays." (e.g. `RWStructuredBuffer`, `StructuredBuffer`)

- Also fix the wrong unit test name: `StructuredBufferNonUniformIdx.ll`
-> `RWBufferNonUniformIdx.ll`

Resolves https://github.com/llvm/llvm-project/issues/162889
Addresses https://github.com/llvm/llvm-project/issues/161852

Added: 
    llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWBufferDynamicIdx.ll
    llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWStructuredBufferDynamicIdx.ll
    llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWBufferNonUniformIdx.ll
    llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageConstIdx.ll

Modified: 
    llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
    llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWStructuredBufferNonUniformIdx.ll

Removed: 
    llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/StructuredBufferNonUniformIdx.ll
    llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageDynIdx.ll


################################################################################
diff  --git a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
index 6760f5a2829d3..61a0bbef90891 100644
--- a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
@@ -1200,6 +1200,23 @@ void addOpAccessChainReqs(const MachineInstr &Instr,
     return;
   }
 
+  bool IsNonUniform =
+      hasNonUniformDecoration(Instr.getOperand(0).getReg(), MRI);
+
+  auto FirstIndexReg = Instr.getOperand(3).getReg();
+  bool FirstIndexIsConstant =
+      Subtarget.getInstrInfo()->isConstantInstr(*MRI.getVRegDef(FirstIndexReg));
+
+  if (StorageClass == SPIRV::StorageClass::StorageClass::StorageBuffer) {
+    if (IsNonUniform)
+      Handler.addRequirements(
+          SPIRV::Capability::StorageBufferArrayNonUniformIndexingEXT);
+    else if (!FirstIndexIsConstant)
+      Handler.addRequirements(
+          SPIRV::Capability::StorageBufferArrayDynamicIndexing);
+    return;
+  }
+
   Register PointeeTypeReg = ResTypeInst->getOperand(2).getReg();
   MachineInstr *PointeeType = MRI.getUniqueVRegDef(PointeeTypeReg);
   if (PointeeType->getOpcode() != SPIRV::OpTypeImage &&
@@ -1208,27 +1225,25 @@ void addOpAccessChainReqs(const MachineInstr &Instr,
     return;
   }
 
-  bool IsNonUniform =
-      hasNonUniformDecoration(Instr.getOperand(0).getReg(), MRI);
   if (isUniformTexelBuffer(PointeeType)) {
     if (IsNonUniform)
       Handler.addRequirements(
           SPIRV::Capability::UniformTexelBufferArrayNonUniformIndexingEXT);
-    else
+    else if (!FirstIndexIsConstant)
       Handler.addRequirements(
           SPIRV::Capability::UniformTexelBufferArrayDynamicIndexingEXT);
   } else if (isInputAttachment(PointeeType)) {
     if (IsNonUniform)
       Handler.addRequirements(
           SPIRV::Capability::InputAttachmentArrayNonUniformIndexingEXT);
-    else
+    else if (!FirstIndexIsConstant)
       Handler.addRequirements(
           SPIRV::Capability::InputAttachmentArrayDynamicIndexingEXT);
   } else if (isStorageTexelBuffer(PointeeType)) {
     if (IsNonUniform)
       Handler.addRequirements(
           SPIRV::Capability::StorageTexelBufferArrayNonUniformIndexingEXT);
-    else
+    else if (!FirstIndexIsConstant)
       Handler.addRequirements(
           SPIRV::Capability::StorageTexelBufferArrayDynamicIndexingEXT);
   } else if (isSampledImage(PointeeType) ||
@@ -1237,14 +1252,14 @@ void addOpAccessChainReqs(const MachineInstr &Instr,
     if (IsNonUniform)
       Handler.addRequirements(
           SPIRV::Capability::SampledImageArrayNonUniformIndexingEXT);
-    else
+    else if (!FirstIndexIsConstant)
       Handler.addRequirements(
           SPIRV::Capability::SampledImageArrayDynamicIndexing);
   } else if (isStorageImage(PointeeType)) {
     if (IsNonUniform)
       Handler.addRequirements(
           SPIRV::Capability::StorageImageArrayNonUniformIndexingEXT);
-    else
+    else if (!FirstIndexIsConstant)
       Handler.addRequirements(
           SPIRV::Capability::StorageImageArrayDynamicIndexing);
   }

diff  --git a/llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWBufferDynamicIdx.ll b/llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWBufferDynamicIdx.ll
new file mode 100644
index 0000000000000..cce1edab100d8
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWBufferDynamicIdx.ll
@@ -0,0 +1,22 @@
+; RUN: llc -O0 -mtriple=spirv1.6-unknown-vulkan1.3-compute %s -o - | FileCheck %s --match-full-lines
+
+%"__cblayout_$Globals" = type <{ i32 }>
+
+ at i = external hidden local_unnamed_addr addrspace(12) global i32, align 4
+ at ReadWriteBuf.str = private unnamed_addr constant [13 x i8] c"ReadWriteBuf\00", align 1
+@"$Globals.cb" = local_unnamed_addr global target("spirv.VulkanBuffer", target("spirv.Layout", %"__cblayout_$Globals", 4, 0), 2, 0) poison
+@"$Globals.str" = private unnamed_addr constant [9 x i8] c"$Globals\00", align 1
+
+; CHECK: OpCapability Shader
+; CHECK: OpCapability StorageTexelBufferArrayDynamicIndexingEXT
+
+define void @main() local_unnamed_addr #0 {
+entry:
+  %"$Globals.cb_h.i.i" = tail call target("spirv.VulkanBuffer", target("spirv.Layout", %"__cblayout_$Globals", 4, 0), 2, 0) @"llvm.spv.resource.handlefromimplicitbinding.tspirv.VulkanBuffer_tspirv.Layout_s___cblayout_$Globalss_4_0t_2_0t"(i32 1, i32 0, i32 1, i32 0, ptr nonnull @"$Globals.str")
+  store target("spirv.VulkanBuffer", target("spirv.Layout", %"__cblayout_$Globals", 4, 0), 2, 0) %"$Globals.cb_h.i.i", ptr @"$Globals.cb", align 8
+  %0 = load i32, ptr addrspace(12) @i, align 4
+  %1 = tail call target("spirv.Image", i32, 5, 2, 0, 0, 2, 33) @llvm.spv.resource.handlefromimplicitbinding.tspirv.Image_i32_5_2_0_0_2_33t(i32 0, i32 0, i32 64, i32 %0, ptr nonnull @ReadWriteBuf.str)
+  %2 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.Image_i32_5_2_0_0_2_33t(target("spirv.Image", i32, 5, 2, 0, 0, 2, 33) %1, i32 98)
+  store i32 99, ptr addrspace(11) %2, align 4
+  ret void
+}
\ No newline at end of file

diff  --git a/llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWStructuredBufferDynamicIdx.ll b/llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWStructuredBufferDynamicIdx.ll
new file mode 100644
index 0000000000000..da69a2f2165c1
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/hlsl-resources/DynamicIdx/RWStructuredBufferDynamicIdx.ll
@@ -0,0 +1,21 @@
+; RUN: llc -O0 -mtriple=spirv1.6-unknown-vulkan1.3-compute %s -o - | FileCheck %s --match-full-lines
+
+%"__cblayout_$Globals" = type <{ i32 }>
+
+ at i = external hidden local_unnamed_addr addrspace(12) global i32, align 4
+ at ReadWriteStructuredBuf.str = private unnamed_addr constant [23 x i8] c"ReadWriteStructuredBuf\00", align 1
+@"$Globals.cb" = local_unnamed_addr global target("spirv.VulkanBuffer", target("spirv.Layout", %"__cblayout_$Globals", 4, 0), 2, 0) poison
+@"$Globals.str" = private unnamed_addr constant [9 x i8] c"$Globals\00", align 1
+
+; CHECK: OpCapability Shader
+; CHECK: OpCapability StorageBufferArrayDynamicIndexing
+define void @main() local_unnamed_addr #0 {
+entry:
+  %"$Globals.cb_h.i.i" = tail call target("spirv.VulkanBuffer", target("spirv.Layout", %"__cblayout_$Globals", 4, 0), 2, 0) @"llvm.spv.resource.handlefromimplicitbinding.tspirv.VulkanBuffer_tspirv.Layout_s___cblayout_$Globalss_4_0t_2_0t"(i32 2, i32 0, i32 1, i32 0, ptr nonnull @"$Globals.str")
+  store target("spirv.VulkanBuffer", target("spirv.Layout", %"__cblayout_$Globals", 4, 0), 2, 0) %"$Globals.cb_h.i.i", ptr @"$Globals.cb", align 8
+  %0 = load i32, ptr addrspace(12) @i, align 4
+  %1 = tail call target("spirv.VulkanBuffer", [0 x i32], 12, 1) @llvm.spv.resource.handlefromimplicitbinding.tspirv.VulkanBuffer_a0i32_12_1t(i32 0, i32 0, i32 64, i32 %0, ptr nonnull @ReadWriteStructuredBuf.str)
+  %2 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0i32_12_1t(target("spirv.VulkanBuffer", [0 x i32], 12, 1) %1, i32 99)
+  store i32 98, ptr addrspace(11) %2, align 4
+  ret void
+}

diff  --git a/llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/StructuredBufferNonUniformIdx.ll b/llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWBufferNonUniformIdx.ll
similarity index 100%
rename from llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/StructuredBufferNonUniformIdx.ll
rename to llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWBufferNonUniformIdx.ll

diff  --git a/llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWStructuredBufferNonUniformIdx.ll b/llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWStructuredBufferNonUniformIdx.ll
index 2a12baf1e3ed4..a820e7a8ce06e 100644
--- a/llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWStructuredBufferNonUniformIdx.ll
+++ b/llvm/test/CodeGen/SPIRV/hlsl-resources/NonUniformIdx/RWStructuredBufferNonUniformIdx.ll
@@ -3,6 +3,7 @@
 
 ; CHECK-DAG: OpCapability Shader
 ; CHECK-DAG: OpCapability ShaderNonUniformEXT
+; CHECK-DAG: OpCapability StorageBufferArrayNonUniformIndexingEXT
 ; CHECK-DAG: OpDecorate {{%[0-9]+}} NonUniformEXT
 ; CHECK-DAG: OpDecorate {{%[0-9]+}} NonUniformEXT
 ; CHECK-DAG: OpDecorate {{%[0-9]+}} NonUniformEXT

diff  --git a/llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageDynIdx.ll b/llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageConstIdx.ll
similarity index 97%
rename from llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageDynIdx.ll
rename to llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageConstIdx.ll
index d00209778e94e..e4ec23171490f 100644
--- a/llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageDynIdx.ll
+++ b/llvm/test/CodeGen/SPIRV/hlsl-resources/StorageImageConstIdx.ll
@@ -4,8 +4,8 @@
 @.str.b0 = private unnamed_addr constant [3 x i8] c"B0\00", align 1
 
 ; CHECK-DAG: OpCapability Shader
-; CHECK-DAG: OpCapability StorageImageArrayDynamicIndexing
 ; CHECK-DAG: OpCapability Image1D
+; CHECK-DAG: OpCapability Int8
 ; CHECK-NOT: OpCapability
 
 ; CHECK-DAG: OpDecorate [[Var:%[0-9]+]] DescriptorSet 3


        


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