[SPIR-V] Add SPV_INTEL_predicated_io extension (#161591)

YixingZhang007 · web-flow · commit f802acf32d07 · 2025-10-08T23:29:01.000+02:00
This PR introduces the support for the SPIR-V extension `SPV_INTEL_predicated_io`. This extension adds predicated load and store instructions. Predicated load performs load from memory if predicate is true; otherwise, it uses default_value as a result. Predicated store performs store of value to memory if predicate is true; otherwise, it does nothing. Reference Specification: https://github.com/intel/llvm/blob/sycl/sycl/doc/design/spirv-extensions/SPV_INTEL_predicated_io.asciidoc
diff --git a/llvm/docs/SPIRVUsage.rst b/llvm/docs/SPIRVUsage.rst
@@ -233,6 +233,8 @@ Below is a list of supported SPIR-V extensions, sorted alphabetically by their e
      - Adds support for 4-bit integer type, and allow this type to be used in cooperative matrices.
    * - ``SPV_KHR_float_controls2``
      - Adds execution modes and decorations to control floating-point computations in both kernels and shaders. It can be used on whole modules and individual instructions.
+   * - ``SPV_INTEL_predicated_io``
+     - Adds predicated load and store instructions that conditionally read from or write to memory based on a boolean predicate.
 
 SPIR-V representation in LLVM IR
 ================================
diff --git a/llvm/lib/Target/SPIRV/MCTargetDesc/SPIRVInstPrinter.cpp b/llvm/lib/Target/SPIRV/MCTargetDesc/SPIRVInstPrinter.cpp
@@ -284,6 +284,17 @@ void SPIRVInstPrinter::printInst(const MCInst *MI, uint64_t Address,
           }
           break;
         }
+        case SPIRV::OpPredicatedLoadINTEL:
+        case SPIRV::OpPredicatedStoreINTEL: {
+          const unsigned NumOps = MI->getNumOperands();
+          if (NumOps > NumFixedOps) {
+            OS << ' ';
+            printSymbolicOperand<OperandCategory::MemoryOperandOperand>(
+                MI, NumOps - 1, OS);
+            break;
+          }
+          break;
+        }
         default:
           printRemainingVariableOps(MI, NumFixedOps, OS);
           break;
diff --git a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
@@ -2419,6 +2419,27 @@ static bool generatePipeInst(const SPIRV::IncomingCall *Call,
   return buildPipeInst(Call, Opcode, Scope, MIRBuilder, GR);
 }
 
+static bool generatePredicatedLoadStoreInst(const SPIRV::IncomingCall *Call,
+                                            MachineIRBuilder &MIRBuilder,
+                                            SPIRVGlobalRegistry *GR) {
+  const SPIRV::DemangledBuiltin *Builtin = Call->Builtin;
+  unsigned Opcode =
+      SPIRV::lookupNativeBuiltin(Builtin->Name, Builtin->Set)->Opcode;
+
+  bool IsSet = Opcode != SPIRV::OpPredicatedStoreINTEL;
+  unsigned ArgSz = Call->Arguments.size();
+  SmallVector<uint32_t, 1> ImmArgs;
+  MachineRegisterInfo *MRI = MIRBuilder.getMRI();
+  // Memory operand is optional and is literal.
+  if (ArgSz > 3)
+    ImmArgs.push_back(
+        getConstFromIntrinsic(Call->Arguments[/*Literal index*/ 3], MRI));
+
+  Register TypeReg = GR->getSPIRVTypeID(Call->ReturnType);
+  return buildOpFromWrapper(MIRBuilder, Opcode, Call,
+                            IsSet ? TypeReg : Register(0), ImmArgs);
+}
+
 static bool buildNDRange(const SPIRV::IncomingCall *Call,
                          MachineIRBuilder &MIRBuilder,
                          SPIRVGlobalRegistry *GR) {
@@ -3019,6 +3040,8 @@ std::optional<bool> lowerBuiltin(const StringRef DemangledCall,
     return generate2DBlockIOINTELInst(Call.get(), MIRBuilder, GR);
   case SPIRV::Pipe:
     return generatePipeInst(Call.get(), MIRBuilder, GR);
+  case SPIRV::PredicatedLoadStore:
+    return generatePredicatedLoadStoreInst(Call.get(), MIRBuilder, GR);
   }
   return false;
 }
diff --git a/llvm/lib/Target/SPIRV/SPIRVBuiltins.td b/llvm/lib/Target/SPIRV/SPIRVBuiltins.td
@@ -70,6 +70,7 @@ def BindlessINTEL : BuiltinGroup;
 def TernaryBitwiseINTEL : BuiltinGroup;
 def Block2DLoadStore : BuiltinGroup;
 def Pipe : BuiltinGroup;
+def PredicatedLoadStore : BuiltinGroup;
 
 //===----------------------------------------------------------------------===//
 // Class defining a demangled builtin record. The information in the record
@@ -752,6 +753,10 @@ defm : DemangledNativeBuiltin<"__spirv_Subgroup2DBlockLoadTransformINTEL", OpenC
 defm : DemangledNativeBuiltin<"__spirv_Subgroup2DBlockPrefetchINTEL", OpenCL_std, Block2DLoadStore, 9, 9, OpSubgroup2DBlockPrefetchINTEL>;
 defm : DemangledNativeBuiltin<"__spirv_Subgroup2DBlockStoreINTEL", OpenCL_std, Block2DLoadStore, 10, 10, OpSubgroup2DBlockStoreINTEL>;
 
+// SPV_INTEL_predicated_io builtin records
+defm : DemangledNativeBuiltin<"__spirv_PredicatedLoadINTEL", OpenCL_std, PredicatedLoadStore, 3, 4, OpPredicatedLoadINTEL>;
+defm : DemangledNativeBuiltin<"__spirv_PredicatedStoreINTEL", OpenCL_std, PredicatedLoadStore, 3, 4, OpPredicatedStoreINTEL>;
+
 //===----------------------------------------------------------------------===//
 // Class defining a work/sub group builtin that should be translated into a
 // SPIR-V instruction using the defined properties.
diff --git a/llvm/lib/Target/SPIRV/SPIRVCommandLine.cpp b/llvm/lib/Target/SPIRV/SPIRVCommandLine.cpp
@@ -151,7 +151,9 @@ static const std::map<std::string, SPIRV::Extension::Extension, std::less<>>
         {"SPV_KHR_bfloat16", SPIRV::Extension::Extension::SPV_KHR_bfloat16},
         {"SPV_EXT_relaxed_printf_string_address_space",
          SPIRV::Extension::Extension::
-             SPV_EXT_relaxed_printf_string_address_space}};
+             SPV_EXT_relaxed_printf_string_address_space},
+        {"SPV_INTEL_predicated_io",
+         SPIRV::Extension::Extension::SPV_INTEL_predicated_io}};
 
 bool SPIRVExtensionsParser::parse(cl::Option &O, StringRef ArgName,
                                   StringRef ArgValue,
diff --git a/llvm/lib/Target/SPIRV/SPIRVInstrInfo.td b/llvm/lib/Target/SPIRV/SPIRVInstrInfo.td
@@ -987,3 +987,9 @@ def OpSubgroup2DBlockPrefetchINTEL: Op<6234, (outs), (ins ID:$element_size, ID:$
 def OpSubgroup2DBlockStoreINTEL: Op<6235, (outs), (ins ID:$element_size, ID:$block_width, ID:$block_height,
                   ID:$block_count, ID:$src_ptr, ID:$dst_base_ptr, ID:$memory_width, ID:$memory_height, ID:$memory_pitch, ID:$coord),
                   "OpSubgroup2DBlockStoreINTEL $element_size $block_width $block_height $block_count $src_ptr $dst_base_ptr $memory_width $memory_height $memory_pitch $coord">;
+
+// SPV_INTEL_predicated_io
+def OpPredicatedLoadINTEL: Op<6528, (outs ID:$res), (ins TYPE:$resType, ID:$ptr, ID:$predicate, ID:$default_value, variable_ops),
+                  "$res = OpPredicatedLoadINTEL $resType $ptr $predicate $default_value">;
+def OpPredicatedStoreINTEL: Op<6529, (outs), (ins ID:$ptr, ID:$object, ID:$predicate, variable_ops),
+                  "OpPredicatedStoreINTEL $ptr $object $predicate">;
diff --git a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
@@ -2035,6 +2035,17 @@ void addInstrRequirements(const MachineInstr &MI,
     // TODO: Add UntypedPointersKHR when implemented.
     break;
   }
+  case SPIRV::OpPredicatedLoadINTEL:
+  case SPIRV::OpPredicatedStoreINTEL: {
+    if (!ST.canUseExtension(SPIRV::Extension::SPV_INTEL_predicated_io))
+      report_fatal_error(
+          "OpPredicated[Load/Store]INTEL instructions require "
+          "the following SPIR-V extension: SPV_INTEL_predicated_io",
+          false);
+    Reqs.addExtension(SPIRV::Extension::SPV_INTEL_predicated_io);
+    Reqs.addCapability(SPIRV::Capability::PredicatedIOINTEL);
+    break;
+  }
 
   default:
     break;
diff --git a/llvm/lib/Target/SPIRV/SPIRVSymbolicOperands.td b/llvm/lib/Target/SPIRV/SPIRVSymbolicOperands.td
@@ -385,6 +385,7 @@ defm SPV_INTEL_int4 : ExtensionOperand<123, [EnvOpenCL]>;
 defm SPV_KHR_float_controls2 : ExtensionOperand<124, [EnvVulkan, EnvOpenCL]>;
 defm SPV_INTEL_tensor_float32_conversion : ExtensionOperand<125, [EnvOpenCL]>;
 defm SPV_KHR_bfloat16 : ExtensionOperand<126, [EnvVulkan, EnvOpenCL]>;
+defm SPV_INTEL_predicated_io : ExtensionOperand<127, [EnvOpenCL]>;
 
 //===----------------------------------------------------------------------===//
 // Multiclass used to define Capabilities enum values and at the same time
@@ -594,6 +595,7 @@ defm SubgroupMatrixMultiplyAccumulateINTEL : CapabilityOperand<6236, 0, 0, [SPV_
 defm Subgroup2DBlockIOINTEL : CapabilityOperand<6228, 0, 0, [SPV_INTEL_2d_block_io], []>;
 defm Subgroup2DBlockTransformINTEL : CapabilityOperand<6229, 0, 0, [SPV_INTEL_2d_block_io], [Subgroup2DBlockIOINTEL]>;
 defm Subgroup2DBlockTransposeINTEL : CapabilityOperand<6230, 0, 0, [SPV_INTEL_2d_block_io], [Subgroup2DBlockIOINTEL]>;
+defm PredicatedIOINTEL : CapabilityOperand<6257, 0, 0, [SPV_INTEL_predicated_io], []>;
 defm Int4TypeINTEL : CapabilityOperand<5112, 0, 0, [SPV_INTEL_int4], []>;
 defm Int4CooperativeMatrixINTEL : CapabilityOperand<5114, 0, 0, [SPV_INTEL_int4], [Int4TypeINTEL, CooperativeMatrixKHR]>;
 defm TensorFloat32RoundingINTEL : CapabilityOperand<6425, 0, 0, [SPV_INTEL_tensor_float32_conversion], []>;
diff --git a/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_predicated_io/predicated_io_generic.ll b/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_predicated_io/predicated_io_generic.ll
@@ -0,0 +1,36 @@
+; RUN: not llc -O0 -mtriple=spirv64-unknown-unknown %s -o %t.spvt 2>&1 | FileCheck %s --check-prefix=CHECK-ERROR
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_predicated_io %s -o - | FileCheck %s
+
+; CHECK-ERROR: LLVM ERROR: OpPredicated[Load/Store]INTEL
+; CHECK-ERROR-SAME: instructions require the following SPIR-V extension: SPV_INTEL_predicated_io
+
+; CHECK-DAG: Capability PredicatedIOINTEL
+; CHECK-DAG: Extension "SPV_INTEL_predicated_io"
+
+; CHECK-DAG: %[[Int32Ty:[0-9]+]] = OpTypeInt 32 0
+; CHECK-DAG: %[[IntPtrTy:[0-9]+]] = OpTypePointer CrossWorkgroup %[[Int32Ty]]
+; CHECK-DAG: %[[BoolTy:[0-9]+]] = OpTypeBool
+; CHECK-DAG: %[[VoidTy:[0-9]+]] = OpTypeVoid
+; CHECK: %[[LoadPtr:[0-9]+]] = OpFunctionParameter %[[IntPtrTy]]
+; CHECK: %[[StorePtr:[0-9]+]] = OpFunctionParameter %[[IntPtrTy]]
+; CHECK: %[[DefaultVal:[0-9]+]] = OpFunctionParameter %[[Int32Ty]]
+; CHECK: %[[StoreObj:[0-9]+]] = OpFunctionParameter %[[Int32Ty]]
+; CHECK: %[[Predicate:[0-9]+]] = OpFunctionParameter %[[BoolTy]]
+; CHECK: PredicatedLoadINTEL %[[Int32Ty]] %[[LoadPtr]] %[[Predicate]] %[[DefaultVal]]
+; CHECK: PredicatedLoadINTEL %[[Int32Ty]] %[[LoadPtr]] %[[Predicate]] %[[DefaultVal]] None
+; CHECK: PredicatedStoreINTEL %[[StorePtr]] %[[StoreObj]] %[[Predicate]]
+; CHECK: PredicatedStoreINTEL %[[StorePtr]] %[[StoreObj]] %[[Predicate]] None
+
+define spir_func void @foo(ptr addrspace(1) %load_pointer, ptr addrspace(1) %store_pointer, i32  %default_value, i32 %store_object, i1 zeroext %predicate) {
+entry:
+  %1 = call spir_func i32 @_Z27__spirv_PredicatedLoadINTELPU3AS1Kibi(ptr addrspace(1) %load_pointer, i1 %predicate, i32 %default_value)
+  %2 = call spir_func i32 @_Z27__spirv_PredicatedLoadINTELPU3AS1Kibii(ptr addrspace(1) %load_pointer, i1 %predicate, i32 %default_value, i32 0)
+  call spir_func void @_Z28__spirv_PredicatedStoreINTELPU3AS1Kiib(ptr addrspace(1) %store_pointer, i32 %store_object, i1 %predicate)
+  call spir_func void @_Z28__spirv_PredicatedStoreINTELPU3AS1Kiibi(ptr addrspace(1) %store_pointer, i32 %store_object, i1 %predicate, i32 0)
+  ret void
+}
+
+declare spir_func i32 @_Z27__spirv_PredicatedLoadINTELPU3AS1Kibi(ptr addrspace(1), i1, i32)
+declare spir_func i32 @_Z27__spirv_PredicatedLoadINTELPU3AS1Kibii(ptr addrspace(1), i1, i32, i32)
+declare spir_func void @_Z28__spirv_PredicatedStoreINTELPU3AS1Kiib(ptr addrspace(1), i32, i1)
+declare spir_func void @_Z28__spirv_PredicatedStoreINTELPU3AS1Kiibi(ptr addrspace(1), i32, i1, i32)
