Implement RegisterMapInterfaceINTEL execution mode (intel#1774)

This PR adds the new execution mode RegisterMapInterfaceINTEL, see the Khronos
SPIRV spec here: KhronosGroup/SPIRV-Registry#176
This execution mode allows specifying a 'register' based interface for FPGA kernels.

The RegisterMapInterfaceINTEL execution mode is added with a 0/1 literal based on
the kernel metadata. When the metadata is:

!ip_interface !N
!N = !{!"csr"}
The translator emits RegisterMapInterfaceINTEL 0, and when the metadata is:

!ip_interface !N
!N = !{!"csr", !"accept_downstream_stall"}
The translator emits RegisterMapInterfaceINTEL 1

NOTE
The new mode is under capability FPGAKernelAttributesv2INTEL which implicitly defines the capability FPGAKernelAttributesv2INTEL.
This PR is very similar to Implement StreamingInterfaceINTEL execution mode intel#1218

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@a9f4f25

Author: tiwaria1

llvm-spirv/lib/SPIRV/PreprocessMetadata.cpp

@@ -229,18 +229,38 @@ void PreprocessMetadataBase::visit(Module *M) {
     if (MDNode *Interface =
             Kernel.getMetadata(kSPIR2MD::IntelFPGAIPInterface)) {
       std::set<std::string> InterfaceStrSet;
-      // Default mode is 'csr' aka !ip_interface !N
-      //                           !N = !{!”csr”}
-      // don't emit any particular SPIR-V for it
+      for (size_t I = 0; I != Interface->getNumOperands(); ++I)
+        InterfaceStrSet.insert(getMDOperandAsString(Interface, I).str());
+
+      // ip_interface metadata will either have Register Map metadata or
+      // Streaming metadata.
+      //
+      // Register Map mode metadata:
+      // Not 'WaitForDoneWrite' mode (to be mapped on '0' literal)
+      // !ip_interface !N
+      // !N = !{!"csr"}
+      // 'WaitForDoneWrite' mode (to be mapped on '1' literal)
+      // !ip_interface !N
+      // !N = !{!"csr", !"wait_for_done_write"}
+      if (InterfaceStrSet.find("csr") != InterfaceStrSet.end()) {
+        int32_t InterfaceMode = 0;
+        if (InterfaceStrSet.find("wait_for_done_write") !=
+            InterfaceStrSet.end())
+          InterfaceMode = 1;
+        EM.addOp()
+            .add(&Kernel)
+            .add(spv::ExecutionModeRegisterMapInterfaceINTEL)
+            .add(InterfaceMode)
+            .done();
+      }
+
       // Streaming mode metadata be like:
       // Not 'stall free' mode (to be mapped on '0' literal)
       // !ip_interface !N
       // !N = !{!"streaming"}
       // 'stall free' mode (to be mapped on '1' literal)
       // !ip_interface !N
       // !N = !{!"streaming", !"stall_free_return"}
-      for (size_t I = 0; I != Interface->getNumOperands(); ++I)
-        InterfaceStrSet.insert(getMDOperandAsString(Interface, I).str());
       if (InterfaceStrSet.find("streaming") != InterfaceStrSet.end()) {
         int32_t InterfaceMode = 0;
         if (InterfaceStrSet.find("stall_free_return") != InterfaceStrSet.end())
@@ -325,17 +345,16 @@ void PreprocessMetadataBase::preprocessVectorComputeMetadata(Module *M,
           FPRoundingModeExecModeMap::map(getFPRoundingMode(Mode));
       spv::ExecutionMode ExecFloatMode =
           FPOperationModeExecModeMap::map(getFPOperationMode(Mode));
-      VCFloatTypeSizeMap::foreach (
-          [&](VCFloatType FloatType, unsigned TargetWidth) {
-            EM.addOp().add(&F).add(ExecRoundMode).add(TargetWidth).done();
-            EM.addOp().add(&F).add(ExecFloatMode).add(TargetWidth).done();
-            EM.addOp()
-                .add(&F)
-                .add(FPDenormModeExecModeMap::map(
-                    getFPDenormMode(Mode, FloatType)))
-                .add(TargetWidth)
-                .done();
-          });
+      VCFloatTypeSizeMap::foreach ([&](VCFloatType FloatType,
+                                       unsigned TargetWidth) {
+        EM.addOp().add(&F).add(ExecRoundMode).add(TargetWidth).done();
+        EM.addOp().add(&F).add(ExecFloatMode).add(TargetWidth).done();
+        EM.addOp()
+            .add(&F)
+            .add(FPDenormModeExecModeMap::map(getFPDenormMode(Mode, FloatType)))
+            .add(TargetWidth)
+            .done();
+      });
     }
     if (Attrs.hasFnAttr(kVCMetadata::VCSLMSize)) {
       SPIRVWord SLMSize = 0;

llvm-spirv/lib/SPIRV/SPIRVReader.cpp

@@ -1257,7 +1257,7 @@ static void replaceOperandWithAnnotationIntrinsicCallResult(Value *&V) {
 template <typename SPIRVInstType>
 void SPIRVToLLVM::transAliasingMemAccess(SPIRVInstType *BI, Instruction *I) {
   static_assert(std::is_same<SPIRVInstType, SPIRVStore>::value ||
-                std::is_same<SPIRVInstType, SPIRVLoad>::value,
+                    std::is_same<SPIRVInstType, SPIRVLoad>::value,
                 "Only stores and loads can be aliased by memory access mask");
   if (BI->SPIRVMemoryAccess::isNoAlias())
     addMemAliasMetadata(I, BI->SPIRVMemoryAccess::getNoAliasInstID(),
@@ -2051,10 +2051,10 @@ Value *SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
 
       case 4: {
         for (int Idx = 0; Idx < 4; ++Idx) {
-          Value *V1 = Builder.CreateShuffleVector(
-              MCache[0], MCache[1], ArrayRef<int>({Idx, Idx + 4}));
-          Value *V2 = Builder.CreateShuffleVector(
-              MCache[2], MCache[3], ArrayRef<int>({Idx, Idx + 4}));
+          Value *V1 = Builder.CreateShuffleVector(MCache[0], MCache[1],
+                                                  ArrayRef<int>{Idx, Idx + 4});
+          Value *V2 = Builder.CreateShuffleVector(MCache[2], MCache[3],
+                                                  ArrayRef<int>{Idx, Idx + 4});
           Value *V3 =
               Builder.CreateShuffleVector(V1, V2, ArrayRef<int>({0, 1, 2, 3}));
           V = Builder.CreateInsertValue(V, V3, Idx);
@@ -4006,6 +4006,27 @@ bool SPIRVToLLVM::transMetadata() {
       F->setMetadata(kSPIR2MD::FmaxMhz,
                      getMDNodeStringIntVec(Context, EM->getLiterals()));
     }
+    // Generate metadata for Intel FPGA register map interface
+    if (auto *EM =
+            BF->getExecutionMode(ExecutionModeRegisterMapInterfaceINTEL)) {
+      std::vector<uint32_t> InterfaceVec = EM->getLiterals();
+      assert(InterfaceVec.size() == 1 &&
+             "Expected RegisterMapInterfaceINTEL to have exactly 1 literal");
+      std::vector<Metadata *> InterfaceMDVec =
+          [&]() -> std::vector<Metadata *> {
+        switch (InterfaceVec[0]) {
+        case 0:
+          return {MDString::get(*Context, "csr")};
+        case 1:
+          return {MDString::get(*Context, "csr"),
+                  MDString::get(*Context, "wait_for_done_write")};
+        default:
+          llvm_unreachable("Invalid register map interface mode");
+        }
+      }();
+      F->setMetadata(kSPIR2MD::IntelFPGAIPInterface,
+                     MDNode::get(*Context, InterfaceMDVec));
+    }
     // Generate metadata for Intel FPGA streaming interface
     if (auto *EM = BF->getExecutionMode(ExecutionModeStreamingInterfaceINTEL)) {
       std::vector<uint32_t> InterfaceVec = EM->getLiterals();

llvm-spirv/lib/SPIRV/SPIRVWriter.cpp

@@ -5032,6 +5032,19 @@ bool LLVMToSPIRVBase::transExecutionMode() {
       case spv::ExecutionModeNumSIMDWorkitemsINTEL:
       case spv::ExecutionModeSchedulerTargetFmaxMhzINTEL:
       case spv::ExecutionModeMaxWorkDimINTEL:
+      case spv::ExecutionModeRegisterMapInterfaceINTEL: {
+        if (!BM->isAllowedToUseExtension(
+                ExtensionID::SPV_INTEL_kernel_attributes))
+          break;
+        AddSingleArgExecutionMode(static_cast<ExecutionMode>(EMode));
+        BM->addExtension(ExtensionID::SPV_INTEL_kernel_attributes);
+        BM->addCapability(CapabilityFPGAKernelAttributesINTEL);
+        // RegisterMapInterfaceINTEL mode is defined by the
+        // CapabilityFPGAKernelAttributesv2INTEL capability and that
+        // capability implicitly defines CapabilityFPGAKernelAttributesINTEL
+        if (EMode == spv::ExecutionModeRegisterMapInterfaceINTEL)
+          BM->addCapability(CapabilityFPGAKernelAttributesv2INTEL);
+      } break;
       case spv::ExecutionModeStreamingInterfaceINTEL: {
         if (!BM->isAllowedToUseExtension(
                 ExtensionID::SPV_INTEL_kernel_attributes))

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVEntry.cpp

@@ -612,6 +612,7 @@ void SPIRVExecutionMode::decode(std::istream &I) {
   case ExecutionModeMaxWorkDimINTEL:
   case ExecutionModeNumSIMDWorkitemsINTEL:
   case ExecutionModeSchedulerTargetFmaxMhzINTEL:
+  case ExecutionModeRegisterMapInterfaceINTEL:
   case ExecutionModeStreamingInterfaceINTEL:
     WordLiterals.resize(1);
     break;

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVEnum.h

@@ -277,6 +277,8 @@ template <> inline void SPIRVMap<SPIRVExecutionModeKind, SPIRVCapVec>::init() {
                {CapabilityVectorComputeINTEL});
   ADD_VEC_INIT(internal::ExecutionModeFastCompositeKernelINTEL,
                {internal::CapabilityFastCompositeINTEL});
+  ADD_VEC_INIT(ExecutionModeRegisterMapInterfaceINTEL,
+               {CapabilityFPGAKernelAttributesv2INTEL});
   ADD_VEC_INIT(ExecutionModeStreamingInterfaceINTEL,
                {CapabilityFPGAKernelAttributesINTEL});
   ADD_VEC_INIT(ExecutionModeNamedBarrierCountINTEL,

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVIsValidEnum.h

@@ -71,6 +71,7 @@ inline bool isValid(spv::ExecutionModel V) {
   case ExecutionModelClosestHitKHR:
   case ExecutionModelMissKHR:
   case ExecutionModelCallableKHR:
+  case ExecutionModeRegisterMapInterfaceINTEL:
   case ExecutionModeStreamingInterfaceINTEL:
     return true;
   default:

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVNameMapEnum.h

@@ -594,6 +594,7 @@ template <> inline void SPIRVMap<Capability, std::string>::init() {
   add(CapabilityFPGALoopControlsINTEL, "FPGALoopControlsINTEL");
   add(CapabilityKernelAttributesINTEL, "KernelAttributesINTEL");
   add(CapabilityFPGAKernelAttributesINTEL, "FPGAKernelAttributesINTEL");
+  add(CapabilityFPGAKernelAttributesv2INTEL, "FPGAKernelAttributesv2INTEL");
   add(CapabilityFPGAMemoryAccessesINTEL, "FPGAMemoryAccessesINTEL");
   add(CapabilityFPGAClusterAttributesINTEL, "FPGAClusterAttributesINTEL");
   add(CapabilityLoopFuseINTEL, "LoopFuseINTEL");

llvm-spirv/spirv-headers-tag.conf

@@ -1 +1 @@
-36c7694279dfb3ea7e6e086e368bb8bee076792a
+295cf5fb3bfe2454360e82b26bae7fc0de699abe

llvm-spirv/test/extensions/INTEL/SPV_INTEL_kernel_attributes/register_map_interface_attribute.ll

@@ -0,0 +1,46 @@
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc --spirv-ext=+SPV_INTEL_kernel_attributes -o %t.spv
+; RUN: llvm-spirv %t.spv -to-text -o %t.spt
+; RUN: FileCheck < %t.spt %s --check-prefix=CHECK-SPIRV
+
+; RUN: llvm-spirv -r -emit-opaque-pointers %t.spv -o %t.rev.bc
+; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-LLVM
+
+; FPGAKernelAttributesv2INTEL implicitly defines FPGAKernelAttributesINTEL
+; CHECK-SPIRV: Capability FPGAKernelAttributesINTEL
+; CHECK-SPIRV: Capability FPGAKernelAttributesv2INTEL
+; CHECK-SPIRV: Extension "SPV_INTEL_kernel_attributes"
+; CHECK-SPIRV: EntryPoint [[#]] [[#KERNEL1:]] "test_1"
+; CHECK-SPIRV: EntryPoint [[#]] [[#KERNEL2:]] "test_2"
+; CHECK-SPIRV: ExecutionMode [[#KERNEL1]] 6160 0
+; CHECK-SPIRV: ExecutionMode [[#KERNEL2]] 6160 1
+; CHECK-SPIRV: Function [[#]] [[#KERNEL1]]
+; CHECK-SPIRV: Function [[#]] [[#KERNEL2]]
+
+; CHECK-LLVM: define spir_kernel void @test_1{{.*}} !ip_interface ![[#NOWAITFORDONEWRITE:]]
+; CHECK-LLVM: define spir_kernel void @test_2{{.*}} !ip_interface ![[#WAITFORDONEWRITE:]]
+; CHECK-LLVM: ![[#NOWAITFORDONEWRITE:]] = !{!"csr"}
+; CHECK-LLVM: ![[#WAITFORDONEWRITE:]] = !{!"csr", !"wait_for_done_write"}
+
+; ModuleID = 'test.bc'
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v16:16:16-v24:32:32-v32:32:32-v48:64:64-v64:64:64-v96:128:128-v128:128:128-v192:256:256-v256:256:256-v512:512:512-v1024:1024:1024"
+target triple = "spir64-unknown-unknown"
+
+; Function Attrs: nounwind
+define spir_kernel void @test_1() #0 !ip_interface !0
+{
+entry:
+  ret void
+}
+
+; Function Attrs: nounwind
+define spir_kernel void @test_2() #0 !ip_interface !1
+{
+entry:
+  ret void
+}
+
+attributes #0 = { nounwind }
+
+!0 = !{!"csr"}
+!1 = !{!"csr", !"wait_for_done_write"}