Added support for StallFreeINTEL (#2237)

Commit also adds new extension metadata FPGAClusterAttributesV2INTEL.
Specification:
https://github.com/KhronosGroup/SPIRV-Registry/blob/main/extensions/INTEL/SPV_INTEL_fpga_cluster_attributes.asciidoc

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@4f0122b

Author: bwlodarcz

llvm-spirv/lib/SPIRV/SPIRVInternal.h

@@ -405,6 +405,7 @@ const static char NoGlobalOffset[] = "no_global_work_offset";
 const static char MaxWGDim[] = "max_global_work_dim";
 const static char NumSIMD[] = "num_simd_work_items";
 const static char StallEnable[] = "stall_enable";
+const static char StallFree[] = "stall_free";
 const static char FmaxMhz[] = "scheduler_target_fmax_mhz";
 const static char LoopFuse[] = "loop_fuse";
 const static char PreferDSP[] = "prefer_dsp";

llvm-spirv/lib/SPIRV/SPIRVReader.cpp

@@ -4545,6 +4545,11 @@ bool SPIRVToLLVM::transFPGAFunctionMetadata(SPIRVFunction *BF, Function *F) {
     MetadataVec.push_back(ConstantAsMetadata::get(getInt32(M, 1)));
     F->setMetadata(kSPIR2MD::StallEnable, MDNode::get(*Context, MetadataVec));
   }
+  if (BF->hasDecorate(DecorationStallFreeINTEL)) {
+    std::vector<Metadata *> MetadataVec;
+    MetadataVec.push_back(ConstantAsMetadata::get(getInt32(M, 1)));
+    F->setMetadata(kSPIR2MD::StallFree, MDNode::get(*Context, MetadataVec));
+  }
   if (BF->hasDecorate(DecorationFuseLoopsInFunctionINTEL)) {
     std::vector<Metadata *> MetadataVec;
     auto Literals =

llvm-spirv/lib/SPIRV/SPIRVWriter.cpp

@@ -1043,6 +1043,14 @@ void LLVMToSPIRVBase::transFPGAFunctionMetadata(SPIRVFunction *BF,
         BF->addDecorate(new SPIRVDecorateStallEnableINTEL(BF));
     }
   }
+  if (MDNode *StallFree = F->getMetadata(kSPIR2MD::StallFree)) {
+    if (BM->isAllowedToUseExtension(
+            ExtensionID::SPV_INTEL_fpga_cluster_attributes)) {
+      if (getMDOperandAsInt(StallFree, 0)) {
+        BF->addDecorate(new SPIRVDecorateStallFreeINTEL(BF));
+      }
+    }
+  }
   if (MDNode *LoopFuse = F->getMetadata(kSPIR2MD::LoopFuse)) {
     if (BM->isAllowedToUseExtension(ExtensionID::SPV_INTEL_loop_fuse)) {
       size_t Depth = getMDOperandAsInt(LoopFuse, 0);
@@ -2676,6 +2684,10 @@ static void transMetadataDecorations(Metadata *MD, SPIRVEntry *Target) {
       Target->addDecorate(new SPIRVDecorateStallEnableINTEL(Target));
       break;
     }
+    case DecorationStallFreeINTEL: {
+      Target->addDecorate(new SPIRVDecorateStallFreeINTEL(Target));
+      break;
+    }
     case DecorationMergeINTEL: {
       ErrLog.checkError(NumOperands == 3, SPIRVEC_InvalidLlvmModule,
                         "MergeINTEL requires exactly 3 extra operands");

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

@@ -173,6 +173,8 @@ class SPIRVDecorate : public SPIRVDecorateGeneric {
       return ExtensionID::SPV_INTEL_float_controls2;
     case DecorationStallEnableINTEL:
       return ExtensionID::SPV_INTEL_fpga_cluster_attributes;
+    case DecorationStallFreeINTEL:
+      return ExtensionID::SPV_INTEL_fpga_cluster_attributes;
     case DecorationFuseLoopsInFunctionINTEL:
       return ExtensionID::SPV_INTEL_loop_fuse;
     case internal::DecorationCallableFunctionINTEL:
@@ -693,6 +695,12 @@ class SPIRVDecorateStallEnableINTEL : public SPIRVDecorate {
       : SPIRVDecorate(spv::DecorationStallEnableINTEL, TheTarget) {}
 };
 
+class SPIRVDecorateStallFreeINTEL : public SPIRVDecorate {
+public:
+  SPIRVDecorateStallFreeINTEL(SPIRVEntry *TheTarget)
+      : SPIRVDecorate(spv::DecorationStallFreeINTEL, TheTarget) {}
+};
+
 class SPIRVDecorateFuseLoopsInFunctionINTEL : public SPIRVDecorate {
 public:
   // Complete constructor for SPIRVDecorateFuseLoopsInFunctionINTEL

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

@@ -466,6 +466,8 @@ template <> inline void SPIRVMap<Decoration, SPIRVCapVec>::init() {
   ADD_VEC_INIT(DecorationMediaBlockIOINTEL, {CapabilityVectorComputeINTEL});
   ADD_VEC_INIT(DecorationStallEnableINTEL,
                {CapabilityFPGAClusterAttributesINTEL});
+  ADD_VEC_INIT(DecorationStallFreeINTEL,
+               {CapabilityFPGAClusterAttributesV2INTEL});
   ADD_VEC_INIT(DecorationFuseLoopsInFunctionINTEL, {CapabilityLoopFuseINTEL});
   ADD_VEC_INIT(DecorationMathOpDSPModeINTEL, {CapabilityFPGADSPControlINTEL});
   ADD_VEC_INIT(DecorationInitiationIntervalINTEL,

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

@@ -169,6 +169,7 @@ template <> inline void SPIRVMap<Decoration, std::string>::init() {
   add(DecorationDontStaticallyCoalesceINTEL, "DontStaticallyCoalesceINTEL");
   add(DecorationPrefetchINTEL, "PrefetchINTEL");
   add(DecorationStallEnableINTEL, "StallEnableINTEL");
+  add(DecorationStallFreeINTEL, "StallFreeINTEL");
   add(DecorationFuseLoopsInFunctionINTEL, "FuseLoopsInFunctionINTEL");
   add(DecorationAliasScopeINTEL, "AliasScopeINTEL");
   add(DecorationNoAliasINTEL, "NoAliasINTEL");
@@ -609,6 +610,7 @@ template <> inline void SPIRVMap<Capability, std::string>::init() {
   add(CapabilityFPGAKernelAttributesv2INTEL, "FPGAKernelAttributesv2INTEL");
   add(CapabilityFPGAMemoryAccessesINTEL, "FPGAMemoryAccessesINTEL");
   add(CapabilityFPGAClusterAttributesINTEL, "FPGAClusterAttributesINTEL");
+  add(CapabilityFPGAClusterAttributesV2INTEL, "FPGAClusterAttributesV2INTEL");
   add(CapabilityLoopFuseINTEL, "LoopFuseINTEL");
   add(CapabilityMemoryAccessAliasingINTEL, "MemoryAccessAliasingINTEL");
   add(CapabilityFPGABufferLocationINTEL, "FPGABufferLocationINTEL");

llvm-spirv/test/extensions/INTEL/SPV_INTEL_fpga_cluster_attributes/function_attributes.ll

@@ -0,0 +1,33 @@
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv --spirv-ext=+SPV_INTEL_fpga_cluster_attributes -spirv-text -o - %t.bc | FileCheck --check-prefix CHECK-SPIRV %s
+; RUN: llvm-spirv --spirv-ext=+SPV_INTEL_fpga_cluster_attributes %t.bc -o %t.spv
+; spirv-val %t.spv
+; RUN: llvm-spirv -r --spirv-ext=+SPV_INTEL_fpga_cluster_attributes %t.spv -o %t.rev.bc
+; RUN: llvm-dis %t.rev.bc -o - | FileCheck --check-prefix CHECK-LLVM %s 
+
+target triple = "spir64-unknown-unknown"
+
+; CHECK-SPIRV-DAG: Capability FPGAClusterAttributesINTEL
+; CHECK-SPIRV-DAG: Capability FPGAClusterAttributesV2INTEL
+; CHECK-SPIRV-DAG: Extension "SPV_INTEL_fpga_cluster_attributes"
+; CHECK-SPIRV-DAG: Decorate [[#STALLENABLE_DEC:]] StallEnableINTEL
+; CHECK-SPIRV-DAG: Decorate [[#STALLFREE_DEC:]] StallFreeINTEL
+; CHECK-SPIRV: Function {{[0-9]+}} [[#STALLENABLE_DEC]] {{[0-9]+}} {{[0-9]+}}
+; CHECK-SPIRV: Function {{[0-9]+}} [[#STALLFREE_DEC]] {{[0-9]+}} {{[0-9]+}}
+; CHECK-LLVM: define spir_func void @test_fpga_stallenable_attr() {{.*}} !stall_enable [[STALL_MD:![0-9]+]]
+; CHECK-LLVM: define spir_func void @test_fpga_stallfree_attr() {{.*}} !stall_free [[STALL_MD]]
+; CHECK-LLVM: [[STALL_MD]] = !{i32 1}
+
+
+define spir_func void @test_fpga_stallenable_attr() !stall_enable !0 {
+entry:
+  ret void
+}
+
+define spir_func void @test_fpga_stallfree_attr() !stall_free !1 {
+entry:
+  ret void
+}
+
+!0 = !{ i32 1 }
+!1 = !{ i32 1 }