FEAT: Added support for the extension SPV_INTEL_fpga_dsp_control

llvm/docs/SPIRVUsage.rst

@@ -212,7 +212,9 @@ list of supported SPIR-V extensions, sorted alphabetically by their extension na
    * - ``SPV_INTEL_ternary_bitwise_function``
      - Adds a bitwise instruction on three operands and a look-up table index for specifying the bitwise operation to perform. 
    * - ``SPV_INTEL_subgroup_matrix_multiply_accumulate``
-     - Adds an instruction to compute the matrix product of an M x K matrix with a K x N matrix and then add an M x N matrix. 
+     - Adds an instruction to compute the matrix product of an M x K matrix with a K x N matrix and then add an M x N matrix.
+   * - ``SPV_INTEL_fpga_dsp_control``
+     - Enables control over whether certain floating-point operations should be implemented using DSP blocks or logic elements on FPGA hardware, allowing fine-tuned optimization of resource usage and performance.
 
 To enable multiple extensions, list them separated by comma. For example, to enable support for atomic operations on floating-point numbers and arbitrary precision integers, use:
 

llvm/lib/Target/SPIRV/SPIRVCommandLine.cpp

@@ -87,6 +87,8 @@ static const std::map<std::string, SPIRV::Extension::Extension, std::less<>>
          SPIRV::Extension::Extension::SPV_KHR_shader_clock},
         {"SPV_KHR_cooperative_matrix",
          SPIRV::Extension::Extension::SPV_KHR_cooperative_matrix},
+        {"SPV_INTEL_fpga_dsp_control",
+         SPIRV::Extension::Extension::SPV_INTEL_fpga_dsp_control},
         {"SPV_KHR_non_semantic_info",
          SPIRV::Extension::Extension::SPV_KHR_non_semantic_info},
         {"SPV_INTEL_long_composites",

llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp

@@ -920,6 +920,8 @@ static void addOpDecorateReqs(const MachineInstr &MI, unsigned DecIndex,
   } else if (Dec == SPIRV::Decoration::FPMaxErrorDecorationINTEL) {
     Reqs.addRequirements(SPIRV::Capability::FPMaxErrorINTEL);
     Reqs.addExtension(SPIRV::Extension::SPV_INTEL_fp_max_error);
+  } else if (Dec == SPIRV::Decoration::MathOpDSPModeINTEL) {
+    Reqs.addExtension(SPIRV::Extension::Extension::SPV_INTEL_fpga_dsp_control);
   }
 }
 
@@ -1976,17 +1978,63 @@ static void handleMIFlagDecoration(MachineInstr &I, const SPIRVSubtarget &ST,
   buildOpDecorate(DstReg, I, TII, SPIRV::Decoration::FPFastMathMode, {FMFlags});
 }
 
-// Walk all functions and add decorations related to MI flags.
+static std::vector<uint32_t>
+getMetaDataValues(std::vector<llvm::MDNode *> &MetaDataList) {
+  std::vector<uint32_t> res;
+  for (auto metaDataNode : MetaDataList) {
+    if (metaDataNode->getNumOperands() > 0) {
+      if (auto *CMD = llvm::dyn_cast<llvm::ConstantAsMetadata>(
+              metaDataNode->getOperand(0))) {
+        if (auto *CI = llvm::dyn_cast<llvm::ConstantInt>(CMD->getValue())) {
+          APInt val = CI->getValue();
+          int64_t decVal = val.getZExtValue();
+          res.push_back(decVal);
+        }
+      }
+    }
+  }
+  return res;
+}
+
+static void handleFunctionDecoration(llvm::Module::const_iterator F,
+                                     const SPIRVInstrInfo &TII,
+                                     MachineModuleInfo *MMI,
+                                     const SPIRVSubtarget &ST,
+                                     MachineInstr &MI) {
+  Register Des = MI.getOperand(0).getReg();
+  MachineInstr *curr = &MI;
+  // dsp controll
+  if (llvm::MDNode *Node = F->getMetadata("prefer_dsp")) {
+    std::vector<llvm::MDNode *> MetaDataList;
+    MetaDataList.push_back(Node);
+    if (llvm::MDNode *Node = F->getMetadata("propagate_dsp_preference"))
+      MetaDataList.push_back(Node);
+    if (ST.canUseExtension(
+            SPIRV::Extension::Extension::SPV_INTEL_fpga_dsp_control)) {
+      std::vector<uint32_t> params = getMetaDataValues(MetaDataList);
+      if (params.size() == 1)
+        params.push_back(0);
+      buildOpDecorate(Des, *curr, TII, SPIRV::Decoration::MathOpDSPModeINTEL,
+                      params);
+    }
+  }
+}
+
+// Walk all functions and add decorations related to MI flags and function metadata.
 static void addDecorations(const Module &M, const SPIRVInstrInfo &TII,
                            MachineModuleInfo *MMI, const SPIRVSubtarget &ST,
                            SPIRV::ModuleAnalysisInfo &MAI) {
   for (auto F = M.begin(), E = M.end(); F != E; ++F) {
     MachineFunction *MF = MMI->getMachineFunction(*F);
     if (!MF)
       continue;
-    for (auto &MBB : *MF)
-      for (auto &MI : MBB)
+    for (auto &MBB : *MF) {
+      for (auto &MI : MBB) {
+        if (MI.getOpcode() == SPIRV::OpFunction)
+          handleFunctionDecoration(F, TII, MMI, ST, MI);
         handleMIFlagDecoration(MI, ST, TII, MAI.Reqs);
+      }
+    }
   }
 }
 

llvm/lib/Target/SPIRV/SPIRVSymbolicOperands.td

@@ -517,6 +517,7 @@ defm MemoryAccessAliasingINTEL : CapabilityOperand<5910, 0, 0, [SPV_INTEL_memory
 defm FPMaxErrorINTEL : CapabilityOperand<6169, 0, 0, [SPV_INTEL_fp_max_error], []>;
 defm TernaryBitwiseFunctionINTEL : CapabilityOperand<6241, 0, 0, [SPV_INTEL_ternary_bitwise_function], []>;
 defm SubgroupMatrixMultiplyAccumulateINTEL : CapabilityOperand<6236, 0, 0, [SPV_INTEL_subgroup_matrix_multiply_accumulate], []>;
+defm FPGADSPControlINTEL : CapabilityOperand<5908, 0, 0, [SPV_INTEL_fpga_dsp_control], []>;
 
 //===----------------------------------------------------------------------===//
 // Multiclass used to define SourceLanguage enum values and at the same time
@@ -1268,6 +1269,7 @@ defm FunctionFloatingPointModeINTEL : DecorationOperand<6080, 0, 0, [], [Functio
 defm AliasScopeINTEL : DecorationOperand<5914, 0, 0, [], [MemoryAccessAliasingINTEL]>;
 defm NoAliasINTEL : DecorationOperand<5915, 0, 0, [], [MemoryAccessAliasingINTEL]>;
 defm FPMaxErrorDecorationINTEL : DecorationOperand<6170, 0, 0, [], [FPMaxErrorINTEL]>;
+defm MathOpDSPModeINTEL : DecorationOperand<5909, 0, 0, [], [FPGADSPControlINTEL]>;
 
 //===----------------------------------------------------------------------===//
 // Multiclass used to define BuiltIn enum values and at the same time

llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_fpga_dsp_control/prefer_dsp.ll

@@ -0,0 +1,78 @@
+; template<typename Function>
+; [[intel::prefer_dsp]]
+; void math_prefer_dsp_propagate(Function f)
+; {
+;   f();
+; }
+
+; int main() {
+;   math_prefer_dsp_propagate([]() {
+;     int a = 0;
+;     a += 1;
+;   });
+
+; return 0;
+; }
+
+
+; RUN: llc -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_fpga_dsp_control %s -o - | FileCheck %s --check-prefixes=CHECK-SPIRV
+
+
+; CHECK-SPIRV: OpCapability FPGADSPControlINTEL
+; CHECK-SPIRV: OpExtension "SPV_INTEL_fpga_dsp_control"
+; CHECK-SPIRV: OpName %[[#FuncNameId:]] "_Z25math_prefer_dsp_propagateIZ4mainE3$_0EvT_"
+; CHECK-SPIRV: OpDecorate %[[#FuncNameId]] MathOpDSPModeINTEL 1 0
+
+
+; ModuleID = 'prefer_dsp.cpp'
+source_filename = "prefer_dsp.cpp"
+target datalayout = "e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64"
+target triple = "spir64-unknown-unknown"
+
+%class.anon = type { i8 }
+
+; Function Attrs: noinline norecurse optnone mustprogress
+define dso_local i32 @main() #0 {
+entry:
+  %retval = alloca i32, align 4
+  %agg.tmp = alloca %class.anon, align 1
+  store i32 0, ptr %retval, align 4
+  call spir_func void @"_Z25math_prefer_dsp_propagateIZ4mainE3$_0EvT_"(ptr byval(%class.anon) align 1 %agg.tmp)
+  ret i32 0
+}
+
+; Function Attrs: noinline optnone mustprogress
+define internal spir_func void @"_Z25math_prefer_dsp_propagateIZ4mainE3$_0EvT_"(ptr byval(%class.anon) align 1 %f) #1 !prefer_dsp !3 {
+entry:
+  call spir_func void @"_ZZ4mainENK3$_0clEv"(ptr nonnull dereferenceable(1) %f)
+  ret void
+}
+
+; Function Attrs: noinline nounwind optnone mustprogress
+define internal spir_func void @"_ZZ4mainENK3$_0clEv"(ptr nonnull dereferenceable(1) %this) #2 align 2 {
+entry:
+  %this.addr = alloca ptr, align 8
+  %a = alloca i32, align 4
+  store ptr %this, ptr %this.addr, align 8
+  %this1 = load ptr, ptr %this.addr, align 8
+  store i32 0, ptr %a, align 4
+  %0 = load i32, ptr %a, align 4
+  %add = add nsw i32 %0, 1
+  store i32 %add, ptr %a, align 4
+  ret void
+}
+
+attributes #0 = { noinline norecurse optnone mustprogress "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { noinline optnone mustprogress "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { noinline nounwind optnone mustprogress "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.module.flags = !{!0}
+!opencl.used.extensions = !{!1}
+!opencl.used.optional.core.features = !{!1}
+!opencl.compiler.options = !{!1}
+!llvm.ident = !{!2}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{}
+!2 = !{!"clang version 13.0.0 (https://github.com/llvm/llvm-project.git 7d09e1d7cf27ce781e83f9d388a7a3e1e6487ead)"}
+!3 = !{i32 1}

llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_fpga_dsp_control/prefer_dsp_propagate.ll

@@ -0,0 +1,78 @@
+; template<typename Function>
+; [[intel::prefer_dsp]]
+; [[intel::propagate_dsp_preference]]
+; void math_prefer_dsp_propagate(Function f)
+; {
+;   f();
+; }
+
+; int main() {
+;   math_prefer_dsp_propagate([]() {
+;     int a = 0;
+;     a += 1;
+;   });
+
+; return 0;
+; }
+
+; RUN: llc -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_fpga_dsp_control %s -o - | FileCheck %s --check-prefixes=CHECK-SPIRV
+
+
+; CHECK-SPIRV: OpCapability FPGADSPControlINTEL
+; CHECK-SPIRV: OpExtension "SPV_INTEL_fpga_dsp_control"
+; CHECK-SPIRV: OpName %[[#FuncNameId:]] "_Z25math_prefer_dsp_propagateIZ4mainE3$_0EvT_"
+; CHECK-SPIRV: OpDecorate %[[#FuncNameId]] MathOpDSPModeINTEL 1 1
+
+
+; ModuleID = 'prefer_dsp_propagate.cpp'
+source_filename = "prefer_dsp_propagate.cpp"
+target datalayout = "e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64"
+target triple = "spir64-unknown-unknown"
+
+%class.anon = type { i8 }
+
+; Function Attrs: noinline norecurse optnone mustprogress
+define dso_local i32 @main() #0 {
+entry:
+  %retval = alloca i32, align 4
+  %agg.tmp = alloca %class.anon, align 1
+  store i32 0, ptr %retval, align 4
+  call spir_func void @"_Z25math_prefer_dsp_propagateIZ4mainE3$_0EvT_"(ptr byval(%class.anon) align 1 %agg.tmp)
+  ret i32 0
+}
+
+; Function Attrs: noinline optnone mustprogress
+define internal spir_func void @"_Z25math_prefer_dsp_propagateIZ4mainE3$_0EvT_"(ptr byval(%class.anon) align 1 %f) #1 !prefer_dsp !3 !propagate_dsp_preference !3 {
+entry:
+  call spir_func void @"_ZZ4mainENK3$_0clEv"(ptr nonnull dereferenceable(1) %f)
+  ret void
+}
+
+; Function Attrs: noinline nounwind optnone mustprogress
+define internal spir_func void @"_ZZ4mainENK3$_0clEv"(ptr nonnull dereferenceable(1) %this) #2 align 2 {
+entry:
+  %this.addr = alloca ptr, align 8
+  %a = alloca i32, align 4
+  store ptr %this, ptr %this.addr, align 8
+  %this1 = load ptr, ptr %this.addr, align 8
+  store i32 0, ptr %a, align 4
+  %0 = load i32, ptr %a, align 4
+  %add = add nsw i32 %0, 1
+  store i32 %add, ptr %a, align 4
+  ret void
+}
+
+attributes #0 = { noinline norecurse optnone mustprogress "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { noinline optnone mustprogress "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { noinline nounwind optnone mustprogress "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.module.flags = !{!0}
+!opencl.used.extensions = !{!1}
+!opencl.used.optional.core.features = !{!1}
+!opencl.compiler.options = !{!1}
+!llvm.ident = !{!2}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{}
+!2 = !{!"clang version 13.0.0 (https://github.com/llvm/llvm-project.git 7d09e1d7cf27ce781e83f9d388a7a3e1e6487ead)"}
+!3 = !{i32 1}