[SYCL] Add extension and implement fp control kernel property

llvm/lib/SYCLLowerIR/CMakeLists.txt

@@ -13,10 +13,11 @@ endif()
 if (NOT TARGET LLVMGenXIntrinsics)
   if (NOT DEFINED LLVMGenXIntrinsics_SOURCE_DIR)
     set(LLVMGenXIntrinsics_GIT_REPO https://github.com/intel/vc-intrinsics.git)
-    # Author: Jinsong Ji <[email protected]>
-    # Date:   Thu Aug 10 14:41:52 2023 +0000
-    #    Guard removed typed pointer enum within version macro
-    set(LLVMGenXIntrinsics_GIT_TAG 17a53f4304463b8e7e639d57ef17479040a8a2ad)
+    # Author: Artur Gainullin <[email protected]>
+    # Date:   Thu Nov 9 00:37:24 2023 +0000
+
+    # Replace old kernel with rewritten kernel in metadata only since LLVM 17
+    set(LLVMGenXIntrinsics_GIT_TAG a8403355ada112b72d1fc7db29fd04325eecee60)
 
     message(STATUS "vc-intrinsics repo is missing. Will try to download it from ${LLVMGenXIntrinsics_GIT_REPO}")
     include(FetchContent)

llvm/lib/SYCLLowerIR/CompileTimePropertiesPass.cpp

@@ -65,6 +65,36 @@ const StringMap<Decor> SpirvDecorMap = {
 };
 #undef SYCL_COMPILE_TIME_PROPERTY
 
+// Masks defined here must be in sync with the SYCL header with fp control
+// kernel property.
+enum FloatControl {
+  RTE = 1,      // Round to nearest or even
+  RTP = 1 << 1, // Round towards +ve inf
+  RTN = 1 << 2, // Round towards -ve inf
+  RTZ = 1 << 3, // Round towards zero
+
+  DENORM_FTZ = 1 << 4,     // Denorm mode flush to zero
+  DENORM_D_ALLOW = 1 << 5, // Denorm mode double allow
+  DENORM_F_ALLOW = 1 << 6, // Denorm mode float allow
+  DENORM_HF_ALLOW = 1 << 7 // Denorm mode half allow
+};
+
+enum FloatControlMask {
+  ROUND_MASK = (RTE | RTP | RTN | RTZ),
+  DENORM_MASK = (DENORM_D_ALLOW | DENORM_F_ALLOW | DENORM_HF_ALLOW)
+};
+
+// SPIRV execution modes for FP control.
+// These opcodes are specified in SPIRV specification (SPV_KHR_float_controls
+// and SPV_INTEL_float_controls2 extensions):
+// https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.pdf
+constexpr uint32_t SPIRV_ROUNDING_MODE_RTE = 4462;       // RoundingModeRTE
+constexpr uint32_t SPIRV_ROUNDING_MODE_RTZ = 4463;       // RoundingModeRTZ
+constexpr uint32_t SPIRV_ROUNDING_MODE_RTP_INTEL = 5620; // RoundingModeRTPINTEL
+constexpr uint32_t SPIRV_ROUNDING_MODE_RTN_INTEL = 5621; // RoundingModeRTNINTEL
+constexpr uint32_t SPIRV_DENORM_FLUSH_TO_ZERO = 4460;    // DenormFlushToZero
+constexpr uint32_t SPIRV_DENORM_PRESERVE = 4459;         // DenormPreserve
+
 /// Builds a metadata node for a SPIR-V decoration (decoration code is
 /// \c uint32_t integers) with no value.
 ///
@@ -282,6 +312,55 @@ attributeToExecModeMetadata(const Attribute &Attr, Function &F) {
   if (!AttrKindStr.startswith("sycl-"))
     return std::nullopt;
 
+  auto AddFPControlMetadataForWidth = [&](int32_t SPIRVFPControl,
+                                          int32_t Width) {
+    auto NamedMD = M.getOrInsertNamedMetadata("spirv.ExecutionMode");
+    SmallVector<Metadata *, 4> ValueVec;
+    ValueVec.push_back(ConstantAsMetadata::get(&F));
+    ValueVec.push_back(ConstantAsMetadata::get(
+        ConstantInt::get(Type::getInt32Ty(Ctx), SPIRVFPControl)));
+    ValueVec.push_back(ConstantAsMetadata::get(
+        ConstantInt::get(Type::getInt32Ty(Ctx), Width)));
+    NamedMD->addOperand(MDNode::get(Ctx, ValueVec));
+  };
+
+  auto AddFPControlMetadata = [&](int32_t SPIRVFPControl) {
+    for (int32_t Width : {64, 32, 16}) {
+      AddFPControlMetadataForWidth(SPIRVFPControl, Width);
+    }
+  };
+
+  if (AttrKindStr == "sycl-floating-point-control") {
+    uint32_t FPControl = getAttributeAsInteger<uint32_t>(Attr);
+    auto IsFPModeSet = [FPControl](FloatControl Flag) -> bool {
+      return (FPControl & Flag) == Flag;
+    };
+
+    if (IsFPModeSet(RTE))
+      AddFPControlMetadata(SPIRV_ROUNDING_MODE_RTE);
+
+    if (IsFPModeSet(RTP))
+      AddFPControlMetadata(SPIRV_ROUNDING_MODE_RTP_INTEL);
+
+    if (IsFPModeSet(RTN))
+      AddFPControlMetadata(SPIRV_ROUNDING_MODE_RTN_INTEL);
+
+    if (IsFPModeSet(RTZ))
+      AddFPControlMetadata(SPIRV_ROUNDING_MODE_RTZ);
+
+    if (IsFPModeSet(DENORM_FTZ))
+      AddFPControlMetadata(SPIRV_DENORM_FLUSH_TO_ZERO);
+
+    if (IsFPModeSet(DENORM_HF_ALLOW))
+      AddFPControlMetadataForWidth(SPIRV_DENORM_PRESERVE, 16);
+
+    if (IsFPModeSet(DENORM_F_ALLOW))
+      AddFPControlMetadataForWidth(SPIRV_DENORM_PRESERVE, 32);
+
+    if (IsFPModeSet(DENORM_D_ALLOW))
+      AddFPControlMetadataForWidth(SPIRV_DENORM_PRESERVE, 64);
+  }
+
   if (AttrKindStr == "sycl-work-group-size" ||
       AttrKindStr == "sycl-work-group-size-hint") {
     // Split values in the comma-separated list integers.

llvm/test/SYCLLowerIR/CompileTimePropertiesPass/fp-control-kernel-properties.ll

@@ -0,0 +1,156 @@
+; RUN: opt -passes=compile-time-properties %s -S | FileCheck %s
+
+
+define spir_kernel void @"Kernel0"() #0 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel1"() #1 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel2"() #2 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel3"() #3 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel4"() #4 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel5"() #5 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel6"() #6 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel7"() #7 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel8"() #8 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel9"() #9 {
+entry:
+  ret void
+}
+
+define spir_kernel void @"Kernel10"() #10 {
+entry:
+  ret void
+}
+
+; SPIRV execution modes for FP control.   | BitMask
+; ROUNDING_MODE_RTE = 4462;               | 00000001
+; ROUNDING_MODE_RTP_INTEL = 5620;         | 00000010
+; ROUNDING_MODE_RTN_INTEL = 5621;         | 00000100
+; ROUNDING_MODE_RTZ = 4463;               | 00001000
+; DEMORM_FLUSH_TO_ZERO = 4460;            | 00010000
+; DENORM_PRESERVE (double) = 4459;        | 00100000
+; DENORM_PRESERVE (float) = 4459;         | 01000000
+; DENORM_PRESERVE (half) = 4459;          | 10000000
+
+; rte + ftz (Default)
+; CHECK: !0 = !{ptr @Kernel0, i32 [[RTE:4462]], i32 64}
+; CHECK: !1 = !{ptr @Kernel0, i32 [[RTE]], i32 32}
+; CHECK: !2 = !{ptr @Kernel0, i32 [[RTE]], i32 16}
+; CHECK: !3 = !{ptr @Kernel0, i32 [[FTZ:4460]], i32 64}
+; CHECK: !4 = !{ptr @Kernel0, i32 [[FTZ]], i32 32}
+; CHECK: !5 = !{ptr @Kernel0, i32 [[FTZ]], i32 16}
+attributes #0 = { "sycl-floating-point-control"="17" }
+
+; rtp + ftz
+; CHECK: !6 = !{ptr @Kernel1, i32 [[RTP:5620]], i32 64}
+; CHECK: !7 = !{ptr @Kernel1, i32 [[RTP]], i32 32}
+; CHECK: !8 = !{ptr @Kernel1, i32 [[RTP]], i32 16}
+; CHECK: !9 = !{ptr @Kernel1, i32 [[FTZ]], i32 64}
+; CHECK: !10 = !{ptr @Kernel1, i32 [[FTZ]], i32 32}
+; CHECK: !11 = !{ptr @Kernel1, i32 [[FTZ]], i32 16}
+attributes #1 = { "sycl-floating-point-control"="18" }
+
+; rtn + ftz
+; CHECK: !12 = !{ptr @Kernel2, i32 [[RTN:5621]], i32 64}
+; CHECK: !13 = !{ptr @Kernel2, i32 [[RTN]], i32 32}
+; CHECK: !14 = !{ptr @Kernel2, i32 [[RTN]], i32 16}
+; CHECK: !15 = !{ptr @Kernel2, i32 [[FTZ]], i32 64}
+; CHECK: !16 = !{ptr @Kernel2, i32 [[FTZ]], i32 32}
+; CHECK: !17 = !{ptr @Kernel2, i32 [[FTZ]], i32 16}
+attributes #2 = { "sycl-floating-point-control"="20" }
+
+; rtz + ftz
+; CHECK: !18 = !{ptr @Kernel3, i32 [[RTZ:4463]], i32 64}
+; CHECK: !19 = !{ptr @Kernel3, i32 [[RTZ]], i32 32}
+; CHECK: !20 = !{ptr @Kernel3, i32 [[RTZ]], i32 16}
+; CHECK: !21 = !{ptr @Kernel3, i32 [[FTZ]], i32 64}
+; CHECK: !22 = !{ptr @Kernel3, i32 [[FTZ]], i32 32}
+; CHECK: !23 = !{ptr @Kernel3, i32 [[FTZ]], i32 16}
+attributes #3 = { "sycl-floating-point-control"="24" }
+
+; rte + denorm_preserve(double)
+; CHECK: !24 = !{ptr @Kernel4, i32 [[RTE]], i32 64}
+; CHECK: !25 = !{ptr @Kernel4, i32 [[RTE]], i32 32}
+; CHECK: !26 = !{ptr @Kernel4, i32 [[RTE]], i32 16}
+; CHECK: !27 = !{ptr @Kernel4, i32 [[DENORM_PRESERVE:4459]], i32 64}
+attributes #4 = { "sycl-floating-point-control"="33" }
+
+; rte + denorm_preserve(float)
+; CHECK: !28 = !{ptr @Kernel5, i32 [[RTE]], i32 64}
+; CHECK: !29 = !{ptr @Kernel5, i32 [[RTE]], i32 32}
+; CHECK: !30 = !{ptr @Kernel5, i32 [[RTE]], i32 16}
+; CHECK: !31 = !{ptr @Kernel5, i32 [[DENORM_PRESERVE]], i32 32}
+attributes #5 = { "sycl-floating-point-control"="65" }
+
+; rte + denorm_preserve(half)
+; CHECK: !32 = !{ptr @Kernel6, i32 [[RTE]], i32 64}
+; CHECK: !33 = !{ptr @Kernel6, i32 [[RTE]], i32 32}
+; CHECK: !34 = !{ptr @Kernel6, i32 [[RTE]], i32 16}
+; CHECK: !35 = !{ptr @Kernel6, i32 [[DENORM_PRESERVE]], i32 16}
+attributes #6 = { "sycl-floating-point-control"="129" }
+
+; rte + denorm_allow
+; CHECK: !36 = !{ptr @Kernel7, i32 [[RTE]], i32 64}
+; CHECK: !37 = !{ptr @Kernel7, i32 [[RTE]], i32 32}
+; CHECK: !38 = !{ptr @Kernel7, i32 [[RTE]], i32 16}
+; CHECK: !39 = !{ptr @Kernel7, i32 [[DENORM_PRESERVE]], i32 16}
+; CHECK: !40 = !{ptr @Kernel7, i32 [[DENORM_PRESERVE]], i32 32}
+; CHECK: !41 = !{ptr @Kernel7, i32 [[DENORM_PRESERVE]], i32 64}
+attributes #7 = { "sycl-floating-point-control"="225" }
+
+; rtz + denorm_preserve(double)
+; CHECK: !42 = !{ptr @Kernel8, i32 [[RTZ]], i32 64}
+; CHECK: !43 = !{ptr @Kernel8, i32 [[RTZ]], i32 32}
+; CHECK: !44 = !{ptr @Kernel8, i32 [[RTZ]], i32 16}
+; CHECK: !45 = !{ptr @Kernel8, i32 [[DENORM_PRESERVE]], i32 64}
+attributes #8 = { "sycl-floating-point-control"="40" }
+
+; rtp + denorm_preserve(float)
+; CHECK: !46 = !{ptr @Kernel9, i32 [[RTP]], i32 64}
+; CHECK: !47 = !{ptr @Kernel9, i32 [[RTP]], i32 32}
+; CHECK: !48 = !{ptr @Kernel9, i32 [[RTP]], i32 16}
+; CHECK: !49 = !{ptr @Kernel9, i32 [[DENORM_PRESERVE]], i32 32}
+attributes #9 = { "sycl-floating-point-control"="66" }
+
+; rtz + denorm_allow
+; CHECK: !50 = !{ptr @Kernel10, i32 [[RTZ]], i32 64}
+; CHECK: !51 = !{ptr @Kernel10, i32 [[RTZ]], i32 32}
+; CHECK: !52 = !{ptr @Kernel10, i32 [[RTZ]], i32 16}
+; CHECK: !53 = !{ptr @Kernel10, i32 [[DENORM_PRESERVE]], i32 16}
+; CHECK: !54 = !{ptr @Kernel10, i32 [[DENORM_PRESERVE]], i32 32}
+; CHECK: !55 = !{ptr @Kernel10, i32 [[DENORM_PRESERVE]], i32 64}
+attributes #10 = { "sycl-floating-point-control"="232" }

llvm/tools/sycl-post-link/ModuleSplitter.cpp

@@ -281,6 +281,52 @@ void collectFunctionsAndGlobalVariablesToExtract(
   }
 }
 
+// Check "spirv.ExecutionMode" named metadata in the module and remove nodes
+// that reference kernels that have dead prototypes or don't reference any
+// kernel at all (nullptr). Dead prototypes are removed as well.
+void processSubModuleNamedMetadata(Module *M) {
+  auto ExecutionModeMD = M->getNamedMetadata("spirv.ExecutionMode");
+  if (!ExecutionModeMD)
+    return;
+
+  bool ContainsNodesToRemove = false;
+  std::vector<MDNode *> ValueVec;
+  for (auto Op : ExecutionModeMD->operands()) {
+    assert(Op->getNumOperands() > 0);
+    if (!Op->getOperand(0)) {
+      ContainsNodesToRemove = true;
+      continue;
+    }
+
+    // If the first operand is not nullptr then it has to be a kernel
+    // function.
+    Value *Val = cast<ValueAsMetadata>(Op->getOperand(0))->getValue();
+    Function *F = cast<Function>(Val);
+    // If kernel function is just a prototype and unused then we can remove it
+    // and later remove corresponding spirv.ExecutionMode metadata node.
+    if (F->isDeclaration() && F->use_empty()) {
+      F->eraseFromParent();
+      ContainsNodesToRemove = true;
+      continue;
+    }
+
+    // Rememver nodes which we need to keep in the module.
+    ValueVec.push_back(Op);
+  }
+  if (!ContainsNodesToRemove)
+    return;
+
+  if (ValueVec.empty()) {
+    // If all nodes need to be removed then just remove named metadata
+    // completely.
+    ExecutionModeMD->eraseFromParent();
+  } else {
+    ExecutionModeMD->clearOperands();
+    for (auto MD : ValueVec)
+      ExecutionModeMD->addOperand(MD);
+  }
+}
+
 ModuleDesc extractSubModule(const ModuleDesc &MD,
                             const SetVector<const GlobalValue *> GVs,
                             EntryPointGroup &&ModuleEntryPoints) {
@@ -577,6 +623,15 @@ void ModuleDesc::cleanup() {
   MPM.addPass(StripDeadDebugInfoPass());  // Remove dead debug info.
   MPM.addPass(StripDeadPrototypesPass()); // Remove dead func decls.
   MPM.run(*M, MAM);
+
+  // Original module may have named metadata (spirv.ExecutionMode) referencing
+  // kernels in the module. Some of the Metadata nodes may reference kernels
+  // which are not included into the extracted submodule, in such case
+  // CloneModule either leaves that metadata nodes as is but they will reference
+  // dead prototype of the kernel or operand will be replace with nullptr. So
+  // process all nodes in the named metadata and remove nodes which are
+  // referencing kernels which are not included into submodule.
+  processSubModuleNamedMetadata(M.get());
 }
 
 bool ModuleDesc::isSpecConstantDefault() const {