Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===-- llvm/Target/TargetOptions.h - Target Options ------------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file defines command line option flags that are shared across various

// targets.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_TARGET_TARGETOPTIONS_H

#define LLVM_TARGET_TARGETOPTIONS_H

#include "llvm/ADT/FloatingPointMode.h"

#include "llvm/MC/MCTargetOptions.h"

#include <memory>

namespace llvm {

  struct fltSemantics;

  class MachineFunction;

  class MemoryBuffer;

  namespace FloatABI {

    enum ABIType {

      Default, // Target-specific (either soft or hard depending on triple, etc).

      Soft,    // Soft float.

      Hard     // Hard float.

    };

  }

  namespace FPOpFusion {

    enum FPOpFusionMode {

      Fast,     // Enable fusion of FP ops wherever it's profitable.

      Standard, // Only allow fusion of 'blessed' ops (currently just fmuladd).

      Strict    // Never fuse FP-ops.

    };

  }

  namespace JumpTable {

    enum JumpTableType {

      Single,          // Use a single table for all indirect jumptable calls.

      Arity,           // Use one table per number of function parameters.

      Simplified,      // Use one table per function type, with types projected

                       // into 4 types: pointer to non-function, struct,

                       // primitive, and function pointer.

      Full             // Use one table per unique function type

    };

  }

  namespace ThreadModel {

    enum Model {

      POSIX,  // POSIX Threads

      Single  // Single Threaded Environment

    };

  }

  enum class BasicBlockSection {

    All,    // Use Basic Block Sections for all basic blocks.  A section

            // for every basic block can significantly bloat object file sizes.

    List,   // Get list of functions & BBs from a file. Selectively enables

            // basic block sections for a subset of basic blocks which can be

            // used to control object size bloats from creating sections.

    Labels, // Do not use Basic Block Sections but label basic blocks.  This

            // is useful when associating profile counts from virtual addresses

            // to basic blocks.

    Preset, // Similar to list but the blocks are identified by passes which

            // seek to use Basic Block Sections, e.g. MachineFunctionSplitter.

            // This option cannot be set via the command line.

    None    // Do not use Basic Block Sections.

  };

  enum class EABI {

    Unknown,

    Default, // Default means not specified

    EABI4,   // Target-specific (either 4, 5 or gnu depending on triple).

    EABI5,

    GNU

  };

  /// Identify a debugger for "tuning" the debug info.

  ///

  /// The "debugger tuning" concept allows us to present a more intuitive

  /// interface that unpacks into different sets of defaults for the various

  /// individual feature-flag settings, that suit the preferences of the

  /// various debuggers.  However, it's worth remembering that debuggers are

  /// not the only consumers of debug info, and some variations in DWARF might

  /// better be treated as target/platform issues. Fundamentally,

  /// o if the feature is useful (or not) to a particular debugger, regardless

  ///   of the target, that's a tuning decision;

  /// o if the feature is useful (or not) on a particular platform, regardless

  ///   of the debugger, that's a target decision.

  /// It's not impossible to see both factors in some specific case.

  enum class DebuggerKind {

    Default, ///< No specific tuning requested.

    GDB,     ///< Tune debug info for gdb.

    LLDB,    ///< Tune debug info for lldb.

    SCE,     ///< Tune debug info for SCE targets (e.g. PS4).

    DBX      ///< Tune debug info for dbx.

  };

  /// Enable abort calls when global instruction selection fails to lower/select

  /// an instruction.

  enum class GlobalISelAbortMode {

    Disable,        // Disable the abort.

    Enable,         // Enable the abort.

    DisableWithDiag // Disable the abort but emit a diagnostic on failure.

  };

  /// Indicates when and how the Swift async frame pointer bit should be set.

  enum class SwiftAsyncFramePointerMode {

    /// Determine whether to set the bit statically or dynamically based

    /// on the deployment target.

    DeploymentBased,

    /// Always set the bit.

    Always,

    /// Never set the bit.

    Never,

  };

  class TargetOptions {

  public:

    TargetOptions()

        : UnsafeFPMath(false), NoInfsFPMath(false), NoNaNsFPMath(false),

          NoTrappingFPMath(true), NoSignedZerosFPMath(false),

          ApproxFuncFPMath(false), EnableAIXExtendedAltivecABI(false),

          HonorSignDependentRoundingFPMathOption(false), NoZerosInBSS(false),

          GuaranteedTailCallOpt(false), StackSymbolOrdering(true),

          EnableFastISel(false), EnableGlobalISel(false), UseInitArray(false),

          LowerGlobalDtorsViaCxaAtExit(false), DisableIntegratedAS(false),

          RelaxELFRelocations(true), FunctionSections(false),

          DataSections(false), IgnoreXCOFFVisibility(false),

          XCOFFTracebackTable(true), UniqueSectionNames(true),

          UniqueBasicBlockSectionNames(false), TrapUnreachable(false),

          NoTrapAfterNoreturn(false), TLSSize(0), EmulatedTLS(false),

          ExplicitEmulatedTLS(false), EnableIPRA(false),

          EmitStackSizeSection(false), EnableMachineOutliner(false),

          EnableMachineFunctionSplitter(false), SupportsDefaultOutlining(false),

          EmitAddrsig(false), EmitCallSiteInfo(false),

          SupportsDebugEntryValues(false), EnableDebugEntryValues(false),

          ValueTrackingVariableLocations(false), ForceDwarfFrameSection(false),

          XRayOmitFunctionIndex(false), DebugStrictDwarf(false),

          Hotpatch(false), PPCGenScalarMASSEntries(false), JMCInstrument(false),

          EnableCFIFixup(false), MisExpect(false),

          FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {}

    /// DisableFramePointerElim - This returns true if frame pointer elimination

    /// optimization should be disabled for the given machine function.

    bool DisableFramePointerElim(const MachineFunction &MF) const;

    /// If greater than 0, override the default value of

    /// MCAsmInfo::BinutilsVersion.

    std::pair<int, int> BinutilsVersion{0, 0};

    /// UnsafeFPMath - This flag is enabled when the

    /// -enable-unsafe-fp-math flag is specified on the command line.  When

    /// this flag is off (the default), the code generator is not allowed to

    /// produce results that are "less precise" than IEEE allows.  This includes

    /// use of X86 instructions like FSIN and FCOS instead of libcalls.

    unsigned UnsafeFPMath : 1;

    /// NoInfsFPMath - This flag is enabled when the

    /// -enable-no-infs-fp-math flag is specified on the command line. When

    /// this flag is off (the default), the code generator is not allowed to

    /// assume the FP arithmetic arguments and results are never +-Infs.

    unsigned NoInfsFPMath : 1;

    /// NoNaNsFPMath - This flag is enabled when the

    /// -enable-no-nans-fp-math flag is specified on the command line. When

    /// this flag is off (the default), the code generator is not allowed to

    /// assume the FP arithmetic arguments and results are never NaNs.

    unsigned NoNaNsFPMath : 1;

    /// NoTrappingFPMath - This flag is enabled when the

    /// -enable-no-trapping-fp-math is specified on the command line. This

    /// specifies that there are no trap handlers to handle exceptions.

    unsigned NoTrappingFPMath : 1;

    /// NoSignedZerosFPMath - This flag is enabled when the

    /// -enable-no-signed-zeros-fp-math is specified on the command line. This

    /// specifies that optimizations are allowed to treat the sign of a zero

    /// argument or result as insignificant.

    unsigned NoSignedZerosFPMath : 1;

    /// ApproxFuncFPMath - This flag is enabled when the

    /// -enable-approx-func-fp-math is specified on the command line. This

    /// specifies that optimizations are allowed to substitute math functions

    /// with approximate calculations

    unsigned ApproxFuncFPMath : 1;

    /// EnableAIXExtendedAltivecABI - This flag returns true when -vec-extabi is

    /// specified. The code generator is then able to use both volatile and

    /// nonvolitle vector registers. When false, the code generator only uses

    /// volatile vector registers which is the default setting on AIX.

    unsigned EnableAIXExtendedAltivecABI : 1;

    /// HonorSignDependentRoundingFPMath - This returns true when the

    /// -enable-sign-dependent-rounding-fp-math is specified.  If this returns

    /// false (the default), the code generator is allowed to assume that the

    /// rounding behavior is the default (round-to-zero for all floating point

    /// to integer conversions, and round-to-nearest for all other arithmetic

    /// truncations).  If this is enabled (set to true), the code generator must

    /// assume that the rounding mode may dynamically change.

    unsigned HonorSignDependentRoundingFPMathOption : 1;

    bool HonorSignDependentRoundingFPMath() const;

    /// NoZerosInBSS - By default some codegens place zero-initialized data to

    /// .bss section. This flag disables such behaviour (necessary, e.g. for

    /// crt*.o compiling).

    unsigned NoZerosInBSS : 1;

    /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is

    /// specified on the commandline. When the flag is on, participating targets

    /// will perform tail call optimization on all calls which use the fastcc

    /// calling convention and which satisfy certain target-independent

    /// criteria (being at the end of a function, having the same return type

    /// as their parent function, etc.), using an alternate ABI if necessary.

    unsigned GuaranteedTailCallOpt : 1;

    /// StackSymbolOrdering - When true, this will allow CodeGen to order

    /// the local stack symbols (for code size, code locality, or any other

    /// heuristics). When false, the local symbols are left in whatever order

    /// they were generated. Default is true.

    unsigned StackSymbolOrdering : 1;

    /// EnableFastISel - This flag enables fast-path instruction selection

    /// which trades away generated code quality in favor of reducing

    /// compile time.

    unsigned EnableFastISel : 1;

    /// EnableGlobalISel - This flag enables global instruction selection.

    unsigned EnableGlobalISel : 1;

    /// EnableGlobalISelAbort - Control abort behaviour when global instruction

    /// selection fails to lower/select an instruction.

    GlobalISelAbortMode GlobalISelAbort = GlobalISelAbortMode::Enable;

    /// Control when and how the Swift async frame pointer bit should

    /// be set.

    SwiftAsyncFramePointerMode SwiftAsyncFramePointer =

        SwiftAsyncFramePointerMode::Always;

    /// UseInitArray - Use .init_array instead of .ctors for static

    /// constructors.

    unsigned UseInitArray : 1;

    /// Use __cxa_atexit to register global destructors; determines how

    /// llvm.global_dtors is lowered.

    unsigned LowerGlobalDtorsViaCxaAtExit : 1;

    /// Disable the integrated assembler.

    unsigned DisableIntegratedAS : 1;

    /// Compress DWARF debug sections.

    DebugCompressionType CompressDebugSections = DebugCompressionType::None;

    unsigned RelaxELFRelocations : 1;

    /// Emit functions into separate sections.

    unsigned FunctionSections : 1;

    /// Emit data into separate sections.

    unsigned DataSections : 1;

    /// Do not emit visibility attribute for xcoff.

    unsigned IgnoreXCOFFVisibility : 1;

    /// Emit XCOFF traceback table.

    unsigned XCOFFTracebackTable : 1;

    unsigned UniqueSectionNames : 1;

    /// Use unique names for basic block sections.

    unsigned UniqueBasicBlockSectionNames : 1;

    /// Emit target-specific trap instruction for 'unreachable' IR instructions.

    unsigned TrapUnreachable : 1;

    /// Do not emit a trap instruction for 'unreachable' IR instructions behind

    /// noreturn calls, even if TrapUnreachable is true.

    unsigned NoTrapAfterNoreturn : 1;

    /// Bit size of immediate TLS offsets (0 == use the default).

    unsigned TLSSize : 8;

    /// EmulatedTLS - This flag enables emulated TLS model, using emutls

    /// function in the runtime library..

    unsigned EmulatedTLS : 1;

    /// Whether -emulated-tls or -no-emulated-tls is set.

    unsigned ExplicitEmulatedTLS : 1;

    /// This flag enables InterProcedural Register Allocation (IPRA).

    unsigned EnableIPRA : 1;

    /// Emit section containing metadata on function stack sizes.

    unsigned EmitStackSizeSection : 1;

    /// Enables the MachineOutliner pass.

    unsigned EnableMachineOutliner : 1;

    /// Enables the MachineFunctionSplitter pass.

    unsigned EnableMachineFunctionSplitter : 1;

    /// Set if the target supports default outlining behaviour.

    unsigned SupportsDefaultOutlining : 1;

    /// Emit address-significance table.

    unsigned EmitAddrsig : 1;

    /// Emit basic blocks into separate sections.

    BasicBlockSection BBSections = BasicBlockSection::None;

    /// Memory Buffer that contains information on sampled basic blocks and used

    /// to selectively generate basic block sections.

    std::shared_ptr<MemoryBuffer> BBSectionsFuncListBuf;

    /// The flag enables call site info production. It is used only for debug

    /// info, and it is restricted only to optimized code. This can be used for

    /// something else, so that should be controlled in the frontend.

    unsigned EmitCallSiteInfo : 1;

    /// Set if the target supports the debug entry values by default.

    unsigned SupportsDebugEntryValues : 1;

    /// When set to true, the EnableDebugEntryValues option forces production

    /// of debug entry values even if the target does not officially support

    /// it. Useful for testing purposes only. This flag should never be checked

    /// directly, always use \ref ShouldEmitDebugEntryValues instead.

     unsigned EnableDebugEntryValues : 1;

    /// NOTE: There are targets that still do not support the debug entry values

    /// production.

    bool ShouldEmitDebugEntryValues() const;

    // When set to true, use experimental new debug variable location tracking,

    // which seeks to follow the values of variables rather than their location,

    // post isel.

    unsigned ValueTrackingVariableLocations : 1;

    /// Emit DWARF debug frame section.

    unsigned ForceDwarfFrameSection : 1;

    /// Emit XRay Function Index section

    unsigned XRayOmitFunctionIndex : 1;

    /// When set to true, don't use DWARF extensions in later DWARF versions.

    /// By default, it is set to false.

    unsigned DebugStrictDwarf : 1;

    /// Emit the hotpatch flag in CodeView debug.

    unsigned Hotpatch : 1;

    /// Enables scalar MASS conversions

    unsigned PPCGenScalarMASSEntries : 1;

    /// Enable JustMyCode instrumentation.

    unsigned JMCInstrument : 1;

    /// Enable the CFIFixup pass.

    unsigned EnableCFIFixup : 1;

    /// When set to true, enable MisExpect Diagnostics

    /// By default, it is set to false

    unsigned MisExpect : 1;

    /// Name of the stack usage file (i.e., .su file) if user passes

    /// -fstack-usage. If empty, it can be implied that -fstack-usage is not

    /// passed on the command line.

    std::string StackUsageOutput;

    /// If greater than 0, override TargetLoweringBase::PrefLoopAlignment.

    unsigned LoopAlignment = 0;

    /// FloatABIType - This setting is set by -float-abi=xxx option is specfied

    /// on the command line. This setting may either be Default, Soft, or Hard.

    /// Default selects the target's default behavior. Soft selects the ABI for

    /// software floating point, but does not indicate that FP hardware may not

    /// be used. Such a combination is unfortunately popular (e.g.

    /// arm-apple-darwin). Hard presumes that the normal FP ABI is used.

    FloatABI::ABIType FloatABIType = FloatABI::Default;

    /// AllowFPOpFusion - This flag is set by the -fp-contract=xxx option.

    /// This controls the creation of fused FP ops that store intermediate

    /// results in higher precision than IEEE allows (E.g. FMAs).

    ///

    /// Fast mode - allows formation of fused FP ops whenever they're

    /// profitable.

    /// Standard mode - allow fusion only for 'blessed' FP ops. At present the

    /// only blessed op is the fmuladd intrinsic. In the future more blessed ops

    /// may be added.

    /// Strict mode - allow fusion only if/when it can be proven that the excess

    /// precision won't effect the result.

    ///

    /// Note: This option only controls formation of fused ops by the

    /// optimizers.  Fused operations that are explicitly specified (e.g. FMA

    /// via the llvm.fma.* intrinsic) will always be honored, regardless of

    /// the value of this option.

    FPOpFusion::FPOpFusionMode AllowFPOpFusion = FPOpFusion::Standard;

    /// ThreadModel - This flag specifies the type of threading model to assume

    /// for things like atomics

    ThreadModel::Model ThreadModel = ThreadModel::POSIX;

    /// EABIVersion - This flag specifies the EABI version

    EABI EABIVersion = EABI::Default;

    /// Which debugger to tune for.

    DebuggerKind DebuggerTuning = DebuggerKind::Default;

  private:

    /// Flushing mode to assume in default FP environment.

    DenormalMode FPDenormalMode;

    /// Flushing mode to assume in default FP environment, for float/vector of

    /// float.

    DenormalMode FP32DenormalMode;

  public:

    void setFPDenormalMode(DenormalMode Mode) {

      FPDenormalMode = Mode;

    }

    void setFP32DenormalMode(DenormalMode Mode) {

      FP32DenormalMode = Mode;

    }

    DenormalMode getRawFPDenormalMode() const {

      return FPDenormalMode;

    }

    DenormalMode getRawFP32DenormalMode() const {

      return FP32DenormalMode;

    }

    DenormalMode getDenormalMode(const fltSemantics &FPType) const;

    /// What exception model to use

    ExceptionHandling ExceptionModel = ExceptionHandling::None;

    /// Machine level options.

    MCTargetOptions MCOptions;

    /// Stores the filename/path of the final .o/.obj file, to be written in the

    /// debug information. This is used for emitting the CodeView S_OBJNAME

    /// record.

    std::string ObjectFilenameForDebug;

  };

} // End llvm namespace

#endif