include/llvm/Target/TargetOptions.h - llvm - Git at Google

 //===-- 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/MC/MCTargetOptions.h"

 namespace llvm {
   class MachineFunction;
   class Module;

   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
     };
   }

   namespace FPDenormal {
     enum DenormalMode {
       IEEE,           // IEEE 754 denormal numbers
       PreserveSign,   // the sign of a flushed-to-zero number is preserved in
                       // the sign of 0
       PositiveZero    // denormals are flushed to positive zero
     };
   }

   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.
   ///
   /// The "tuning" should be used to set defaults for individual feature flags
   /// in DwarfDebug; if a given feature has a more specific command-line option,
   /// that option should take precedence over the tuning.
   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).
   };

   /// 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.
   };

   class TargetOptions {
   public:
     TargetOptions()
         : PrintMachineCode(false), UnsafeFPMath(false), NoInfsFPMath(false),
           NoNaNsFPMath(false), NoTrappingFPMath(false),
           NoSignedZerosFPMath(false),
           HonorSignDependentRoundingFPMathOption(false), NoZerosInBSS(false),
           GuaranteedTailCallOpt(false), StackSymbolOrdering(true),
           EnableFastISel(false), EnableGlobalISel(false), UseInitArray(false),
           DisableIntegratedAS(false), RelaxELFRelocations(false),
           FunctionSections(false), DataSections(false),
           UniqueSectionNames(true), TrapUnreachable(false),
           NoTrapAfterNoreturn(false), EmulatedTLS(false),
           ExplicitEmulatedTLS(false), EnableIPRA(false),
           EmitStackSizeSection(false), EnableMachineOutliner(false),
           SupportsDefaultOutlining(false), EmitAddrsig(false) {}

     /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
     /// option is specified on the command line, and should enable debugging
     /// output from the code generator.
     unsigned PrintMachineCode : 1;

     /// DisableFramePointerElim - This returns true if frame pointer elimination
     /// optimization should be disabled for the given machine function.
     bool DisableFramePointerElim(const MachineFunction &MF) const;

     /// 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;

     /// 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;

     /// StackAlignmentOverride - Override default stack alignment for target.
     unsigned StackAlignmentOverride = 0;

     /// 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;

     /// UseInitArray - Use .init_array instead of .ctors for static
     /// constructors.
     unsigned UseInitArray : 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;

     unsigned UniqueSectionNames : 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;

     /// 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;

     /// Set if the target supports default outlining behaviour.
     unsigned SupportsDefaultOutlining : 1;

     /// Emit address-significance table.
     unsigned EmitAddrsig : 1;

     /// 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 -fuse-fp-ops=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;

     /// FPDenormalMode - This flags specificies which denormal numbers the code
     /// is permitted to require.
     FPDenormal::DenormalMode FPDenormalMode = FPDenormal::IEEE;

     /// What exception model to use
     ExceptionHandling ExceptionModel = ExceptionHandling::None;

     /// Machine level options.
     MCTargetOptions MCOptions;
   };

 } // End llvm namespace

 #endif
	//===-- 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/MC/MCTargetOptions.h"

	namespace llvm {
	class MachineFunction;
	class Module;

	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
	};
	}

	namespace FPDenormal {
	enum DenormalMode {
	IEEE, // IEEE 754 denormal numbers
	PreserveSign, // the sign of a flushed-to-zero number is preserved in
	// the sign of 0
	PositiveZero // denormals are flushed to positive zero
	};
	}

	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.
	///
	/// The "tuning" should be used to set defaults for individual feature flags
	/// in DwarfDebug; if a given feature has a more specific command-line option,
	/// that option should take precedence over the tuning.
	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).
	};

	/// 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.
	};

	class TargetOptions {
	public:
	TargetOptions()
	: PrintMachineCode(false), UnsafeFPMath(false), NoInfsFPMath(false),
	NoNaNsFPMath(false), NoTrappingFPMath(false),
	NoSignedZerosFPMath(false),
	HonorSignDependentRoundingFPMathOption(false), NoZerosInBSS(false),
	GuaranteedTailCallOpt(false), StackSymbolOrdering(true),
	EnableFastISel(false), EnableGlobalISel(false), UseInitArray(false),
	DisableIntegratedAS(false), RelaxELFRelocations(false),
	FunctionSections(false), DataSections(false),
	UniqueSectionNames(true), TrapUnreachable(false),
	NoTrapAfterNoreturn(false), EmulatedTLS(false),
	ExplicitEmulatedTLS(false), EnableIPRA(false),
	EmitStackSizeSection(false), EnableMachineOutliner(false),
	SupportsDefaultOutlining(false), EmitAddrsig(false) {}

	/// PrintMachineCode - This flag is enabled when the -print-machineinstrs
	/// option is specified on the command line, and should enable debugging
	/// output from the code generator.
	unsigned PrintMachineCode : 1;

	/// DisableFramePointerElim - This returns true if frame pointer elimination
	/// optimization should be disabled for the given machine function.
	bool DisableFramePointerElim(const MachineFunction &MF) const;

	/// 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;

	/// 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;

	/// StackAlignmentOverride - Override default stack alignment for target.
	unsigned StackAlignmentOverride = 0;

	/// 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;

	/// UseInitArray - Use .init_array instead of .ctors for static
	/// constructors.
	unsigned UseInitArray : 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;

	unsigned UniqueSectionNames : 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;

	/// 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;

	/// Set if the target supports default outlining behaviour.
	unsigned SupportsDefaultOutlining : 1;

	/// Emit address-significance table.
	unsigned EmitAddrsig : 1;

	/// 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 -fuse-fp-ops=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;

	/// FPDenormalMode - This flags specificies which denormal numbers the code
	/// is permitted to require.
	FPDenormal::DenormalMode FPDenormalMode = FPDenormal::IEEE;

	/// What exception model to use
	ExceptionHandling ExceptionModel = ExceptionHandling::None;

	/// Machine level options.
	MCTargetOptions MCOptions;
	};

	} // End llvm namespace

	#endif