Options which control the emission from CIRCT to Verilog. More...

#include <LoweringOptions.h>

Collaboration diagram for circt::LoweringOptions:

[legend]

Public Types
enum	{ DEFAULT_TERM_LIMIT = 256 }
	This is the maximum number of terms in an expression before that expression spills a wire. More...

enum	{ DEFAULT_LINE_LENGTH = 90 }
	This is the target width of lines in an emitted Verilog source file in columns. More...

enum	LocationInfoStyle { Plain , WrapInAtSquareBracket , None }
	This option controls emitted location information style. More...

enum	WireSpillingHeuristic : unsigned { SpillLargeTermsWithNamehints = 1 }
	This controls extra wire spilling performed in PrepareForEmission to improve readablitiy and debuggability. More...

enum	{ DEFAULT_NAMEHINT_TERM_LIMIT = 3 }

using	ErrorHandlerT = llvm::function_ref< void(llvm::Twine)>
	Error callback type used to indicate errors parsing the options string. More...

Public Member Functions
	LoweringOptions ()=default
	Create a LoweringOptions with the default values. More...

	LoweringOptions (llvm::StringRef options, ErrorHandlerT errorHandler)
	Create a LoweringOptions and read in options from a string, overriding only the set options in the string. More...

	LoweringOptions (mlir::ModuleOp module)
	Create a LoweringOptions with values loaded from an MLIR ModuleOp. More...

void	parse (llvm::StringRef options, ErrorHandlerT callback)
	Read in options from a string, overriding only the set options in the string. More...

std::string	toString () const
	Returns a string representation of the options. More...

void	setAsAttribute (mlir::ModuleOp module)
	Write the verilog emitter options to a module's attributes. More...

void	parseFromAttribute (mlir::ModuleOp module)
	Load any emitter options from the module. More...

bool	isWireSpillingHeuristicEnabled (WireSpillingHeuristic heurisic) const

Static Public Member Functions
static mlir::StringAttr	getAttributeFrom (mlir::ModuleOp module)
	Return the value of the `circt.loweringOptions` in the specified module if present, or a null attribute if not. More...

Public Attributes
bool	noAlwaysComb = false
	If true, emits `sv.alwayscomb` as Verilog `always @(*)` statements. More...

bool	allowExprInEventControl = false
	If true, expressions are allowed in the sensitivity list of `always` statements, otherwise they are forced to be simple wires. More...

bool	disallowPackedArrays = false
	If true, eliminate packed arrays for tools that don't support them (e.g. More...

bool	disallowPackedStructAssignments = false
	If true, eliminate packed struct assignments in favor of a wire + assignments to the individual fields. More...

bool	disallowLocalVariables = false
	If true, do not emit SystemVerilog locally scoped "automatic" or logic declarations - emit top level wire and reg's instead. More...

bool	enforceVerifLabels = false
	If true, verification statements like `assert`, `assume`, and `cover` will always be emitted with a label. More...

unsigned	maximumNumberOfTermsPerExpression = DEFAULT_TERM_LIMIT

unsigned	emittedLineLength = DEFAULT_LINE_LENGTH

bool	explicitBitcast = false
	Add an explicit bitcast for avoiding bitwidth mismatch LINT errors. More...

bool	emitReplicatedOpsToHeader = false
	If true, replicated ops are emitted to a header file. More...

enum circt::LoweringOptions::LocationInfoStyle	locationInfoStyle = Plain

bool	disallowPortDeclSharing = false
	If true, every port is declared separately (each includes direction and type (e.g., `input [3:0]`)). More...

bool	printDebugInfo = false
	Print debug info. More...

bool	disallowMuxInlining = false
	If true, every mux expression is spilled to a wire. More...

unsigned	wireSpillingHeuristicSet = 0

unsigned	wireSpillingNamehintTermLimit = DEFAULT_NAMEHINT_TERM_LIMIT

bool	disallowExpressionInliningInPorts = false
	If true, every expression passed to an instance port is driven by a wire. More...

bool	mitigateVivadoArrayIndexConstPropBug = false
	If true, every expression used as an array index is driven by a wire, and the wire is marked as `(* keep = "true" *)`. More...

bool	emitWireInPorts = false
	If true, emit `wire` in port lists rather than nothing. More...

bool	emitBindComments = false
	If true, emit a comment wherever an instance wasn't printed, because it's emitted elsewhere as a bind. More...

bool	omitVersionComment = false
	If true, do not emit a version comment at the top of each verilog file. More...

bool	caseInsensitiveKeywords = false
	If true, then unique names that collide with keywords case insensitively. More...

bool	emitVerilogLocations = false
	If true, then update the the mlir to include output verilog locations. More...

bool	fixUpEmptyModules = false
	If true, add a dummy wire to empty modules to prevent tools from regarding the module as blackbox. More...

Detailed Description

Options which control the emission from CIRCT to Verilog.

Definition at line 27 of file LoweringOptions.h.

Member Typedef Documentation

◆ ErrorHandlerT

using circt::LoweringOptions::ErrorHandlerT = llvm::function_ref<void(llvm::Twine)>

Error callback type used to indicate errors parsing the options string.

Definition at line 29 of file LoweringOptions.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

This is the maximum number of terms in an expression before that expression spills a wire.

Enumerator
DEFAULT_TERM_LIMIT

Definition at line 91 of file LoweringOptions.h.

◆ anonymous enum

anonymous enum

This is the target width of lines in an emitted Verilog source file in columns.

Enumerator
DEFAULT_LINE_LENGTH

Definition at line 96 of file LoweringOptions.h.

◆ anonymous enum

anonymous enum

Enumerator
DEFAULT_NAMEHINT_TERM_LIMIT

Definition at line 137 of file LoweringOptions.h.

◆ LocationInfoStyle

enum circt::LoweringOptions::LocationInfoStyle

This option controls emitted location information style.

Enumerator
Plain
WrapInAtSquareBracket
None

Definition at line 106 of file LoweringOptions.h.

◆ WireSpillingHeuristic

enum circt::LoweringOptions::WireSpillingHeuristic : unsigned

This controls extra wire spilling performed in PrepareForEmission to improve readablitiy and debuggability.

Enumerator
SpillLargeTermsWithNamehints

Definition at line 125 of file LoweringOptions.h.

Constructor & Destructor Documentation

◆ LoweringOptions() [1/3]

circt::LoweringOptions::LoweringOptions ( )

default

Create a LoweringOptions with the default values.

◆ LoweringOptions() [2/3]

circt::LoweringOptions::LoweringOptions	(	llvm::StringRef	options,
		ErrorHandlerT	errorHandler
	)

Create a LoweringOptions and read in options from a string, overriding only the set options in the string.

◆ LoweringOptions() [3/3]

LoweringOptions::LoweringOptions ( mlir::ModuleOp module )

Create a LoweringOptions with values loaded from an MLIR ModuleOp.

This loads a string attribute with the key circt.loweringOptions. If there is an error parsing the attribute this will print an error using the ModuleOp.

Definition at line 29 of file LoweringOptions.cpp.

References parseFromAttribute().

Member Function Documentation

◆ getAttributeFrom()

StringAttr LoweringOptions::getAttributeFrom ( mlir::ModuleOp module )

static

Return the value of the circt.loweringOptions in the specified module if present, or a null attribute if not.

Definition at line 196 of file LoweringOptions.cpp.

Referenced by parseFromAttribute().

◆ isWireSpillingHeuristicEnabled()

bool circt::LoweringOptions::isWireSpillingHeuristicEnabled ( WireSpillingHeuristic heurisic ) const

inline

Definition at line 133 of file LoweringOptions.h.

References wireSpillingHeuristicSet.

Referenced by toString().

◆ parse()

void LoweringOptions::parse	(	llvm::StringRef	options,
		ErrorHandlerT	callback
	)

Read in options from a string, overriding only the set options in the string.

Definition at line 52 of file LoweringOptions.cpp.

References allowExprInEventControl, caseInsensitiveKeywords, DEFAULT_LINE_LENGTH, DEFAULT_NAMEHINT_TERM_LIMIT, DEFAULT_TERM_LIMIT, disallowExpressionInliningInPorts, disallowLocalVariables, disallowMuxInlining, disallowPackedArrays, disallowPackedStructAssignments, disallowPortDeclSharing, emitBindComments, emitReplicatedOpsToHeader, emittedLineLength, emitVerilogLocations, emitWireInPorts, enforceVerifLabels, explicitBitcast, fixUpEmptyModules, locationInfoStyle, maximumNumberOfTermsPerExpression, mitigateVivadoArrayIndexConstPropBug, noAlwaysComb, omitVersionComment, parseLocationInfoStyle(), parseWireSpillingHeuristic(), printDebugInfo, wireSpillingHeuristicSet, and wireSpillingNamehintTermLimit.

Referenced by circt::LoweringOptionsParser::parse(), and parseFromAttribute().

◆ parseFromAttribute()

void LoweringOptions::parseFromAttribute ( mlir::ModuleOp module )

Load any emitter options from the module.

If there is an error validating the attribute, this will print an error using the ModuleOp.

Definition at line 205 of file LoweringOptions.cpp.

References getAttributeFrom(), and parse().

Referenced by LoweringOptions().

◆ setAsAttribute()

void LoweringOptions::setAsAttribute ( mlir::ModuleOp module )

Write the verilog emitter options to a module's attributes.

Definition at line 200 of file LoweringOptions.cpp.

References circt::calyx::direction::get(), and toString().

◆ toString()

std::string LoweringOptions::toString ( ) const

Returns a string representation of the options.

Definition at line 133 of file LoweringOptions.cpp.

References allowExprInEventControl, assert(), caseInsensitiveKeywords, DEFAULT_LINE_LENGTH, DEFAULT_TERM_LIMIT, disallowExpressionInliningInPorts, disallowLocalVariables, disallowMuxInlining, disallowPackedArrays, disallowPackedStructAssignments, disallowPortDeclSharing, emitBindComments, emitReplicatedOpsToHeader, emittedLineLength, emitVerilogLocations, emitWireInPorts, enforceVerifLabels, explicitBitcast, fixUpEmptyModules, isWireSpillingHeuristicEnabled(), locationInfoStyle, maximumNumberOfTermsPerExpression, mitigateVivadoArrayIndexConstPropBug, noAlwaysComb, omitVersionComment, and printDebugInfo.

Referenced by setAsAttribute().

Member Data Documentation

◆ allowExprInEventControl

bool circt::LoweringOptions::allowExprInEventControl = false

If true, expressions are allowed in the sensitivity list of always statements, otherwise they are forced to be simple wires.

Some EDA tools rely on these being simple wires.

Definition at line 69 of file LoweringOptions.h.

Referenced by isExpressionUnableToInline(), parse(), and toString().

◆ caseInsensitiveKeywords

bool circt::LoweringOptions::caseInsensitiveKeywords = false

If true, then unique names that collide with keywords case insensitively.

This is used to avoid stricter lint warnings which, e.g., treat "REG" as a Verilog keyword.

Definition at line 165 of file LoweringOptions.h.

Referenced by circt::ExportVerilog::GlobalNameResolver::GlobalNameResolver(), parse(), and toString().

◆ disallowExpressionInliningInPorts

bool circt::LoweringOptions::disallowExpressionInliningInPorts = false

If true, every expression passed to an instance port is driven by a wire.

Some lint tools dislike expressions being inlined into input ports so this option avoids such warnings.

Definition at line 143 of file LoweringOptions.h.

Referenced by legalizeHWModule(), parse(), and toString().

◆ disallowLocalVariables

bool circt::LoweringOptions::disallowLocalVariables = false

If true, do not emit SystemVerilog locally scoped "automatic" or logic declarations - emit top level wire and reg's instead.

Definition at line 81 of file LoweringOptions.h.

Referenced by legalizeHWModule(), parse(), and toString().

◆ disallowMuxInlining

bool circt::LoweringOptions::disallowMuxInlining = false

If true, every mux expression is spilled to a wire.

Definition at line 121 of file LoweringOptions.h.

Referenced by circt::ExportVerilog::isExpressionEmittedInline(), parse(), and toString().

◆ disallowPackedArrays

bool circt::LoweringOptions::disallowPackedArrays = false

If true, eliminate packed arrays for tools that don't support them (e.g.

Yosys).

Definition at line 73 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ disallowPackedStructAssignments

bool circt::LoweringOptions::disallowPackedStructAssignments = false

If true, eliminate packed struct assignments in favor of a wire + assignments to the individual fields.

Definition at line 77 of file LoweringOptions.h.

Referenced by legalizeHWModule(), parse(), and toString().

◆ disallowPortDeclSharing

bool circt::LoweringOptions::disallowPortDeclSharing = false

If true, every port is declared separately (each includes direction and type (e.g., input [3:0])).

When false (default), ports share declarations when possible.

Definition at line 115 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ emitBindComments

bool circt::LoweringOptions::emitBindComments = false

If true, emit a comment wherever an instance wasn't printed, because it's emitted elsewhere as a bind.

Definition at line 157 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ emitReplicatedOpsToHeader

bool circt::LoweringOptions::emitReplicatedOpsToHeader = false

If true, replicated ops are emitted to a header file.

Definition at line 103 of file LoweringOptions.h.

Referenced by createSplitOutputFile(), exportSplitVerilogImpl(), exportVerilogImpl(), parse(), and toString().

◆ emittedLineLength

unsigned circt::LoweringOptions::emittedLineLength = DEFAULT_LINE_LENGTH

Definition at line 97 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ emitVerilogLocations

bool circt::LoweringOptions::emitVerilogLocations = false

If true, then update the the mlir to include output verilog locations.

Definition at line 168 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ emitWireInPorts

bool circt::LoweringOptions::emitWireInPorts = false

If true, emit wire in port lists rather than nothing.

Used in cases where `default_nettype is not set to wire.

Definition at line 153 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ enforceVerifLabels

bool circt::LoweringOptions::enforceVerifLabels = false

If true, verification statements like assert, assume, and cover will always be emitted with a label.

If the statement has no label in the IR, a generic one will be created. Some EDA tools require verification statements to be labeled.

Definition at line 87 of file LoweringOptions.h.

Referenced by legalizeModuleLocalNames(), parse(), and toString().

◆ explicitBitcast

bool circt::LoweringOptions::explicitBitcast = false

Add an explicit bitcast for avoiding bitwidth mismatch LINT errors.

Definition at line 100 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ fixUpEmptyModules

bool circt::LoweringOptions::fixUpEmptyModules = false

If true, add a dummy wire to empty modules to prevent tools from regarding the module as blackbox.

Definition at line 172 of file LoweringOptions.h.

Referenced by parse(), circt::ExportVerilog::prepareHWModule(), and toString().

◆ locationInfoStyle

enum circt::LoweringOptions::LocationInfoStyle circt::LoweringOptions::locationInfoStyle = Plain

Referenced by parse(), and toString().

◆ maximumNumberOfTermsPerExpression

unsigned circt::LoweringOptions::maximumNumberOfTermsPerExpression = DEFAULT_TERM_LIMIT

Definition at line 92 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ mitigateVivadoArrayIndexConstPropBug

bool circt::LoweringOptions::mitigateVivadoArrayIndexConstPropBug = false

If true, every expression used as an array index is driven by a wire, and the wire is marked as (* keep = "true" *).

Certain versions of Vivado produce incorrect synthesis results for certain arithmetic ops inlined into the array index.

Definition at line 149 of file LoweringOptions.h.

Referenced by legalizeHWModule(), parse(), and toString().

◆ noAlwaysComb

bool circt::LoweringOptions::noAlwaysComb = false

If true, emits sv.alwayscomb as Verilog always @(*) statements.

Otherwise, print them as always_comb.

Definition at line 64 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ omitVersionComment

bool circt::LoweringOptions::omitVersionComment = false

If true, do not emit a version comment at the top of each verilog file.

Definition at line 160 of file LoweringOptions.h.

Referenced by circt::ExportVerilog::SharedEmitterState::collectOpsForFile(), parse(), and toString().

◆ printDebugInfo

bool circt::LoweringOptions::printDebugInfo = false

Print debug info.

Definition at line 118 of file LoweringOptions.h.

Referenced by parse(), and toString().

◆ wireSpillingHeuristicSet

unsigned circt::LoweringOptions::wireSpillingHeuristicSet = 0

Definition at line 131 of file LoweringOptions.h.

Referenced by isWireSpillingHeuristicEnabled(), and parse().

◆ wireSpillingNamehintTermLimit

unsigned circt::LoweringOptions::wireSpillingNamehintTermLimit = DEFAULT_NAMEHINT_TERM_LIMIT

Definition at line 138 of file LoweringOptions.h.

Referenced by parse().

The documentation for this struct was generated from the following files:

/home/runner/work/circt-www/circt-www/circt_src/include/circt/Support/LoweringOptions.h
/home/runner/work/circt-www/circt-www/circt_src/lib/Support/LoweringOptions.cpp

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Typedef Documentation

◆ ErrorHandlerT

Member Enumeration Documentation

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ LocationInfoStyle

◆ WireSpillingHeuristic

Constructor & Destructor Documentation

◆ LoweringOptions() [1/3]

◆ LoweringOptions() [2/3]

◆ LoweringOptions() [3/3]

Member Function Documentation

◆ getAttributeFrom()

◆ isWireSpillingHeuristicEnabled()

◆ parse()

◆ parseFromAttribute()

◆ setAsAttribute()

◆ toString()

Member Data Documentation

◆ allowExprInEventControl

◆ caseInsensitiveKeywords

◆ disallowExpressionInliningInPorts

◆ disallowLocalVariables

◆ disallowMuxInlining

◆ disallowPackedArrays

◆ disallowPackedStructAssignments

◆ disallowPortDeclSharing

◆ emitBindComments

◆ emitReplicatedOpsToHeader

◆ emittedLineLength

◆ emitVerilogLocations

◆ emitWireInPorts

◆ enforceVerifLabels

◆ explicitBitcast

◆ fixUpEmptyModules

◆ locationInfoStyle

◆ maximumNumberOfTermsPerExpression

◆ mitigateVivadoArrayIndexConstPropBug

◆ noAlwaysComb

◆ omitVersionComment

◆ printDebugInfo

◆ wireSpillingHeuristicSet

◆ wireSpillingNamehintTermLimit