Exception indicating that a blackbox wasn't found
Handle source for Verilog ExtModules (BlackBoxes)
Handle source for Verilog ExtModules (BlackBoxes)
This transform handles the moving of Verilog source for black boxes into the target directory so that it can be accessed by verilator or other backend compilers While parsing it's annotations it looks for a BlackBoxTargetDir annotation that will set the directory where the Verilog will be written. This annotation is typically be set by the execution harness, or directly in the tests
Finds and detects combinational logic loops in a circuit, if any exist.
Finds and detects combinational logic loops in a circuit, if any exist. Returns the input circuit with no modifications.
firrtl.transforms.CheckCombLoops.CombLoopException
if a loop is found
The pass will throw exceptions on "false paths"
,The pass relies on ExtModulePathAnnotations to find loops through ExtModules
,The pass looks for loops through combinational-read memories
,Output form: Low FIRRTL (identity transform)
,Input form: Low FIRRTL
Combine Cat DoPrims
Combine Cat DoPrims
Expands the arguments of any Cat DoPrims if they are references to other Cat DoPrims. Operates only on Cat DoPrims that are node values.
Use MaxCatLenAnnotation to limit the number of elements that can be concatenated. The default maximum number of elements is 10.
Dead Code Elimination (DCE)
Dead Code Elimination (DCE)
Performs DCE by constructing a global dependency graph starting with top-level outputs, external module ports, and simulation constructs as circuit sinks. External modules can optionally be eligible for DCE via the OptimizableExtModuleAnnotation.
Dead code is eliminated across module boundaries. Wires, ports, registers, and memories are all eligible for removal. Components marked with a DontTouchAnnotation will be treated as a circuit sink and thus anything that drives such a marked component will NOT be removed.
This transform preserves deduplication. All instances of a given firrtl.ir.DefModule are treated as the same individual module. Thus, while certain instances may have dead code due to the circumstances of their instantiation in their parent module, they will still not be removed. To remove such modules, use the NoDedupAnnotation to prevent deduplication.
Only use on legal Firrtl.
Only use on legal Firrtl.
Specifically, the restriction of instance loops must have been checked, or else this pass can infinitely recurse
A component that should be preserved
A component that should be preserved
DCE treats the component as a top-level sink of the circuit
Replaces adding a negative literal with subtracting that literal
Replaces adding a negative literal with subtracting that literal
Verilator has a lint warning if a literal is negated in an expression, because it adds a bit to the literal and thus not all expressions in the add are the same. This is fixed here when we directly subtract the literal instead.
Takes flatten annotations for module instances and modules and inline the entire hierarchy of modules down from the annotations.
Takes flatten annotations for module instances and modules and inline the entire hierarchy of modules down from the annotations. This transformation instantiates and is based on the InlineInstances transformation.
Instances of extmodules are not (and cannot be) inlined
,Flattening a module means inlining all its fully-defined child instances
Tags an annotation to be consumed by this transform
Flatten register update
Flatten register update
This transform flattens register updates into a single expression on the rhs of connection to the register
Splits a module into multiple modules by grouping its components via GroupAnnotation's Tries to deduplicate the resulting circuit
Specifies a group of components, within a module, to pull out into their own module Components that are only connected to a group's components will also be included
Specifies a group of components, within a module, to pull out into their own module Components that are only connected to a group's components will also be included
components in this group
suggested name of the new module
suggested name of the instance of the new module
suggested suffix of any output ports of the new module
suggested suffix of any input ports of the new module
Splits a module into multiple modules by grouping its components via GroupAnnotation's
Transform that applies an identity function.
Transform that applies an identity function. This returns an unmodified CircuitState.
Infers the concrete type of ResetTypes by their connections
Infers the concrete type of ResetTypes by their connections
There are 3 cases 1. An abstract reset driven by and/or driving only asynchronous resets will be inferred as asynchronous reset 1. An abstract reset driven by and/or driving both asynchronous and synchronous resets will error 1. Otherwise, the reset is inferred as synchronous (i.e. the abstract reset is only invalidated or is driven by or drives only synchronous resets)
This transform should be run before DedupModules so that similar Modules from generator languages like Chisel can infer differently
,This is a global inference because ports can be of type ResetType
Inline nodes that are simple bits
Inline nodes that are simple casts
Inline nodes that are simple nots
Turns andr for expression > 64-bit into equality check with all ones
Turns andr for expression > 64-bit into equality check with all ones
Workaround a bug in Verilator v4.026 - v4.032 (inclusive). For context, see https://github.com/verilator/verilator/issues/2300
Ensure Clocks to be emitted are legal Verilog
A case class that represents a net in the circuit.
A case class that represents a net in the circuit. This is necessary since combinational loop checking is an analysis on the netlist of the circuit; the fields are specialized for low FIRRTL. Since all wires are ground types, a given ground type net may only be a subfield of an instance or a memory port. Therefore, it is uniquely specified within its module context by its name, its optional parent instance (a WDefInstance or WDefMemory), and its optional memory port name.
A component, e.g.
A component, e.g. register etc. Must be declared only once under the TopAnnotation
An firrtl.ir.ExtModule that can be optimized
An firrtl.ir.ExtModule that can be optimized
Firrtl does not know the semantics of an external module. This annotation provides some "greybox" information that the external module does not have any side effects. In particular, this means that the external module can be Dead Code Eliminated.
Unlike DontTouchAnnotation, we don't care if the annotation is deleted
Transform that removes collisions with reserved keywords
Remove Synchronous Reset
Remove Synchronous Reset
This pass must run after LowerTypes
Replace wires with nodes in a legal, flow-forward order
Replace wires with nodes in a legal, flow-forward order
This pass must run after LowerTypes because Aggregate-type wires have multiple connections that may be impossible to order in a flow-foward way
Rename Modules
Rename Modules
using namespace created by analyses.GetNamespace, create unique names for modules
Replaces non-expanding arithmetic
Replaces non-expanding arithmetic
In the case where the result of add
or sub
immediately throws away the expanded msb, this
transform will replace the operation with a non-expanding operator addw
or subw
respectively.
This replaces some FIRRTL primops with ops that are not actually legal FIRRTL. They are useful for emission to languages that support non-expanding arithmetic (like Verilog)
Lowers memories without splitting them, but without the complexity of ReplaceMemMacros
Transform that removes collisions with Verilog keywords
Utility functions for DedupModules
If this Annotation exists in an AnnotationSeq, then the firrtl.transforms.DedupModules transform will *NOT* be run on the circuit.
If this Annotation exists in an AnnotationSeq, then the firrtl.transforms.DedupModules transform will *NOT* be run on the circuit.
Indicate that DCE should not be run