CHANGELOG.md

Unreleased

New Features

• Added conversion of severity system tasks and elaboration system tasks (e.g., $info) into $display tasks that include source file and scope information; pass -E SeverityTask to disable this new conversion
• Added parsing support for not, strong, weak, nexttime, and s_nexttime in assertion property expressions
• Added --bugpoint utility for minimizing test cases for issue submission

Bug Fixes

• Fixed --write path/to/dir/ with directives like `default_nettype
• Fixed logic incorrectly converted to wire even when provided to a task or function output port
• Fixed conversion of enum item names and typenames nested deeply within the left-hand side of an assignment
• Fixed input signed ports of interface-using modules producing invalid declarations after inlining
• Fixed inlining of interfaces and interface-bound modules containing port declarations tagged with an attribute
• Fixed stray attributes producing invalid nested output when attached to inlined interfaces and interface-bounds modules
• Fixed `resetall not resetting the `default_nettype

Other Enhancements

• --write path/to/dir/ can now also be used with --pass-through

v0.0.12

Breaking Changes

• Removed deprecated CLI flags -d/-e/-i, which have been aliased to -D/-E/-I with a warning since late 2019

New Features

• unique, unique0, and priority case statements now produce corresponding parallel_case and full_case statement attributes
• Added support for attributes in unary, binary, and ternary expressions
• Added support for streaming concatenations within ternary expressions
• Added support for shadowing interface names with local typenames
• Added support for passing through wait statements

Bug Fixes

• Fixed signed unsized literals with a leading 1 bit (e.g., 'sb1, 'sh8f) incorrectly sign-extending in size and type casts
• Fixed conflicting genvar names when inlining interfaces and modules that use them; all genvars are now given a design-wide unique name
• Fixed unconverted structs within explicit type casts
• Fixed byte order of strings in size casts
• Fixed unconverted multidimensional struct fields within dimension queries
• Fixed non-typenames (e.g., from packages or subsequent declarations) improperly shadowing the names of struct pattern fields
• Fixed shadowing of interface array indices passed to port connections
• Fixed failure to resolve typenames suffixed with dimensions in contexts permitting both types and expressions, e.g., $bits(T[W-1:0])
• Fixed an issue that prevented parsing tasks and functions with inout ports
• Fixed errant constant folding of shadowed non-trivial localparams
• Fixed conversion of function calls with no arguments passed to other functions
• Fixed certain non-ANSI style port declarations being incorrectly reported as incompatible

Other Enhancements

• always_comb and always_latch now reliably execute at time zero
• Added error checking for unresolved typenames
• Added constant folding for || and &&
• input reg module ports are now converted to input wire
• x | |y and x & &y are now output as x | (|y) and x & (&y)

v0.0.11

New Features

• Added -y/--libdir for specifying library directories from which to automatically load modules and interfaces used in the design that are not found in the provided input files
• Added --top for pruning unneeded modules during conversion
• Added --write path/to/dir/ for creating an output .v in the specified preexisting directory for each module in the converted result
• The string data type is now dropped from parameters and localparams
• Added support for passing through sequence and property declarations

Bug Fixes

• Fixed crash when converting multi-dimensional arrays or arrays of structs or unions used in certain expressions involving unbased unsized literals
• Fixed module-level localparams being needlessly inlined when forming longest static prefixes, which could cause deep recursion and run out of memory on some designs
• Fixed overzealous removal of explicitly unconnected ports (e.g., .a())
• Fixed an issue that left always_comb, always_latch, and always_ff unconverted when tagged with an attribute
• Fixed unneeded scoping of constant function calls used in type lookups
• /*/ is no longer interpreted as a self-closing block comment, e.g., $display("a"/*/,"b"/* */); previously printed "ab", but now prints "a"
• Fixed missing begin/end when disambiguating procedural branches tagged with an attribute
• Fixed keywords included in the "1364-2001" and "1364-2001-noconfig" begin_keywords version specifiers

Other Enhancements

• Added elaboration for accesses to fields of struct constants, which can substantially improve conversion speed on some designs
• Added constant folding for comparisons involving string literals
• Port connection attributes (e.g., pulp_soc.sv) are now ignored with a warning rather than failing to parse
• Improved error message when specifying an extraneous named port connection
• Improved error message for an unfinished conditional directive, e.g., an ifdef with no endif
• Added checks for accidental usage of interface or module names as type names

v0.0.10

Breaking Changes

• --write adjacent no longer forbids overwriting existing generated files

New Features

• Added support for assignments within expressions (e.g., x = ++y;)
• Added support for excluding the conversion of unbased unsized literals (e.g., '1, 'x) via --exclude UnbasedUniszed
• Added support for enumerated type ranges (e.g., enum { X[3:5] })
• Added support for complex event expressions (e.g., @(x ^ y))
• Added support for the SystemVerilog edge event
• Added support for cycle delay ranges in assertion sequence expressions
• Added support for procedural continuous assignments (assign/deassign and force/release)
• Added conversion for do while loops
• Added support for hierarchical calls to functions with no inputs
• Added support for passing through DPI imports and exports
• Added support for passing through functions with output ports
• Extended applicability of simplified Yosys-compatible for loop elaboration

Other Enhancements

• Certain errors raised during conversion now also provide hierarchical and approximate source location information to help locate the error

Bug Fixes

• Fixed inadvertent design behavior changes caused by constant folding removing intentional width-extending operations such as + 0 and * 1
• Fixed forced conversion to reg of data sensed in an edge-controlled procedural assignment
• always_comb and always_latch now generate explicit sensitivity lists where necessary because of calls to functions which reference non-local data
• Fixed signed struct fields being converted to unsigned expressions when accessed directly
• Fixed conversion of casts using structs containing multi-dimensional fields
• Fixed incorrect name resolution conflicts raised during interface inlining
• Fixed handling of interface instances which shadow other declarations
• Fixed names like <pkg>_<name> being shadowed by elaborated packages

v0.0.9

Breaking Changes

• Unsized number literals exceeding the maximum width of 32 bits (e.g., 'h1_ffff_ffff, 4294967296) are now truncated and produce a warning, rather than being silently extended
  • Support for unsized number literals exceeding the standard-imposed 32-bit limit can be re-enabled with --oversized-numbers
• Input source files are now decoded as UTF-8 on all platforms, with transcoding failures tolerated, enabling reading files encoded using other ASCII supersets (e.g., Latin-1)

New Features

• Added support for non-ANSI style port declarations where the port declaration is separate from the corresponding net or variable declaration
• Added support for typed value parameters declared in parameter port lists without explicitly providing a leading parameter or localparam marker
• Added support for tasks and functions with implicit port directions
• Added support for parameters which use a type-of as the data type
• Added support for bare delay controls with real number delays
• Added support for deferred immediate assertions

Other Enhancements

• Explicitly-sized number literals with non-zero bits exceeding the given width (e.g., 1'b11, 3'sd8, 2'o7) are now truncated and produce a warning, rather than yielding a cryptic error
• Number literals with leading zeroes which extend beyond the width of the literal (e.g., 1'b01, 'h0_FFFF_FFFF) now produce a warning
• Non-positive integer size casts are now detected and forbidden
• Negative indices in struct pattern literals are now detected and forbidden
• Escaped vendor block comments in macro bodies are now tolerated
• Illegal bit-selects and part-selects of scalar struct fields are now detected and forbidden, rather than yielding an internal assertion failure

Bug Fixes

• Fixed parsing of sized ports with implicit directions
• Fixed flattening of arrays used in nested ternary expressions
• Fixed preprocessing of line comments which are neither preceded nor followed by whitespace except for the newline which terminates the comment
• Fixed parsing of alternate spacings of @(*)
• Fixed conversion of interface-based typedefs when used with explicit modports, unpacked arrays, or in designs with multi-dimensional instances
• Fixed conversion of module-scoped references to modports
• Fixed conversion of references to modports nested within types in expressions
• Fixed assertion removal in verbose mode causing orphaned statements

v0.0.8

Future releases will have complete change logs.