Commit Graph

638 Commits

Author SHA1 Message Date
Rupert Swarbrick ee2b5b7ed1 Generate an RTLIL representation of bind constructs
This code now takes the AST nodes of type AST_BIND and generates a
representation in the RTLIL for them.

This is a little tricky, because a binding of the form:

    bind baz foo_t foo_i (.arg (1 + bar));

means "make an instance of foo_t called foo_i, instantiate it inside
baz and connect the port arg to the result of the expression 1+bar".
Of course, 1+bar needs a cell for the addition. Where should that cell
live?

With this patch, the Binding structure that represents the construct
is itself an AST::AstModule module. This lets us put the adder cell
inside it. We'll pull the contents out and plonk them into 'baz' when
we actually do the binding operation as part of the hierarchy pass.

Of course, we don't want RTLIL::Binding to contain an
AST::AstModule (since kernel code shouldn't depend on a frontend), so
we define RTLIL::Binding as an abstract base class and put the
AST-specific code into an AST::Binding subclass. This is analogous to
the AST::AstModule class.
2021-08-13 17:11:35 -06:00
Zachary Snow 4fec3a85cd genrtlil: add width detection for AST_PREFIX nodes 2021-07-29 20:55:31 -04:00
Marcelina Kościelnicka 8bdc019730 verilog: Emit $meminit_v2 cell.
Fixes #2447.
2021-07-28 23:18:38 +02:00
Rupert Swarbrick 414154dd27 Add support for parsing the SystemVerilog 'bind' construct
This doesn't do anything useful yet: the patch just adds support for
the syntax to the lexer and parser and adds some tests to check the
syntax parses properly. This generates AST nodes, but doesn't yet
generate RTLIL.

Since our existing hierarchical_identifier parser doesn't allow bit
selects (so you can't do something like foo[1].bar[2].baz), I've also
not added support for a trailing bit select (the "constant_bit_select"
non-terminal in "bind_target_instance" in the spec). If we turn out to
need this in future, we'll want to augment hierarchical_identifier and
its other users too.

Note that you can't easily use the BNF from the spec:

    bind_directive ::=
        "bind" bind_target_scope [ : bind_target_instance_list]
               bind_instantiation ;
      | "bind" bind_target_instance bind_instantiation ;

even if you fix the lookahead problem, because code like this matches
both branches in the BNF:

    bind a b b_i (.*);

The problem is that 'a' could either be a module name or a degenerate
hierarchical reference. This seems to be a genuine syntactic
ambiguity, which the spec resolves (p739) by saying that we have to
wait until resolution time (the hierarchy pass) and take whatever is
defined, treating 'a' as an instance name if it names both an instance
and a module.

To keep the parser simple, it currently accepts this invalid syntax:

    bind a.b : c d e (.*);

This is invalid because we're in the first branch of the BNF above, so
the "a.b" term should match bind_target_scope: a module or interface
identifier, not an arbitrary hierarchical identifier.

This will fail in the hierarchy pass (when it's implemented in a
future patch).
2021-07-16 09:31:39 -04:00
Zachary Snow a9c8ca21d5 sv: fix two struct access bugs
- preserve signedness of struct members
- fix initial width detection of struct members (e.g., in case expressions)
2021-07-15 11:57:20 -04:00
Marcelina Kościelnicka 009940f56c rtlil: Make Process handling more uniform with Cell and Wire.
- add a backlink to module from Process
- make constructor and destructor protected, expose Module functions
  to add and remove processes
2021-07-12 00:47:34 +02:00
Zachary Snow 4446cfa524 sv: fix a few struct and enum memory leaks 2021-07-06 12:15:08 -04:00
Xiretza 62a42c317c ast: delete wires and localparams after finishing const evaluation 2021-06-14 13:56:51 -04:00
Xiretza 091295a5a5 verilog: fix leaking ASTNodes 2021-06-14 13:56:51 -04:00
Xiretza 9ca5a91724 ast: fix error condition causing assert to fail
type2str returns a string that doesn't start with $ or \, so it can't be
assigned to an IdString.
2021-06-14 13:56:51 -04:00
Claire Xen 55e8f5061a
Merge pull request #2817 from YosysHQ/claire/fixemails
Fixing old e-mail addresses and deadnames
2021-06-09 13:22:52 +02:00
Zachary Snow 2e697f5655 verilog: check for module scope identifiers during width detection
The recent fix for case expression width detection causes the width of
the expressions to be queried before they are simplified. Because the
logic supporting module scope identifiers only existed in simplify,
looking them up would fail during width detection. This moves the logic
to a common helper used in both simplify() and detectSignWidthWorker().
2021-06-08 15:03:16 -04:00
Zachary Snow c79fbfe0a1 mem2reg: tolerate out of bounds constant accesses
This brings the mem2reg behavior in line with the nomem2reg behavior.
2021-06-08 15:02:57 -04:00
Claire Xenia Wolf 72787f52fc Fixing old e-mail addresses and deadnames
s/((Claire|Xen|Xenia|Clifford)\s+)+(Wolf|Xen)\s+<(claire|clifford)@(symbioticeda.com|clifford.at|yosyshq.com)>/Claire Xenia Wolf <claire@yosyshq.com>/gi;
s/((Nina|Nak|N\.)\s+)+Engelhardt\s+<nak@(symbioticeda.com|yosyshq.com)>/N. Engelhardt <nak@yosyshq.com>/gi;
s/((David)\s+)+Shah\s+<(dave|david)@(symbioticeda.com|yosyshq.com|ds0.me)>/David Shah <dave@ds0.me>/gi;
s/((Miodrag)\s+)+Milanovic\s+<(miodrag|micko)@(symbioticeda.com|yosyshq.com)>/Miodrag Milanovic <micko@yosyshq.com>/gi;
s,https?://www.clifford.at/yosys/,http://yosyshq.net/yosys/,g;
2021-06-08 00:39:36 +02:00
Zachary Snow 8cfed1a979 sv: support tasks and functions within packages 2021-06-01 13:17:41 -04:00
Zachary Snow 0795b3ec07 verilog: fix case expression sign and width handling
- The case expression and case item expressions are extended to the
  maximum width among them, and are only interpreted as signed if all of
  them are signed
- Add overall width and sign detection for AST_CASE
- Add sign argument to genWidthRTLIL helper
- Coverage for both const and non-const case statements
2021-05-25 16:16:46 -04:00
Rupert Swarbrick 3421979f00 Change the type of current_module to Module
The current_module global is needed so that genRTLIL has somewhere to
put cells and wires that it generates as it makes sense of expressions
that it sees. However, that doesn't actually need to be an AstModule:
the Module base class is enough.

This patch should cause no functional change, but the point is that
it's now possible to call genRTLIL with a module that isn't an
AstModule as "current_module". This will be needed for 'bind' support.
2021-05-13 23:44:48 -04:00
Rupert Swarbrick 51ed4a7149 Use range-based for loop in AST::process
No functional change: just get rid of the explicit iterator and
replace (*it)-> with child->. It's even the same number of characters,
but is hopefully a little easier to read.
2021-05-13 23:37:27 -04:00
Zachary Snow c58bb1d2e1 ast: make design available to process_module() 2021-03-24 10:21:00 -04:00
Marcelina Kościelnicka 8740fdf1d7 ast: Use better parameter serialization for paramod names.
Calling log_signal is problematic for several reasons:

- with recent changes, empty string is serialized as { }, which violates
  the "no spaces in IdString" rule
- the type (plain / real / signed / string) is dropped, wrongly conflating
  functionally different values and potentially introducing a subtle
  elaboration bug

Instead, use a custom simple serialization scheme.
2021-03-18 00:52:00 +01:00
Xiretza 092e923330 verilog: fix buf/not primitives with multiple outputs
From IEEE1364-2005, section 7.3 buf and not gates:

> These two logic gates shall have one input and one or more outputs.
> The last terminal in the terminal list shall connect to the input of the
> logic gate, and the other terminals shall connect to the outputs of
> the logic gate.

yosys does not follow this and instead interprets the first argument as
the output, the second as the input and ignores the rest.
2021-03-17 11:44:03 -04:00
Zachary Snow 4f187d53c5 verilog: support module scope identifiers in parametric modules 2021-03-16 11:01:30 -04:00
Zachary Snow 640b9927fa sv: allow globals in one file to depend on globals in another
This defers the simplification of globals so that globals in one file
may depend on globals in other files. Adds a simplify() call downstream
because globals are appended at the end.
2021-03-12 11:22:41 -05:00
Zachary Snow cb9f3b6abf verilog: disallow overriding global parameters
It was previously possible to override global parameters on a
per-instance basis. This could be dangerous when using positional
parameter bindings, hiding oversupplied parameters.
2021-03-11 12:36:51 -05:00
whitequark 26e01a67db
Merge pull request #2643 from zachjs/fix-param-no-default-log
Fix param without default log line
2021-03-08 16:36:03 -08:00
Marcelina Kościelnicka 89c74ffd71 verilog: Use proc memory writes in the frontend. 2021-03-08 20:16:29 +01:00
Zachary Snow bdc4fd0e92 Fix param without default log line 2021-03-07 16:06:25 -05:00
whitequark 9bb839c613
Merge pull request #2626 from zachjs/param-no-default
sv: support for parameters without default values
2021-03-07 05:48:03 -08:00
whitequark 72ae15c77c
Merge pull request #2632 from zachjs/width-limit
verilog: impose limit on maximum expression width
2021-03-07 03:45:41 -08:00
Zachary Snow b1a8e73a60 sv: fix some edge cases for unbased unsized literals
- Fix explicit size cast of unbased unsized literals
- Fix unbased unsized literal bound directly to port
- Output `is_unsized` flag in `dumpAst`
2021-03-06 15:20:34 -05:00
Zachary Snow c18ddbcd82 verilog: impose limit on maximum expression width
Designs with unreasonably wide expressions would previously get stuck
allocating memory forever.
2021-03-04 15:20:52 -05:00
Zachary Snow d738b2c127 sv: support for parameters without default values
- Modules with a parameter without a default value will be automatically
  deferred until the hierarchy pass
- Allows for parameters without defaults as module items, rather than
  just int the `parameter_port_list`, despite being forbidden in the LRM
- Check for parameters without defaults that haven't been overriden
- Add location info to parameter/localparam declarations
2021-03-02 10:43:53 -05:00
whitequark ca5f5ffcd6
Merge pull request #2615 from zachjs/genrtlil-conflict
genrtlil: improve name conflict error messaging
2021-03-01 08:10:19 -08:00
Zachary Snow bbff844acd genrtlil: improve name conflict error messaging 2021-02-26 18:08:23 -05:00
Michael Singer 04b41ed04a Implement $countones, $isunknown and $onehot{,0} 2021-02-26 12:28:58 -05:00
Michael Singer 8434ba5a3b Implement $countbits function 2021-02-26 12:28:58 -05:00
Zachary Snow 22bed38540 Extend simplify() recursion warning 2021-02-26 12:11:23 -05:00
Marcelina Kościelnicka f4f471f342 frontend: Make helper functions for printing locations. 2021-02-23 23:51:52 +01:00
whitequark ad2960adb7
Merge pull request #2594 from zachjs/func-arg-width
verilog: fix sizing of constant args for tasks/functions
2021-02-23 21:46:16 +00:00
Zachary Snow b6af90fe20 verilog: fix sizing of constant args for tasks/functions
- Simplify synthetic localparams for normal calls to update their width
    - This step was inadvertently removed alongside `added_mod_children`
- Support redeclaration of constant function arguments
    - `eval_const_function` never correctly handled this, but the issue
      was not exposed in the existing tests until the recent change to
      always attempt constant function evaluation when all-const args
      are used
- Check asserts in const_arg_loop and const_func tests
- Add coverage for width mismatch error cases
2021-02-21 15:44:43 -05:00
Zachary Snow 8de2e863af verilog: support recursive functions using ternary expressions
This adds a mechanism for marking certain portions of elaboration as
occurring within unevaluated ternary branches. To enable elaboration of
the overall ternary, this also adds width detection for these
unelaborated function calls.
2021-02-12 14:43:42 -05:00
whitequark 326f1c9db4
Merge pull request #2573 from zachjs/repeat-call
verilog: refactored constant function evaluation
2021-02-11 19:56:41 +00:00
Zachary Snow 4b2f977331 genrtlil: fix signed port connection codegen failures
This fixes binding signed memory reads, signed unary expressions, and
signed complex SigSpecs to ports. This also sets `is_signed` for wires
generated from signed params when -pwires is used. Though not necessary
for any of the current usages, `is_signed` is now appropriately set when
the `extendWidth` helper is used.
2021-02-05 19:51:30 -05:00
Zachary Snow b93b6f4285 verilog: refactored constant function evaluation
Elaboration now attempts constant evaluation of any function call with
only constant arguments, regardless of the context or contents of the
function. This removes the concept of "recommended constant evaluation"
which previously applied to functions with `for` loops or which were
(sometimes erroneously) identified as recursive. Any function call in a
constant context (e.g., `localparam`) or which contains a constant-only
procedural construct (`while` or `repeat`) in its body will fail as
before if constant evaluation does not succeed.
2021-02-04 10:18:27 -05:00
whitequark baf1875307
Merge pull request #2529 from zachjs/unnamed-genblk
verilog: significant block scoping improvements
2021-02-04 09:57:28 +00:00
Zachary Snow fe74b0cd95 verilog: significant block scoping improvements
This change set contains a number of bug fixes and improvements related to
scoping and resolution in generate and procedural blocks. While many of the
frontend changes are interdependent, it may be possible bring the techmap
changes in under a separate PR.

Declarations within unnamed generate blocks previously encountered issues
because the data declarations were left un-prefixed, breaking proper scoping.
The LRM outlines behavior for generating names for unnamed generate blocks. The
original goal was to add this implicit labelling, but doing so exposed a number
of issues downstream. Additional testing highlighted other closely related scope
resolution issues, which have been fixed. This change also adds support for
block item declarations within unnamed blocks in SystemVerilog mode.

1. Unlabled generate blocks are now implicitly named according to the LRM in
   `label_genblks`, which is invoked at the beginning of module elaboration
2. The Verilog parser no longer wraps explicitly named generate blocks in a
   synthetic unnamed generate block to avoid creating extra hierarchy levels
   where they should not exist
3. The techmap phase now allows special control identifiers to be used outside
   of the topmost scope, which is necessary because such wires and cells often
   appear in unlabeled generate blocks, which now prefix the declarations within
4. Some techlibs required modifications because they relied on the previous
   invalid scope resolution behavior
5. `expand_genblock` has been simplified, now only expanding the outermost
   scope, completely deferring the inspection and elaboration of nested scopes;
   names are now resolved by looking in the innermost scope and stepping outward
6. Loop variables now always become localparams during unrolling, allowing them
   to be resolved and shadowed like any other identifier
7. Identifiers in synthetic function call scopes are now prefixed and resolved
   in largely the same manner as other blocks
     before: `$func$\func_01$tests/simple/scopes.blk.v:60$5$\blk\x`
      after: `\func_01$func$tests/simple/scopes.v:60$5.blk.x`
8. Support identifiers referencing a local generate scope nested more
   than 1 level deep, i.e. `B.C.x` while within generate scope `A`, or using a
   prefix of a current or parent scope, i.e. `B.C.D.x` while in `A.B`, `A.B.C`,
   or `A.B.C.D`
9. Variables can now be declared within unnamed blocks in SystemVerilog mode

Addresses the following issues: 656, 2423, 2493
2021-01-31 09:42:09 -05:00
Marcelina Kościelnicka a4c04d1b90 ast: fix dump_vlog display of casex/casez
The first child of AST_CASE is the case expression, it's subsequent
childrean that are AST_COND* and can be used to discriminate the type of
the case.
2021-01-29 16:28:15 +01:00
David Shah 09311b6581 dpi: Support for chandle type
Signed-off-by: David Shah <dave@ds0.me>
2021-01-23 22:24:31 +00:00
Kamil Rakoczy 61501e3266 Fix input/output attributes when resolving typedef of wire
Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com>
2021-01-18 17:31:22 +01:00
Zachary Snow 2085d9a55d verilog: improved support for recursive functions 2020-12-31 18:33:59 -07:00