Commit graph

86 commits

Author SHA1 Message Date
whitequark 2492f490f5 back.rtlil: use a more principled approach to attributes. NFC.
This also refactors the RTLIL builder to use a more aspect-oriented
approach.
2019-07-08 09:10:09 +00:00
whitequark 82903e493a back.rtlil: emit \src attributes for processes via Switch and Assign.
The locations are unfortunately not very precise, but they provide
some improvement over status quo.
2019-07-03 16:27:54 +00:00
whitequark ea25806971 back.rtlil: emit \sig$next wires instead of \$next\sig. NFC.
Just a bit more readable.
2019-07-02 18:06:50 +00:00
whitequark dd5e513e42 back.rtlil: do not emit $next wires for comb signals.
According to RTLIL semantics (that was undocumented before today),
the only purpose of `sync always` is to enable inference of latches,
because there is no other way to express them in terms of RTLIL
processes without ending up with a combinatorial loop. But, nMigen
specifically avoids latches, so this is not necessary.

This change results in major improvements in Verilog readability.

See also #98.
2019-07-02 18:05:34 +00:00
whitequark f75a0163f9 back.rtlil: fix Array regression in 32446831.
Fixes #117.
2019-07-01 01:53:56 +00:00
whitequark 32446831b4 hdl.{ast,dsl}, back.{pysim,rtlil}: allow multiple case values.
This means that instead of:

    with m.Case(0b00):
        <body>
    with m.Case(0b01):
        <body>

it is legal to write:

    with m.Case(0b00, 0b01):
        <body>

with no change in semantics, and slightly nicer RTLIL or Verilog
output.

Fixes #103.
2019-06-28 04:37:08 +00:00
whitequark 48d4ee4031 hdl.ir, back.rtlil: allow specifying attributes on instances.
Fixes #107.
2019-06-28 04:14:38 +00:00
whitequark d2d8c2b8bf back.rtlil: mask memory init values.
This handles both init values that are too wide, which happens if
their magnitude is too high, or if they're negative.

Fixes #96.
2019-06-11 03:43:09 +00:00
whitequark f17375a60b back.rtlil: allow specifying platform for convert(). 2019-05-26 17:10:56 +00:00
whitequark 921f506e69 back.rtlil: assign undriven signals to their reset value.
Fixes #35.
2019-05-13 08:33:55 +00:00
whitequark 585514e6ed hdl.ir: rework named port handling for Instances.
The main purpose of this rework is cleanup, to avoid specifying
the direction of input ports in an implicit, ad-hoc way using
the named ports and ports dictionaries.

While working on this I realized that output ports can be connected
to anything that is valid on LHS, so this is now supported too.
2019-04-22 07:46:47 +00:00
whitequark 85ae99c1b4 back.rtlil: emit nmigen.hierarchy attribute.
Fixes #54.
2019-04-21 07:55:08 +00:00
whitequark 083016d747 back.rtlil: only expand legalized values in Array/Part context on RHS.
Otherwise the following code fails to compile:

    index = Signal(1)
    array = Array(range(2))
    with m.If(0 == array[index]):
        m.d.sync += index.eq(0)

Fixes #51.
2019-04-21 06:43:31 +00:00
whitequark f22106e5ef back.rtlil: allow record slices on LHS. 2019-04-20 08:12:29 +00:00
whitequark a57c72d606 back.rtlil: fix off-by-one in Part legalization.
Fixes #52.
2019-03-28 05:12:12 +00:00
whitequark 43e4833ddb back.rtlil: accept ast.Const as cell parameter. 2019-01-26 23:25:54 +00:00
whitequark b133eb735f back.rtlil: accept any elaboratable, not just fragments. 2019-01-26 16:11:29 +00:00
whitequark b50b47d984 hdl.ast: give Assert and Assume their own src_loc.
This helps with patterns like `Assert(fsm.ongoing("IDLE"))`, which
would otherwise point into nMigen internals.
2019-01-19 00:08:51 +00:00
whitequark 66466a8a0e back.rtlil: only emit each AnyConst/AnySeq cell once.
These are semantically like signals, not like constants.
2019-01-18 01:34:48 +00:00
whitequark 198efcad31 hdl.xfrm: add SampleLowerer. 2019-01-17 01:41:02 +00:00
whitequark f2425001aa back.rtlil: slightly nicer naming for $next signals. NFC. 2019-01-16 17:20:38 +00:00
whitequark 935bf2d8cf back.rtlil: rename \sig$next to $next$sig.
These used to serve a useful purpose being public, back when the RTLIL
backend was immature. Not anymore; now they merely clutter up views
in gtkwave and so on.
2019-01-16 14:51:20 +00:00
whitequark 6191760c30 Unbreak 655d02d5. 2019-01-15 23:09:10 +00:00
William D. Jones 655d02d5b8 back.rtlil: Generate $anyconst and $anyseq cells. 2019-01-15 22:52:45 +00:00
whitequark ef1e0b8d55 back.rtlil: translate empty slices correctly. 2019-01-02 18:14:29 +00:00
William D. Jones f31055a4ef back.rtlil: Generate RTLIL for Assert/Assume statements. 2019-01-02 11:17:39 +00:00
whitequark 1a9dcd2f28 back.rtlil: fix typo. 2019-01-01 08:50:28 +00:00
whitequark ae3c5834ed back.rtlil: match shape of Array elements to ArrayProxy shape.
Fixes #15.
2018-12-31 03:43:34 +00:00
whitequark cdc40eaa9b back.rtlil: fix typo. 2018-12-31 03:37:38 +00:00
whitequark 92a96e1644 hdl.rec: add basic record support. 2018-12-28 13:22:10 +00:00
whitequark b4fbef65ca back.rtlil: clarify $verilog_initial_trigger behavior. NFC. 2018-12-26 06:45:57 +00:00
whitequark 010ddb96b5 back.rtlil: unbreak d47c1f8a. 2018-12-24 19:11:07 +00:00
whitequark d47c1f8a8a back.rtlil: use one $meminit cell, not one per word.
This is *far* more efficient.
2018-12-24 11:53:58 +00:00
whitequark 98f554aa08 hdl.xfrm, back.rtlil: implement and use LHSGroupFilter.
This is a refactoring to simplify reusing the filtering code in
simulation, and separate that concern from backends in general.
2018-12-24 02:17:28 +00:00
whitequark 1c7c75a254 hdl.xfrm: implement SwitchCleaner, for pruning empty switches. 2018-12-24 02:02:59 +00:00
whitequark fc0fb9d89f back.rtlil: always output negative values as two's complement.
- is valid in RTLIL but means something entirely different.
2018-12-24 01:38:32 +00:00
whitequark 5702767263 back.rtlil: emit dummy logic to work around Verilog deficiencies. 2018-12-23 10:14:42 +00:00
whitequark 9faa1d3742 back.rtlil: do not translate empty fragments.
The resulting Verilog confuses some frontends.
2018-12-23 09:20:02 +00:00
whitequark 45a474788c back.rtlil: only translate switch tests once.
This seems to affect synthesis with Yosys but only marginally.
It is mostly a speed and readability improvement.
2018-12-23 07:17:52 +00:00
whitequark 2b6ddbb713 back.rtlil: fix swapped operands in mux codegen. 2018-12-23 06:47:38 +00:00
whitequark 59c7540aeb back.rtlil: split processes as finely as possible.
This makes simulation work correctly (by introducing delta cycles,
and therefore, making the overall Verilog simulation deterministic)
at the price of pessimizing mux trees generated by Yosys and Synplify
frontends, sometimes severely.
2018-12-22 10:03:16 +00:00
whitequark d29929912f back.rtlil: remove useless condition. NFC. 2018-12-22 07:24:15 +00:00
whitequark 37b81309d3 back.rtlil: always initialize the entire memory.
This avoids reading 'x from the memory in simulation. In general,
FPGA memories can only be initialized in block granularity, and
zero-initializing is cheap, so this is not a significant issue with
resource consumption.
2018-12-22 05:27:42 +00:00
whitequark 8d58cbf230 back.rtlil: more consistent prefixing for subfragment port wires. 2018-12-21 04:21:11 +00:00
whitequark 2b4a8510ca back.rtlil: implement memories. 2018-12-21 01:55:59 +00:00
whitequark 6672ab2e3f back.rtlil: explicitly pad constants with zeroes.
I'm not sure what exactly RTLIL does when a constant isn't as long
as its bit width, and there's no reason to keep the ambiguity.
2018-12-21 01:51:18 +00:00
whitequark 221f108fbe back.rtlil: fix translation of Cat. 2018-12-21 01:48:02 +00:00
whitequark f7fec804ec ir: allow non-Signals in Instance ports. 2018-12-20 23:40:40 +00:00
whitequark c7f9386eab fhdl.ir: add black-box fragments, fragment parameters, and Instance. 2018-12-17 22:55:39 +00:00
whitequark 8d1639a5a8 hdl, back: add and use SignalSet/SignalDict. 2018-12-17 17:21:29 +00:00