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Replace DelayInfo with DelayPair/DelayQuad

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This replaces the arch-specific DelayInfo structure with new DelayPair
(min/max only) and DelayQuad (min/max for both rise and fall) structures
that form part of common code.

This further reduces the amount of arch-specific code; and also provides
useful data structures for timing analysis which will need to delay
with pairs/quads of delays as it is improved.

While there may be a small performance cost to arches that didn't
separate the rise/fall cases (arches that aren't currently separating
the min/max cases just need to be fixed...) in DelayInfo, my expectation
is that inlining will mean this doesn't make much difference.

Signed-off-by: gatecat <gatecat@ds0.me>
This commit is contained in:
gatecat
2021-02-19 10:39:57 +00:00
parent 8376db94a7
commit 7922b3bfc4
33 changed files with 243 additions and 498 deletions
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25
docs/archapi.md
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@@ -43,21 +43,6 @@ With the exception of `ArchNetInfo` and `ArchCellInfo`, the following types shou
A scalar type that is used to represent delays. May be an integer or float type.
### DelayInfo
A struct representing the delay across a timing arc. Must provide a `+` operator for getting the combined delay of two arcs, and the following methods to access concrete timings:
```
delay_t minRaiseDelay() const { return delay; }
delay_t maxRaiseDelay() const { return delay; }
delay_t minFallDelay() const { return delay; }
delay_t maxFallDelay() const { return delay; }
delay_t minDelay() const { return delay; }
delay_t maxDelay() const { return delay; }
```
### BelId
A type representing a bel name. `BelId()` must construct a unique null-value. Must provide `==`, `!=`, and `<` operators and a specialization for `std::hash<BelId>`.
@@ -332,7 +317,7 @@ will make the given wire available.
*BaseArch default: returns `getBoundWireNet(wire)`*
### DelayInfo getWireDelay(WireId wire) const
### DelayQuad getWireDelay(WireId wire) const
Get the delay for a wire.
@@ -448,7 +433,7 @@ Get the destination wire for a pip.
Bi-directional switches (transfer gates) are modeled using two
anti-parallel pips.
### DelayInfo getPipDelay(PipId pip) const
### DelayQuad getPipDelay(PipId pip) const
Get the delay for a pip.
@@ -541,9 +526,9 @@ actual penalty used is a multiple of this value (i.e. a weighted version of this
Convert an `delay_t` to an actual real-world delay in nanoseconds.
### DelayInfo getDelayFromNS(float v) const
### delay_t getDelayFromNS(float v) const
Convert a real-world delay in nanoseconds to a DelayInfo with equal min/max rising/falling values.
Convert a real-world delay in nanoseconds to a `delay_t`.
### uint32\_t getDelayChecksum(delay\_t v) const
@@ -609,7 +594,7 @@ Return the decal and X/Y position for the graphics representing a group.
Cell Delay Methods
------------------
### bool getCellDelay(const CellInfo \*cell, IdString fromPort, IdString toPort, DelayInfo &delay) const
### bool getCellDelay(const CellInfo \*cell, IdString fromPort, IdString toPort, DelayQuad &delay) const
Returns the delay for the specified path through a cell in the `&delay` argument. The method returns
false if there is no timing relationship from `fromPort` to `toPort`.