caiyu/nextpnr
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Refactor common placement functions out of SA placer for use in legaliser

Browse Source 
Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-06-27 12:00:13 +02:00
parent 09c0d96105
commit 2cc7ade05b
4 changed files with 138 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
common/nextpnr.h
View File

@ -200,7 +200,7 @@ struct BaseCtx
BaseCtx()
{
//assert(IdString::global_ctx == nullptr);
// assert(IdString::global_ctx == nullptr);
IdString::global_ctx = this;
idstring_str_to_idx = new std::unordered_map<std::string, int>;
@ -229,6 +229,7 @@ struct Context : Arch
bool verbose = false;
bool debug = false;
bool force = false;
bool timing_driven = true;
Context(ArchArgs args) : Arch(args) {}

92
common/place_common.cc Normal file
View File

@ -0,0 +1,92 @@
/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2018 David Shah <david@symbioticeda.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#include "place_common.h"
#include <cmath>
#include "log.h"
#include "util.h"
NEXTPNR_NAMESPACE_BEGIN
// Get the total estimated wirelength for a net
wirelen_t get_net_wirelength(const Context *ctx, const NetInfo *net, float &tns)
{
wirelen_t wirelength = 0;
int driver_x, driver_y;
bool driver_gb;
CellInfo *driver_cell = net->driver.cell;
if (!driver_cell)
return 0;
if (driver_cell->bel == BelId())
return 0;
ctx->estimatePosition(driver_cell->bel, driver_x, driver_y, driver_gb);
WireId drv_wire = ctx->getWireBelPin(driver_cell->bel, ctx->portPinFromId(net->driver.port));
if (driver_gb)
return 0;
float worst_slack = 1000;
int xmin = driver_x, xmax = driver_x, ymin = driver_y, ymax = driver_y;
for (auto load : net->users) {
if (load.cell == nullptr)
continue;
CellInfo *load_cell = load.cell;
if (load_cell->bel == BelId())
continue;
if (ctx->timing_driven) {
WireId user_wire = ctx->getWireBelPin(load_cell->bel, ctx->portPinFromId(load.port));
delay_t raw_wl = ctx->estimateDelay(drv_wire, user_wire);
float slack = ctx->getDelayNS(load.budget) - ctx->getDelayNS(raw_wl);
if (slack < 0)
tns += slack;
worst_slack = std::min(slack, worst_slack);
}
int load_x, load_y;
bool load_gb;
ctx->estimatePosition(load_cell->bel, load_x, load_y, load_gb);
if (load_gb)
continue;
xmin = std::min(xmin, load_x);
ymin = std::min(ymin, load_y);
xmax = std::max(xmax, load_x);
ymax = std::max(ymax, load_y);
}
if (ctx->timing_driven) {
wirelength = wirelen_t((((ymax - ymin) + (xmax - xmin)) * std::min(5.0, (1.0 + std::exp(-worst_slack / 5)))));
} else {
wirelength = wirelen_t((ymax - ymin) + (xmax - xmin));
}
return wirelength;
}
// Get the total wirelength for a cell
wirelen_t get_cell_wirelength(const Context *ctx, const CellInfo *cell)
{
std::set<IdString> nets;
for (auto p : cell->ports) {
nets.insert(p.first);
}
wirelen_t wirelength = 0;
float tns = 0;
for (auto n : nets) {
wirelength += get_net_wirelength(ctx, ctx->nets.at(n).get(), tns);
}
return wirelength;
}
NEXTPNR_NAMESPACE_END

40
common/place_common.h Normal file
View File

@ -0,0 +1,40 @@
/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2018 David Shah <david@symbioticeda.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#ifndef PLACE_COMMON_H
#define PLACE_COMMON_H
#include "nextpnr.h"
NEXTPNR_NAMESPACE_BEGIN
typedef int64_t wirelen_t;
// Return the wirelength of a net
wirelen_t get_net_wirelength(const Context *ctx, const NetInfo *net, float &tns);
// Return the wirelength of all nets connected to a cell
wirelen_t get_cell_wirelength(const Context *ctx, const CellInfo *cell);
// Place a single cell in the lowest wirelength Bel available, optionally requiring validity check
bool place_single_cell(const Context *ctx, CellInfo *cell, bool require_legality);
NEXTPNR_NAMESPACE_END
#endif

61
common/place_sa.cc
View File

@ -37,11 +37,10 @@
#include <string.h>
#include <vector>
#include "log.h"
#include "place_common.h"
NEXTPNR_NAMESPACE_BEGIN
typedef int64_t wirelen_t;
class SAPlacer
{
public:
@ -138,7 +137,7 @@ class SAPlacer
curr_wirelength = 0;
curr_tns = 0;
for (auto &net : ctx->nets) {
wirelen_t wl = get_wirelength(net.second.get(), curr_tns);
wirelen_t wl = get_net_wirelength(ctx, net.second.get(), curr_tns);
wirelengths[net.first] = wl;
curr_wirelength += wl;
}
@ -212,7 +211,7 @@ class SAPlacer
curr_wirelength = 0;
curr_tns = 0;
for (auto &net : ctx->nets) {
wirelen_t wl = get_wirelength(net.second.get(), curr_tns);
wirelen_t wl = get_net_wirelength(ctx, net.second.get(), curr_tns);
wirelengths[net.first] = wl;
curr_wirelength += wl;
}
@ -289,58 +288,6 @@ class SAPlacer
}
}
// Get the total estimated wirelength for a net
wirelen_t get_wirelength(NetInfo *net, float &tns)
{
wirelen_t wirelength = 0;
int driver_x, driver_y;
bool driver_gb;
CellInfo *driver_cell = net->driver.cell;
if (!driver_cell)
return 0;
if (driver_cell->bel == BelId())
return 0;
ctx->estimatePosition(driver_cell->bel, driver_x, driver_y, driver_gb);
WireId drv_wire = ctx->getWireBelPin(driver_cell->bel, ctx->portPinFromId(net->driver.port));
if (driver_gb)
return 0;
float worst_slack = 1000;
int xmin = driver_x, xmax = driver_x, ymin = driver_y, ymax = driver_y;
for (auto load : net->users) {
if (load.cell == nullptr)
continue;
CellInfo *load_cell = load.cell;
if (load_cell->bel == BelId())
continue;
if (timing_driven) {
WireId user_wire = ctx->getWireBelPin(load_cell->bel, ctx->portPinFromId(load.port));
delay_t raw_wl = ctx->estimateDelay(drv_wire, user_wire);
float slack = ctx->getDelayNS(load.budget) - ctx->getDelayNS(raw_wl);
if (slack < 0)
tns += slack;
worst_slack = std::min(slack, worst_slack);
}
int load_x, load_y;
bool load_gb;
ctx->estimatePosition(load_cell->bel, load_x, load_y, load_gb);
if (load_gb)
continue;
xmin = std::min(xmin, load_x);
ymin = std::min(ymin, load_y);
xmax = std::max(xmax, load_x);
ymax = std::max(ymax, load_y);
}
if (timing_driven) {
wirelength =
wirelen_t((((ymax - ymin) + (xmax - xmin)) * std::min(5.0, (1.0 + std::exp(-worst_slack / 5)))));
} else {
wirelength = wirelen_t((ymax - ymin) + (xmax - xmin));
}
return wirelength;
}
// Attempt a SA position swap, return true on success or false on failure
bool try_swap_position(CellInfo *cell, BelId newBel)
{
@ -387,7 +334,7 @@ class SAPlacer
for (auto net : update) {
new_wirelength -= wirelengths.at(net->name);
float temp_tns = 0;
wirelen_t net_new_wl = get_wirelength(net, temp_tns);
wirelen_t net_new_wl = get_net_wirelength(ctx, net, temp_tns);
new_wirelength += net_new_wl;
new_lengths.push_back(std::make_pair(net->name, net_new_wl));
}