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vvp fix for pr3296466. 

This patch reworks the tran island code to allow it to handle cases where
tran primitives cross-connect different bits of the same vector.
This commit is contained in:
Martin Whitaker 2011-06-12 13:10:16 +01:00 committed by Stephen Williams
parent 4e86274ff2
commit 6ffd19cd7e
2 changed files with 106 additions and 249 deletions
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352
vvp/island_tran.cc
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2008-2010 Stephen Williams (steve@icarus.com)
* Copyright (c) 2008-2011 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
@ -33,34 +33,17 @@ class vvp_island_tran : public vvp_island {
struct vvp_island_branch_tran : public vvp_island_branch {
// Behavior. (This stuff should be moved to a derived
// class. The members here are specific to the tran island
// class.)
vvp_island_branch_tran(vvp_net_t*en__, bool active_high__,
unsigned width__, unsigned part__,
unsigned offset__);
bool run_test_enabled();
void run_resolution();
void clear_resolution_flags() { flags_ &= ~0x0f; }
void mark_done(unsigned ab) { flags_ |= 1 << ab; }
bool test_done(unsigned ab) const { return flags_ & (1<<ab); }
void clear_visited(unsigned ab) { flags_ &= ~(4 << ab); }
void mark_visited(unsigned ab) { flags_ |= 4 << ab; }
bool test_visited(unsigned ab) const { return flags_ & (4<<ab); }
// Use the peek only for diagnostic purposes.
int peek_flags() const { return flags_; }
void run_output();
vvp_net_t*en;
unsigned width, part, offset;
bool active_high;
bool enabled_flag;
private:
int flags_;
};
vvp_island_branch_tran::vvp_island_branch_tran(vvp_net_t*en__,
@ -71,7 +54,6 @@ vvp_island_branch_tran::vvp_island_branch_tran(vvp_net_t*en__,
: en(en__), width(width__), part(part__), offset(offset__),
active_high(active_high__)
{
flags_ = 0;
enabled_flag = en__ ? false : true;
}
@ -91,10 +73,7 @@ void vvp_island_tran::run_island()
{
// Test to see if any of the branches are enabled. This loop
// tests the enabled inputs for all the branches and caches
// the results in the enabled_flag for each branch. The
// run_test_enabled() method also clears all the processing
// flags for the branches so that we are in a good start
// state.
// the results in the enabled_flag for each branch.
bool runnable = false;
for (vvp_island_branch*cur = branches_ ; cur ; cur = cur->next_branch) {
vvp_island_branch_tran*tmp = dynamic_cast<vvp_island_branch_tran*>(cur);
@ -108,13 +87,17 @@ void vvp_island_tran::run_island()
assert(tmp);
tmp->run_resolution();
}
// Now output the resolved values.
for (vvp_island_branch*cur = branches_ ; cur ; cur = cur->next_branch) {
vvp_island_branch_tran*tmp = dynamic_cast<vvp_island_branch_tran*>(cur);
assert(tmp);
tmp->run_output();
}
}
bool vvp_island_branch_tran::run_test_enabled()
{
// Clear all the flags.
clear_resolution_flags();
vvp_island_port*ep = en? dynamic_cast<vvp_island_port*> (en->fun) : 0;
// If there is no ep port (no "enabled" input) then this is a
@ -158,260 +141,133 @@ bool vvp_island_branch_tran::run_test_enabled()
return true;
}
static void island_send_value(list<vvp_branch_ptr_t>&connections, const vvp_vector8_t&val)
static void push_value_through_branches(const vvp_vector8_t&val,
list<vvp_branch_ptr_t>&connections);
static void push_value_through_branch(const vvp_vector8_t&val,
vvp_branch_ptr_t cur)
{
for (list<vvp_branch_ptr_t>::iterator idx = connections.begin()
; idx != connections.end() ; ++ idx ) {
vvp_island_branch_tran*branch = BRANCH_TRAN(cur.ptr());
vvp_island_branch*tmp_ptr = idx->ptr();
// If the branch is not enabled, skip.
if (! branch->enabled_flag)
return;
unsigned tmp_ab = idx->port();
island_send_value(tmp_ab? tmp_ptr->b : tmp_ptr->a, val);
unsigned src_ab = cur.port();
unsigned dst_ab = src_ab^1;
vvp_net_t*dst_net = dst_ab? branch->b : branch->a;
vvp_island_port*dst_port = dynamic_cast<vvp_island_port*>(dst_net->fun);
vvp_vector8_t old_val = dst_port->value;
// If the port on the other side has not yet been visited,
// get its input value.
if (dst_port->value.size() == 0)
dst_port->value = island_get_value(dst_net);
// If we don't yet have an initial value for the port, skip.
if (dst_port->value.size() == 0)
return;
// Now resolve the pushed value with whatever values we have
// previously collected (and resolved) for the port.
if (branch->width == 0) {
// There are no part selects.
dst_port->value = resolve(dst_port->value, val);
} else if (dst_ab == 1) {
// The other side is a strict subset (part select)
// of this side.
vvp_vector8_t tmp = val.subvalue(branch->offset, branch->part);
dst_port->value = resolve(dst_port->value, tmp);
} else {
// The other side is a superset of this side.
vvp_vector8_t tmp = part_expand(val, branch->width, branch->offset);
dst_port->value = resolve(dst_port->value, tmp);
}
// If the resolved value for the port has changed, push the new
// value back into the network.
if (! dst_port->value.eeq(old_val)) {
list<vvp_branch_ptr_t> connections;
vvp_branch_ptr_t dst_side(branch, dst_ab);
island_collect_node(connections, dst_side);
push_value_through_branches(dst_port->value, connections);
}
}
static void mark_done_flags(list<vvp_branch_ptr_t>&connections)
{
for (list<vvp_branch_ptr_t>::iterator idx = connections.begin()
; idx != connections.end() ; ++ idx ) {
vvp_island_branch*tmp_ptr = idx->ptr();
vvp_island_branch_tran*cur = dynamic_cast<vvp_island_branch_tran*>(tmp_ptr);
unsigned tmp_ab = idx->port();
cur->mark_done(tmp_ab);
}
}
static void mark_visited_flags(list<vvp_branch_ptr_t>&connections)
{
for (list<vvp_branch_ptr_t>::iterator idx = connections.begin()
; idx != connections.end() ; ++ idx ) {
vvp_island_branch*tmp_ptr = idx->ptr();
vvp_island_branch_tran*cur = dynamic_cast<vvp_island_branch_tran*>(tmp_ptr);
assert(cur);
unsigned tmp_ab = idx->port();
cur->mark_visited(tmp_ab);
}
}
static void clear_visited_flags(list<vvp_branch_ptr_t>&connections)
{
for (list<vvp_branch_ptr_t>::iterator idx = connections.begin()
; idx != connections.end() ; ++ idx ) {
vvp_island_branch_tran*tmp_ptr = BRANCH_TRAN(idx->ptr());
unsigned tmp_ab = idx->port();
tmp_ptr->clear_visited(tmp_ab);
}
}
static vvp_vector8_t get_value_from_branch(vvp_branch_ptr_t cur);
static void resolve_values_from_connections(vvp_vector8_t&val,
list<vvp_branch_ptr_t>&connections)
{
for (list<vvp_branch_ptr_t>::iterator idx = connections.begin()
; idx != connections.end() ; ++ idx ) {
vvp_vector8_t tmp = get_value_from_branch(*idx);
if (val.size() == 0)
val = tmp;
else if (tmp.size() != 0)
val = resolve(val, tmp);
}
}
static vvp_vector8_t get_value_from_branch(vvp_branch_ptr_t cur)
{
vvp_island_branch_tran*ptr = BRANCH_TRAN(cur.ptr());
assert(ptr);
unsigned ab = cur.port();
unsigned ab_other = ab^1;
// If the branch link is disabled, return nil.
if (ptr->enabled_flag == false)
return vvp_vector8_t();
vvp_branch_ptr_t other (ptr, ab_other);
// If the branch other side is already visited, return
// nil. This prevents recursion loops.
if (ptr->test_visited(ab_other))
return vvp_vector8_t();
// Other side net, and port value.
vvp_net_t*net_other = ab? ptr->a : ptr->b;
vvp_vector8_t val_other = island_get_value(net_other);
// recurse
list<vvp_branch_ptr_t> connections;
island_collect_node(connections, other);
mark_visited_flags(connections);
resolve_values_from_connections(val_other, connections);
// Remove/unwind visited flags
clear_visited_flags(connections);
if (val_other.size() == 0)
return val_other;
if (ptr->width) {
if (ab == 0) {
val_other = part_expand(val_other, ptr->width, ptr->offset);
} else {
val_other = val_other.subvalue(ptr->offset, ptr->part);
}
}
return val_other;
}
/*
* Try to recursively push a fully resolved value back through the
* graph. This can save many span iterations through the graph by
* marking as done that are obviously and easily done. But it is
* better to be conservative here.
*
* The connections list is filled with connections that are already
* marked done, and the val is the resolved value. We are going to try
* to follow branches to see if we can push the value further and mark
* the other side done as well.
*/
static void push_value_through_branches(const vvp_vector8_t&val,
list<vvp_branch_ptr_t>&connections)
{
for (list<vvp_branch_ptr_t>::iterator idx = connections.begin()
; idx != connections.end() ; ++ idx ) {
vvp_island_branch_tran*tmp_ptr = BRANCH_TRAN(idx->ptr());
unsigned tmp_ab = idx->port();
unsigned other_ab = tmp_ab^1;
// If other side already done, skip
if (tmp_ptr->test_done(other_ab))
continue;
// If link is not enabled, skip.
if (! tmp_ptr->enabled_flag)
continue;
vvp_net_t*other_net = other_ab? tmp_ptr->b : tmp_ptr->a;
if (tmp_ptr->width == 0) {
// There are no part selects, so we can safely
// Mark this end as done.
tmp_ptr->mark_done(other_ab);
island_send_value(other_net, val);
} else if (other_ab == 1) {
// The other side is a strict subset (part select)
// of this side, so we can mark this end as done.
tmp_ptr->mark_done(other_ab);
vvp_vector8_t tmp = val.subvalue(tmp_ptr->offset, tmp_ptr->part);
island_send_value(other_net, tmp);
} else {
// Otherwise, the other side is not fully
// specified (is a subset of the done side) so we
// can't take this shortcut.
}
push_value_through_branch(val, *idx);
}
}
/*
* This method resolves the value for a branch recursively. It uses
* recursive descent to span the graph of branches, collecting values
* that need to be resolved together.
* recursive descent to span the graph of branches, pushing values
* through the network until a stable state is reached.
*/
void vvp_island_branch_tran::run_resolution()
{
// Collect all the branch endpoints that are joined to my A
// side.
list<vvp_branch_ptr_t> connections;
bool processed_a_side = false;
vvp_vector8_t val;
vvp_island_port*port;
// The "flags" member is a bitmask that marks whether an
// endpoint of a branch has been visited. If flags&1, then the
// A side has been visited. If flags&2, then the B side has
// been visited. The flags help us avoid recursion when doing
// spanning trees.
// If the A side has already been completed, then skip it.
if (! test_done(0)) {
processed_a_side = true;
// If the A side port hasn't already been visited, then push
// its input value through all the branches connected to it.
port = dynamic_cast<vvp_island_port*>(a->fun);
if (port->value.size() == 0) {
vvp_branch_ptr_t a_side(this, 0);
island_collect_node(connections, a_side);
// Mark my A side as done. Do this early to prevent recursing
// back. All the connections that share this port are also
// done. Make sure their flags are set appropriately.
mark_done_flags(connections);
port->value = island_get_value(a);
if (port->value.size() != 0)
push_value_through_branches(port->value, connections);
// Start with my branch-point value.
val = island_get_value(a);
mark_visited_flags(connections); // Mark as visited.
// Now scan the other sides of all the branches connected to
// my A side. The get_value_from_branch() will recurse as
// necessary to depth-first walk the graph.
resolve_values_from_connections(val, connections);
// A side is done.
island_send_value(connections, val);
// Clear the visited flags. This must be done so that other
// branches can read this input value.
clear_visited_flags(connections);
// Try to push the calculated value out through the
// branches. This is useful for A-side results because
// there is a high probability that the other side of
// all the connected branches is fully specified by this
// result.
push_value_through_branches(val, connections);
connections.clear();
}
// If the B side got taken care of by above, then this branch
// is done. Stop now.
if (test_done(1))
return;
// Do the same for the B side port. Note that if the branch
// is enabled, the B side port will have already been visited
// when we resolved the A side port.
port = dynamic_cast<vvp_island_port*>(b->fun);
if (port->value.size() == 0) {
vvp_branch_ptr_t b_side(this, 1);
island_collect_node(connections, b_side);
// Repeat the above for the B side.
port->value = island_get_value(b);
if (port->value.size() != 0)
push_value_through_branches(port->value, connections);
connections.clear();
island_collect_node(connections, vvp_branch_ptr_t(this, 1));
mark_done_flags(connections);
connections.clear();
}
}
if (enabled_flag && processed_a_side) {
// If this is a connected branch, then we know from the
// start that we have all the bits needed to complete
// the B side. Even if the B side is a part select, the
// simple part select must be correct because the
// recursive resolve_values_from_connections above must
// of cycled back to the B side of myself when resolving
// the connections.
if (width != 0)
val = val.subvalue(offset, part);
void vvp_island_branch_tran::run_output()
{
vvp_island_port*port;
} else {
// If this branch is not enabled, then the B-side must
// be processed on its own.
val = island_get_value(b);
mark_visited_flags(connections);
resolve_values_from_connections(val, connections);
clear_visited_flags(connections);
// If the A side port hasn't already been updated, send the
// resolved value to the output.
port = dynamic_cast<vvp_island_port*>(a->fun);
if (port->value.size() != 0) {
island_send_value(a, port->value);
port->value = vvp_vector8_t::nil;
}
island_send_value(connections, val);
// Do the same for the B side port.
port = dynamic_cast<vvp_island_port*>(b->fun);
if (port->value.size() != 0) {
island_send_value(b, port->value);
port->value = vvp_vector8_t::nil;
}
}
void compile_island_tran(char*label)
@ -454,7 +310,7 @@ void compile_island_tranvp(char*island, char*pa, char*pb,
free(island);
vvp_island_branch_tran*br = new vvp_island_branch_tran(NULL, false,
wid, par, off) ;
wid, par, off);
use_island->add_branch(br, pa, pb);

3
vvp/vvp_island.h
View File

@ -1,7 +1,7 @@
#ifndef __vvp_island_H
#define __vvp_island_H
/*
* Copyright (c) 2008 Stephen Williams (steve@icarus.com)
* Copyright (c) 2008,2011 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
@ -139,6 +139,7 @@ class vvp_island_port : public vvp_net_fun_t {
public:
vvp_vector8_t invalue;
vvp_vector8_t outvalue;
vvp_vector8_t value;
private:
vvp_island*island_;