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Handle multiple active specify delays. 

Fix handling of cases where multiple specified delays are activated
for a given output. Need to apply the standard selection criteria
that gets the minimum value.
This commit is contained in:
Stephen Williams 2008-04-25 17:17:51 -07:00
parent abaab602bc
commit 81e12bf7f6
1 changed files with 38 additions and 9 deletions
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47
vvp/delay.cc
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@ -22,6 +22,7 @@
#include "vpi_priv.h"
#include <iostream>
#include <cstdlib>
#include <list>
#include <assert.h>
void vvp_delay_t::calculate_min_delay_()
@ -392,17 +393,24 @@ void vvp_fun_modpath::recv_vec4(vvp_net_ptr_t port, const vvp_vector4_t&bit)
if (cur_vec4_.eeq(bit))
return;
/* Select a time delay source that applies. */
vvp_fun_modpath_src*src = 0;
/* Select a time delay source that applies. Notice that there
may be multiple delay sources that apply, so collect all
the candidates into a list first. */
list<vvp_fun_modpath_src*>candidate_list;
vvp_time64_t candidate_wake_time = 0;
for (vvp_fun_modpath_src*cur = src_list_ ; cur ; cur=cur->next_) {
/* Skip paths that are disabled by conditions. */
if (cur->condition_flag_ == false)
continue;
if (src == 0) {
src = cur;
} else if (cur->wake_time_ > src->wake_time_) {
src = cur;
if (candidate_list.empty()) {
candidate_list.push_back(cur);
candidate_wake_time = cur->wake_time_;
} else if (cur->wake_time_ == candidate_wake_time) {
candidate_list.push_back(cur);
} else if (cur->wake_time_ > candidate_wake_time) {
candidate_list.assign(1, cur);
candidate_wake_time = cur->wake_time_;
} else {
continue; /* Skip this entry. */
}
@ -412,16 +420,24 @@ void vvp_fun_modpath::recv_vec4(vvp_net_ptr_t port, const vvp_vector4_t&bit)
match. This may happen, for example, if the set of
conditional delays is incomplete, leaving some cases
uncovered. In that case, just pass the data without delay */
if (src == 0) {
if (candidate_list.empty()) {
cur_vec4_ = bit;
schedule_generic(this, 0, false);
return;
}
assert(src);
/* Now given that we have a list of candidate delays, find for
each if the 12 numbers the minimum from all the
candidates. This minimum set becomes the chosen delay to
use. */
vvp_time64_t out_at[12];
vvp_time64_t now = schedule_simtime();
typedef list<vvp_fun_modpath_src*>::const_iterator iter_t;
iter_t cur = candidate_list.begin();
vvp_fun_modpath_src*src = *cur;
for (unsigned idx = 0 ; idx < 12 ; idx += 1) {
out_at[idx] = src->wake_time_ + src->delay_[idx];
if (out_at[idx] <= now)
@ -430,6 +446,19 @@ void vvp_fun_modpath::recv_vec4(vvp_net_ptr_t port, const vvp_vector4_t&bit)
out_at[idx] -= now;
}
for (cur ++ ; cur != candidate_list.end() ; cur ++) {
src = *cur;
for (unsigned idx = 0 ; idx < 12 ; idx += 1) {
vvp_time64_t tmp = src->wake_time_ + src->delay_[idx];
if (tmp <= now)
tmp = 0;
else
tmp -= now;
if (tmp < out_at[idx])
out_at[idx] = tmp;
}
}
/* Given the scheduled output time, create an output event. */
vvp_time64_t use_delay = delay_from_edge(cur_vec4_.value(0),
bit.value(0),