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authorClifford Wolf <clifford@clifford.at>2017-01-26 09:19:28 +0100
committerClifford Wolf <clifford@clifford.at>2017-01-26 09:19:28 +0100
commit45e10c1c892a7f3082beb9a15aeaaada52267742 (patch)
tree574ccd798842a7856687b3f23f6bb551c7025665 /passes/fsm/fsm_expand.cc
parent49b816048833d25921e45bfb248643acbf23b8de (diff)
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Be more conservative with merging large cells into FSMs
Diffstat (limited to 'passes/fsm/fsm_expand.cc')
-rw-r--r--passes/fsm/fsm_expand.cc20
1 files changed, 17 insertions, 3 deletions
diff --git a/passes/fsm/fsm_expand.cc b/passes/fsm/fsm_expand.cc
index 0a2166b99..2c344a1c1 100644
--- a/passes/fsm/fsm_expand.cc
+++ b/passes/fsm/fsm_expand.cc
@@ -54,13 +54,27 @@ struct FsmExpand
if (cell->getPort("\\A").size() < 2)
return true;
+ int in_bits = 0;
RTLIL::SigSpec new_signals;
- if (cell->hasPort("\\A"))
+
+ if (cell->hasPort("\\A")) {
+ in_bits += GetSize(cell->getPort("\\A"));
new_signals.append(assign_map(cell->getPort("\\A")));
- if (cell->hasPort("\\B"))
+ }
+
+ if (cell->hasPort("\\B")) {
+ in_bits += GetSize(cell->getPort("\\B"));
new_signals.append(assign_map(cell->getPort("\\B")));
- if (cell->hasPort("\\S"))
+ }
+
+ if (cell->hasPort("\\S")) {
+ in_bits += GetSize(cell->getPort("\\S"));
new_signals.append(assign_map(cell->getPort("\\S")));
+ }
+
+ if (in_bits > 8)
+ return false;
+
if (cell->hasPort("\\Y"))
new_signals.append(assign_map(cell->getPort("\\Y")));