ffinit: Fortify the code a bit.

This fixes handling of messy cases involving repeatedly setting and
removing the same init bit.

diff --git a/kernel/ffinit.h b/kernel/ffinit.h
index 49747692f23972e5f32bc86cf5fd4f4bcf95da51..025b0c8626dff750381f4257c632399440c78371 100644 (file)
--- a/kernel/ffinit.h
+++ b/kernel/ffinit.h
@@ -83,22 +83,24 @@ struct FfInitVals
 
        void set_init(RTLIL::SigBit bit, RTLIL::State val)
        {
-               bit = (*sigmap)(bit);
-               auto it = initbits.find(bit);
-               if (it != initbits.end()) {
-                       auto it2 = it->second.second.wire->attributes.find(ID::init);
-                       it2->second[it->second.second.offset] = val;
-               } else {
-                       log_assert(bit.wire);
-                       initbits[bit] = std::make_pair(val,bit);
-                       auto it2 = bit.wire->attributes.find(ID::init);
-                       if (it2 != bit.wire->attributes.end()) {
-                               it2->second[bit.offset] = val;
-                       } else {
-                               Const cval(State::Sx, GetSize(bit.wire));
-                               cval[bit.offset] = val;
-                               bit.wire->attributes[ID::init] = cval;
-                       }
+               SigBit mbit = (*sigmap)(bit);
+               SigBit abit = bit;
+               auto it = initbits.find(mbit);
+               if (it != initbits.end())
+                       abit = it->second.second;
+               else if (val == State::Sx)
+                       return;
+               log_assert(abit.wire);
+               initbits[mbit] = std::make_pair(val,abit);
+               auto it2 = abit.wire->attributes.find(ID::init);
+               if (it2 != abit.wire->attributes.end()) {
+                       it2->second[abit.offset] = val;
+                       if (it2->second.is_fully_undef())
+                               abit.wire->attributes.erase(it2);
+               } else if (val != State::Sx) {
+                       Const cval(State::Sx, GetSize(abit.wire));
+                       cval[abit.offset] = val;
+                       abit.wire->attributes[ID::init] = cval;
                }
        }
 
@@ -111,14 +113,7 @@ struct FfInitVals
 
        void remove_init(RTLIL::SigBit bit)
        {
-               auto it = initbits.find((*sigmap)(bit));
-               if (it != initbits.end()) {
-                       auto it2 = it->second.second.wire->attributes.find(ID::init);
-                       it2->second[it->second.second.offset] = State::Sx;
-                       if (it2->second.is_fully_undef())
-                               it->second.second.wire->attributes.erase(it2);
-                       initbits.erase(it);
-               }
+               set_init(bit, State::Sx);
        }
 
        void remove_init(const RTLIL::SigSpec &sig)