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case/x/z synthesis with constant case expression. 

If the case expression is constant, then the guards probably are
not, and the synthesis should be handled differently.
This commit is contained in:
Stephen Williams 2014-06-13 18:22:24 -07:00
parent f8dc430fe5
commit 6d2fa6e579
1 changed files with 9 additions and 2 deletions
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11
synth2.cc
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@ -252,7 +252,14 @@ bool NetCase::synth_async(Design*des, NetScope*scope,
NexusSet&nex_map, NetBus&nex_out, NexusSet&nex_map, NetBus&nex_out,
NetBus&accumulated_nex_out) NetBus&accumulated_nex_out)
{ {
if (type()==NetCase::EQZ) if (type()==NetCase::EQZ || type()==NetCase::EQX)
return synth_async_casez_(des, scope, nex_map, nex_out, accumulated_nex_out);
// Special case: If the case expression is constant, then this
// is a pattern where the guards are non-constant and tested
// against a constant case. Handle this as chained conditions
// instead.
if (dynamic_cast<NetEConst*> (expr_))
return synth_async_casez_(des, scope, nex_map, nex_out, accumulated_nex_out); return synth_async_casez_(des, scope, nex_map, nex_out, accumulated_nex_out);
/* Synthesize the select expression. */ /* Synthesize the select expression. */
@ -298,7 +305,7 @@ bool NetCase::synth_async(Design*des, NetScope*scope,
} }
NetEConst*ge = dynamic_cast<NetEConst*>(items_[item].guard); NetEConst*ge = dynamic_cast<NetEConst*>(items_[item].guard);
assert(ge); ivl_assert(*this, ge);
verinum gval = ge->value(); verinum gval = ge->value();
unsigned sel_idx = gval.as_ulong(); unsigned sel_idx = gval.as_ulong();