const: fix comparison and hash

YosysHQ · Aug 14, 2024 · 3214b7b · 3214b7b
1 parent 754a7b9
commit 3214b7b
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Showing 2 changed files with 15 additions and 14 deletions.
diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
@@ -299,16 +299,15 @@ RTLIL::Const::~Const() {
 		check(false);
 }
 
-bool RTLIL::Const::operator <(const RTLIL::Const &other) const
+bool RTLIL::Const::operator<(const RTLIL::Const &other) const
 {
-	if (is_str() != other.is_str())
-		return decode_string() < other.decode_string();
-
-	if (get_if_str())
+	if (is_str() && other.is_str())
 		return str_ < other.str_;
 
-	bitvectype& bv = get_bits();
-	auto other_bv = other.get_bits();
+	// If either operand isn't a string, we have to construct a copy
+	// to bitvectorize without unpacking either operand
+	bitvectype &bv = is_str() ? Const(*this).bits() : get_bits();
+	bitvectype &other_bv = other.is_str() ? Const(other).bits() : other.get_bits();
 
 	if (bv.size() != other_bv.size())
 		return bv.size() < other_bv.size();
@@ -321,13 +320,13 @@ bool RTLIL::Const::operator <(const RTLIL::Const &other) const
 
 bool RTLIL::Const::operator ==(const RTLIL::Const &other) const
 {
-	if (is_str() != other.is_str())
-		return decode_string() == other.decode_string();
-
-	if (get_if_str())
+	if (is_str() && other.is_str())
 		return get_str() == other.get_str();
 
-	return get_bits() == other.get_bits();
+	bitvectype &bv = is_str() ? Const(*this).bits() : get_bits();
+	bitvectype &other_bv = other.is_str() ? Const(other).bits() : other.get_bits();
+
+	return bv == other_bv;
 }
 
 bool RTLIL::Const::operator !=(const RTLIL::Const &other) const

diff --git a/kernel/rtlil.h b/kernel/rtlil.h
@@ -805,8 +805,10 @@ struct RTLIL::Const
 		unsigned int h = mkhash_init;
 
 		if(is_str()) {
-			for (auto c : get_str())
-				h = mkhash(h, c);
+			// Copy to avoid unpacking `this`
+			Const c = Const(*this);
+			for (auto b : c.bits())
+				h = mkhash(h, b);
 		} else {
 			for (auto b : get_bits())
 				h = mkhash(h, b);