Merge pull request #2496 from whitequark/cxxrtl-fixes

cxxrtl: various improvements

3 files changed, 32 insertions, 9 deletions

diff --git a/backends/cxxrtl/cxxrtl.h b/backends/cxxrtl/cxxrtl.h
index 3c315c7df..0a6bcb849 100644
--- a/backends/cxxrtl/cxxrtl.h
+++ b/backends/cxxrtl/cxxrtl.h
@@ -317,6 +317,14 @@ struct value : public expr_base<value<Bits>> {
 		return sext_cast<NewBits>()(*this);
 	}
 
+	// Bit replication is far more efficient than the equivalent concatenation.
+	template<size_t Count>
+	CXXRTL_ALWAYS_INLINE
+	value<Bits * Count> repeat() const {
+		static_assert(Bits == 1, "repeat() is implemented only for 1-bit values");
+		return *this ? value<Bits * Count>().bit_not() : value<Bits * Count>();
+	}
+
 	// Operations with run-time parameters (offsets, amounts, etc).
 	//
 	// These operations are used for computations.
diff --git a/backends/cxxrtl/cxxrtl_backend.cc b/backends/cxxrtl/cxxrtl_backend.cc
index 9875aba60..916303bfe 100644
--- a/backends/cxxrtl/cxxrtl_backend.cc
+++ b/backends/cxxrtl/cxxrtl_backend.cc
@@ -832,11 +832,26 @@ struct CxxrtlWorker {
 		} else if (sig.is_chunk()) {
 			return dump_sigchunk(sig.as_chunk(), is_lhs, for_debug);
 		} else {
-			dump_sigchunk(*sig.chunks().rbegin(), is_lhs, for_debug);
-			for (auto it = sig.chunks().rbegin() + 1; it != sig.chunks().rend(); ++it) {
-				f << ".concat(";
-				dump_sigchunk(*it, is_lhs, for_debug);
-				f << ")";
+			bool first = true;
+			auto chunks = sig.chunks();
+			for (auto it = chunks.rbegin(); it != chunks.rend(); it++) {
+				if (!first)
+					f << ".concat(";
+				bool is_complex = dump_sigchunk(*it, is_lhs, for_debug);
+				if (!is_lhs && it->width == 1) {
+					size_t repeat = 1;
+					while ((it + repeat) != chunks.rend() && *(it + repeat) == *it)
+						repeat++;
+					if (repeat > 1) {
+						if (is_complex)
+							f << ".val()";
+						f << ".repeat<" << repeat << ">()";
+					}
+					it += repeat - 1;
+				}
+				if (!first)
+					f << ")";
+				first = false;
 			}
 			return true;
 		}
@@ -1702,19 +1717,19 @@ struct CxxrtlWorker {
 					continue;
 				}
 				if (!module->get_bool_attribute(ID(cxxrtl_blackbox)) || wire->port_id != 0)
-					f << indent << "changed |= " << mangle(wire) << ".commit();\n";
+					f << indent << "if (" << mangle(wire) << ".commit()) changed = true;\n";
 			}
 			if (!module->get_bool_attribute(ID(cxxrtl_blackbox))) {
 				for (auto memory : module->memories) {
 					if (!writable_memories[memory.second])
 						continue;
-					f << indent << "changed |= " << mangle(memory.second) << ".commit();\n";
+					f << indent << "if (" << mangle(memory.second) << ".commit()) changed = true;\n";
 				}
 				for (auto cell : module->cells()) {
 					if (is_internal_cell(cell->type))
 						continue;
 					const char *access = is_cxxrtl_blackbox_cell(cell) ? "->" : ".";
-					f << indent << "changed |= " << mangle(cell) << access << "commit();\n";
+					f << indent << "if (" << mangle(cell) << access << "commit()) changed = true;\n";
 				}
 			}
 			f << indent << "return changed;\n";
diff --git a/backends/cxxrtl/cxxrtl_capi.h b/backends/cxxrtl/cxxrtl_capi.h
index 7d9c60ac5..2df2b7287 100644
--- a/backends/cxxrtl/cxxrtl_capi.h
+++ b/backends/cxxrtl/cxxrtl_capi.h
@@ -272,7 +272,7 @@ struct cxxrtl_object *cxxrtl_get_parts(cxxrtl_handle handle, const char *name, s
 // This function is a shortcut for the most common use of `cxxrtl_get_parts`. It asserts that,
 // if the object exists, it consists of a single part. If assertions are disabled, it returns NULL
 // for multi-part objects.
-inline struct cxxrtl_object *cxxrtl_get(cxxrtl_handle handle, const char *name) {
+static inline struct cxxrtl_object *cxxrtl_get(cxxrtl_handle handle, const char *name) {
 	size_t parts = 0;
 	struct cxxrtl_object *object = cxxrtl_get_parts(handle, name, &parts);
 	assert(object == NULL || parts == 1);