diff --git a/Makefile b/Makefile
index 62f7f339e..a8224281b 100644
--- a/Makefile
+++ b/Makefile
@@ -171,7 +171,7 @@ ifeq ($(OS), Haiku)
 CXXFLAGS += -D_DEFAULT_SOURCE
 endif
 
-YOSYS_VER := 0.49+10
+YOSYS_VER := 0.49+17
 
 # Note: We arrange for .gitcommit to contain the (short) commit hash in
 # tarballs generated with git-archive(1) using .gitattributes. The git repo
diff --git a/passes/techmap/alumacc.cc b/passes/techmap/alumacc.cc
index fa286aebc..b185b0b40 100644
--- a/passes/techmap/alumacc.cc
+++ b/passes/techmap/alumacc.cc
@@ -406,11 +406,6 @@ struct AlumaccWorker
 			RTLIL::SigSpec B = sigmap(cell->getPort(ID::B));
 			RTLIL::SigSpec Y = sigmap(cell->getPort(ID::Y));
 
-			if (B < A && GetSize(B)) {
-				cmp_less = !cmp_less;
-				std::swap(A, B);
-			}
-
 			alunode_t *n = nullptr;
 
 			for (auto node : sig_alu[RTLIL::SigSig(A, B)])
@@ -419,6 +414,16 @@ struct AlumaccWorker
 					break;
 				}
 
+			if (n == nullptr) {
+				for (auto node : sig_alu[RTLIL::SigSig(B, A)])
+					if (node->is_signed == is_signed && node->invert_b && node->c == State::S1) {
+						n = node;
+						cmp_less = !cmp_less;
+						std::swap(A, B);
+						break;
+					}
+			}
+
 			if (n == nullptr) {
 				n = new alunode_t;
 				n->a = A;
@@ -446,9 +451,6 @@ struct AlumaccWorker
 			RTLIL::SigSpec B = sigmap(cell->getPort(ID::B));
 			RTLIL::SigSpec Y = sigmap(cell->getPort(ID::Y));
 
-			if (B < A && GetSize(B))
-				std::swap(A, B);
-
 			alunode_t *n = nullptr;
 
 			for (auto node : sig_alu[RTLIL::SigSig(A, B)])
@@ -457,6 +459,14 @@ struct AlumaccWorker
 					break;
 				}
 
+			if (n == nullptr) {
+				for (auto node : sig_alu[RTLIL::SigSig(B, A)])
+					if (node->is_signed == is_signed && node->invert_b && node->c == State::S1) {
+						n = node;
+						break;
+					}
+			}
+
 			if (n != nullptr) {
 				log("  creating $alu model for %s (%s): merged with %s.\n", log_id(cell), log_id(cell->type), log_id(n->cells.front()));
 				n->cells.push_back(cell);