Add workaround for CBMC bug to SimpleC back-end

diff --git a/backends/simplec/simplec.cc b/backends/simplec/simplec.cc
index 5768e3499fcf576754195bad386010a2bcdd30bd..c9656caff7ab3056845c5899edfb5a68a8988777 100644 (file)
--- a/backends/simplec/simplec.cc
+++ b/backends/simplec/simplec.cc
@@ -482,7 +482,9 @@ struct SimplecWorker
                        string a_expr = a.wire ? util_get_bit(work->prefix + cid(a.wire->name), a.wire->width, a.offset) : a.data ? "1" : "0";
                        string b_expr = b.wire ? util_get_bit(work->prefix + cid(b.wire->name), b.wire->width, b.offset) : b.data ? "1" : "0";
                        string s_expr = s.wire ? util_get_bit(work->prefix + cid(s.wire->name), s.wire->width, s.offset) : s.data ? "1" : "0";
-                       string expr = stringf("%s ? %s : %s", s_expr.c_str(), b_expr.c_str(), a_expr.c_str());
+
+                       // casts to bool are a workaround for CBMC bug (https://github.com/diffblue/cbmc/issues/933)
+                       string expr = stringf("%s ? (bool)%s : (bool)%s", s_expr.c_str(), b_expr.c_str(), a_expr.c_str());
 
                        log_assert(y.wire);
                        funct_declarations.push_back(util_set_bit(work->prefix + cid(y.wire->name), y.wire->width, y.offset, expr) +