Added AstNode::MEM2REG_FL_CMPLX_LHS

diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index f89af633e8130d300df4ad85dbf84f608dbabbc9..8253a2052bf9d3e913c6874e368dd0be856f795b 100644 (file)
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -188,6 +188,7 @@ namespace AST
                        MEM2REG_FL_SET_ELSE  = 0x00000400,
                        MEM2REG_FL_SET_ASYNC = 0x00000800,
                        MEM2REG_FL_EQ2       = 0x00001000,
+                       MEM2REG_FL_CMPLX_LHS = 0x00002000,
 
                        /* proc flags */
                        MEM2REG_FL_EQ1       = 0x01000000,

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 7a98e2712836ccbf9a34f340ca6f5db3f2f4a140..0b0e46f2c77da4433badf971225fd9715a1a5550 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -90,6 +90,9 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
                                if ((memflags & AstNode::MEM2REG_FL_SET_INIT) && (memflags & AstNode::MEM2REG_FL_SET_ELSE))
                                        goto verbose_activate;
 
+                               if (memflags & AstNode::MEM2REG_FL_CMPLX_LHS)
+                                       goto verbose_activate;
+
                                // log("Note: Not replacing memory %s with list of registers (flags=0x%08lx).\n", mem->str.c_str(), long(memflags));
                                continue;
 
@@ -1757,6 +1760,21 @@ void AstNode::replace_ids(std::map<std::string, std::string> &rules)
                child->replace_ids(rules);
 }
 
+// helper function for mem2reg_as_needed_pass1
+static void mark_memories_assign_lhs_complex(std::map<AstNode*, std::set<std::string>> &mem2reg_places,
+               std::map<AstNode*, uint32_t> &mem2reg_candidates, AstNode *that)
+{
+       for (auto &child : that->children)
+               mark_memories_assign_lhs_complex(mem2reg_places, mem2reg_candidates, child);
+
+       if (that->type == AST_IDENTIFIER && that->id2ast && that->id2ast->type == AST_MEMORY) {
+               AstNode *mem = that->id2ast;
+               if (!(mem2reg_candidates[mem] & AstNode::MEM2REG_FL_CMPLX_LHS))
+                       mem2reg_places[mem].insert(stringf("%s:%d", that->filename.c_str(), that->linenum));
+               mem2reg_candidates[mem] |= AstNode::MEM2REG_FL_CMPLX_LHS;
+       }
+}
+
 // find memories that should be replaced by registers
 void AstNode::mem2reg_as_needed_pass1(std::map<AstNode*, std::set<std::string>> &mem2reg_places,
                std::map<AstNode*, uint32_t> &mem2reg_candidates, std::map<AstNode*, uint32_t> &proc_flags, uint32_t &flags)
@@ -1766,6 +1784,10 @@ void AstNode::mem2reg_as_needed_pass1(std::map<AstNode*, std::set<std::string>>
 
        if (type == AST_ASSIGN || type == AST_ASSIGN_LE || type == AST_ASSIGN_EQ)
        {
+               // mark all memories that are used in a complex expression on the left side of an assignment
+               for (auto &lhs_child : children[0]->children)
+                       mark_memories_assign_lhs_complex(mem2reg_places, mem2reg_candidates, lhs_child);
+
                if (children[0]->type == AST_IDENTIFIER && children[0]->id2ast && children[0]->id2ast->type == AST_MEMORY)
                {
                        AstNode *mem = children[0]->id2ast;