Merge pull request YosysHQ#2338 from zachjs/const-branch-finish

Propagate const_fold through generate blocks and branches

frontends/ast/simplify.cc

@@ -1807,7 +1807,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 
 			if (type == AST_GENFOR) {
 				for (size_t i = 0; i < buf->children.size(); i++) {
-					buf->children[i]->simplify(false, false, false, stage, -1, false, false);
+					buf->children[i]->simplify(const_fold, false, false, stage, -1, false, false);
 					current_ast_mod->children.push_back(buf->children[i]);
 				}
 			} else {
@@ -1883,7 +1883,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 		}
 
 		for (size_t i = 0; i < children.size(); i++) {
-			children[i]->simplify(false, false, false, stage, -1, false, false);
+			children[i]->simplify(const_fold, false, false, stage, -1, false, false);
 			current_ast_mod->children.push_back(children[i]);
 		}
 
@@ -1920,7 +1920,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			}
 
 			for (size_t i = 0; i < buf->children.size(); i++) {
-				buf->children[i]->simplify(false, false, false, stage, -1, false, false);
+				buf->children[i]->simplify(const_fold, false, false, stage, -1, false, false);
 				current_ast_mod->children.push_back(buf->children[i]);
 			}
 
@@ -1999,7 +1999,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			}
 
 			for (size_t i = 0; i < buf->children.size(); i++) {
-				buf->children[i]->simplify(false, false, false, stage, -1, false, false);
+				buf->children[i]->simplify(const_fold, false, false, stage, -1, false, false);
 				current_ast_mod->children.push_back(buf->children[i]);
 			}
 

tests/simple/const_branch_finish.v

@@ -0,0 +1,39 @@
+`define CONSTANT_CHECK \
+	if (WIDTH === 'bx) begin \
+		$display("FAIL"); \
+		$finish; \
+	end
+
+module top;
+	parameter WIDTH = 32;
+	integer j;
+	initial begin
+		`CONSTANT_CHECK
+		if (WIDTH == 32) begin : procedural_conditional_block
+			`CONSTANT_CHECK
+		end
+		case (WIDTH)
+			32: `CONSTANT_CHECK
+			default: ;
+		endcase
+		for (j = 0; j < 2; j = j + 1) begin : procedural_loop_block
+			`CONSTANT_CHECK
+		end
+	end
+	generate
+		begin : unconditional_block
+			initial `CONSTANT_CHECK
+		end
+		if (WIDTH == 32) begin : conditional_block
+			initial `CONSTANT_CHECK
+		end
+		case (WIDTH)
+			32: initial `CONSTANT_CHECK
+			default: ;
+		endcase
+		genvar i;
+		for (i = 0; i < 2; i = i + 1) begin : loop_block
+			initial `CONSTANT_CHECK
+		end
+	endgenerate
+endmodule