self-hosted: better IR for empty fn

andrewrk · andrewrk · commit 69e60e351b8b · 2018-07-12T15:22:23.000-04:00
avoids a void
diff --git a/src-self-hosted/ir.zig b/src-self-hosted/ir.zig
@@ -574,9 +574,7 @@ pub const Builder = struct {
         }
 
         _ = try irb.genDefersForBlock(child_scope, outer_block_scope, Scope.Defer.Kind.ScopeExit);
-        const result = try Instruction.Const.buildVoid(irb, child_scope, false);
-        result.setGenerated();
-        return result;
+        return try Instruction.Const.buildVoid(irb, child_scope, true);
     }
 
     fn genDefersForBlock(
@@ -648,8 +646,7 @@ pub async fn gen(module: *Module, body_node: *ast.Node, scope: *Scope, parsed_fi
 
     const result = try irb.genNode(body_node, scope, LVal.None);
     if (!result.isNoReturn()) {
-        const void_inst = try Instruction.Const.buildVoid(&irb, scope, false);
-        (try Instruction.Return.build(&irb, scope, void_inst)).setGenerated();
+        (try Instruction.Return.build(&irb, scope, result)).setGenerated();
     }
 
     return irb.finish();

Original file line number	Diff line number	Diff line change
`@@ -574,9 +574,7 @@ pub const Builder = struct {`
`574`	`574`	`}`
`575`	`575`
`576`	`576`	`_ = try irb.genDefersForBlock(child_scope, outer_block_scope, Scope.Defer.Kind.ScopeExit);`
`577`		`- const result = try Instruction.Const.buildVoid(irb, child_scope, false);`
`578`		`- result.setGenerated();`
`579`		`- return result;`
	`577`	`+ return try Instruction.Const.buildVoid(irb, child_scope, true);`
`580`	`578`	`}`
`581`	`579`
`582`	`580`	`fn genDefersForBlock(`
`@@ -648,8 +646,7 @@ pub async fn gen(module: Module, body_node: ast.Node, scope: *Scope, parsed_fi`
`648`	`646`
`649`	`647`	`const result = try irb.genNode(body_node, scope, LVal.None);`
`650`	`648`	`if (!result.isNoReturn()) {`
`651`		`- const void_inst = try Instruction.Const.buildVoid(&irb, scope, false);`
`652`		`- (try Instruction.Return.build(&irb, scope, void_inst)).setGenerated();`
	`649`	`+ (try Instruction.Return.build(&irb, scope, result)).setGenerated();`
`653`	`650`	`}`
`654`	`651`
`655`	`652`	`return irb.finish();`