[Codegen] Skip wb emission when they are no children objects

vchuravy · vchuravy · commit 4650b7cc3fa6 · 2021-07-01T22:12:29.000+02:00
diff --git a/src/cgutils.cpp b/src/cgutils.cpp
@@ -3104,6 +3104,9 @@ static void emit_write_barrier(jl_codectx_t &ctx, Value *parent, Value *ptr)
 
 static void emit_write_barrier(jl_codectx_t &ctx, Value *parent, ArrayRef<Value*> ptrs)
 {
+    // if there are no child objects we can skip emission
+    if (ptrs.empty())
+        return;
     SmallVector<Value*, 8> decay_ptrs;
     decay_ptrs.push_back(maybe_decay_untracked(ctx, emit_bitcast(ctx, parent, T_prjlvalue)));
     for (auto ptr : ptrs) {

Original file line number	Diff line number	Diff line change
`@@ -3104,6 +3104,9 @@ static void emit_write_barrier(jl_codectx_t &ctx, Value parent, Value ptr)`
`3104`	`3104`
`3105`	`3105`	`static void emit_write_barrier(jl_codectx_t &ctx, Value parent, ArrayRef<Value> ptrs)`
`3106`	`3106`	`{`
	`3107`	`+ // if there are no child objects we can skip emission`
	`3108`	`+ if (ptrs.empty())`
	`3109`	`+ return;`
`3107`	`3110`	`SmallVector<Value*, 8> decay_ptrs;`
`3108`	`3111`	`decay_ptrs.push_back(maybe_decay_untracked(ctx, emit_bitcast(ctx, parent, T_prjlvalue)));`
`3109`	`3112`	`for (auto ptr : ptrs) {`