runtime: precisely scan globals on all platforms

transform/optimizer_internal_test.go

@@ -0,0 +1,33 @@
+package transform
+
+import (
+	"testing"
+
+	"tinygo.org/x/go-llvm"
+)
+
+func TestBlockGlobalAllocPromotionUses(t *testing.T) {
+	ctx := llvm.NewContext()
+	defer ctx.Dispose()
+	buf, err := llvm.NewMemoryBufferFromFile("testdata/optimizer-alloc-uses.ll")
+	if err != nil {
+		t.Fatal(err)
+	}
+	mod, err := ctx.ParseIR(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer mod.Dispose()
+
+	blockGlobalAllocPromotion(mod)
+	if err := llvm.VerifyModule(mod, llvm.ReturnStatusAction); err != nil {
+		t.Fatal(err)
+	}
+	marker := mod.NamedFunction("tinygo.gc.alloc.marker")
+	if marker.IsNil() {
+		t.Fatal("allocation marker was not created")
+	}
+	if uses := getUses(marker); len(uses) != 1 {
+		t.Fatalf("got %d marker uses, want 1", len(uses))
+	}
+}