uppsrc/Painter/BufferPainter.h:325:82: warning: control reaches end of non-void function [-Wreturn-type]
        BufferPainter&     NoImageCache(bool b = true)             { ImageCache(false); }
                                                                                        ^

if(pathattr.mtx_serial != preclip_mtx_serial || 1) {

BufferPainter painter(ib);

painter.Create(ib);

void App::Paint(Draw& w)
{
	Size sz = GetSize();
	if(ctrl.transparent) {
		for(int y = 0; y < sz.cy; y += 32)
			for(int x = 0; x < sz.cx; x += 32)
				w.DrawRect(x, y, 32, 32, (x ^ y) & 32 ? Color(254, 172, 120) : Color(124, 135, 253));
	}
	ImageBuffer ib(sz);
	{
		//BufferPainter sw(ib, ctrl.quality); // Removed
		csw.Create(ib, ctrl.quality); // Added
		
		BufferPainter &sw=csw;
		
		if(ctrl.transparent)
			sw.Clear(RGBAZero());
		else
			sw.Clear(White());
		sw.Co(ctrl.mt);
		DoPaint(sw);
		
		sw.Finish(); // Added
	}
	w.DrawImage(0, 0, ib);
	
}

pathattr.mtx = attr.mtx = Xform2D::Identity();

void BufferPainter::Create(ImageBuffer& ib, int mode_)
{
	ip = &ib;

	if(mode_ != mode || (Size)size != ib.GetSize()) {
		mode = mode_;

		rasterizer.Create(ib.GetWidth(), ib.GetHeight(), mode == MODE_SUBPIXEL);
		paths.Alloc(BATCH_SIZE);
		path_info = paths;

		ClearPath();

		render_cx = ib.GetWidth();
		if(mode == MODE_SUBPIXEL) {
			render_cx *= 3;
			subpixel.Alloc(render_cx + 30);
		}
		size = ib.GetSize();
	}

	Attr& a = attr;
	a.cap = LINECAP_BUTT;
	a.join = LINEJOIN_MITER;
	a.miter_limit = 4;
	a.evenodd = false;
	a.hasclip = false;
	a.cliplevel = 0;
	a.opacity = 1;
	a.dash = NULL;
	a.mask = false;
	a.invert = false;
	a.mtx_serial = 0;

	gradientn = Null;

	jobcount = fillcount = 0;
	cojob.Clear();
	cofill.Clear();

	attrstack.Clear();
	clip.Clear();
	mask.Clear();
	onpathstack.Clear();
	pathlenstack.Clear();
	onpath.Clear();

	preclip_mtx_serial = -1;
	path_index = 0;
}

void BufferPainter::Create(ImageBuffer& ib, int mode_)
{
	ip = &ib;
	
	if(mode_ != mode || (Size)size != ib.GetSize()) {
		mode = mode_;
	
		rasterizer.Create(ib.GetWidth(), ib.GetHeight(), mode == MODE_SUBPIXEL);
	
		render_cx = ib.GetWidth();
		if(mode == MODE_SUBPIXEL) {
			render_cx *= 3;
			subpixel.Alloc(render_cx + 30);
		}
		size = ib.GetSize();
	}

	if(!paths)
		paths.Alloc(BATCH_SIZE);

	path_info = paths;

	ClearPath();

	Attr& a = attr;
	a.cap = LINECAP_BUTT;
	a.join = LINEJOIN_MITER;
	a.miter_limit = 4;
	a.evenodd = false;
	a.hasclip = false;
	a.cliplevel = 0;
	a.opacity = 1;
	a.dash = NULL;
	a.mask = false;
	a.invert = false;
	a.mtx_serial = 0;
	
	gradientn = Null;
	
	jobcount = fillcount = 0;
	cojob.Clear();
	cofill.Clear();

	attrstack.Clear();
	clip.Clear();
	mask.Clear();
	onpathstack.Clear();
	pathlenstack.Clear();
	onpath.Clear();

	preclip_mtx_serial = -1;
	path_index = 0;
}

#include <CtrlLib/CtrlLib.h>
#include <Painter/Painter.h>

using namespace Upp;

class PainterBench : public TopWindow {
public:
	Painting p;
	FileSel fs;
	
	void Open(){
		if(fs.ExecuteOpen("Select a painting to view")){
			p.Clear();
			p.Serialize(FileIn(fs.Get()));
		}
	}
	virtual bool Key(dword key, int count){
		switch(key){
			case K_CTRL_O:
				Open();
				return true;
		}
		return false;
	}
	
	typedef PainterBench CLASSNAME;

	PainterBench(){
		Sizeable();
	}
		
	virtual void Paint(Draw &draw){
		int64 STtiming=0;
		int64 MTtiming=0;
		
		ImageBuffer ib(GetSize());
		{
			BufferPainter bpainter(ib);
			bpainter.Co(true);
			bpainter.PreClipDashed();
			bpainter.Clear(White());
			bpainter.EvenOdd();
			
			int64 t0=usecs();
			bpainter.Paint(p);
			int64 t1=usecs();
			MTtiming=t1-t0;
			
		}
		{
			BufferPainter bpainter(ib);
			bpainter.Co(false);
			bpainter.PreClipDashed();
			bpainter.Clear(White());
			bpainter.EvenOdd();
			
			int64 t0=usecs();
			bpainter.Paint(p);
			int64 t1=usecs();
			STtiming=t1-t0;
			
		}
		
		SetSurface(draw,Rect(ib.GetSize()),ib,ib.GetSize(),Point(0,0));
		
		double gain=(double)STtiming/(double)(0.1+MTtiming); // Avoid div by zero
		Title(Format("Rendering MT took %lld us, ST took %lld us, MT gain is %.2f",MTtiming,STtiming,gain));
	}
};

GUI_APP_MAIN
{
	PainterBench().Run();
}