diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index b843ebf4370476..9dd28e38c3bf18 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -438,9 +438,16 @@ func Main(archInit func(*Arch)) {
 	}
 
 	ssaDump = os.Getenv("GOSSAFUNC")
-	if strings.HasSuffix(ssaDump, "+") {
-		ssaDump = ssaDump[:len(ssaDump)-1]
-		ssaDumpStdout = true
+	if ssaDump != "" {
+		if strings.HasSuffix(ssaDump, "+") {
+			ssaDump = ssaDump[:len(ssaDump)-1]
+			ssaDumpStdout = true
+		}
+		spl := strings.Split(ssaDump, ":")
+		if len(spl) > 1 {
+			ssaDump = spl[0]
+			ssaDumpCFG = spl[1]
+		}
 	}
 
 	trackScopes = flagDWARF
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index 7a4152a9e6d489..27af607d6f0e50 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -26,6 +26,7 @@ var ssaCaches []ssa.Cache
 
 var ssaDump string     // early copy of $GOSSAFUNC; the func name to dump output for
 var ssaDumpStdout bool // whether to dump to stdout
+var ssaDumpCFG string  // generate CFGs for these phases
 const ssaDumpFile = "ssa.html"
 
 // ssaDumpInlined holds all inlined functions when ssaDump contains a function name.
@@ -155,7 +156,7 @@ func buildssa(fn *Node, worker int) *ssa.Func {
 	s.softFloat = s.config.SoftFloat
 
 	if printssa {
-		s.f.HTMLWriter = ssa.NewHTMLWriter(ssaDumpFile, s.f.Frontend(), name)
+		s.f.HTMLWriter = ssa.NewHTMLWriter(ssaDumpFile, s.f.Frontend(), name, ssaDumpCFG)
 		// TODO: generate and print a mapping from nodes to values and blocks
 		dumpSourcesColumn(s.f.HTMLWriter, fn)
 		s.f.HTMLWriter.WriteAST("AST", astBuf)
diff --git a/src/cmd/compile/internal/ssa/func.go b/src/cmd/compile/internal/ssa/func.go
index d73d39ce288f51..7e7e2042d9da54 100644
--- a/src/cmd/compile/internal/ssa/func.go
+++ b/src/cmd/compile/internal/ssa/func.go
@@ -43,6 +43,7 @@ type Func struct {
 	PrintOrHtmlSSA bool        // true if GOSSAFUNC matches, true even if fe.Log() (spew phase results to stdout) is false.
 
 	scheduled bool // Values in Blocks are in final order
+	laidout   bool // Blocks are ordered
 	NoSplit   bool // true if function is marked as nosplit.  Used by schedule check pass.
 
 	// when register allocation is done, maps value ids to locations
diff --git a/src/cmd/compile/internal/ssa/html.go b/src/cmd/compile/internal/ssa/html.go
index d76d7c7b334650..3ea83f90a271cb 100644
--- a/src/cmd/compile/internal/ssa/html.go
+++ b/src/cmd/compile/internal/ssa/html.go
@@ -11,6 +11,7 @@ import (
 	"html"
 	"io"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -20,9 +21,10 @@ type HTMLWriter struct {
 	Logger
 	w    io.WriteCloser
 	path string
+	dot  *dotWriter
 }
 
-func NewHTMLWriter(path string, logger Logger, funcname string) *HTMLWriter {
+func NewHTMLWriter(path string, logger Logger, funcname, cfgMask string) *HTMLWriter {
 	out, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
 	if err != nil {
 		logger.Fatalf(src.NoXPos, "%v", err)
@@ -32,6 +34,7 @@ func NewHTMLWriter(path string, logger Logger, funcname string) *HTMLWriter {
 		logger.Fatalf(src.NoXPos, "%v", err)
 	}
 	html := HTMLWriter{w: out, Logger: logger, path: filepath.Join(pwd, path)}
+	html.dot = newDotWriter(cfgMask)
 	html.start(funcname)
 	return &html
 }
@@ -211,6 +214,25 @@ dd.ssa-prog {
     color: gray;
 }
 
+.zoom {
+	position: absolute;
+	float: left;
+	white-space: nowrap;
+	background-color: #eee;
+}
+
+.zoom a:link, .zoom a:visited  {
+    text-decoration: none;
+    color: blue;
+    font-size: 16px;
+    padding: 4px 2px;
+}
+
+svg {
+    cursor: default;
+    outline: 1px solid #eee;
+}
+
 .highlight-aquamarine     { background-color: aquamarine; }
 .highlight-coral          { background-color: coral; }
 .highlight-lightpink      { background-color: lightpink; }
@@ -236,6 +258,18 @@ dd.ssa-prog {
 .outline-maroon         { outline: maroon solid 2px; }
 .outline-black          { outline: black solid 2px; }
 
+ellipse.outline-blue           { stroke-width: 2px; stroke: blue; }
+ellipse.outline-red            { stroke-width: 2px; stroke: red; }
+ellipse.outline-blueviolet     { stroke-width: 2px; stroke: blueviolet; }
+ellipse.outline-darkolivegreen { stroke-width: 2px; stroke: darkolivegreen; }
+ellipse.outline-fuchsia        { stroke-width: 2px; stroke: fuchsia; }
+ellipse.outline-sienna         { stroke-width: 2px; stroke: sienna; }
+ellipse.outline-gold           { stroke-width: 2px; stroke: gold; }
+ellipse.outline-orangered      { stroke-width: 2px; stroke: orangered; }
+ellipse.outline-teal           { stroke-width: 2px; stroke: teal; }
+ellipse.outline-maroon         { stroke-width: 2px; stroke: maroon; }
+ellipse.outline-black          { stroke-width: 2px; stroke: black; }
+
 </style>
 
 <script type="text/javascript">
@@ -413,6 +447,38 @@ window.onload = function() {
         }
         td[i].style.display = 'table-cell';
     }
+
+    // find all svg block nodes, add their block classes
+    var nodes = document.querySelectorAll('*[id^="graph_node_"]');
+    for (var i = 0; i < nodes.length; i++) {
+    	var node = nodes[i];
+    	var name = node.id.toString();
+    	var block = name.substring(name.lastIndexOf("_")+1);
+    	node.classList.remove("node");
+    	node.classList.add(block);
+        node.addEventListener('click', ssaBlockClicked);
+        var ellipse = node.getElementsByTagName('ellipse')[0];
+        ellipse.classList.add(block);
+        ellipse.addEventListener('click', ssaBlockClicked);
+    }
+
+    // make big graphs smaller
+    var targetScale = 0.5;
+    var nodes = document.querySelectorAll('*[id^="svg_graph_"]');
+    // TODO: Implement smarter auto-zoom using the viewBox attribute
+    // and in case of big graphs set the width and height of the svg graph to
+    // maximum allowed.
+    for (var i = 0; i < nodes.length; i++) {
+    	var node = nodes[i];
+    	var name = node.id.toString();
+    	var phase = name.substring(name.lastIndexOf("_")+1);
+    	var gNode = document.getElementById("g_graph_"+phase);
+    	var scale = gNode.transform.baseVal.getItem(0).matrix.a;
+    	if (scale > targetScale) {
+    		node.width.baseVal.value *= targetScale / scale;
+    		node.height.baseVal.value *= targetScale / scale;
+    	}
+    }
 };
 
 function toggle_visibility(id) {
@@ -423,7 +489,74 @@ function toggle_visibility(id) {
         e.style.display = 'block';
     }
 }
-</script>
+
+// TODO: scale the graph with the viewBox attribute.
+function graphReduce(id) {
+    var node = document.getElementById(id);
+    if (node) {
+    		node.width.baseVal.value *= 0.9;
+    		node.height.baseVal.value *= 0.9;
+    }
+    return false;
+}
+
+function graphEnlarge(id) {
+    var node = document.getElementById(id);
+    if (node) {
+    		node.width.baseVal.value *= 1.1;
+    		node.height.baseVal.value *= 1.1;
+    }
+    return false;
+}
+
+function makeDraggable(event) {
+    var svg = event.target;
+    if (window.PointerEvent) {
+        svg.addEventListener('pointerdown', startDrag);
+        svg.addEventListener('pointermove', drag);
+        svg.addEventListener('pointerup', endDrag);
+        svg.addEventListener('pointerleave', endDrag);
+    } else {
+        svg.addEventListener('mousedown', startDrag);
+        svg.addEventListener('mousemove', drag);
+        svg.addEventListener('mouseup', endDrag);
+        svg.addEventListener('mouseleave', endDrag);
+    }
+
+    var point = svg.createSVGPoint();
+    var isPointerDown = false;
+    var pointerOrigin;
+    var viewBox = svg.viewBox.baseVal;
+
+    function getPointFromEvent (event) {
+        point.x = event.clientX;
+        point.y = event.clientY;
+
+        // We get the current transformation matrix of the SVG and we inverse it
+        var invertedSVGMatrix = svg.getScreenCTM().inverse();
+        return point.matrixTransform(invertedSVGMatrix);
+    }
+
+    function startDrag(event) {
+        isPointerDown = true;
+        pointerOrigin = getPointFromEvent(event);
+    }
+
+    function drag(event) {
+        if (!isPointerDown) {
+            return;
+        }
+        event.preventDefault();
+
+        var pointerPosition = getPointFromEvent(event);
+        viewBox.x -= (pointerPosition.x - pointerOrigin.x);
+        viewBox.y -= (pointerPosition.y - pointerOrigin.y);
+    }
+
+    function endDrag(event) {
+        isPointerDown = false;
+    }
+}</script>
 
 </head>`)
 	w.WriteString("<body>")
@@ -431,7 +564,7 @@ function toggle_visibility(id) {
 	w.WriteString(html.EscapeString(name))
 	w.WriteString("</h1>")
 	w.WriteString(`
-<a href="#" onclick="toggle_visibility('help');" id="helplink">help</a>
+<a href="#" onclick="toggle_visibility('help');return false;" id="helplink">help</a>
 <div id="help">
 
 <p>
@@ -449,6 +582,11 @@ Faded out values and blocks are dead code that has not been eliminated.
 Values printed in italics have a dependency cycle.
 </p>
 
+<p>
+<b>CFG</b>: Dashed edge is for unlikely branches. Blue color is for backward edges.
+Edge with a dot means that this edge follows the order in which blocks were laidout.
+</p>
+
 </div>
 `)
 	w.WriteString("<table>")
@@ -473,8 +611,8 @@ func (w *HTMLWriter) WriteFunc(phase, title string, f *Func) {
 	if w == nil {
 		return // avoid generating HTML just to discard it
 	}
-	w.WriteColumn(phase, title, "", f.HTML())
-	// TODO: Add visual representation of f's CFG.
+	//w.WriteColumn(phase, title, "", f.HTML())
+	w.WriteColumn(phase, title, "", f.HTML(phase, w.dot))
 }
 
 // FuncLines contains source code for a function to be displayed
@@ -704,17 +842,142 @@ func (b *Block) LongHTML() string {
 	return s
 }
 
-func (f *Func) HTML() string {
-	var buf bytes.Buffer
-	fmt.Fprint(&buf, "<code>")
-	p := htmlFuncPrinter{w: &buf}
+func (f *Func) HTML(phase string, dot *dotWriter) string {
+	buf := new(bytes.Buffer)
+	if dot != nil {
+		dot.writeFuncSVG(buf, phase, f)
+	}
+	fmt.Fprint(buf, "<code>")
+	p := htmlFuncPrinter{w: buf}
 	fprintFunc(p, f)
 
 	// fprintFunc(&buf, f) // TODO: HTML, not text, <br /> for line breaks, etc.
-	fmt.Fprint(&buf, "</code>")
+	fmt.Fprint(buf, "</code>")
 	return buf.String()
 }
 
+func (d *dotWriter) writeFuncSVG(w io.Writer, phase string, f *Func) {
+	if d.broken {
+		return
+	}
+	if _, ok := d.phases[phase]; !ok {
+		return
+	}
+	cmd := exec.Command(d.path, "-Tsvg")
+	pipe, err := cmd.StdinPipe()
+	if err != nil {
+		d.broken = true
+		fmt.Println(err)
+		return
+	}
+	buf := new(bytes.Buffer)
+	cmd.Stdout = buf
+	bufErr := new(bytes.Buffer)
+	cmd.Stderr = bufErr
+	err = cmd.Start()
+	if err != nil {
+		d.broken = true
+		fmt.Println(err)
+		return
+	}
+	fmt.Fprint(pipe, `digraph "" { margin=0; size="4,40"; ranksep=.2; `)
+	id := strings.Replace(phase, " ", "-", -1)
+	fmt.Fprintf(pipe, `id="g_graph_%s";`, id)
+	fmt.Fprintf(pipe, `node [style=filled,fillcolor=white,fontsize=16,fontname="Menlo,Times,serif",margin="0.01,0.03"];`)
+	fmt.Fprintf(pipe, `edge [fontsize=16,fontname="Menlo,Times,serif"];`)
+	for i, b := range f.Blocks {
+		if b.Kind == BlockInvalid {
+			continue
+		}
+		layout := ""
+		if f.laidout {
+			layout = fmt.Sprintf(" #%d", i)
+		}
+		fmt.Fprintf(pipe, `%v [label="%v%s\n%v",id="graph_node_%v_%v",tooltip="%v"];`, b, b, layout, b.Kind, id, b, b.LongString())
+	}
+	indexOf := make([]int, f.NumBlocks())
+	for i, b := range f.Blocks {
+		indexOf[b.ID] = i
+	}
+	layoutDrawn := make([]bool, f.NumBlocks())
+
+	ponums := make([]int32, f.NumBlocks())
+	_ = postorderWithNumbering(f, ponums)
+	isBackEdge := func(from, to ID) bool {
+		return ponums[from] <= ponums[to]
+	}
+
+	for _, b := range f.Blocks {
+		for i, s := range b.Succs {
+			style := "solid"
+			color := "black"
+			arrow := "vee"
+			if b.unlikelyIndex() == i {
+				style = "dashed"
+			}
+			if f.laidout && indexOf[s.b.ID] == indexOf[b.ID]+1 {
+				// Red color means ordered edge. It overrides other colors.
+				arrow = "dotvee"
+				layoutDrawn[s.b.ID] = true
+			} else if isBackEdge(b.ID, s.b.ID) {
+				color = "blue"
+			}
+			fmt.Fprintf(pipe, `%v -> %v [label=" %d ",style="%s",color="%s",arrowhead="%s"];`, b, s.b, i, style, color, arrow)
+		}
+	}
+	if f.laidout {
+		fmt.Fprintln(pipe, `edge[constraint=false,color=gray,style=solid,arrowhead=dot];`)
+		colors := [...]string{"#eea24f", "#f38385", "#f4d164", "#ca89fc", "gray"}
+		ci := 0
+		for i := 1; i < len(f.Blocks); i++ {
+			if layoutDrawn[f.Blocks[i].ID] {
+				continue
+			}
+			fmt.Fprintf(pipe, `%s -> %s [color="%s"];`, f.Blocks[i-1], f.Blocks[i], colors[ci])
+			ci = (ci + 1) % len(colors)
+		}
+	}
+	fmt.Fprint(pipe, "}")
+	pipe.Close()
+	err = cmd.Wait()
+	if err != nil {
+		d.broken = true
+		fmt.Printf("dot: %s\n%v\n", err, bufErr.String())
+		return
+	}
+
+	svgID := "svg_graph_" + id
+	fmt.Fprintf(w, `<div class="zoom"><button onclick="return graphReduce('%s');">-</button> <button onclick="return graphEnlarge('%s');">+</button></div>`, svgID, svgID)
+	// For now, an awful hack: edit the html as it passes through
+	// our fingers, finding '<svg ' and injecting needed attributes after it.
+	err = d.copyUntil(w, buf, `<svg `)
+	if err != nil {
+		fmt.Printf("injecting attributes: %s\n", err)
+		return
+	}
+	fmt.Fprintf(w, ` id="%s" onload="makeDraggable(evt)" `, svgID)
+	io.Copy(w, buf)
+}
+
+func (b *Block) unlikelyIndex() int {
+	switch b.Likely {
+	case BranchLikely:
+		return 1
+	case BranchUnlikely:
+		return 0
+	}
+	return -1
+}
+
+func (d *dotWriter) copyUntil(w io.Writer, buf *bytes.Buffer, sep string) error {
+	i := bytes.Index(buf.Bytes(), []byte(sep))
+	if i == -1 {
+		return fmt.Errorf("couldn't find dot sep %q", sep)
+	}
+	_, err := io.CopyN(w, buf, int64(i+len(sep)))
+	return err
+}
+
 type htmlFuncPrinter struct {
 	w io.Writer
 }
@@ -752,7 +1015,6 @@ func (p htmlFuncPrinter) endBlock(b *Block) {
 	fmt.Fprint(p.w, b.LongHTML())
 	io.WriteString(p.w, "</li>")
 	io.WriteString(p.w, "</ul>")
-	// io.WriteString(p.w, "</span>")
 }
 
 func (p htmlFuncPrinter) value(v *Value, live bool) {
@@ -780,3 +1042,63 @@ func (p htmlFuncPrinter) named(n LocalSlot, vals []*Value) {
 	}
 	fmt.Fprintf(p.w, "</li>")
 }
+
+type dotWriter struct {
+	path   string
+	broken bool
+	phases map[string]bool // keys specify phases with CFGs
+}
+
+// newDotWriter returns non-nil value when mask is valid.
+// dotWriter will generate SVGs only for the phases specifed in the mask.
+// mask can contain following patterns and combinations of them:
+// *   - all of them;
+// x-y - x through y, inclusive;
+// x,y - x and y, but not the passes between.
+func newDotWriter(mask string) *dotWriter {
+	if mask == "" {
+		return nil
+	}
+	// User can specify phase name with _ instead of spaces.
+	mask = strings.Replace(mask, "_", " ", -1)
+	ph := make(map[string]bool)
+	ranges := strings.Split(mask, ",")
+	for _, r := range ranges {
+		spl := strings.Split(r, "-")
+		if len(spl) > 2 {
+			fmt.Printf("range is not valid: %v\n", mask)
+			return nil
+		}
+		var first, last int
+		if mask == "*" {
+			first = 0
+			last = len(passes) - 1
+		} else {
+			first = passIdxByName(spl[0])
+			last = passIdxByName(spl[len(spl)-1])
+		}
+		if first < 0 || last < 0 || first > last {
+			fmt.Printf("range is not valid: %v\n", r)
+			return nil
+		}
+		for p := first; p <= last; p++ {
+			ph[passes[p].name] = true
+		}
+	}
+
+	path, err := exec.LookPath("dot")
+	if err != nil {
+		fmt.Println(err)
+		return nil
+	}
+	return &dotWriter{path: path, phases: ph}
+}
+
+func passIdxByName(name string) int {
+	for i, p := range passes {
+		if p.name == name {
+			return i
+		}
+	}
+	return -1
+}
diff --git a/src/cmd/compile/internal/ssa/layout.go b/src/cmd/compile/internal/ssa/layout.go
index 78d5dc77fed23e..338cd91c47feba 100644
--- a/src/cmd/compile/internal/ssa/layout.go
+++ b/src/cmd/compile/internal/ssa/layout.go
@@ -143,5 +143,7 @@ blockloop:
 			}
 		}
 	}
+	f.laidout = true
 	return order
+	//f.Blocks = order
 }