diff --git a/src/cmd/compile/internal/ssa/compile.go b/src/cmd/compile/internal/ssa/compile.go
index dbdd027716..444475d67a 100644
--- a/src/cmd/compile/internal/ssa/compile.go
+++ b/src/cmd/compile/internal/ssa/compile.go
@@ -160,15 +160,12 @@ func Compile(f *Func) {
 	phaseName = ""
 }
 
-// TODO: should be a config field
-var dumpFileSeq int
-
 // dumpFile creates a file from the phase name and function name
 // Dumping is done to files to avoid buffering huge strings before
 // output.
 func (f *Func) dumpFile(phaseName string) {
-	dumpFileSeq++
-	fname := fmt.Sprintf("%s_%02d__%s.dump", f.Name, dumpFileSeq, phaseName)
+	f.dumpFileSeq++
+	fname := fmt.Sprintf("%s_%02d__%s.dump", f.Name, int(f.dumpFileSeq), phaseName)
 	fname = strings.Replace(fname, " ", "_", -1)
 	fname = strings.Replace(fname, "/", "_", -1)
 	fname = strings.Replace(fname, ":", "_", -1)
diff --git a/src/cmd/compile/internal/ssa/func.go b/src/cmd/compile/internal/ssa/func.go
index 4b9189fb3e..9e40b6214c 100644
--- a/src/cmd/compile/internal/ssa/func.go
+++ b/src/cmd/compile/internal/ssa/func.go
@@ -44,9 +44,10 @@ type Func struct {
 	PrintOrHtmlSSA bool           // true if GOSSAFUNC matches, true even if fe.Log() (spew phase results to stdout) is false.
 	ruleMatches    map[string]int // number of times countRule was called during compilation for any given string
 
-	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.
+	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.
+	dumpFileSeq uint8 // the sequence numbers of dump file. (%s_%02d__%s.dump", funcname, dumpFileSeq, phaseName)
 
 	// when register allocation is done, maps value ids to locations
 	RegAlloc []Location