diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index 9b67fe99ad..6d727a5f6e 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -65,6 +65,7 @@ func buildssa(fn *Node) *ssa.Func {
 	s.f.Name = name
 	s.exitCode = fn.Func.Exit
 	s.panics = map[funcLine]*ssa.Block{}
+	s.config.DebugTest = s.config.DebugHashMatch("GOSSAHASH", name)
 
 	if name == os.Getenv("GOSSAFUNC") {
 		// TODO: tempfile? it is handy to have the location
diff --git a/src/cmd/compile/internal/ssa/config.go b/src/cmd/compile/internal/ssa/config.go
index 6c891a55db..bd59bb36ab 100644
--- a/src/cmd/compile/internal/ssa/config.go
+++ b/src/cmd/compile/internal/ssa/config.go
@@ -33,6 +33,7 @@ type Config struct {
 	nacl            bool                       // GOOS=nacl
 	use387          bool                       // GO386=387
 	NeedsFpScratch  bool                       // No direct move between GP and FP register sets
+	DebugTest       bool                       // as a debugging aid for binary search using GOSSAHASH, make buggy new code conditional on this
 	sparsePhiCutoff uint64                     // Sparse phi location algorithm used above this #blocks*#variables score
 	curFunc         *Func