From 709e893d2402cf49e9556b376f3003ed82567b02 Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Thu, 3 Jan 2019 13:39:30 +0100
Subject: prog: don't produce the same program when mutating with hints

No point in producing the same program as result of mutation with hints.
So don't do it.
---
 prog/hints.go | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'prog/hints.go')

diff --git a/prog/hints.go b/prog/hints.go
index 8ac3ed735..16ffe783e 100644
--- a/prog/hints.go
+++ b/prog/hints.go
@@ -209,6 +209,9 @@ func shrinkExpand(v uint64, compMap CompMap) []uint64 {
 				// Replace size least significant bits of v with
 				// corresponding bits of newV. Leave the rest of v as it was.
 				replacer := (v &^ mask) | newV
+				if replacer == v {
+					continue
+				}
 				// TODO(dvyukov): should we try replacing with arg+/-1?
 				// This could trigger some off-by-ones.
 				if replacers == nil {
-- 
cgit mrf-deployment