From: Michael Munday <munday@ca.ibm.com>
Date: Fri, 23 Sep 2016 14:38:50 +0000 (-0400)
Subject: cmd/compile: recognize OpS390XLoweredNilCheck as a nil check in the scheduler
X-Git-Tag: go1.8beta1~1186
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=120e9ff34f577376f8d1c25a8966c88e0e92fee5;p=gostls13.git

cmd/compile: recognize OpS390XLoweredNilCheck as a nil check in the scheduler

Before this change a nil check on s390x could be scheduled after the
target pointer has been dereferenced.

Change-Id: I7ea40a4b52f975739f6db183a2794be4981c4e3d
Reviewed-on: https://go-review.googlesource.com/29730
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
---

diff --git a/src/cmd/compile/internal/ssa/schedule.go b/src/cmd/compile/internal/ssa/schedule.go
index 135d908259..411c09b971 100644
--- a/src/cmd/compile/internal/ssa/schedule.go
+++ b/src/cmd/compile/internal/ssa/schedule.go
@@ -97,7 +97,10 @@ func schedule(f *Func) {
 					f.Fatalf("LoweredGetClosurePtr appeared outside of entry block, b=%s", b.String())
 				}
 				score[v.ID] = ScorePhi
-			case v.Op == OpAMD64LoweredNilCheck || v.Op == OpPPC64LoweredNilCheck || v.Op == OpARMLoweredNilCheck || v.Op == OpARM64LoweredNilCheck || v.Op == Op386LoweredNilCheck || v.Op == OpMIPS64LoweredNilCheck:
+			case v.Op == OpAMD64LoweredNilCheck || v.Op == OpPPC64LoweredNilCheck ||
+				v.Op == OpARMLoweredNilCheck || v.Op == OpARM64LoweredNilCheck ||
+				v.Op == Op386LoweredNilCheck || v.Op == OpMIPS64LoweredNilCheck ||
+				v.Op == OpS390XLoweredNilCheck:
 				// Nil checks must come before loads from the same address.
 				score[v.ID] = ScoreNilCheck
 			case v.Op == OpPhi: