cmd/compile: ensure TESTQconst AuxInt is in range

Fixes #19555

Change-Id: I7aa0551a90f6bb630c0ba721f3525a8a9cf793fd
Reviewed-on: https://go-review.googlesource.com/38164
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

3 files changed, 42 insertions, 6 deletions

diff --git a/src/cmd/compile/internal/ssa/gen/AMD64.rules b/src/cmd/compile/internal/ssa/gen/AMD64.rules
index 3e68a2a732..ca760cad15 100644
--- a/src/cmd/compile/internal/ssa/gen/AMD64.rules
+++ b/src/cmd/compile/internal/ssa/gen/AMD64.rules
@@ -1406,11 +1406,11 @@
 (CMPBconst (ANDLconst [c] x) [0]) -> (TESTBconst [int64(int8(c))] x)
 
 // Convert TESTx to TESTxconst if possible.
-(TESTQ (MOVQconst [c]) x) && c < 1<<31 -> (TESTQconst [c] x)
+(TESTQ (MOVQconst [c]) x) && is32Bit(c) -> (TESTQconst [c] x)
 (TESTL (MOVLconst [c]) x) -> (TESTLconst [c] x)
 (TESTW (MOVLconst [c]) x) -> (TESTWconst [c] x)
 (TESTB (MOVLconst [c]) x) -> (TESTBconst [c] x)
-(TESTQ x (MOVQconst [c])) && c < 1<<31 -> (TESTQconst [c] x)
+(TESTQ x (MOVQconst [c])) && is32Bit(c) -> (TESTQconst [c] x)
 (TESTL x (MOVLconst [c])) -> (TESTLconst [c] x)
 (TESTW x (MOVLconst [c])) -> (TESTWconst [c] x)
 (TESTB x (MOVLconst [c])) -> (TESTBconst [c] x)
diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
index 2a7291c502..e581dfe513 100644
--- a/src/cmd/compile/internal/ssa/rewriteAMD64.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go
@@ -16360,7 +16360,7 @@ func rewriteValueAMD64_OpAMD64TESTQ(v *Value, config *Config) bool {
 		return true
 	}
 	// match: (TESTQ (MOVQconst [c]) x)
-	// cond: c < 1<<31
+	// cond: is32Bit(c)
 	// result: (TESTQconst [c] x)
 	for {
 		v_0 := v.Args[0]
@@ -16369,7 +16369,7 @@ func rewriteValueAMD64_OpAMD64TESTQ(v *Value, config *Config) bool {
 		}
 		c := v_0.AuxInt
 		x := v.Args[1]
-		if !(c < 1<<31) {
+		if !(is32Bit(c)) {
 			break
 		}
 		v.reset(OpAMD64TESTQconst)
@@ -16378,7 +16378,7 @@ func rewriteValueAMD64_OpAMD64TESTQ(v *Value, config *Config) bool {
 		return true
 	}
 	// match: (TESTQ x (MOVQconst [c]))
-	// cond: c < 1<<31
+	// cond: is32Bit(c)
 	// result: (TESTQconst [c] x)
 	for {
 		x := v.Args[0]
@@ -16387,7 +16387,7 @@ func rewriteValueAMD64_OpAMD64TESTQ(v *Value, config *Config) bool {
 			break
 		}
 		c := v_1.AuxInt
-		if !(c < 1<<31) {
+		if !(is32Bit(c)) {
 			break
 		}
 		v.reset(OpAMD64TESTQconst)
diff --git a/test/fixedbugs/issue19555.go b/test/fixedbugs/issue19555.go
new file mode 100644
index 0000000000..53b2ebde51
--- /dev/null
+++ b/test/fixedbugs/issue19555.go
@@ -0,0 +1,36 @@
+// compile
+
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type NodeLink struct{}
+
+// A role our end of NodeLink is intended to play
+type LinkRole int64
+
+const (
+	LinkServer LinkRole = iota // link created as server
+	LinkClient                 // link created as client
+
+	// for testing:
+	linkNoRecvSend LinkRole = 1 << 16 // do not spawn serveRecv & serveSend
+	linkFlagsMask  LinkRole = (1<<32 - 1) << 16
+)
+
+func NewNodeLink(role LinkRole) *NodeLink {
+	var nextConnId uint32
+	switch role &^ linkFlagsMask {
+	case LinkServer:
+		nextConnId = 0 // all initiated by us connId will be even
+	case LinkClient:
+		nextConnId = 1 // ----//---- odd
+	default:
+		panic("invalid conn role")
+	}
+
+	_ = nextConnId
+	return nil
+}