cmd/gc: fix bad checknil with ints on 32 bit compilers

Fixes issue 7413.

LGTM=rsc
R=remyoudompheng
CC=golang-codereviews, r, rsc
https://codereview.appspot.com/69180044

1 files changed, 24 insertions, 0 deletions

diff --git a/test/nilptr4.go b/test/nilptr4.go
new file mode 100644
index 000000000..3dd7d4e02
--- /dev/null
+++ b/test/nilptr4.go
@@ -0,0 +1,24 @@
+// build
+
+// Copyright 2014 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.
+
+// Test that the compiler does not crash during compilation.
+
+package main
+
+import "unsafe"
+
+// Issue 7413
+func f1() {
+	type t struct {
+		i int
+	}
+
+	var v *t
+	_ = int(uintptr(unsafe.Pointer(&v.i)))
+	_ = int32(uintptr(unsafe.Pointer(&v.i)))
+}
+
+func main() {}