tree b59832701fd8586994b9086ab70c62f55c912f61
parent a453eebae76296a39a1ded5bd2bffa78bedf40bd
author Ian Lance Taylor <iant@golang.org> 1566305291 -0700
committer Ian Lance Taylor <iant@golang.org> 1566335120 +0000

compiler, runtime: implement shifts by signed amounts

Shifting by signed types is a new language feature in Go 1.13.

This requires a patch to the testsuite:

    Index: go.test/test/fixedbugs/bug073.go
    ===================================================================
    --- go.test/test/fixedbugs/bug073.go	(revision 274239)
    +++ go.test/test/fixedbugs/bug073.go	(working copy)
    @@ -1,4 +1,4 @@
    -// errorcheck
    +// compile

     // Copyright 2009 The Go Authors. All rights reserved.
     // Use of this source code is governed by a BSD-style
    @@ -7,8 +7,8 @@
     package main

     func main() {
    -	var s int = 0;
    -	var x int = 0;
    -	x = x << s;  // ERROR "illegal|inval|shift"
    -	x = x >> s;  // ERROR "illegal|inval|shift"
    +	var s int = 0
    +	var x int = 0
    +	x = x << s // as of 1.13, these are ok
    +	x = x >> s // as of 1.13, these are ok
     }

Updates golang/go#19113

Change-Id: Ida01c07dff6c5f1f47559083374688ff3800b272
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/190977
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>