cmd/compile: run generic deadcode in -N mode

Late opt pass may generate dead stores, which messes up store
chain calculation in later passes. Run generic deadcode even
in -N mode to remove them.

Fixes #26163.

Change-Id: I8276101717bb978d5980e6c7998f53fd8d0ae10f
Reviewed-on: https://go-review.googlesource.com/121856
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Cherry Zhang 2018-06-30 17:46:25 -04:00
parent 398a8ed653
commit 3f54e8537a
2 changed files with 18 additions and 1 deletions

View file

@ -373,7 +373,7 @@ var passes = [...]pass{
{name: "softfloat", fn: softfloat, required: true},
{name: "late opt", fn: opt, required: true}, // TODO: split required rules and optimizing rules
{name: "dead auto elim", fn: elimDeadAutosGeneric},
{name: "generic deadcode", fn: deadcode},
{name: "generic deadcode", fn: deadcode, required: true}, // remove dead stores, which otherwise mess up store chain
{name: "check bce", fn: checkbce},
{name: "branchelim", fn: branchelim},
{name: "fuse", fn: fuse},

View file

@ -0,0 +1,17 @@
// compile -N -d=softfloat
// Copyright 2018 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.
// Issue 26163: dead store generated in late opt messes
// up store chain calculation.
package p
var i int
var A = ([]*int{})[i]
var F func(float64, complex128) int
var C chan complex128
var B = F(1, 1+(<-C))