From 1c05b9b02441f95cce82bed971b7a2204e8bbf6d Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Sat, 23 Oct 2021 10:16:41 -0700 Subject: [release-branch.go1.17] cmd/compile: fix fuse pass to do CFG surgery correctly removePred and removeArg do different things. removePred moves the last predecessor to index k, whereas removeArg slides all the args k or greater down by 1 index. Kind of unfortunate different behavior in things named similarly. Fixes #49129 Change-Id: I9ae409bdac744e713f4c121f948e43db6fdc8542 Reviewed-on: https://go-review.googlesource.com/c/go/+/358117 Trust: Keith Randall Run-TryBot: Keith Randall TryBot-Result: Go Bot Reviewed-by: Cuong Manh Le (cherry picked from commit 8dbf3e9393400d72d313e5616c88873e07692c70) Reviewed-on: https://go-review.googlesource.com/c/go/+/358118 Reviewed-by: Austin Clements Run-TryBot: Cuong Manh Le --- src/cmd/compile/internal/ssa/fuse_branchredirect.go | 6 +++++- test/fixedbugs/issue49122.go | 16 ++++++++++++++++ 2 files changed, 21 insertions(+), 1 deletion(-) create mode 100644 test/fixedbugs/issue49122.go diff --git a/src/cmd/compile/internal/ssa/fuse_branchredirect.go b/src/cmd/compile/internal/ssa/fuse_branchredirect.go index 1b8b307bca..ba5220bd87 100644 --- a/src/cmd/compile/internal/ssa/fuse_branchredirect.go +++ b/src/cmd/compile/internal/ssa/fuse_branchredirect.go @@ -78,7 +78,11 @@ func fuseBranchRedirect(f *Func) bool { if v.Op != OpPhi { continue } - v.RemoveArg(k) + n := len(v.Args) + v.Args[k].Uses-- + v.Args[k] = v.Args[n-1] + v.Args[n-1] = nil + v.Args = v.Args[:n-1] phielimValue(v) } // Fix up child to have one more predecessor. diff --git a/test/fixedbugs/issue49122.go b/test/fixedbugs/issue49122.go new file mode 100644 index 0000000000..c62a627dae --- /dev/null +++ b/test/fixedbugs/issue49122.go @@ -0,0 +1,16 @@ +// compile + +// Copyright 2021 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 main + +var B []bool +var N int + +func f(p bool, m map[bool]bool) bool { + var q bool + _ = p || N&N < N || B[0] || B[0] + return p && q && m[q] +} -- cgit v1.2.3-54-g00ecf