From 195e20a9768468d580231e62e37e6fb0525ed20e Mon Sep 17 00:00:00 2001 From: Todd Neal Date: Mon, 24 Apr 2017 11:20:09 -0400 Subject: [release-branch.go1.8] cmd/compile: ignore types when considering tuple select for CSE Fixes #20097 Change-Id: I3c9626ccc8cd0c46a7081ea8650b2ff07a5d4fcd Reviewed-on: https://go-review.googlesource.com/41505 Run-TryBot: Todd Neal TryBot-Result: Gobot Gobot Reviewed-by: Keith Randall Reviewed-on: https://go-review.googlesource.com/43997 Run-TryBot: Chris Broadfoot Reviewed-by: Brad Fitzpatrick --- src/cmd/compile/internal/ssa/cse.go | 10 +++++++--- test/fixedbugs/issue20097.go | 18 ++++++++++++++++++ 2 files changed, 25 insertions(+), 3 deletions(-) create mode 100644 test/fixedbugs/issue20097.go diff --git a/src/cmd/compile/internal/ssa/cse.go b/src/cmd/compile/internal/ssa/cse.go index 4e07c89b88..9ab18d89e9 100644 --- a/src/cmd/compile/internal/ssa/cse.go +++ b/src/cmd/compile/internal/ssa/cse.go @@ -313,9 +313,13 @@ func cmpVal(v, w *Value, auxIDs auxmap) Cmp { // that generate memory. return lt2Cmp(v.ID < w.ID) } - - if tc := v.Type.Compare(w.Type); tc != CMPeq { - return tc + // OpSelect is a pseudo-op. We need to be more agressive + // regarding CSE to keep multiple OpSelect's of the same + // argument from existing. + if v.Op != OpSelect0 && v.Op != OpSelect1 { + if tc := v.Type.Compare(w.Type); tc != CMPeq { + return tc + } } if v.Aux != w.Aux { diff --git a/test/fixedbugs/issue20097.go b/test/fixedbugs/issue20097.go new file mode 100644 index 0000000000..236a1bd40a --- /dev/null +++ b/test/fixedbugs/issue20097.go @@ -0,0 +1,18 @@ +// 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. + +// Issue 20097: ensure that we CSE multiple Select ops with +// the same underlying type + +package main + +type T int64 + +func f(x, y int64) (int64, T) { + a := x / y + b := T(x) / T(y) + return a, b +} -- cgit v1.2.3-54-g00ecf