diff options
| -rw-r--r-- | src/cmd/compile/internal/ssa/cse.go | 10 | ||||
| -rw-r--r-- | test/fixedbugs/issue20097.go | 18 |
2 files changed, 25 insertions, 3 deletions
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 +} |