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 <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Todd Neal 2017-04-24 11:20:09 -04:00
parent 46b88c9fbc
commit 08dca4c649
2 changed files with 25 additions and 3 deletions

View file

@ -322,9 +322,13 @@ func cmpVal(v, w *Value, auxIDs auxmap) types.Cmp {
// that generate memory.
return lt2Cmp(v.ID < w.ID)
}
if tc := v.Type.Compare(w.Type); tc != types.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 != types.CMPeq {
return tc
}
}
if v.Aux != w.Aux {