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; RUN: opt -simple-loop-unswitch -enable-nontrivial-unswitch -verify-memoryssa -S %s | FileCheck %s
; REQUIRES: asserts
target triple = "x86_64-unknown-linux-gnu"
declare void @foo()
; In Test1, there are no definitions. MemorySSA updates insert trivial phis and remove them.
; Verify all are removed, considering the SLU pass leaves unreachable blocks hanging when the MSSA updates are done.
; CHECK-LABEL: @Test1
define void @Test1(i32) {
header:
br label %outer
outer.loopexit.split: ; preds = %continue
br label %outer.loopexit
outer.loopexit: ; preds = %outer.loopexit.split.us, %outer.loopexit.split
br label %outer
outer: ; preds = %outer.loopexit, %header
br i1 false, label %outer.split.us, label %outer.split
outer.split.us: ; preds = %outer
br label %inner.us
inner.us: ; preds = %continue.us, %outer.split.us
br label %overflow.us
overflow.us: ; preds = %inner.us
br label %continue.us
continue.us: ; preds = %overflow.us
br i1 true, label %outer.loopexit.split.us, label %inner.us
outer.loopexit.split.us: ; preds = %continue.us
br label %outer.loopexit
outer.split: ; preds = %outer
br label %inner
inner: ; preds = %continue, %outer.split
br label %switchme
switchme: ; preds = %inner
switch i32 %0, label %continue [
i32 88, label %go_out
i32 99, label %case2
]
case2: ; preds = %switchme
br label %continue
continue: ; preds = %case2, %switchme
br i1 true, label %outer.loopexit.split, label %inner
go_out: ; preds = %switchme
unreachable
}
; In Test2 there is a single def (call to foo). There are already Phis in place that are cloned when unswitching.
; Ensure MemorySSA remains correct. Due to SLU's pruned cloning, continue.us2 becomes unreachable, with an empty Phi that is later cleaned.
; CHECK-LABEL: @Test2
define void @Test2(i32) {
header:
br label %outer
outer.loopexit.split: ; preds = %continue
br label %outer.loopexit
outer.loopexit: ; preds = %outer.loopexit.split.us, %outer.loopexit.split
br label %outer
outer: ; preds = %outer.loopexit, %header
br i1 false, label %outer.split.us, label %outer.split
outer.split.us: ; preds = %outer
br label %inner.us
inner.us: ; preds = %continue.us, %outer.split.us
br label %overflow.us
overflow.us: ; preds = %inner.us
br label %continue.us
continue.us: ; preds = %overflow.us
br i1 true, label %outer.loopexit.split.us, label %inner.us
outer.loopexit.split.us: ; preds = %continue.us
br label %outer.loopexit
outer.split: ; preds = %outer
br label %inner
inner: ; preds = %continue, %outer.split
br label %switchme
switchme: ; preds = %inner
switch i32 %0, label %continue [
i32 88, label %go_out
i32 99, label %case2
]
case2: ; preds = %switchme
call void @foo()
br label %continue
continue: ; preds = %case2, %switchme
br i1 true, label %outer.loopexit.split, label %inner
go_out: ; preds = %switchme
unreachable
}
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