; RUN: opt -passes='loop-mssa(simple-loop-unswitch<nontrivial>),instcombine,indvars' -S %s | FileCheck %s
; This used to crash in SCEVExpander when there were congruent phis with and
; undef incoming value from the loop header. The -loop-unswitch -passes=instcombine is
; necessary to create just this pattern, which is essentially a nop and gets
; folded away aggressively if spelled out in IR directly.
; PR 20093
@c = external global ptr, align 8
define void @test1() {
entry:
br i1 undef, label %for.end12, label %for.cond.preheader
for.cond.preheader: ; preds = %entry
%0 = load ptr, ptr @c, align 8
%1 = load ptr, ptr %0, align 8
%2 = load i32, ptr %1, align 4
br label %for.body
for.body: ; preds = %for.cond.backedge, %for.body9.us, %for.cond.preheader
%3 = phi ptr [ %1, %for.cond.preheader ], [ %3, %for.cond.backedge ], [ %6, %for.body9.us ]
%4 = phi i32 [ %2, %for.cond.preheader ], [ undef, %for.cond.backedge ], [ %7, %for.body9.us ]
%i.024 = phi i32 [ 0, %for.cond.preheader ], [ %inc, %for.cond.backedge ], [ 0, %for.body9.us ]
%tobool1 = icmp eq i32 %4, 0
br i1 %tobool1, label %if.end, label %for.cond.backedge
if.end: ; preds = %for.body
%5 = load i32, ptr %3, align 4
%tobool4 = icmp eq i32 %5, 0
br i1 %tobool4, label %for.cond3, label %for.body9.preheader
for.body9.preheader: ; preds = %if.end
%tobool8 = icmp eq i32 %i.024, 1
br i1 %tobool8, label %for.body9.us, label %for.body9
for.body9.us: ; preds = %for.body9.preheader
%6 = load ptr, ptr undef, align 8
%7 = load i32, ptr %6, align 4
br label %for.body
for.cond3: ; preds = %for.cond3, %if.end
br label %for.cond3
for.body9: ; preds = %for.body9, %for.body9.preheader
br label %for.body9
for.cond.backedge: ; preds = %for.body
%inc = add nsw i32 %i.024, 1
br i1 false, label %for.body, label %for.end12
for.end12: ; preds = %for.cond.backedge, %entry
ret void
; CHECK-LABEL: @test1
; CHECK-NOT: phi
}
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