llvm-project/llvm/test/Transforms/GVN/critical-edge-split-failure.ll

50 lines
2.2 KiB
LLVM

; RUN: opt -gvn -S -o - %s | FileCheck %s
; RUN: opt -passes=gvn -S -o - %s | FileCheck %s
%struct.sk_buff = type opaque
@l2tp_recv_dequeue_session = external dso_local local_unnamed_addr global i32, align 4
@l2tp_recv_dequeue_skb = external dso_local local_unnamed_addr global %struct.sk_buff*, align 8
@l2tp_recv_dequeue_session_2 = external dso_local local_unnamed_addr global i32, align 4
@l2tp_recv_dequeue_session_0 = external dso_local local_unnamed_addr global i32, align 4
declare void @llvm.assume(i1 noundef)
define dso_local void @l2tp_recv_dequeue() local_unnamed_addr {
entry:
%0 = load i32, i32* @l2tp_recv_dequeue_session, align 4
%conv = sext i32 %0 to i64
%1 = inttoptr i64 %conv to %struct.sk_buff*
%2 = load i32, i32* @l2tp_recv_dequeue_session_2, align 4
%tobool.not = icmp eq i32 %2, 0
br label %for.cond
for.cond: ; preds = %if.end, %entry
%storemerge = phi %struct.sk_buff* [ %1, %entry ], [ null, %if.end ]
store %struct.sk_buff* %storemerge, %struct.sk_buff** @l2tp_recv_dequeue_skb, align 8
br i1 %tobool.not, label %if.end, label %if.then
if.then: ; preds = %for.cond
%ns = bitcast %struct.sk_buff* %storemerge to i32*
%3 = load i32, i32* %ns, align 4
store i32 %3, i32* @l2tp_recv_dequeue_session_0, align 4
; Splitting the critical edge from if.then to if.end will fail, but should not
; cause an infinite loop in GVN. If we can one day split edges of callbr
; indirect targets, great!
; CHECK: callbr void asm sideeffect "", "X,~{dirflag},~{fpsr},~{flags}"(i8* blockaddress(@l2tp_recv_dequeue, %if.end))
; CHECK-NEXT: to label %asm.fallthrough.i [label %if.end]
callbr void asm sideeffect "", "X,~{dirflag},~{fpsr},~{flags}"(i8* blockaddress(@l2tp_recv_dequeue, %if.end))
to label %asm.fallthrough.i [label %if.end]
asm.fallthrough.i: ; preds = %if.then
br label %if.end
if.end: ; preds = %asm.fallthrough.i, %if.then, %for.cond
%ns1 = bitcast %struct.sk_buff* %storemerge to i32*
%4 = load i32, i32* %ns1, align 4
%tobool2.not = icmp eq i32 %4, 0
tail call void @llvm.assume(i1 %tobool2.not)
br label %for.cond
}