1; RUN: opt -S -aarch64-stack-tagging %s -o - | FileCheck %s 2target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128" 3target triple = "aarch64-unknown-linux-android29" 4 5@stackbuf = dso_local local_unnamed_addr global i8* null, align 8 6@jbuf = dso_local global [32 x i64] zeroinitializer, align 8 7 8declare void @may_jump() 9 10define dso_local noundef i1 @_Z6targetv() sanitize_memtag { 11entry: 12 %buf = alloca [4096 x i8], align 1 13 %call = call i32 @setjmp(i64* noundef getelementptr inbounds ([32 x i64], [32 x i64]* @jbuf, i64 0, i64 0)) 14 switch i32 %call, label %while.body [ 15 i32 1, label %return 16 i32 2, label %sw.bb1 17 ] 18 19sw.bb1: ; preds = %entry 20 br label %return 21 22while.body: ; preds = %entry 23 %0 = getelementptr inbounds [4096 x i8], [4096 x i8]* %buf, i64 0, i64 0 24 call void @llvm.lifetime.start.p0i8(i64 4096, i8* nonnull %0) #10 25 store i8* %0, i8** @stackbuf, align 8 26 ; may_jump may call longjmp, going back to the switch (and then the return), 27 ; bypassing the lifetime.end. This is why we need to untag on the return, 28 ; rather than the lifetime.end. 29 call void @may_jump() 30 call void @llvm.lifetime.end.p0i8(i64 4096, i8* nonnull %0) #10 31 br label %return 32 33; CHECK-LABEL: return: 34; CHECK: call void @llvm.aarch64.settag 35return: ; preds = %entry, %while.body, %sw.bb1 36 %retval.0 = phi i1 [ true, %while.body ], [ true, %sw.bb1 ], [ false, %entry ] 37 ret i1 %retval.0 38} 39 40declare i32 @setjmp(i64* noundef) returns_twice 41 42declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) 43declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) 44 45