1; RUN: opt < %s -passes='require<profile-summary>,function(codegenprepare)' -S -mtriple=x86_64 | FileCheck %s --implicit-check-not="llvm.fake.use" 2; 3; When performing return duplication to enable 4; tail call optimization we clone fake uses that exist in the to-be-eliminated 5; return block into the predecessor blocks. When doing this with fake uses 6; of PHI-nodes, they cannot be easily copied, but require the correct operand. 7; We are currently not able to do this correctly, so we suppress the cloning 8; of such fake uses at the moment. 9; 10; There should be no fake use of a call result in any of the resulting return 11; blocks. 12 13; Fake uses of `this` should be duplicated into both return blocks. 14; CHECK: if.then: 15; CHECK: @llvm.fake.use({{.*}}this 16; CHECK: if.else: 17; CHECK: @llvm.fake.use({{.*}}this 18 19; CHECK: declare void @llvm.fake.use 20 21source_filename = "test.ll" 22 23%class.a = type { i8 } 24 25declare i32 @foo(ptr nonnull dereferenceable(1)) local_unnamed_addr 26declare i32 @bar(ptr nonnull dereferenceable(1)) local_unnamed_addr 27 28define hidden void @func(ptr nonnull dereferenceable(1) %this) local_unnamed_addr align 2 optdebug { 29entry: 30 %b = getelementptr inbounds %class.a, ptr %this, i64 0, i32 0 31 %0 = load i8, i8* %b, align 1 32 %tobool.not = icmp eq i8 %0, 0 33 br i1 %tobool.not, label %if.else, label %if.then 34 35if.then: ; preds = %entry 36 %call = tail call i32 @foo(ptr nonnull dereferenceable(1) %this) 37 %call2 = tail call i32 @bar(ptr nonnull dereferenceable(1) %this) 38 br label %if.end 39 40if.else: ; preds = %entry 41 %call4 = tail call i32 @bar(ptr nonnull dereferenceable(1) %this) 42 %call5 = tail call i32 @foo(ptr nonnull dereferenceable(1) %this) 43 br label %if.end 44 45if.end: ; preds = %if.else, %if.then 46 %call4.sink = phi i32 [ %call4, %if.else ], [ %call, %if.then ] 47 notail call void (...) @llvm.fake.use(i32 %call4.sink) 48 notail call void (...) @llvm.fake.use(ptr nonnull %this) 49 ret void 50} 51