1 ; RUN: opt < %s -deadargelim -S | FileCheck %s 2 3 %Ty = type { i32, i32 } 4 5 ; sanity check that the argument and return value are both dead 6 ; CHECK-LABEL: define internal void @test1() 7 8 define internal %Ty* @test1(%Ty* %this) { 9 ret %Ty* %this 10 } 11 12 ; do not keep alive the return value of a function with a dead 'returned' argument 13 ; CHECK-LABEL: define internal void @test2() 14 15 define internal %Ty* @test2(%Ty* returned %this) { 16 ret %Ty* %this 17 } 18 19 ; dummy to keep 'this' alive 20 @dummy = global %Ty* null 21 22 ; sanity check that return value is dead 23 ; CHECK-LABEL: define internal void @test3(%Ty* %this) 24 25 define internal %Ty* @test3(%Ty* %this) { 26 store volatile %Ty* %this, %Ty** @dummy 27 ret %Ty* %this 28 } 29 30 ; keep alive return value of a function if the 'returned' argument is live 31 ; CHECK-LABEL: define internal %Ty* @test4(%Ty* returned %this) 32 33 define internal %Ty* @test4(%Ty* returned %this) { 34 store volatile %Ty* %this, %Ty** @dummy 35 ret %Ty* %this 36 } 37 38 ; don't do this if 'returned' is on the call site... 39 ; CHECK-LABEL: define internal void @test5(%Ty* %this) 40 41 define internal %Ty* @test5(%Ty* %this) { 42 store volatile %Ty* %this, %Ty** @dummy 43 ret %Ty* %this 44 } 45 46 define %Ty* @caller(%Ty* %this) { 47 %1 = call %Ty* @test1(%Ty* %this) 48 %2 = call %Ty* @test2(%Ty* %this) 49 %3 = call %Ty* @test3(%Ty* %this) 50 %4 = call %Ty* @test4(%Ty* %this) 51 ; ...instead, drop 'returned' form the call site 52 ; CHECK: call void @test5(%Ty* %this) 53 %5 = call %Ty* @test5(%Ty* returned %this) 54 ret %Ty* %this 55 } 56
