1 ; RUN: llc -verify-machineinstrs -mtriple=arm64-apple-ios7.0 -o - %s | FileCheck %s 2 @var = global void()* zeroinitializer 3 4 declare void @bar() 5 6 define void @foo() { 7 ; CHECK-LABEL: foo: 8 %func = load void()*, void()** @var 9 10 ; Calling a function encourages @foo to use a callee-saved register, 11 ; which makes it a natural choice for the tail call itself. But we don't 12 ; want that: the final "br xN" has to use a temporary or argument 13 ; register. 14 call void @bar() 15 16 tail call void %func() 17 ; CHECK: br {{x([0-79]|1[0-8])}} 18 ret void 19 } 20 21 ; No matter how tempting it is, LLVM should not use x30 since that'll be 22 ; restored to its incoming value before the "br". 23 define void @test_x30_tail() { 24 ; CHECK-LABEL: test_x30_tail: 25 ; CHECK: mov [[DEST:x[0-9]+]], x30 26 ; CHECK: br [[DEST]] 27 %addr = call i8* @llvm.returnaddress(i32 0) 28 %faddr = bitcast i8* %addr to void()* 29 tail call void %faddr() 30 ret void 31 } 32 33 declare i8* @llvm.returnaddress(i32) 34
