llvm/test/CodeGen/ARM/v8m-tail-call.ll
Sanne Wouda 90365ceb11 [ARM] Change TCReturn to tBL if tailcall optimization fails.
Summary:
The tail call optimisation is performed before register allocation, so
at that point we don't know if LR is being spilt or not. If LR was spilt
to the stack, then we cannot do a tail call optimisation. That would
involve popping back into LR which is not possible in Thumb1 code.

Reviewers: rengolin, jmolloy, rovka, olista01

Reviewed By: olista01

Subscribers: llvm-commits, aemerson

Differential Revision: https://reviews.llvm.org/D29020

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294000 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-03 11:15:53 +00:00

24 lines
386 B
LLVM

; RUN: llc %s -o - -mtriple=thumbv8m.base | FileCheck %s
define void @test() {
; CHECK-LABEL: test:
entry:
%call = tail call i32 @foo()
%tail = tail call i32 @foo()
ret void
; CHECK: bl foo
; CHECK: bl foo
; CHECK-NOT: b foo
}
define void @test2() {
; CHECK-LABEL: test2:
entry:
%tail = tail call i32 @foo()
ret void
; CHECK: b foo
; CHECK-NOT: bl foo
}
declare i32 @foo()