llvm/test/CodeGen/AVR/frameaddress.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
; RUN: llc < %s -mtriple=avr | FileCheck %s

declare ptr @llvm.frameaddress.p0(i32 immarg)
declare void @use(ptr)

; The frame pointer is Y (r29:r28), which is set up to contain the stack
; pointer after the frame has been allocated.
define ptr @frameaddress_0() {
; CHECK-LABEL: frameaddress_0:
; CHECK:       ; %bb.0:
; CHECK-NEXT:    push r28
; CHECK-NEXT:    push r29
; CHECK-NEXT:    in r28, 61
; CHECK-NEXT:    in r29, 62
; CHECK-NEXT:    mov r24, r28
; CHECK-NEXT:    mov r25, r29
; CHECK-NEXT:    pop r29
; CHECK-NEXT:    pop r28
; CHECK-NEXT:    ret
  %1 = call ptr @llvm.frameaddress.p0(i32 0)
  ret ptr %1
}

; Walking the frame chain is not possible, because the slot holding the
; caller's Y is at a function dependent offset above Y. Return zero instead.
define ptr @frameaddress_1() {
; CHECK-LABEL: frameaddress_1:
; CHECK:       ; %bb.0:
; CHECK-NEXT:    ldi r24, 0
; CHECK-NEXT:    ldi r25, 0
; CHECK-NEXT:    ret
  %1 = call ptr @llvm.frameaddress.p0(i32 1)
  ret ptr %1
}

; Local objects are addressed relative to Y, the same value that is returned
; by llvm.frameaddress(0).
define ptr @frameaddress_alloca() {
; CHECK-LABEL: frameaddress_alloca:
; CHECK:       ; %bb.0:
; CHECK-NEXT:    push r28
; CHECK-NEXT:    push r29
; CHECK-NEXT:    in r28, 61
; CHECK-NEXT:    in r29, 62
; CHECK-NEXT:    sbiw r28, 4
; CHECK-NEXT:    in r0, 63
; CHECK-NEXT:    cli
; CHECK-NEXT:    out 62, r29
; CHECK-NEXT:    out 63, r0
; CHECK-NEXT:    out 61, r28
; CHECK-NEXT:    ldi r24, 42
; CHECK-NEXT:    std Y+1, r24
; CHECK-NEXT:    mov r24, r28
; CHECK-NEXT:    mov r25, r29
; CHECK-NEXT:    adiw r24, 1
; CHECK-NEXT:    rcall use
; CHECK-NEXT:    mov r24, r28
; CHECK-NEXT:    mov r25, r29
; CHECK-NEXT:    adiw r28, 4
; CHECK-NEXT:    in r0, 63
; CHECK-NEXT:    cli
; CHECK-NEXT:    out 62, r29
; CHECK-NEXT:    out 63, r0
; CHECK-NEXT:    out 61, r28
; CHECK-NEXT:    pop r29
; CHECK-NEXT:    pop r28
; CHECK-NEXT:    ret
  %x = alloca i8, i32 4
  store i8 42, ptr %x
  call void @use(ptr %x)
  %1 = call ptr @llvm.frameaddress.p0(i32 0)
  ret ptr %1
}