llvm/test/CodeGen/ARM/fold-stack-adjust.ll

; Disable shrink-wrapping on the first test otherwise we wouldn't
; exerce the path for PR18136.
; RUN: llc -mtriple=thumbv7-apple-none-macho < %s -enable-shrink-wrap=false | FileCheck %s
; RUN: llc -mtriple=thumbv6m-apple-none-macho -disable-fp-elim < %s | FileCheck %s --check-prefix=CHECK-T1
; RUN: llc -mtriple=thumbv7-apple-darwin-ios -disable-fp-elim < %s | FileCheck %s --check-prefix=CHECK-IOS
; RUN: llc -mtriple=thumbv7--linux-gnueabi -disable-fp-elim < %s | FileCheck %s --check-prefix=CHECK-LINUX


declare void @bar(i8*)

%bigVec = type [2 x double]

@var = global %bigVec zeroinitializer

define void @check_simple() minsize {
; CHECK-LABEL: check_simple:
; CHECK: push {r3, r4, r5, r6, r7, lr}
; CHECK-NOT: sub sp, sp,
; ...
; CHECK-NOT: add sp, sp,
; CHECK: pop {r0, r1, r2, r3, r7, pc}

; CHECK-T1-LABEL: check_simple:
; CHECK-T1: push {r3, r4, r5, r6, r7, lr}
; CHECK-T1: add r7, sp, #16
; CHECK-T1-NOT: sub sp, sp,
; ...
; CHECK-T1-NOT: add sp, sp,
; CHECK-T1: pop {r0, r1, r2, r3, r7, pc}

  ; iOS always has a frame pointer and messing with the push affects
  ; how it's set in the prologue. Make sure we get that right.
; CHECK-IOS-LABEL: check_simple:
; CHECK-IOS: push {r3, r4, r5, r6, r7, lr}
; CHECK-NOT: sub sp,
; CHECK-IOS: add r7, sp, #16
; CHECK-NOT: sub sp,
; ...
; CHECK-NOT: add sp,
; CHEC: pop {r3, r4, r5, r6, r7, pc}

  %var = alloca i8, i32 16
  call void @bar(i8* %var)
  ret void
}

define void @check_simple_too_big() minsize {
; CHECK-LABEL: check_simple_too_big:
; CHECK: push {r7, lr}
; CHECK: sub sp,
; ...
; CHECK: add sp,
; CHECK: pop {r7, pc}
  %var = alloca i8, i32 64
  call void @bar(i8* %var)
  ret void
}

define void @check_vfp_fold() minsize {
; CHECK-LABEL: check_vfp_fold:
; CHECK: push {r[[GLOBREG:[0-9]+]], lr}
; CHECK: vpush {d6, d7, d8, d9}
; CHECK-NOT: sub sp,
; ...
; CHECK-NOT: add sp,
; CHECK: vpop {d6, d7, d8, d9}
; CHECK: pop {r[[GLOBREG]], pc}

  ; iOS uses aligned NEON stores here, which is convenient since we
  ; want to make sure that works too.
; CHECK-IOS-LABEL: check_vfp_fold:
; CHECK-IOS: push {r4, r7, lr}
; CHECK-IOS: sub.w r4, sp, #16
; CHECK-IOS: bfc r4, #0, #4
; CHECK-IOS: mov sp, r4
; CHECK-IOS: vst1.64 {d8, d9}, [r4:128]
; CHECK-IOS: sub sp, #16
; ...
; CHECK-IOS: add r4, sp, #16
; CHECK-IOS: vld1.64 {d8, d9}, [r4:128]
; CHECK-IOS: mov sp, r4
; CHECK-IOS: pop {r4, r7, pc}

  %var = alloca i8, i32 16

  call void asm "", "r,~{d8},~{d9}"(i8* %var)
  call void @bar(i8* %var)

  ret void
}

; This function should use just enough space that the "add sp, sp, ..." could be
; folded in except that doing so would clobber the value being returned.
define i64 @check_no_return_clobber() minsize {
; CHECK-LABEL: check_no_return_clobber:
; CHECK: push {r1, r2, r3, r4, r5, r6, r7, lr}
; CHECK-NOT: sub sp,
; ...
; CHECK: add sp, #24
; CHECK: pop {r7, pc}

  ; Just to keep iOS FileCheck within previous function:
; CHECK-IOS-LABEL: check_no_return_clobber:

  %var = alloca i8, i32 20
  call void @bar(i8* %var)
  ret i64 0
}

define arm_aapcs_vfpcc double @check_vfp_no_return_clobber() minsize {
; CHECK-LABEL: check_vfp_no_return_clobber:
; CHECK: push {r[[GLOBREG:[0-9]+]], lr}
; CHECK: vpush {d0, d1, d2, d3, d4, d5, d6, d7, d8, d9}
; CHECK-NOT: sub sp,
; ...
; CHECK: add sp, #64
; CHECK: vpop {d8, d9}
; CHECK: pop {r[[GLOBREG]], pc}

  %var = alloca i8, i32 64

  %tmp = load %bigVec, %bigVec* @var
  call void @bar(i8* %var)
  store %bigVec %tmp, %bigVec* @var

  ret double 1.0
}

@dbl = global double 0.0

; PR18136: there was a bug determining where the first eligible pop in a
; basic-block was when the entire block was epilogue code.
define void @test_fold_point(i1 %tst) minsize {
; CHECK-LABEL: test_fold_point:

  ; Important to check for beginning of basic block, because if it gets
  ; if-converted the test is probably no longer checking what it should.
; CHECK: %end
; CHECK-NEXT: vpop {d7, d8}
; CHECK-NEXT: pop {r4, pc}

  ; With a guaranteed frame-pointer, we want to make sure that its offset in the
  ; push block is correct, even if a few registers have been tacked onto a later
  ; vpush (PR18160).
; CHECK-IOS-LABEL: test_fold_point:
; CHECK-IOS: push {r4, r7, lr}
; CHECK-IOS-NEXT: add r7, sp, #4
; CHECK-IOS-NEXT: vpush {d7, d8}

  ; We want some memory so there's a stack adjustment to fold...
  %var = alloca i8, i32 8

  ; We want a long-lived floating register so that a callee-saved dN is used and
  ; there's both a vpop and a pop.
  %live_val = load double, double* @dbl
  br i1 %tst, label %true, label %end
true:
  call void @bar(i8* %var)
  store double %live_val, double* @dbl
  br label %end
end:
  ; We want the epilogue to be the only thing in a basic block so that we hit
  ; the correct edge-case (first inst in block is correct one to adjust).
  ret void
}

define void @test_varsize(...) minsize {
; CHECK-T1-LABEL: test_varsize:
; CHECK-T1: sub	sp, #16
; CHECK-T1: push	{r5, r6, r7, lr}
; ...
; CHECK-T1: pop	{r2, r3, r7}
; CHECK-T1: pop {[[POP_REG:r[0-3]]]}
; CHECK-T1: add	sp, #16
; CHECK-T1: bx	[[POP_REG]]

; CHECK-LABEL: test_varsize:
; CHECK: sub	sp, #16
; CHECK: push	{r5, r6, r7, lr}
; ...
; CHECK: pop.w	{r2, r3, r7, lr}
; CHECK: add	sp, #16
; CHECK: bx	lr

  %var = alloca i8, i32 8
  call void @llvm.va_start(i8* %var)
  call void @bar(i8* %var)
  ret void
}

%"MyClass" = type { i8*, i32, i32, float, float, float, [2 x i8], i32, i32* }

declare float @foo()

declare void @bar3()

declare %"MyClass"* @bar2(%"MyClass"* returned, i16*, i32, float, float, i32, i32, i1 zeroext, i1 zeroext, i32)

define fastcc float @check_vfp_no_return_clobber2(i16* %r, i16* %chars, i32 %length, i1 zeroext %flag) minsize {
entry:
; CHECK-LINUX-LABEL: check_vfp_no_return_clobber2
; CHECK-LINUX: vpush	{d0, d1, d2, d3, d4, d5, d6, d7, d8}
; CHECK-NOT: sub sp,
; ...
; CHECK-LINUX: add sp
; CHECK-LINUX: vpop {d8}
  %run = alloca %"MyClass", align 4
  %call = call %"MyClass"* @bar2(%"MyClass"* %run, i16* %chars, i32 %length, float 0.000000e+00, float 0.000000e+00, i32 1, i32 1, i1 zeroext false, i1 zeroext true, i32 3)
  %call1 = call float @foo()
  %cmp = icmp eq %"MyClass"* %run, null
  br i1 %cmp, label %exit, label %if.then

if.then:                                          ; preds = %entry
  call void @bar3()
  br label %exit

exit:                                             ; preds = %if.then, %entry
  ret float %call1
}

declare void @use_arr(i32*)
define void @test_fold_reuse() minsize {
; CHECK-LABEL: test_fold_reuse:
; CHECK: push.w {r4, r7, r8, lr}
; CHECK: sub sp, #24
; [...]
; CHECK: add sp, #24
; CHECK: pop.w {r4, r7, r8, pc}
  %arr = alloca i8, i32 24
  call void asm sideeffect "", "~{r8},~{r4}"()
  call void @bar(i8* %arr)
  ret void
}

declare void @llvm.va_start(i8*) nounwind