mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-22 18:54:02 +01:00
a5f7171155
In mandatory tail calling conventions we might have to deallocate stack space used by our arguments before return. This happens after popping CSRs, so the pop cannot be turned into the return itself in this case. The else branch here was already a nop, so removing it as a tidy-up.
206 lines
5.5 KiB
LLVM
206 lines
5.5 KiB
LLVM
; RUN: llc -verify-machineinstrs < %s -mtriple=thumbv7k-apple-watchos | FileCheck %s
|
|
|
|
declare tailcc void @callee_stack0()
|
|
declare tailcc void @callee_stack4([4 x i32], i32)
|
|
declare tailcc void @callee_stack20([4 x i32], [5 x i32])
|
|
declare extern_weak tailcc void @callee_weak()
|
|
|
|
define tailcc void @caller_to0_from0() nounwind {
|
|
; CHECK-LABEL: _caller_to0_from0:
|
|
|
|
tail call tailcc void @callee_stack0()
|
|
ret void
|
|
; CHECK-NOT: add
|
|
; CHECK-NOT: sub
|
|
; CHECK: b.w _callee_stack0
|
|
}
|
|
|
|
define tailcc void @caller_to0_from4([4 x i32], i32) {
|
|
; CHECK-LABEL: _caller_to0_from4:
|
|
|
|
tail call tailcc void @callee_stack0()
|
|
ret void
|
|
|
|
; CHECK: add sp, #16
|
|
; CHECK-NEXT: b.w _callee_stack0
|
|
}
|
|
|
|
define tailcc void @caller_to4_from0() {
|
|
; Key point is that the "42" should go #16 below incoming stack
|
|
; pointer (we didn't have arg space to reuse).
|
|
tail call tailcc void @callee_stack4([4 x i32] undef, i32 42)
|
|
ret void
|
|
|
|
; CHECK-LABEL: _caller_to4_from0:
|
|
; CHECK: sub sp, #16
|
|
; CHECK: movs [[TMP:r[0-9]+]], #42
|
|
; CHECK: str [[TMP]], [sp]
|
|
; CHECK-NOT: add sp
|
|
; CHECK: b.w _callee_stack4
|
|
|
|
}
|
|
|
|
define tailcc void @caller_to4_from4([4 x i32], i32 %a) {
|
|
; CHECK-LABEL: _caller_to4_from4:
|
|
; CHECK-NOT: sub sp
|
|
; Key point is that the "%a" should go where at SP on entry.
|
|
tail call tailcc void @callee_stack4([4 x i32] undef, i32 42)
|
|
ret void
|
|
|
|
; CHECK: str {{r[0-9]+}}, [sp]
|
|
; CHECK-NOT: add sp
|
|
; CHECK-NEXT: b.w _callee_stack4
|
|
}
|
|
|
|
define tailcc void @caller_to20_from4([4 x i32], i32 %a) {
|
|
; CHECK-LABEL: _caller_to20_from4:
|
|
; CHECK: sub sp, #16
|
|
|
|
; Important point is that the call reuses the "dead" argument space
|
|
; above %a on the stack. If it tries to go below incoming-SP then the
|
|
; _callee will not deallocate the space, even in tailcc.
|
|
tail call tailcc void @callee_stack20([4 x i32] undef, [5 x i32] [i32 1, i32 2, i32 3, i32 4, i32 5])
|
|
|
|
; CHECK: str {{.*}}, [sp]
|
|
; CHECK: str {{.*}}, [sp, #4]
|
|
; CHECK: str {{.*}}, [sp, #8]
|
|
; CHECK: str {{.*}}, [sp, #12]
|
|
; CHECK: str {{.*}}, [sp, #16]
|
|
; CHECK-NOT: add sp
|
|
; CHECK-NOT: sub sp
|
|
; CHECK: b.w _callee_stack20
|
|
ret void
|
|
}
|
|
|
|
|
|
define tailcc void @caller_to4_from24([4 x i32], i64 %a, i64 %b, i64 %c) {
|
|
; CHECK-LABEL: _caller_to4_from24:
|
|
|
|
|
|
; Key point is that the "%a" should go where at #16 above SP on entry.
|
|
tail call tailcc void @callee_stack4([4 x i32] undef, i32 42)
|
|
ret void
|
|
|
|
; CHECK: str {{.*}}, [sp, #16]
|
|
; CHECK: add sp, #16
|
|
; CHECK-NEXT: b.w _callee_stack4
|
|
}
|
|
|
|
|
|
define tailcc void @caller_to20_from20([4 x i32], [5 x i32] %a) {
|
|
; CHECK-LABEL: _caller_to20_from20:
|
|
; CHECK-NOT: add sp,
|
|
; CHECK-NOT: sub sp,
|
|
|
|
; Here we want to make sure that both loads happen before the stores:
|
|
; otherwise either %a or %b.w will be wrongly clobbered.
|
|
tail call tailcc void @callee_stack20([4 x i32] undef, [5 x i32] %a)
|
|
ret void
|
|
|
|
; If these ever get interleaved make sure aliasing slots don't clobber each
|
|
; other.
|
|
; CHECK: ldrd {{.*}}, {{.*}}, [sp, #12]
|
|
; CHECK: ldm.w sp,
|
|
; CHECK: stm.w
|
|
; CHECK: strd
|
|
; CHECK-NEXT: b.w _callee_stack20
|
|
}
|
|
|
|
define tailcc void @disable_tail_calls() nounwind "disable-tail-calls"="true" {
|
|
; CHECK-LABEL: disable_tail_calls:
|
|
|
|
tail call tailcc void @callee_stack0()
|
|
ret void
|
|
|
|
; CHECK: bl _callee_stack0
|
|
; CHECK: ret
|
|
}
|
|
|
|
define tailcc void @normal_ret_with_stack([4 x i32], i32 %a) {
|
|
; CHECK: _normal_ret_with_stack:
|
|
; CHECK: add sp, #16
|
|
; CHECK: bx lr
|
|
ret void
|
|
}
|
|
|
|
declare { [2 x float] } @get_vec2()
|
|
|
|
define void @fromC_totail() {
|
|
; COMMON-LABEL: fromC_totail:
|
|
; COMMON: puch {r4, lr}
|
|
; COMMON: sub sp, #8
|
|
|
|
; COMMON-NOT: sub sp,
|
|
; COMMON: movs [[TMP:r[0-9]+]], #42
|
|
; COMMON: str [[TMP]], [sp]
|
|
; COMMON: bl _callee_stack4
|
|
; We must reset the stack to where it was before the call by undoing its extra stack pop.
|
|
; COMMON: sub sp, #16
|
|
; COMMON: str [[TMP]], [sp]
|
|
; COMMON: bl callee_stack4
|
|
; COMMON: sub sp, #16
|
|
|
|
call tailcc void @callee_stack4([4 x i32] undef, i32 42)
|
|
call tailcc void @callee_stack4([4 x i32] undef, i32 42)
|
|
ret void
|
|
}
|
|
|
|
define void @fromC_totail_noreservedframe(i32 %len) {
|
|
; COMMON-LABEL: fromC_totail_noreservedframe:
|
|
; COMMON: sub.w sp, sp, r{{.*}}
|
|
|
|
; COMMON: movs [[TMP:r[0-9]+]], #42
|
|
; Note stack is subtracted here to allocate space for arg
|
|
; COMMON: sub.w sp, #16
|
|
; COMMON: str [[TMP]], [sp]
|
|
; COMMON: bl _callee_stack4
|
|
; And here.
|
|
; COMMON: sub sp, #16
|
|
; COMMON: str [[TMP]], [sp]
|
|
; COMMON: bl _callee_stack4
|
|
; But not restored here because callee_stack8 did that for us.
|
|
; COMMON-NOT: sub sp,
|
|
|
|
; Variable sized allocation prevents reserving frame at start of function so each call must allocate any stack space it needs.
|
|
%var = alloca i32, i32 %len
|
|
|
|
call tailcc void @callee_stack4([4 x i32] undef, i32 42)
|
|
call tailcc void @callee_stack4([4 x i32] undef, i32 42)
|
|
ret void
|
|
}
|
|
|
|
declare void @Ccallee_stack4([4 x i32], i32)
|
|
|
|
define tailcc void @fromtail_toC() {
|
|
; COMMON-LABEL: fromtail_toC:
|
|
; COMMON: push {r4, lr}
|
|
; COMMON: sub sp, #8
|
|
|
|
; COMMON-NOT: sub sp,
|
|
; COMMON: movs [[TMP:r[0-9]+]], #42
|
|
; COMMON: str [[TMP]], [sp]
|
|
; COMMON: bl _Ccallee_stack4
|
|
; C callees will return with the stack exactly where we left it, so we mustn't try to fix anything.
|
|
; COMMON-NOT: add sp,
|
|
; COMMON-NOT: sub sp,
|
|
; COMMON: str [[TMP]], [sp]{{$}}
|
|
; COMMON: bl _Ccallee_stack4
|
|
; COMMON-NOT: sub sp,
|
|
|
|
call void @Ccallee_stack4([4 x i32] undef, i32 42)
|
|
call void @Ccallee_stack4([4 x i32] undef, i32 42)
|
|
ret void
|
|
}
|
|
|
|
; Don't try to return by popping pc if there's stack to reclaim.
|
|
define tailcc void @notail_stackclean([4 x i32], i32) {
|
|
; COMMON-LABEL: notail_stackclean:
|
|
; COMMON: pop {r7, lr}
|
|
; COMMON: add sp, #8
|
|
; COMMON: bx lr
|
|
|
|
|
|
call void @callee_stack0()
|
|
ret void
|
|
}
|