llvm/test/CodeGen/ARM/2007-01-19-InfiniteLoop.ll
Oliver Stannard a04e9e4a0a [ARM] Generate consistent frame records for Thumb2
There is not an official documented ABI for frame pointers in Thumb2,
but we should try to emit something which is useful.

We use r7 as the frame pointer for Thumb code, which currently means
that if a function needs to save a high register (r8-r11), it will get
pushed to the stack between the frame pointer (r7) and link register
(r14). This means that while a stack unwinder can follow the chain of
frame pointers up the stack, it cannot know the offset to lr, so does
not know which functions correspond to the stack frames.

To fix this, we need to push the callee-saved registers in two batches,
with the first push saving the low registers, fp and lr, and the second
push saving the high registers. This is already implemented, but
previously only used for iOS. This patch turns it on for all Thumb2
targets when frame pointers are required by the ABI, and the frame
pointer is r7 (Windows uses r11, so this isn't a problem there). If
frame pointer elimination is enabled we still emit a single push/pop
even if we need a frame pointer for other reasons, to avoid increasing
code size.

We must also ensure that lr is pushed to the stack when using a frame
pointer, so that we end up with a complete frame record. Situations that
could cause this were rare, because we already push lr in most
situations so that we can return using the pop instruction.

Differential Revision: https://reviews.llvm.org/D23516



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279506 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-23 09:19:22 +00:00

113 lines
5.2 KiB
LLVM

; RUN: llc < %s -mtriple=arm-apple-ios -mattr=+v6,+vfp2 | FileCheck %s
; RUN: llc < %s -mtriple=arm-apple-ios -mattr=+v6,+vfp2 | FileCheck --check-prefix=DOMAIN %s
; The execution domain checking code would translate vmovs to vorr whether or not
; we had NEON instructions. Verify we don't if we're not compiled with NEON.
; DOMAIN-NOT: vorr
@quant_coef = external global [6 x [4 x [4 x i32]]] ; <[6 x [4 x [4 x i32]]]*> [#uses=1]
@dequant_coef = external global [6 x [4 x [4 x i32]]] ; <[6 x [4 x [4 x i32]]]*> [#uses=1]
@A = external global [4 x [4 x i32]] ; <[4 x [4 x i32]]*> [#uses=1]
; CHECK-LABEL: dct_luma_sp:
define fastcc i32 @dct_luma_sp(i32 %block_x, i32 %block_y, i32* %coeff_cost) "no-frame-pointer-elim"="true" {
entry:
; Make sure to use base-updating stores for saving callee-saved registers.
; CHECK: push
; CHECK-NOT: sub sp
; CHECK: push
%predicted_block = alloca [4 x [4 x i32]], align 4 ; <[4 x [4 x i32]]*> [#uses=1]
br label %cond_next489
cond_next489: ; preds = %cond_false, %bb471
%j.7.in = load i8, i8* null ; <i8> [#uses=1]
%i.8.in = load i8, i8* null ; <i8> [#uses=1]
%i.8 = zext i8 %i.8.in to i32 ; <i32> [#uses=4]
%j.7 = zext i8 %j.7.in to i32 ; <i32> [#uses=4]
%tmp495 = getelementptr [4 x [4 x i32]], [4 x [4 x i32]]* %predicted_block, i32 0, i32 %i.8, i32 %j.7 ; <i32*> [#uses=2]
%tmp496 = load i32, i32* %tmp495 ; <i32> [#uses=2]
%tmp502 = load i32, i32* null ; <i32> [#uses=1]
%tmp542 = getelementptr [6 x [4 x [4 x i32]]], [6 x [4 x [4 x i32]]]* @quant_coef, i32 0, i32 0, i32 %i.8, i32 %j.7 ; <i32*> [#uses=1]
%tmp543 = load i32, i32* %tmp542 ; <i32> [#uses=1]
%tmp548 = ashr i32 0, 0 ; <i32> [#uses=3]
%tmp561 = sub i32 0, %tmp496 ; <i32> [#uses=3]
%abscond563 = icmp sgt i32 %tmp561, -1 ; <i1> [#uses=1]
%abs564 = select i1 %abscond563, i32 %tmp561, i32 0 ; <i32> [#uses=1]
%tmp572 = mul i32 %abs564, %tmp543 ; <i32> [#uses=1]
%tmp574 = add i32 %tmp572, 0 ; <i32> [#uses=1]
%tmp576 = ashr i32 %tmp574, 0 ; <i32> [#uses=7]
%tmp579 = icmp eq i32 %tmp548, %tmp576 ; <i1> [#uses=1]
br i1 %tmp579, label %bb712, label %cond_next589
cond_next589: ; preds = %cond_next489
%tmp605 = getelementptr [6 x [4 x [4 x i32]]], [6 x [4 x [4 x i32]]]* @dequant_coef, i32 0, i32 0, i32 %i.8, i32 %j.7 ; <i32*> [#uses=1]
%tmp606 = load i32, i32* %tmp605 ; <i32> [#uses=1]
%tmp612 = load i32, i32* null ; <i32> [#uses=1]
%tmp629 = load i32, i32* null ; <i32> [#uses=1]
%tmp629a = sitofp i32 %tmp629 to double ; <double> [#uses=1]
%tmp631 = fmul double %tmp629a, 0.000000e+00 ; <double> [#uses=1]
%tmp632 = fadd double 0.000000e+00, %tmp631 ; <double> [#uses=1]
%tmp642 = call fastcc i32 @sign( i32 %tmp576, i32 %tmp561 ) ; <i32> [#uses=1]
%tmp650 = mul i32 %tmp606, %tmp642 ; <i32> [#uses=1]
%tmp656 = mul i32 %tmp650, %tmp612 ; <i32> [#uses=1]
%tmp658 = shl i32 %tmp656, 0 ; <i32> [#uses=1]
%tmp659 = ashr i32 %tmp658, 6 ; <i32> [#uses=1]
%tmp660 = sub i32 0, %tmp659 ; <i32> [#uses=1]
%tmp666 = sub i32 %tmp660, %tmp496 ; <i32> [#uses=1]
%tmp667 = sitofp i32 %tmp666 to double ; <double> [#uses=2]
call void @levrun_linfo_inter( i32 %tmp576, i32 0, i32* null, i32* null )
%tmp671 = fmul double %tmp667, %tmp667 ; <double> [#uses=1]
%tmp675 = fadd double %tmp671, 0.000000e+00 ; <double> [#uses=1]
%tmp678 = fcmp oeq double %tmp632, %tmp675 ; <i1> [#uses=1]
br i1 %tmp678, label %cond_true679, label %cond_false693
cond_true679: ; preds = %cond_next589
%abscond681 = icmp sgt i32 %tmp548, -1 ; <i1> [#uses=1]
%abs682 = select i1 %abscond681, i32 %tmp548, i32 0 ; <i32> [#uses=1]
%abscond684 = icmp sgt i32 %tmp576, -1 ; <i1> [#uses=1]
%abs685 = select i1 %abscond684, i32 %tmp576, i32 0 ; <i32> [#uses=1]
%tmp686 = icmp slt i32 %abs682, %abs685 ; <i1> [#uses=1]
br i1 %tmp686, label %cond_next702, label %cond_false689
cond_false689: ; preds = %cond_true679
%tmp739 = icmp eq i32 %tmp576, 0 ; <i1> [#uses=1]
br i1 %tmp579, label %bb737, label %cond_false708
cond_false693: ; preds = %cond_next589
ret i32 0
cond_next702: ; preds = %cond_true679
ret i32 0
cond_false708: ; preds = %cond_false689
ret i32 0
bb712: ; preds = %cond_next489
ret i32 0
bb737: ; preds = %cond_false689
br i1 %tmp739, label %cond_next791, label %cond_true740
cond_true740: ; preds = %bb737
%tmp761 = call fastcc i32 @sign( i32 %tmp576, i32 0 ) ; <i32> [#uses=1]
%tmp780 = load i32, i32* null ; <i32> [#uses=1]
%tmp785 = getelementptr [4 x [4 x i32]], [4 x [4 x i32]]* @A, i32 0, i32 %i.8, i32 %j.7 ; <i32*> [#uses=1]
%tmp786 = load i32, i32* %tmp785 ; <i32> [#uses=1]
%tmp781 = mul i32 %tmp780, %tmp761 ; <i32> [#uses=1]
%tmp787 = mul i32 %tmp781, %tmp786 ; <i32> [#uses=1]
%tmp789 = shl i32 %tmp787, 0 ; <i32> [#uses=1]
%tmp790 = ashr i32 %tmp789, 6 ; <i32> [#uses=1]
br label %cond_next791
cond_next791: ; preds = %cond_true740, %bb737
%ilev.1 = phi i32 [ %tmp790, %cond_true740 ], [ 0, %bb737 ] ; <i32> [#uses=1]
%tmp796 = load i32, i32* %tmp495 ; <i32> [#uses=1]
%tmp798 = add i32 %tmp796, %ilev.1 ; <i32> [#uses=1]
%tmp812 = mul i32 0, %tmp502 ; <i32> [#uses=0]
%tmp818 = call fastcc i32 @sign( i32 0, i32 %tmp798 ) ; <i32> [#uses=0]
unreachable
}
declare i32 @sign(i32, i32)
declare void @levrun_linfo_inter(i32, i32, i32*, i32*)