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<p>Thank you for catching this and fixing it. Danger of only
building R+A. <br>
</p>
<p>Oddly, I didn't receive a single build bot notification for this
failure. <br>
</p>
<p>Philip<br>
</p>
<div class="moz-cite-prefix">On 7/22/19 8:14 PM, Richard Trieu
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAPUYKWmMFGBzRFRBPPnBEW9FnHBQi6+4V3pW853WudgYtVqurA@mail.gmail.com">
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<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Mon, Jul 22, 2019 at 4:32
PM Philip Reames via llvm-commits <<a
href="mailto:llvm-commits@lists.llvm.org"
moz-do-not-send="true">llvm-commits@lists.llvm.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">Author: reames<br>
Date: Mon Jul 22 16:33:18 2019<br>
New Revision: 366765<br>
<br>
URL: <a
href="http://llvm.org/viewvc/llvm-project?rev=366765&view=rev"
rel="noreferrer" target="_blank" moz-do-not-send="true">http://llvm.org/viewvc/llvm-project?rev=366765&view=rev</a><br>
Log:<br>
[Statepoints] Fix a bug in statepoint lowering for functions
w/no-realign-stack<br>
<br>
We were silently using the ABI alignment for all of the
stores generated for deopt and gc values. We'd gotten the
alignment of the stack slot itself properly reduced (via
MachineFrameInfo's clamping), but having the MMO on the
store incorrect was enough for us to generate an aligned
store to a unaligned location.<br>
<br>
The simplest fix would have been to just pass the alignment
to the helper function, but once we do that, the helper
function doesn't really help. So, inline it and directly
call the MMO version of DAG.getStore with a properly
constructed MMO.<br>
<br>
Note that there's a separate performance possibility here.
Even if we *can* realign stacks, we probably don't *want to*
if all of the stores are in slowpaths. But that's a later
patch, if at all. :)<br>
<br>
<br>
Modified:<br>
llvm/trunk/lib/CodeGen/SelectionDAG/StatepointLowering.cpp<br>
llvm/trunk/test/CodeGen/X86/statepoint-no-realign-stack.ll<br>
<br>
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/StatepointLowering.cpp<br>
URL: <a
href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/StatepointLowering.cpp?rev=366765&r1=366764&r2=366765&view=diff"
rel="noreferrer" target="_blank" moz-do-not-send="true">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/StatepointLowering.cpp?rev=366765&r1=366764&r2=366765&view=diff</a><br>
==============================================================================<br>
---
llvm/trunk/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
(original)<br>
+++
llvm/trunk/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
Mon Jul 22 16:33:18 2019<br>
@@ -389,10 +389,17 @@ spillIncomingStatepointValue(SDValue
Inc<br>
"Bad spill: stack slot does not match!");<br>
#endif<br>
<br>
+ // Note: Using the alignment of the spill slot (rather
than the abi or<br>
+ // preferred alignment) is required for correctness
when dealing with spill<br>
+ // slots with preferred alignments larger than frame
alignment..<br>
auto &MF = Builder.DAG.getMachineFunction();<br>
auto PtrInfo = MachinePointerInfo::getFixedStack(MF,
Index);<br>
+ auto *StoreMMO =<br>
+ MF.getMachineMemOperand(PtrInfo,
MachineMemOperand::MOStore, <br>
+ MFI.getObjectSize(Index),<br>
+
MFI.getObjectAlignment(Index));<br>
</blockquote>
<div> </div>
<div>MFI here refers to a variable above that is in a debug
only section, which fails to build in non-debug builds. In
r366773 that section is no longer debug only to fix the
build.</div>
<div><br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
Chain = Builder.DAG.getStore(Chain,
Builder.getCurSDLoc(), Incoming, Loc,<br>
- PtrInfo);<br>
+ StoreMMO);<br>
<br>
MMO = getMachineMemOperand(MF,
*cast<FrameIndexSDNode>(Loc));<br>
<br>
<br>
Modified:
llvm/trunk/test/CodeGen/X86/statepoint-no-realign-stack.ll<br>
URL: <a
href="http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/statepoint-no-realign-stack.ll?rev=366765&r1=366764&r2=366765&view=diff"
rel="noreferrer" target="_blank" moz-do-not-send="true">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/statepoint-no-realign-stack.ll?rev=366765&r1=366764&r2=366765&view=diff</a><br>
==============================================================================<br>
---
llvm/trunk/test/CodeGen/X86/statepoint-no-realign-stack.ll
(original)<br>
+++
llvm/trunk/test/CodeGen/X86/statepoint-no-realign-stack.ll
Mon Jul 22 16:33:18 2019<br>
@@ -35,14 +35,13 @@ define void @can_realign(<8 x
i32>* %p)<br>
ret void<br>
}<br>
<br>
-; TODO: currently shows incorrect codegen, FIXME<br>
define void @no_realign(<8 x i32>* %p)
"no-realign-stack" {<br>
; CHECK-LABEL: no_realign:<br>
; CHECK: # %bb.0:<br>
; CHECK-NEXT: subq $40, %rsp<br>
; CHECK-NEXT: .cfi_def_cfa_offset 48<br>
; CHECK-NEXT: vmovaps (%rdi), %ymm0<br>
-; CHECK-NEXT: vmovaps %ymm0, (%rsp)<br>
+; CHECK-NEXT: vmovups %ymm0, (%rsp)<br>
; CHECK-NEXT: vzeroupper<br>
; CHECK-NEXT: callq foo<br>
; CHECK-NEXT: .Ltmp1:<br>
<br>
<br>
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</blockquote>
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