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Hi,
<div class=""><br class="">
</div>
<div class="">After investigating, I still haven’t found the issue here. The code looks sensible, and there are only two places where the returned attribute affects codegen: setting the preserved mask and marking the zero’th parameter as used:</div>
<div class=""><br class="">
</div>
<div class="">
<div class=""> if (i == 0 && isThisReturn) {</div>
<div class=""> assert(!VA.needsCustom() && VA.getLocVT() == MVT::i64 &&</div>
<div class=""> "unexpected return calling convention register assignment");</div>
<div class=""> InVals.push_back(ThisVal);</div>
<div class=""> continue;</div>
<div class=""> }</div>
<div class=""><br class="">
</div>
<div class="">I’ve determined that the mask setting isn’t causing the issue, the above code is. But I’m not exactly sure why…</div>
<div class=""><br class="">
</div>
<div class="">Cheers,</div>
<div class=""><br class="">
</div>
<div class="">James</div>
<div>
<blockquote type="cite" class="">
<div class="">On 11 Jul 2016, at 13:06, Hal Finkel <<a href="mailto:hfinkel@anl.gov" class="">hfinkel@anl.gov</a>> wrote:</div>
<br class="Apple-interchange-newline">
<div class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">-----
Original Message -----</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
From: "James Molloy" <<a href="mailto:James.Molloy@arm.com" class="">James.Molloy@arm.com</a>><br class="">
To: "Hal Finkel" <<a href="mailto:hfinkel@anl.gov" class="">hfinkel@anl.gov</a>><br class="">
Cc: "Tim Northover" <<a href="mailto:t.p.northover@gmail.com" class="">t.p.northover@gmail.com</a>>, "renato golin" <<a href="mailto:renato.golin@linaro.org" class="">renato.golin@linaro.org</a>>,<span class="Apple-converted-space"> </span><a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a><br class="">
Sent: Monday, July 11, 2016 2:57:33 AM<br class="">
Subject: Re: [llvm] r275042 - Revert r275027 - Let FuncAttrs infer the 'returned' argument attribute<br class="">
<br class="">
Hi Hal,<br class="">
<br class="">
I’ll try and attack this today. I don’t suppose you noticed if any<br class="">
stage1 builders went awry too? That would help with getting it<br class="">
debugged quicker.<br class="">
</blockquote>
<br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">Thanks!
Unfortunately, no. Only the self-hosting builders were unhappy as far as I can tell.</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">-Hal</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
<br class="">
Cheers,<br class="">
<br class="">
James<br class="">
<blockquote type="cite" class="">On 11 Jul 2016, at 06:11, Hal Finkel <<a href="mailto:hfinkel@anl.gov" class="">hfinkel@anl.gov</a>> wrote:<br class="">
<br class="">
Hi Tim, James, Renato,<br class="">
<br class="">
I'm not sure who is the best person to ask about this, but adding<br class="">
code to infer the 'returned' attribute on function arguments seems<br class="">
to cause the AArch64 backend to miscompile conspicuously:<br class="">
<br class="">
<a href="http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/2564" class="">http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/2564</a><br class="">
<br class="">
The other backends don't seem to have a problem, but then again,<br class="">
only ARM and AArch64 have special handling for 'returned'<br class="">
arguments. AArch64ISelLowering.cpp has, in part:<br class="">
<br class="">
if (VA.isRegLoc()) {<br class="">
if (realArgIdx == 0 && Flags.isReturned() && Outs[0].VT ==<br class="">
MVT::i64) {<br class="">
assert(VA.getLocVT() == MVT::i64 &&<br class="">
"unexpected calling convention register assignment");<br class="">
assert(!Ins.empty() && Ins[0].VT == MVT::i64 &&<br class="">
"unexpected use of 'returned'");<br class="">
...<br class="">
<br class="">
and ARMISelLowering.cpp seems very similar.<br class="">
<br class="">
Any idea what's going on?<br class="">
<br class="">
To test, unrevert this commit (and r275043 for the few Clang test<br class="">
changes).<br class="">
<br class="">
Thanks again,<br class="">
Hal<br class="">
<br class="">
----- Original Message -----<br class="">
<blockquote type="cite" class="">From: "Hal Finkel via llvm-commits" <llvm-commits@lists.llvm.org><br class="">
To: llvm-commits@lists.llvm.org<br class="">
Sent: Sunday, July 10, 2016 11:51:24 PM<br class="">
Subject: [llvm] r275042 - Revert r275027 - Let FuncAttrs infer the<br class="">
'returned' argument attribute<br class="">
<br class="">
Author: hfinkel<br class="">
Date: Sun Jul 10 23:51:23 2016<br class="">
New Revision: 275042<br class="">
<br class="">
URL: http://llvm.org/viewvc/llvm-project?rev=275042&view=rev<br class="">
Log:<br class="">
Revert r275027 - Let FuncAttrs infer the 'returned' argument<br class="">
attribute<br class="">
<br class="">
Reverting r275027 and r275033. These seem to cause miscompiles on<br class="">
the<br class="">
AArch64 buildbot.<br class="">
<br class="">
Modified:<br class="">
llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp<br class="">
llvm/trunk/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll<br class="">
llvm/trunk/test/Transforms/FunctionAttrs/nocapture.ll<br class="">
llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll<br class="">
<br class="">
Modified: llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp<br class="">
URL:<br class="">
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp?rev=275042&r1=275041&r2=275042&view=diff<br class="">
==============================================================================<br class="">
--- llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp (original)<br class="">
+++ llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp Sun Jul 10<br class="">
23:51:23 2016<br class="">
@@ -42,7 +42,6 @@ using namespace llvm;<br class="">
STATISTIC(NumReadNone, "Number of functions marked readnone");<br class="">
STATISTIC(NumReadOnly, "Number of functions marked readonly");<br class="">
STATISTIC(NumNoCapture, "Number of arguments marked nocapture");<br class="">
-STATISTIC(NumReturned, "Number of arguments marked returned");<br class="">
STATISTIC(NumReadNoneArg, "Number of arguments marked readnone");<br class="">
STATISTIC(NumReadOnlyArg, "Number of arguments marked readonly");<br class="">
STATISTIC(NumNoAlias, "Number of function returns marked<br class="">
noalias");<br class="">
@@ -484,53 +483,6 @@ determinePointerReadAttrs(Argument *A,<br class="">
return IsRead ? Attribute::ReadOnly : Attribute::ReadNone;<br class="">
}<br class="">
<br class="">
-/// Deduce returned attributes for the SCC.<br class="">
-static bool addArgumentReturnedAttrs(const SCCNodeSet &SCCNodes)<br class="">
{<br class="">
- bool Changed = false;<br class="">
-<br class="">
- AttrBuilder B;<br class="">
- B.addAttribute(Attribute::Returned);<br class="">
-<br class="">
- // Check each function in turn, determining if an argument is<br class="">
always returned.<br class="">
- for (Function *F : SCCNodes) {<br class="">
- // We can infer and propagate function attributes only when<br class="">
we<br class="">
know that the<br class="">
- // definition we'll get at link time is *exactly* the<br class="">
definition<br class="">
we see now.<br class="">
- // For more details, see GlobalValue::mayBeDerefined.<br class="">
- if (!F->hasExactDefinition())<br class="">
- continue;<br class="">
-<br class="">
- if (F->getReturnType()->isVoidTy())<br class="">
- continue;<br class="">
-<br class="">
- auto FindRetArg = [&]() -> Value * {<br class="">
- Value *RetArg = nullptr;<br class="">
- for (BasicBlock &BB : *F)<br class="">
- if (auto *Ret = dyn_cast<ReturnInst>(BB.getTerminator()))<br class="">
{<br class="">
- // Note that stripPointerCasts should look through<br class="">
functions with<br class="">
- // returned arguments.<br class="">
- Value *RetVal =<br class="">
Ret->getReturnValue()->stripPointerCasts();<br class="">
- if (RetVal->getType() == F->getReturnType() &&<br class="">
isa<Argument>(RetVal)) {<br class="">
- if (!RetArg)<br class="">
- RetArg = RetVal;<br class="">
- else if (RetArg != RetVal)<br class="">
- return nullptr;<br class="">
- }<br class="">
- }<br class="">
-<br class="">
- return RetArg;<br class="">
- };<br class="">
-<br class="">
- if (Value *RetArg = FindRetArg()) {<br class="">
- auto *A = cast<Argument>(RetArg);<br class="">
- A->addAttr(AttributeSet::get(F->getContext(), A->getArgNo()<br class="">
+<br class="">
1, B));<br class="">
- ++NumReturned;<br class="">
- Changed = true;<br class="">
- }<br class="">
- }<br class="">
-<br class="">
- return Changed;<br class="">
-}<br class="">
-<br class="">
/// Deduce nocapture attributes for the SCC.<br class="">
static bool addArgumentAttrs(const SCCNodeSet &SCCNodes) {<br class="">
bool Changed = false;<br class="">
@@ -1072,7 +1024,6 @@ PreservedAnalyses PostOrderFunctionAttrs<br class="">
}<br class="">
<br class="">
bool Changed = false;<br class="">
- Changed |= addArgumentReturnedAttrs(SCCNodes);<br class="">
Changed |= addReadAttrs(SCCNodes, AARGetter);<br class="">
Changed |= addArgumentAttrs(SCCNodes);<br class="">
<br class="">
@@ -1138,7 +1089,6 @@ static bool runImpl(CallGraphSCC &SCC, A<br class="">
SCCNodes.insert(F);<br class="">
}<br class="">
<br class="">
- Changed |= addArgumentReturnedAttrs(SCCNodes);<br class="">
Changed |= addReadAttrs(SCCNodes, AARGetter);<br class="">
Changed |= addArgumentAttrs(SCCNodes);<br class="">
<br class="">
<br class="">
Modified:<br class="">
llvm/trunk/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll<br class="">
URL:<br class="">
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll?rev=275042&r1=275041&r2=275042&view=diff<br class="">
==============================================================================<br class="">
---<br class="">
llvm/trunk/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll<br class="">
(original)<br class="">
+++<br class="">
llvm/trunk/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll<br class="">
Sun Jul 10 23:51:23 2016<br class="">
@@ -14,7 +14,7 @@ define i32* @b(i32 *%q) {<br class="">
ret i32* %tmp<br class="">
}<br class="">
<br class="">
-; CHECK: define i32* @c(i32* readnone returned %r)<br class="">
+; CHECK: define i32* @c(i32* readnone %r)<br class="">
@g = global i32 0<br class="">
define i32* @c(i32 *%r) {<br class="">
%a = icmp eq i32* %r, null<br class="">
<br class="">
Modified: llvm/trunk/test/Transforms/FunctionAttrs/nocapture.ll<br class="">
URL:<br class="">
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionAttrs/nocapture.ll?rev=275042&r1=275041&r2=275042&view=diff<br class="">
==============================================================================<br class="">
--- llvm/trunk/test/Transforms/FunctionAttrs/nocapture.ll<br class="">
(original)<br class="">
+++ llvm/trunk/test/Transforms/FunctionAttrs/nocapture.ll Sun Jul<br class="">
10<br class="">
23:51:23 2016<br class="">
@@ -1,7 +1,7 @@<br class="">
; RUN: opt < %s -functionattrs -S | FileCheck %s<br class="">
@g = global i32* null; <i32**> [#uses=1]<br class="">
<br class="">
-; CHECK: define i32* @c1(i32* readnone returned %q)<br class="">
+; CHECK: define i32* @c1(i32* readnone %q)<br class="">
define i32* @c1(i32* %q) {<br class="">
ret i32* %q<br class="">
}<br class="">
@@ -140,7 +140,7 @@ define void @test1_1(i8* %x1_1, i8* %y1_<br class="">
ret void<br class="">
}<br class="">
<br class="">
-; CHECK: define i8* @test1_2(i8* nocapture readnone %x1_2, i8*<br class="">
returned %y1_2)<br class="">
+; CHECK: define i8* @test1_2(i8* nocapture readnone %x1_2, i8*<br class="">
%y1_2)<br class="">
define i8* @test1_2(i8* %x1_2, i8* %y1_2) {<br class="">
call void @test1_1(i8* %x1_2, i8* %y1_2)<br class="">
store i32* null, i32** @g<br class="">
@@ -168,7 +168,7 @@ define void @test4_1(i8* %x4_1) {<br class="">
ret void<br class="">
}<br class="">
<br class="">
-; CHECK: define i8* @test4_2(i8* nocapture readnone %x4_2, i8*<br class="">
readnone returned %y4_2, i8* nocapture readnone %z4_2)<br class="">
+; CHECK: define i8* @test4_2(i8* nocapture readnone %x4_2, i8*<br class="">
readnone %y4_2, i8* nocapture readnone %z4_2)<br class="">
define i8* @test4_2(i8* %x4_2, i8* %y4_2, i8* %z4_2) {<br class="">
call void @test4_1(i8* null)<br class="">
store i32* null, i32** @g<br class="">
<br class="">
Modified: llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll<br class="">
URL:<br class="">
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll?rev=275042&r1=275041&r2=275042&view=diff<br class="">
==============================================================================<br class="">
--- llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll<br class="">
(original)<br class="">
+++ llvm/trunk/test/Transforms/FunctionAttrs/readattrs.ll Sun Jul<br class="">
10<br class="">
23:51:23 2016<br class="">
@@ -11,7 +11,7 @@ define void @test1_2(i8* %x1_2, i8* %y1_<br class="">
ret void<br class="">
}<br class="">
<br class="">
-; CHECK: define i8* @test2(i8* readnone returned %p)<br class="">
+; CHECK: define i8* @test2(i8* readnone %p)<br class="">
define i8* @test2(i8* %p) {<br class="">
store i32 0, i32* @x<br class="">
ret i8* %p<br class="">
@@ -53,7 +53,7 @@ define void @test7_1(i32* inalloca %a) {<br class="">
ret void<br class="">
}<br class="">
<br class="">
-; CHECK: define i32* @test8_1(i32* readnone returned %p)<br class="">
+; CHECK: define i32* @test8_1(i32* readnone %p)<br class="">
define i32* @test8_1(i32* %p) {<br class="">
entry:<br class="">
ret i32* %p<br class="">
<br class="">
<br class="">
_______________________________________________<br class="">
llvm-commits mailing list<br class="">
llvm-commits@lists.llvm.org<br class="">
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits<br class="">
<br class="">
</blockquote>
<br class="">
--<br class="">
Hal Finkel<br class="">
Assistant Computational Scientist<br class="">
Leadership Computing Facility<br class="">
Argonne National Laboratory<br class="">
<br class="">
</blockquote>
<br class="">
IMPORTANT NOTICE: The contents of this email and any attachments are<br class="">
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recipient, please notify the sender immediately and do not disclose<br class="">
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or copy the information in any medium. Thank you.<br class="">
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Finkel</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
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Computational Scientist</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">
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