<div dir="ltr">I'm still seeing stage2/3 miscompares of clang during bootstrap with this. Reverted in r329910.</div><br><div class="gmail_quote"><div dir="ltr">On Thu, Apr 12, 2018 at 12:40 AM Michael Zolotukhin via llvm-commits <<a href="mailto:llvm-commits@lists.llvm.org">llvm-commits@lists.llvm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: mzolotukhin<br>
Date: Wed Apr 11 16:37:53 2018<br>
New Revision: 329865<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=329865&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=329865&view=rev</a><br>
Log:<br>
Reapply "[PR16756] Use SSAUpdaterBulk in JumpThreading." one more time.<br>
<br>
This reapplies commit r329644.<br>
<br>
Modified:<br>
llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp<br>
<br>
Modified: llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp?rev=329865&r1=329864&r2=329865&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp?rev=329865&r1=329864&r2=329865&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp (original)<br>
+++ llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp Wed Apr 11 16:37:53 2018<br>
@@ -66,6 +66,7 @@<br>
#include "llvm/Transforms/Utils/BasicBlockUtils.h"<br>
#include "llvm/Transforms/Utils/Cloning.h"<br>
#include "llvm/Transforms/Utils/SSAUpdater.h"<br>
+#include "llvm/Transforms/Utils/SSAUpdaterBulk.h"<br>
#include "llvm/Transforms/Utils/ValueMapper.h"<br>
#include <algorithm><br>
#include <cassert><br>
@@ -1989,9 +1990,13 @@ bool JumpThreadingPass::ThreadEdge(Basic<br>
// now have to update all uses of the value to use either the original value,<br>
// the cloned value, or some PHI derived value. This can require arbitrary<br>
// PHI insertion, of which we are prepared to do, clean these up now.<br>
- SSAUpdater SSAUpdate;<br>
+ SSAUpdaterBulk SSAUpdate;<br>
SmallVector<Use*, 16> UsesToRename;<br>
+<br>
+ unsigned VarNum = 0;<br>
for (Instruction &I : *BB) {<br>
+ UsesToRename.clear();<br>
+<br>
// Scan all uses of this instruction to see if it is used outside of its<br>
// block, and if so, record them in UsesToRename.<br>
for (Use &U : I.uses()) {<br>
@@ -2008,19 +2013,15 @@ bool JumpThreadingPass::ThreadEdge(Basic<br>
// If there are no uses outside the block, we're done with this instruction.<br>
if (UsesToRename.empty())<br>
continue;<br>
+ SSAUpdate.AddVariable(VarNum, I.getName(), I.getType());<br>
<br>
- DEBUG(dbgs() << "JT: Renaming non-local uses of: " << I << "\n");<br>
-<br>
- // We found a use of I outside of BB. Rename all uses of I that are outside<br>
- // its block to be uses of the appropriate PHI node etc. See ValuesInBlocks<br>
- // with the two values we know.<br>
- SSAUpdate.Initialize(I.getType(), I.getName());<br>
- SSAUpdate.AddAvailableValue(BB, &I);<br>
- SSAUpdate.AddAvailableValue(NewBB, ValueMapping[&I]);<br>
-<br>
- while (!UsesToRename.empty())<br>
- SSAUpdate.RewriteUse(*UsesToRename.pop_back_val());<br>
- DEBUG(dbgs() << "\n");<br>
+ // We found a use of I outside of BB - we need to rename all uses of I that<br>
+ // are outside its block to be uses of the appropriate PHI node etc.<br>
+ SSAUpdate.AddAvailableValue(VarNum, BB, &I);<br>
+ SSAUpdate.AddAvailableValue(VarNum, NewBB, ValueMapping[&I]);<br>
+ for (auto U : UsesToRename)<br>
+ SSAUpdate.AddUse(VarNum, U);<br>
+ VarNum++;<br>
}<br>
<br>
// Ok, NewBB is good to go. Update the terminator of PredBB to jump to<br>
@@ -2037,6 +2038,10 @@ bool JumpThreadingPass::ThreadEdge(Basic<br>
{DominatorTree::Insert, PredBB, NewBB},<br>
{DominatorTree::Delete, PredBB, BB}});<br>
<br>
+ // Apply all updates we queued with DDT and get the updated Dominator Tree.<br>
+ DominatorTree *DT = &DDT->flush();<br>
+ SSAUpdate.RewriteAllUses(DT);<br>
+<br>
// At this point, the IR is fully up to date and consistent. Do a quick scan<br>
// over the new instructions and zap any that are constants or dead. This<br>
// frequently happens because of phi translation.<br>
<br>
<br>
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</blockquote></div>