Merge commit 'cfe09ed28d8a65b671e8b7a716a933e98e810e32'

Conflicts:
	lib/Target/ARM/ARMFrameLowering.cpp
	lib/Target/Mips/MipsRegisterInfo.cpp
	lib/Target/X86/X86ISelLowering.cpp
	lib/Transforms/IPO/ExtractGV.cpp
	tools/Makefile
	tools/gold/gold-plugin.cpp

The only interesting conflict was X86ISelLowering.ccp, which
meant I had to essentially revert r167104. The problem is that we are
using ESP as the stack pointer in X86ISelLowering and RSP as the
stack pointer in X86FrameLowering, and that revision made them
both consistently use X86RegisterInfo to determine which to use.

1 files changed, 14 insertions, 1 deletions

diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp
index b654111eba..5e05c83c35 100644
--- a/lib/Transforms/Utils/LCSSA.cpp
+++ b/lib/Transforms/Utils/LCSSA.cpp
@@ -53,6 +53,8 @@ namespace {
 
     // Cached analysis information for the current function.
     DominatorTree *DT;
+    LoopInfo *LI;
+    ScalarEvolution *SE;
     std::vector<BasicBlock*> LoopBlocks;
     PredIteratorCache PredCache;
     Loop *L;
@@ -117,6 +119,8 @@ bool LCSSA::runOnLoop(Loop *TheLoop, LPPassManager &LPM) {
   L = TheLoop;
   
   DT = &getAnalysis<DominatorTree>();
+  LI = &getAnalysis<LoopInfo>();
+  SE = getAnalysisIfAvailable<ScalarEvolution>();
 
   // Get the set of exiting blocks.
   SmallVector<BasicBlock*, 8> ExitBlocks;
@@ -156,6 +160,12 @@ bool LCSSA::runOnLoop(Loop *TheLoop, LPPassManager &LPM) {
       MadeChange |= ProcessInstruction(I, ExitBlocks);
     }
   }
+
+  // If we modified the code, remove any caches about the loop from SCEV to
+  // avoid dangling entries.
+  // FIXME: This is a big hammer, can we clear the cache more selectively?
+  if (SE && MadeChange)
+    SE->forgetLoop(L);
   
   assert(L->isLCSSAForm(*DT));
   PredCache.clear();
@@ -245,7 +255,7 @@ bool LCSSA::ProcessInstruction(Instruction *Inst,
     // Remember that this phi makes the value alive in this block.
     SSAUpdate.AddAvailableValue(ExitBB, PN);
   }
-  
+
   // Rewrite all uses outside the loop in terms of the new PHIs we just
   // inserted.
   for (unsigned i = 0, e = UsesToRewrite.size(); i != e; ++i) {
@@ -260,6 +270,9 @@ bool LCSSA::ProcessInstruction(Instruction *Inst,
 
     if (isa<PHINode>(UserBB->begin()) &&
         isExitBlock(UserBB, ExitBlocks)) {
+      // Tell the VHs that the uses changed. This updates SCEV's caches.
+      if (UsesToRewrite[i]->get()->hasValueHandle())
+        ValueHandleBase::ValueIsRAUWd(*UsesToRewrite[i], UserBB->begin());
       UsesToRewrite[i]->set(UserBB->begin());
       continue;
     }