[llvm-commits] [llvm] r60501 - in /llvm/trunk: include/llvm/Transforms/Utils/BasicBlockUtils.h include/llvm/Transforms/Utils/Local.h lib/Transforms/Scalar/CondPropagate.cpp lib/Transforms/Utils/BasicBlockUtils.cpp lib/Transforms/Utils/SimplifyCFG.cpp lib/Transforms/Utils/UnrollLoop.cpp
Chris Lattner
sabre at nondot.org
Wed Dec 3 11:44:11 PST 2008
Author: lattner
Date: Wed Dec 3 13:44:02 2008
New Revision: 60501
URL: http://llvm.org/viewvc/llvm-project?rev=60501&view=rev
Log:
Factor some code into a new FoldSingleEntryPHINodes method.
Modified:
llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h
llvm/trunk/include/llvm/Transforms/Utils/Local.h
llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp
llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
llvm/trunk/lib/Transforms/Utils/UnrollLoop.cpp
Modified: llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h?rev=60501&r1=60500&r2=60501&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h Wed Dec 3 13:44:02 2008
@@ -30,6 +30,14 @@
/// predecessors.
void DeleteDeadBlock(BasicBlock *BB);
+
+/// FoldSingleEntryPHINodes - We know that BB has one predecessor. If there are
+/// any single-entry PHI nodes in it, fold them away. This handles the case
+/// when all entries to the PHI nodes in a block are guaranteed equal, such as
+/// when the block has exactly one predecessor.
+void FoldSingleEntryPHINodes(BasicBlock *BB);
+
+
/// MergeBlockIntoPredecessor - Attempts to merge a block into its predecessor,
/// if possible. The return value indicates success or failure.
bool MergeBlockIntoPredecessor(BasicBlock* BB, Pass* P = 0);
Modified: llvm/trunk/include/llvm/Transforms/Utils/Local.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Local.h?rev=60501&r1=60500&r2=60501&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Wed Dec 3 13:44:02 2008
@@ -56,7 +56,7 @@
SmallVectorImpl<Instruction*> *DeadInst = 0);
//===----------------------------------------------------------------------===//
-// Control Flow Graph Restructuring...
+// Control Flow Graph Restructuring.
//
/// MergeBasicBlockIntoOnlyPred - BB is a block with one predecessor and its
Modified: llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp?rev=60501&r1=60500&r2=60501&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp Wed Dec 3 13:44:02 2008
@@ -14,12 +14,13 @@
#define DEBUG_TYPE "condprop"
#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Type.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
@@ -95,13 +96,9 @@
BB != BI->getSuccessor(0)) {
BasicBlock *Succ = BI->getSuccessor(0);
- // If Succ has any PHI nodes, they are all single-entry PHI's.
- while (PHINode *PN = dyn_cast<PHINode>(Succ->begin())) {
- assert(PN->getNumIncomingValues() == 1 &&
- "PHI doesn't match parent block");
- PN->replaceAllUsesWith(PN->getIncomingValue(0));
- PN->eraseFromParent();
- }
+ // If Succ has any PHI nodes, they are all single-entry PHI's. Eliminate
+ // them.
+ FoldSingleEntryPHINodes(Succ);
// Remove BI.
BI->eraseFromParent();
@@ -205,11 +202,7 @@
// OldSucc had multiple successors. If ToBB has multiple predecessors, then
// the edge between them would be critical, which we already took care of.
// If ToBB has single operand PHI node then take care of it here.
- while (PHINode *PN = dyn_cast<PHINode>(ToBB->begin())) {
- assert(PN->getNumIncomingValues() == 1 && "Critical Edge Found!");
- PN->replaceAllUsesWith(PN->getIncomingValue(0));
- PN->eraseFromParent();
- }
+ FoldSingleEntryPHINodes(ToBB);
// Update PHI nodes in OldSucc to know that FromBB no longer branches to it.
OldSucc->removePredecessor(FromBB);
Modified: llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp?rev=60501&r1=60500&r2=60501&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp Wed Dec 3 13:44:02 2008
@@ -54,6 +54,24 @@
BB->eraseFromParent();
}
+/// FoldSingleEntryPHINodes - We know that BB has one predecessor. If there are
+/// any single-entry PHI nodes in it, fold them away. This handles the case
+/// when all entries to the PHI nodes in a block are guaranteed equal, such as
+/// when the block has exactly one predecessor.
+void llvm::FoldSingleEntryPHINodes(BasicBlock *BB) {
+ if (!isa<PHINode>(BB->begin()))
+ return;
+
+ while (PHINode *PN = dyn_cast<PHINode>(BB->begin())) {
+ if (PN->getIncomingValue(0) != PN)
+ PN->replaceAllUsesWith(PN->getIncomingValue(0));
+ else
+ PN->replaceAllUsesWith(UndefValue::get(PN->getType()));
+ PN->eraseFromParent();
+ }
+}
+
+
/// MergeBlockIntoPredecessor - Attempts to merge a block into its predecessor,
/// if possible. The return value indicates success or failure.
bool llvm::MergeBlockIntoPredecessor(BasicBlock* BB, Pass* P) {
Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=60501&r1=60500&r2=60501&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Wed Dec 3 13:44:02 2008
@@ -1101,10 +1101,7 @@
// Degenerate case of a single entry PHI.
if (PN->getNumIncomingValues() == 1) {
- if (PN->getIncomingValue(0) != PN)
- PN->replaceAllUsesWith(PN->getIncomingValue(0));
- else
- PN->replaceAllUsesWith(UndefValue::get(PN->getType()));
+ FoldSingleEntryPHINodes(PN->getParent());
PN->eraseFromParent();
return true;
}
Modified: llvm/trunk/lib/Transforms/Utils/UnrollLoop.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/UnrollLoop.cpp?rev=60501&r1=60500&r2=60501&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/UnrollLoop.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/UnrollLoop.cpp Wed Dec 3 13:44:02 2008
@@ -25,13 +25,14 @@
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
#include <cstdio>
using namespace llvm;
-/* TODO: Should these be here or in LoopUnroll? */
+// TODO: Should these be here or in LoopUnroll?
STATISTIC(NumCompletelyUnrolled, "Number of loops completely unrolled");
STATISTIC(NumUnrolled, "Number of loops unrolled (completely or otherwise)");
@@ -68,11 +69,7 @@
// multiple duplicate (but guaranteed to be equal) entries for the
// incoming edges. This occurs when there are multiple edges from
// OnlyPred to OnlySucc.
- //
- while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) {
- PN->replaceAllUsesWith(PN->getIncomingValue(0));
- BB->getInstList().pop_front(); // Delete the phi node...
- }
+ FoldSingleEntryPHINodes(BB);
// Delete the unconditional branch from the predecessor...
OnlyPred->getInstList().pop_back();
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