now that @GOTOFF is no longer represented as a suffix on a

[oota-llvm.git] / lib / Analysis / LoopInfo.cpp

diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index e9256b74140f0f46315560c5a64374691448f4c4..453af5a5555af83c8b3ea58eb8bd8d78f296a27d 100644 (file)
--- a/lib/Analysis/LoopInfo.cpp
+++ b/lib/Analysis/LoopInfo.cpp
@@ -21,6 +21,7 @@
 #include "llvm/Assembly/Writer.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include <algorithm>
@@ -56,7 +57,7 @@ bool Loop::isLoopInvariant(Value *V) const {
 /// loop-invariant.
 ///
 bool Loop::isLoopInvariant(Instruction *I) const {
-  return !contains(I->getParent());
+  return !contains(I);
 }
 
 /// makeLoopInvariant - If the given value is an instruciton inside of the
@@ -243,6 +244,11 @@ unsigned Loop::getSmallConstantTripMultiple() const {
         case BinaryOperator::Mul:
           Result = dyn_cast<ConstantInt>(BO->getOperand(1));
           break;
+        case BinaryOperator::Shl:
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(1)))
+            if (CI->getValue().getActiveBits() <= 5)
+              return 1u << CI->getZExtValue();
+          break;
         default:
           break;
         }
@@ -263,14 +269,13 @@ bool Loop::isLCSSAForm() const {
   SmallPtrSet<BasicBlock *, 16> LoopBBs(block_begin(), block_end());
 
   for (block_iterator BI = block_begin(), E = block_end(); BI != E; ++BI) {
-    BasicBlock  *BB = *BI;
-    for (BasicBlock ::iterator I = BB->begin(), E = BB->end(); I != E;++I)
+    BasicBlock *BB = *BI;
+    for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;++I)
       for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
            ++UI) {
         BasicBlock *UserBB = cast<Instruction>(*UI)->getParent();
-        if (PHINode *P = dyn_cast<PHINode>(*UI)) {
+        if (PHINode *P = dyn_cast<PHINode>(*UI))
           UserBB = P->getIncomingBlock(UI);
-        }
 
         // Check the current block, as a fast-path.  Most values are used in
         // the same block they are defined in.
@@ -286,12 +291,14 @@ bool Loop::isLCSSAForm() const {
 /// the LoopSimplify form transforms loops to, which is sometimes called
 /// normal form.
 bool Loop::isLoopSimplifyForm() const {
-  // Normal-form loops have a preheader.
-  if (!getLoopPreheader())
-    return false;
-  // Normal-form loops have a single backedge.
-  if (!getLoopLatch())
-    return false;
+  // Normal-form loops have a preheader, a single backedge, and all of their
+  // exits have all their predecessors inside the loop.
+  return getLoopPreheader() && getLoopLatch() && hasDedicatedExits();
+}
+
+/// hasDedicatedExits - Return true if no exit block for the loop
+/// has a predecessor that is outside the loop.
+bool Loop::hasDedicatedExits() const {
   // Sort the blocks vector so that we can use binary search to do quick
   // lookups.
   SmallPtrSet<BasicBlock *, 16> LoopBBs(block_begin(), block_end());
@@ -310,12 +317,12 @@ bool Loop::isLoopSimplifyForm() const {
 
 /// getUniqueExitBlocks - Return all unique successor blocks of this loop.
 /// These are the blocks _outside of the current loop_ which are branched to.
-/// This assumes that loop is in canonical form.
+/// This assumes that loop exits are in canonical form.
 ///
 void
 Loop::getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const {
-  assert(isLoopSimplifyForm() &&
-         "getUniqueExitBlocks assumes the loop is in canonical form!");
+  assert(hasDedicatedExits() &&
+         "getUniqueExitBlocks assumes the loop has canonical form exits!");
 
   // Sort the blocks vector so that we can use binary search to do quick
   // lookups.
@@ -379,6 +386,10 @@ BasicBlock *Loop::getUniqueExitBlock() const {
   return 0;
 }
 
+void Loop::dump() const {
+  print(dbgs());
+}
+
 //===----------------------------------------------------------------------===//
 // LoopInfo implementation
 //