[llvm-commits] CVS: llvm/lib/Transforms/Scalar/LICM.cpp
Chris Lattner
lattner at cs.uiuc.edu
Sat Jun 19 04:04:02 PDT 2004
Changes in directory llvm/lib/Transforms/Scalar:
LICM.cpp updated: 1.61 -> 1.62
---
Log message:
Fix one source of nondeterminism in the -licm pass: the hoist pass
was processing blocks in whatever order they happened to end up in the
dominator tree data structure. Force an ordering.
---
Diffs of the changes: (+16 -2)
Index: llvm/lib/Transforms/Scalar/LICM.cpp
diff -u llvm/lib/Transforms/Scalar/LICM.cpp:1.61 llvm/lib/Transforms/Scalar/LICM.cpp:1.62
--- llvm/lib/Transforms/Scalar/LICM.cpp:1.61 Thu Jun 17 02:26:52 2004
+++ llvm/lib/Transforms/Scalar/LICM.cpp Sat Jun 19 03:56:43 2004
@@ -40,6 +40,7 @@
#include "llvm/Analysis/AliasSetTracker.h"
#include "llvm/Analysis/Dominators.h"
#include "llvm/Support/CFG.h"
+#include "llvm/Support/StableBasicBlockNumbering.h"
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
#include "llvm/Transforms/Utils/Local.h"
#include "Support/CommandLine.h"
@@ -81,6 +82,7 @@
LoopInfo *LI; // Current LoopInfo
DominatorTree *DT; // Dominator Tree for the current Loop...
DominanceFrontier *DF; // Current Dominance Frontier
+ StableBasicBlockNumbering *BBNum; // Stable IDs for basic blocks
// State that is updated as we process loops
bool Changed; // Set to true when we change anything.
@@ -203,7 +205,7 @@
/// runOnFunction - For LICM, this simply traverses the loop structure of the
/// function, hoisting expressions out of loops if possible.
///
-bool LICM::runOnFunction(Function &) {
+bool LICM::runOnFunction(Function &F) {
Changed = false;
// Get our Loop and Alias Analysis information...
@@ -212,6 +214,10 @@
DF = &getAnalysis<DominanceFrontier>();
DT = &getAnalysis<DominatorTree>();
+ // Get a stable numbering of basic blocks.
+ StableBasicBlockNumbering CurBBNum(&F);
+ BBNum = &CurBBNum;
+
// Hoist expressions out of all of the top-level loops.
for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I) {
AliasSetTracker AST(*AA);
@@ -337,8 +343,16 @@
}
const std::vector<DominatorTree::Node*> &Children = N->getChildren();
+ std::vector<std::pair<unsigned, DominatorTree::Node*> > ChildrenWithIDs;
+ ChildrenWithIDs.reserve(Children.size());
+ for (unsigned i = 0, e = Children.size(); i != e; ++i) {
+ unsigned ID = BBNum->getNumber(Children[i]->getBlock());
+ ChildrenWithIDs.push_back(std::make_pair(ID, Children[i]));
+ }
+
+ std::sort(ChildrenWithIDs.begin(), ChildrenWithIDs.end());
for (unsigned i = 0, e = Children.size(); i != e; ++i)
- HoistRegion(Children[i]);
+ HoistRegion(ChildrenWithIDs[i].second);
}
/// canSinkOrHoistInst - Return true if the hoister and sinker can handle this
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