From: Christian König christian.koe...@amd.com
The loop handling in the CFG structurizer incorrectly assumed
that only BasicBlock nodes can have a back edge, but that is
also possible for the exit edges of subregions.
Fixing 4 more piglit tests on radeonsi.
Signed-off-by: Christian König christian.koe...@amd.com
---
lib/Target/R600/AMDGPUStructurizeCFG.cpp | 135 ++
1 file changed, 81 insertions(+), 54 deletions(-)
diff --git a/lib/Target/R600/AMDGPUStructurizeCFG.cpp
b/lib/Target/R600/AMDGPUStructurizeCFG.cpp
index 70622e7..9528fc2 100644
--- a/lib/Target/R600/AMDGPUStructurizeCFG.cpp
+++ b/lib/Target/R600/AMDGPUStructurizeCFG.cpp
@@ -120,9 +120,9 @@ class AMDGPUStructurizeCFG : public RegionPass {
void buildPredicate(BranchInst *Term, unsigned Idx,
BBPredicates Pred, bool Invert);
- void analyzeBlock(BasicBlock *BB);
+ void analyzeNode(RegionNode *N);
- void analyzeLoop(BasicBlock *BB, unsigned LoopIdx);
+ void analyzeLoop(RegionNode *N);
void collectInfos();
@@ -227,72 +227,92 @@ void AMDGPUStructurizeCFG::buildPredicate(BranchInst
*Term, unsigned Idx,
Pred[Parent] = Cond;
}
-/// \brief Analyze the successors of each block and build up predicates
-void AMDGPUStructurizeCFG::analyzeBlock(BasicBlock *BB) {
- pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
+/// \brief Analyze the predecessors of each block and build up predicates
+void AMDGPUStructurizeCFG::analyzeNode(RegionNode *N) {
RegionInfo *RI = ParentRegion-getRegionInfo();
+ BasicBlock *BB = N-getEntry();
BBPredicates Pred = Predicates[BB];
- for (; PI != PE; ++PI) {
+ for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
+ PI != PE; ++PI) {
+
+// Handle the case where multiple regions start at the same block
+Region *R = *PI != ParentRegion-getEntry() ?
+RI-getRegionFor(*PI) : ParentRegion;
-// Ignore self loops
-if (*PI == BB)
+// Edge from inside a subregion to its entry, ignore it
+if (R == N)
continue;
-BranchInst *Term = castBranchInst((*PI)-getTerminator());
+if (R == ParentRegion) {
-for (unsigned i = 0, e = Term-getNumSuccessors(); i != e; ++i) {
- BasicBlock *Succ = Term-getSuccessor(i);
- if (Succ != BB)
-continue;
+ // It's a top level block in our region
+ BranchInst *Term = castBranchInst((*PI)-getTerminator());
+ for (unsigned i = 0, e = Term-getNumSuccessors(); i != e; ++i) {
+BasicBlock *Succ = Term-getSuccessor(i);
+if (Succ != BB)
+ continue;
+
+// Ignore self loops
+if (*PI != BB)
+ buildPredicate(Term, i, Pred, false);
+
+if (!Visited.count(*PI)) {
+ if (!LoopStart)
+LoopStart = BB;
- // Handle the case where multiple regions start at the same block
- Region *R = *PI != ParentRegion-getEntry() ?
- RI-getRegionFor(*PI) : ParentRegion;
+ buildPredicate(Term, i, LoopPred, true);
+}
+ }
- if (R == ParentRegion) {
-// It's a top level block in our region
-buildPredicate(Term, i, Pred, false);
+} else if (ParentRegion-contains(R)) {
- } else if (ParentRegion-contains(R)) {
-// It's a block in a sub region
-while(R-getParent() != ParentRegion)
- R = R-getParent();
+ // It's an exit from a sub region
+ while(R-getParent() != ParentRegion)
+R = R-getParent();
-Pred[R-getEntry()] = BoolTrue;
+ BasicBlock *Entry = R-getEntry();
+ Pred[Entry] = BoolTrue;
+ if (!Visited.count(Entry)) {
+if (!LoopStart)
+ LoopStart = BB;
- } else {
-// It's a branch from outside into our parent region
-Pred[*PI] = BoolTrue;
+LoopPred[Entry] = BoolFalse;
}
+
+} else {
+ // It's a branch from outside into our entry region
+ Pred[*PI] = BoolTrue;
}
}
}
-/// \brief Analyze the conditions leading to loop to a previous block
-void AMDGPUStructurizeCFG::analyzeLoop(BasicBlock *BB, unsigned LoopIdx) {
- BranchInst *Term = castBranchInst(BB-getTerminator());
+/// \brief Determine the end of the loop
+void AMDGPUStructurizeCFG::analyzeLoop(RegionNode *N) {
- for (unsigned i = 0, e = Term-getNumSuccessors(); i != e; ++i) {
-BasicBlock *Succ = Term-getSuccessor(i);
+ if (N-isSubRegion()) {
+// Test for exit as back edge
+BasicBlock *Exit = N-getNodeAsRegion()-getExit();
+if (Visited.count(Exit))
+ LoopEnd = N-getEntry();
-// Ignore it if it's not a back edge
-if (!Visited.count(Succ))
- continue;
+ } else {
+// Test for sucessors as back edge
+BasicBlock *BB = N-getNodeAsBasicBlock();
+BranchInst *Term = castBranchInst(BB-getTerminator());
-buildPredicate(Term, i, LoopPred, true);
+for (unsigned i = 0, e = Term-getNumSuccessors(); i != e; ++i) {
+ BasicBlock *Succ = Term-getSuccessor(i);
