Merge pull request #12926 from gottesmm/pr-7d7ad787aa26105e196576774cbf2188fdd8b1b0

Author: swift-ci

include/swift/SILOptimizer/Utils/CFG.h

@@ -125,6 +125,16 @@ bool hasCriticalEdges(SILFunction &F, bool OnlyNonCondBr);
 bool splitAllCriticalEdges(SILFunction &F, bool OnlyNonCondBr,
                            DominanceInfo *DT, SILLoopInfo *LI);
 
+/// \brief Split all cond_br critical edges with non-trivial arguments in the
+/// function updating the dominator tree and loop information (if they are not
+/// set to null).
+///
+/// A current invariant of Ownership SIL is that cond_br can only have critical
+/// edges with non-trivial arguments. This simplifies computation.
+bool splitAllCondBrCriticalEdgesWithNonTrivialArgs(SILFunction &F,
+                                                   DominanceInfo *DT,
+                                                   SILLoopInfo *LI);
+
 /// \brief Merge a basic block ending in a branch with its successor
 /// if possible. If dominance information or loop info is non null update it.
 /// Return true if block was merged.

lib/SILOptimizer/Utils/CFG.cpp

@@ -930,3 +930,36 @@ void swift::completeJointPostDominanceSet(
   // list. These are the remaining parts of our joint post-dominance closure.
   copy(MustVisitSuccessorBlocks, std::back_inserter(Result));
 }
+
+bool swift::splitAllCondBrCriticalEdgesWithNonTrivialArgs(SILFunction &Fn,
+                                                          DominanceInfo *DT,
+                                                          SILLoopInfo *LI) {
+  // Find our targets.
+  llvm::SmallVector<std::pair<SILBasicBlock *, unsigned>, 8> Targets;
+  for (auto &Block : Fn) {
+    auto *CBI = dyn_cast<CondBranchInst>(Block.getTerminator());
+    if (!CBI)
+      continue;
+
+    // See if our true index is a critical edge. If so, add block to the list
+    // and continue. If the false edge is also critical, we will handle it at
+    // the same time.
+    if (isCriticalEdge(CBI, CondBranchInst::TrueIdx)) {
+      Targets.emplace_back(&Block, CondBranchInst::TrueIdx);
+    }
+
+    if (!isCriticalEdge(CBI, CondBranchInst::FalseIdx)) {
+      continue;
+    }
+
+    Targets.emplace_back(&Block, CondBranchInst::FalseIdx);
+  }
+
+  for (auto P : Targets) {
+    SILBasicBlock *Block = P.first;
+    unsigned Index = P.second;
+    auto *Result = splitCriticalEdge(Block->getTerminator(), Index, DT, LI);
+    (void)Result;
+    assert(Result);
+  }
+}