Merge pull request swiftlang#34496 from atrick/silopt-critedge-flag

Author: swift-ci

lib/SIL/Verifier/SILVerifier.cpp

@@ -65,6 +65,10 @@ static llvm::cl::opt<bool> VerifyDIHoles(
 static llvm::cl::opt<bool> SkipConvertEscapeToNoescapeAttributes(
     "verify-skip-convert-escape-to-noescape-attributes", llvm::cl::init(false));
 
+// Allow unit tests to gradually migrate toward -allow-critical-edges=false.
+static llvm::cl::opt<bool> AllowCriticalEdges("allow-critical-edges",
+                                              llvm::cl::init(true));
+
 // The verifier is basically all assertions, so don't compile it with NDEBUG to
 // prevent release builds from triggering spurious unused variable warnings.
 
@@ -5147,7 +5151,7 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
   }
 
   void verifyBranches(const SILFunction *F) {
-    // Verify that there is no non_condbr critical edge.
+    // Verify no critical edge.
     auto isCriticalEdgePred = [](const TermInst *T, unsigned EdgeIdx) {
       assert(T->getSuccessors().size() > EdgeIdx && "Not enough successors");
 
@@ -5170,10 +5174,11 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
       const TermInst *TI = BB.getTerminator();
       CurInstruction = TI;
 
-      // Check for non-cond_br critical edges.
-      if (isa<CondBranchInst>(TI)) {
+      // FIXME: In OSSA, critical edges will never be allowed.
+      // In Lowered SIL, they are allowed on unconditional branches only.
+      //   if (!(isSILOwnershipEnabled() && F->hasOwnership()))
+      if (AllowCriticalEdges && isa<CondBranchInst>(TI))
         continue;
-      }
 
       for (unsigned Idx = 0, e = BB.getSuccessors().size(); Idx != e; ++Idx) {
         require(!isCriticalEdgePred(TI, Idx),

test/SILOptimizer/copyforward_ossa.sil

@@ -1,4 +1,4 @@
-// RUN: %target-sil-opt  -enable-sil-verify-all %s -copy-forwarding -enable-copyforwarding -enable-destroyhoisting | %FileCheck %s
+// RUN: %target-sil-opt  -enable-sil-verify-all %s -copy-forwarding -enable-copyforwarding -enable-destroyhoisting -allow-critical-edges=false | %FileCheck %s
 
 // This is the ossa version of CopyForwarding tests
 sil_stage raw
@@ -209,9 +209,12 @@ bb1:                                              // Preds: bb0
   copy_addr %0 to [initialization] %5 : $*T     // id: %6
   %7 = apply %4<T>(%5) : $@convention(thin) <τ_0_0> (@in τ_0_0) -> ()
   dealloc_stack %5 : $*T         // id: %8
-  br bb2                                          // id: %9
+  br bb3                                          // id: %9
 
-bb2:                                              // Preds: bb0 bb1
+bb2:
+  br bb3
+
+bb3:                                              // Preds: bb0 bb1
   destroy_addr %0 : $*T                           // id: %10
   %11 = tuple ()                                  // user: %12
   return %11 : $()                                // id: %12